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How to butcher a choke in 8 easy steps

107.219.46.222
Posted on March 8, 2015 at 22:49:34
Sidewinder
Audiophile

Posts: 254
Joined: April 13, 2001
 Here's my attempt at modifying a brand new Hammond 159ZB 320mH choke with Teflon 12 gauge silver plated copper wire, just like the good doctor ordered. It's so easy. Just took me about 15 minutes to do it. It's not that neat but this was my first try.

First slit the covering



Next open wide to reveal the connections:



Snip it



Desolder the leads and throw them in the trash. Then carefully straighten the curly choke wire:



Insert choke lead into the 12 gauge bundle. It's a tight fit but it will go in about .5 inch. Solder the bundle. The joint will soak up a lot of solder. Heat shrink the connection.



Fold the new leads over and add another layer of heat shrink:



Epoxy the the leads. In my next choke I may add a lot more epoxy:



Cover and tie wrap. You may add as many tie wraps as you like, but what you see here is very stable and there is no stress on the thin choke wires when I bend the Teflon wire.



I don't know if the new wiring will make a difference or not and I am not about to conduct an A-B listening session to find out. But since I got one shot at this build, the 12 gauge wire can't hurt. Let me know how to improve on this technique. Thanks drlomu for the inspiration or is it the insanity.
Regards,
David

 

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RE: How to butcher a choke in 8 easy steps, posted on March 9, 2015 at 00:30:20
rage
Audiophile

Posts: 793
Joined: December 17, 2010
 I've found gorilla glue expands and secures the whole thing well. I like what you did here better than how Jeff does his.

I would not recomend this to anyone however at least you soldered to the magnet wire.

I found epoxy didn't work well. As I recall I had crackling sounds as the epoxy was hard and the mechanical buzzing of those chokes would cause noise with the movement of the epoxy. Kind of scary actually. LOL

Just don't cut up any nice 18lbs Heyboer PTs or leadouts on nice output transformers. At least a choke you are only out ~ $25.

 

Gorilla Glue, posted on March 9, 2015 at 06:20:06
FenderLover
 Does this glue last? I've used it on items around the house and noticed that the seams become brittle and crack after a few years.


Thanks!

 

OMG, you forgot the Quad-Around-Wrap technology!, posted on March 9, 2015 at 06:31:02
Maxamillion
Audiophile

Posts: 856
Location: New Jersey
Joined: May 26, 2006
 Doomed.

 

That is mid-fi. You cannot have a halfway dynamic sounding, posted on March 9, 2015 at 07:14:16
Bas Horneman
Audiophile

Posts: 4086
Joined: March 28, 2001
 amplifier with that kind of hookup wire. It HAS TO BE: paralleled Kimber Kable TCSS prefereably 4 per side...then and only then can it be considered HI-FI..try it out and listen to it yourself.

 

RE: Gorilla Glue, posted on March 9, 2015 at 07:17:03
rage
Audiophile

Posts: 793
Joined: December 17, 2010
 Its pretty much a very dense polyurethane foam. If you leave it exposed to UV (the sun) it will degrade fast.

From what I've done with it I find it quite durable. Ugly but durable.

 

RE: How to butcher a choke in 8 easy steps, posted on March 9, 2015 at 07:52:55
drlowmu
Manufacturer

Posts: 9730
Location: East of Kansas City
Joined: January 10, 2005



Not done quite right, sorry.

The winding wire needs to be terminated into the lead outs properly, wrapped around the lead out 360 degrees, about three times, as was done in this pictured original construction, above, and on the Stancors.

I did four times around pre soldering. Will the winding wire take the stress of all the re-bending and not break ????

Tape over the original outer covering, moisture and safety, in the long term.

Above we can see above how Heyboer, certainly a different winder than Stancor, terminated into my double TCSS, without me telling them to do it that way !!

The three times wrap around is likely GOOD practice !! Live and learn.

Oh well, your new Hammond 159ZB ( ZB for zee best :-) !! ) was only $12.07 each.

Jeff Medwin

 

Only double TCSS???, posted on March 9, 2015 at 08:54:35
Lew
Audiophile

Posts: 10912
Location: Bethesda, Maryland
Joined: December 11, 2000
 I thought the magic was only attainable with three strands of TCSS. Too bad you have to toss that Heyboer. Live and learn. (Sorry. Could not resist, and you love the jibes anyway.)

 

Hi Bas...., posted on March 9, 2015 at 08:59:51
drlowmu
Manufacturer

Posts: 9730
Location: East of Kansas City
Joined: January 10, 2005
 Bas,

That is a $12.07 7.8 Ohm choke he is modding, so, its not " mid fi " ( above 20 Ohms DCR, but rather.. " ultra hi fi " ( under 10 Ohms DCR ). Just needs lead surgery to be optimal.

The Kimber TCSS is pure copper, so there was a LIMIT as to how much one can parallel, and not "lose highs". On a Choke, or a Power Transformer, it was three. That means the normal 19 AWG TCSS became about 15 AWG, at its limit. In audio circuits, no more than two ( became 16 AWG ) seemed OK on retaining top end.

The 12 AWG wire is multi stranded copper with silver in it, so, we can use a single run of twelve and NOT lose top end. That would be like the conductivity, transfer efficiency of about six TCSS, but without the high end loss, and the messiness of multiple wiring in parallel,( which didn't bother me if the circuit was more dynamic, and performed more true to life.) Regards.

Jeff Medwin

 

Hi Jeff, I was just trying to be funny...nt..., posted on March 9, 2015 at 10:24:18
Bas Horneman
Audiophile

Posts: 4086
Joined: March 28, 2001
 .

 

RE: Hi Bas...., posted on March 9, 2015 at 11:28:28
Al Noakes
 Use Dr Halijaks F.O.M on that choke and report back...

Al

 

RE: How to butcher a choke in 8 easy steps, posted on March 9, 2015 at 11:33:08
Al Noakes
 If you were to say to me that you had the most miraculous discovery since the beginning of audio with that choke I would instantly dismiss you as a crackpot . I know it only cost $12.88 but now it's F.U.C.T . What are you aiming to achieve apart from mildly haemorraging money ?

Do yourself a favour and throw it away .

Al

 

Sidewinder....................., posted on March 9, 2015 at 11:38:28
drlowmu
Manufacturer

Posts: 9730
Location: East of Kansas City
Joined: January 10, 2005
 FWIW, "panheadchopper", audiophile in Pittsburg, listened to various low DCR chokes, installed them first stock-leaded, and then he re-worked leads, and he heard an improvement after doing the conversion.

Have fun on the Altec Valencias, and please tell us all what you hear.

Jeff

 

+1 - It's crap now (nt), posted on March 9, 2015 at 13:07:02
Triode_Kingdom
Audiophile

Posts: 10049
Location: Central Texas
Joined: September 24, 2006
 nada aqui

 

RE: How to butcher a choke in 8 easy steps, posted on March 9, 2015 at 16:32:21
Sidewinder
Audiophile

Posts: 254
Joined: April 13, 2001
 Please explain to me how the modded choke is now FUCck-T. All connections are intact and secured. Try as I can, I could not break the connections as shown. Maybe you have experience in FUC-Kin Sheeit up. Don't worry my Sheeit is just fine.
Regards,
David

 

Oh, it's you again. NT, posted on March 9, 2015 at 16:36:39
Sidewinder
Audiophile

Posts: 254
Joined: April 13, 2001
 Can't get enough? READ the Subject line.

 

RE: Gorilla Glue, posted on March 9, 2015 at 21:00:17
hennfarm
Audiophile

Posts: 535
Location: Oregon
Joined: October 8, 2008
 Try shoe goo, iI use it to hold all kinds of stuff put. JH

 

RE: Gorilla Glue, posted on March 9, 2015 at 21:51:32
drlowmu
Manufacturer

Posts: 9730
Location: East of Kansas City
Joined: January 10, 2005
 miss Shoe Goo nah.

Walmart carries it, under ten dollars.

 

Backup and try again, posted on March 10, 2015 at 00:02:29
Sidewinder
Audiophile

Posts: 254
Joined: April 13, 2001
 No problem with my method. But your method is cool too.
Here I wrapped the choke wire around about 3 times and soldered.



Heat shrink and tape it down with blue tape:



Cover wires with original covering and add more blue tape and strap it down tight:




The connections are stable and tight. They're not going anywhere
Regards,
David

 

Excellent...., posted on March 10, 2015 at 00:39:48
drlowmu
Manufacturer

Posts: 9730
Location: East of Kansas City
Joined: January 10, 2005
 I was too conservative - about breaking the winding wire. Damn, if YOU can do it "direct" Sidewinder, I ought to ALSO give it a good TRY !!

Thanks, I learned from you !!! Awesome dude.

Hammond 159ZB $12.08 at Mouser. Ha !!!

Wait till you hear THAT B+ Filter, with the right-sized new DC LINK caps, on the Valencias with your new Type 45 SE amp ...wow.

You realize it yet ??? .... I am going to have you "do" your Power Transformer leads, under the end bells, also !!! High Voltage winding, rectifier tube winding, and the primary. One time, carefully.

I wonder if all the usual detractors will approve. No matter,...... we'll just DO IT and dig it. Lot'sa FUN.

Jeff Medwin

 

Too bad Panhead, posted on March 10, 2015 at 04:19:00
1973shovel
Audiophile

Posts: 10117
Location: Greenville SC
Joined: February 25, 2007
 Didn't stick around to answer many questions. I posted what I feel is a viable question regarding the voltages in his Dynaco MKIIIs affecting the sound, but it was never addressed.

I tried to give him the benefit of the doubt, but his "Hey, this is my first post anywhere!", gushing over his results of low H, low DCR chokes, and then splitting, didn't inspire confidence. It felt more like a plant than someone sharing their results and then being willing to have an honest discussion about them.



 

A Mercedes and a bus..., posted on March 10, 2015 at 06:54:15
andy evans
Audiophile

Posts: 4382
Joined: October 20, 2000
 Putting a tiny piece of wire on the end of a huge length of wire inside a choke sounds to me like doing a 300 mile journey by bus and jumping into a Mercedes for the last 200 yards, then saying how much more pleasant the journey was in a Mercedes.

But who am I to know…..

 

RE: A Mercedes and a bus..., posted on March 10, 2015 at 07:25:26
Al Noakes
 Exactly ! If there was 10A passing through that choke I could understand the use of that wire . According to Jeff's mentor , Dr Halijak :

'A choke must have some internal resistance and its non-standard figure of merit is the ratio R over L. The best choke is the one with the smallest figure of merit and the best power supply has the least series resistance. It is not too difficult to obtain R over L = 10 but one can easily obtain R over L = 30 or more. The latter should be avoided but the ongoing shows that in a way it is unavoidable.'

Those chokes have a F.O.M of 7.8/0.32=24.75 which is on the borderline between low-fi and audio junk . A slight contradiction but according to Jeff and his rather small band of choke-choppers , it is a worthwhile mod...

Al

 

The Analogy...., posted on March 10, 2015 at 07:34:59
drlowmu
Manufacturer

Posts: 9730
Location: East of Kansas City
Joined: January 10, 2005
 Here is what to conceptualize Andy,

The wire around the core is fixed, and we ALL have to take the 300 mile journey / vacation ? on the bus, and we ALL have to stay for a week.

The problem occurs when the car you were using, to get to and from the bus, has a hole in its trunk, and loses HALF of the things in your suitcase, which sprung-open in a bumpy non-bus transit.

So, you arrived at the bus station, at the start of the week long vacation, with half of your luggage, and you arrive home after your journey's end, with only one quarter of the belongings you originally left home with.

I say, you should not lose three quarters of the belongings in your suitcase, while traveling to and from the bus !!!

An inch of bad wire can ruin the musical experience, Some wire runs we simply can't control, but DO make an effort on what is available to you, if you begin to THINK fresh about it.

The technique applies to power transformers, not chokes only !!! "An inch of bad wire can ruin the musical experience."

Sidewinder's new 45 SE amp build, with multiple 7.8 Ohm inductors, and good internal wire, will kick a** and dynamically destroy, anything you have ever heard, using car trunks with holes in them.

Jeff Medwin

 

Also....., posted on March 10, 2015 at 07:53:40
drlowmu
Manufacturer

Posts: 9730
Location: East of Kansas City
Joined: January 10, 2005
 Chokes also have to be " 20 Ohms or less " which was the VERY FIRST THING my audio mentor, Bob Fulton, told me in 1982 when I started with DHT amps.

Bet 99% are well over 20 Ohms. Thats simply mid-fi AL !!!

Under 20 Ohms is hi fi, under 10 Ohms is ultra hi fi. Very simple !!!

Combine Dr. Halijak and Bob Fulton, and you got a chance at a pretty good amp, but do not lose 3/4s of the luggage in the wiring.

Jeff Medwin

 

RE: Too bad Panhead, posted on March 10, 2015 at 08:05:12
drlowmu
Manufacturer

Posts: 9730
Location: East of Kansas City
Joined: January 10, 2005
 He may not be comfortable posting. If you would like to find out more, I could possibly arrange to get you his phone number, and you two guys can have a real time back-and-forth discussion ! I know he likes to use the phone, and is VERY enthusiastic about what he is hearing, experimenting with, when he communicates to me.

Jeff Medwin

 

RE: A Mercedes and a bus..., posted on March 10, 2015 at 11:56:02
Tre'
Industry Professional

Posts: 17306
Location: So. Cal.
Joined: February 9, 2002
 "Those chokes have a F.O.M of 7.8/0.32=24.75 which is on the borderline between low-fi and audio junk ."

But what happens when we look at the rest of what Dr. Halijak had to say?

" 15 ( choke ) + 70 ( rectifier ) + 70 ( power transformer resistances )
------------------------------------------------------------------- = 103
1.5 ( HY )

( the 70 ohm power transformer resistance is a guess )

If four 5U4GB are placed in parallel one has :

15 + (0.25 ) ( 70 ) + 70
___ = 68
1.5

Both figures of merit are way above the original 10 but your listening experiment told you that 68 was alright; this actual figure of merit is the best you can do because the largest power transformer was used and the smallest resistance available choke was used. You can see that stock power supplies are not anywhere near being the best cases *. Most tube and transistor electronic engineers are unconcious about power supplies, but good.


* Also the best cases need not have zero internal resistance - a utopian goal. One strives for minimal non-zero resistance !! "

To me that says that the resistance of all the chokes and the power transformer needs to be as low as possible.

What's wrong with that?

Well, Dr. Halijak doesn't get into what other problems arise when the DCR is low.

1. unless you have a critical inductance input choke the rectifier tube has a minimum series resistance per plate requirement that will not be meet.

2. Using chokes with really low DRC makes to harder to "tune" the supply so that it doesn't ring.


I would still like to have my question from years ago answered.

"What is the effective DCR of a power supply for the period of time, each cycle, while both diodes are simultaneously off (not conducting)?


Tre'


Have Fun and Enjoy the Music
"Still Working the Problem"

 

RE: A Mercedes and a bus..., posted on March 10, 2015 at 15:55:29
cpotl
Audiophile

Posts: 1002
Location: Texas
Joined: December 6, 2009
 "Putting a tiny piece of wire on the end of a huge length of wire inside a choke sounds to me like doing a 300 mile journey by bus and jumping into a Mercedes for the last 200 yards, then saying how much more pleasant the journey was in a Mercedes."

A very reasonable analogy. Unfortunately, however, it is an impossible task to argue with logic against the faith-based preachings of the "lses" believers...

Chris

 

RE: A Mercedes and a bus..., posted on March 10, 2015 at 20:14:25
tube wrangler
Manufacturer

Posts: 2484
Location: USA
Joined: January 29, 2007
 I'm not trying to be argumentative-- just sayin'-----.

Wire INSIDE the laminations behaves differently than wire OUTSIDE the lam-stack. If it's in the magnetic loop, it's a calculated part of the whole choke-- this means that the lams are calculated in with the wire INSIDE to form the inductance, reactance and resistance TOTAL recipe for the choke..

Any wire OUTSIDE this field is just another interconnect-- just another conducting wire in the amplifier.

Now, once outside the choke's magnetic field, it becomes VERY important what that wire's electrical-- and thus, sonic-- properties are.

---Dennis---

 

My question was meant to be generic, posted on March 11, 2015 at 02:51:55
1973shovel
Audiophile

Posts: 10117
Location: Greenville SC
Joined: February 25, 2007
 It was directed at Panheadchopper's Dynaco MK-III post, because they're amps I happen to own. But the question could be applied to almost any amp where the resistance value of the choke is reduced. (Link to my question below).

I suppose you could broker Panheadchopper's phone number for me, but I suspect that given his moniker, we'd likely do a lot more talking about Shovelheads and Panheads (old Harleys, for those not aware of it) than we would amps.

In the meantime, would you care to respond to my question? When you reduce the DCR of a choke, do you compensate by adding resistance to other sections of a circuit, to bring voltages within operating parameters?

Thanks.

 

you have *GOT* to be kidding me, posted on March 11, 2015 at 05:04:33
PakProtector
Audiophile

Posts: 12366
Joined: May 14, 2002
 This looks much more like a steaming pile of Marketing because you can't do anything about the coil wire. Said coil wire is doing just the same thing to those poor electrons regardless of what is going on where you can't molest it.

It is quite like the Mercedes/Bus analogy...you get to arrive in front of everybody in a Benz, and will foster the illusion that you made the entire trip in it.
cheers,
Douglas

Friend, I would not hurt thee for the world...but thou art standing where I am about to shoot.

 

This forum should be named Nutjob Audio (nt), posted on March 11, 2015 at 07:41:11
Triode_Kingdom
Audiophile

Posts: 10049
Location: Central Texas
Joined: September 24, 2006
 nada aqui

 

RE: My question was meant to be generic, posted on March 11, 2015 at 08:04:39
drlowmu
Manufacturer

Posts: 9730
Location: East of Kansas City
Joined: January 10, 2005
 Hi,

I will ask Panhead if he will take a call, and get back to you ASAP.

I always figured your moniker meant vintage Harley !!

You ask: "When you reduce the DCR of a choke, do you compensate by adding resistance to other sections of a circuit, to bring voltages within operating parameters?"

Well, you can, if necessary, add resistances to the power supply going to the front end stages, that is usually NOT a problem to do, if needed.

But, adding to the Finals is a whole different thing. We wanna have as LOW a series resistances as we can get , to the Finals !!!.

Lets talk MK 3s. Lets say, the stock choke is 55 Ohms, and we, as ONE example, replace it with two small 7.8 Ohm chokes - totaling 15.6 Ohms. So, the stock single L/C filter is replaced with / becomes L1/C1/L2/C2. 55 Ohms minus 14.6 Ohms is a reduction of 39.4 Ohms in series to the Finals.

Lets say, the whole MK.3 pulls 140 mA., what is the voltage increase with the lowered series choke resistances ?

That is Ohms Law, 0.014 A. times 39.4 Ohms, equals 5.15 VDC increase of the B+. Lets say the B+ was 425 VDC, well, that is only a 1.3 % increase in B+. However, the MK. 3 PLAYs a whole lot different, according to what Panhead tells me. AS I recall, Mark used 2 HY at 9.5 Ohms, a single choke replaced.

I HOPE I have answered your Question OK. Will ask Mark if you two motorcycle enthusiasts can speak !!! Later !!

Jeff

 

RE: This forum should be named Nutjob Audio (nt), posted on March 11, 2015 at 09:46:12
mach1
Audiophile

Posts: 399
Location: Brisvegas
Joined: April 24, 2005
 Unfortunately, due to the dysfunctionality of the bored it has long had that reputation.

 

and what of the self-made designer whom winds his own transformers with NO lacquer on the wire; better still?, posted on March 11, 2015 at 10:27:33
Cleantimestream
Audiophile

Posts: 7551
Location: Kentucky
Joined: June 30, 2005
 ~!
The Mind has No Firewall~ U.S. Army War College.

 

Now that's Ultra low DCR!, posted on March 11, 2015 at 11:04:49
gusser
Audiophile

Posts: 3649
Location: So. California
Joined: September 6, 2006
 x

 

RE: My question was meant to be generic, posted on March 11, 2015 at 11:07:57
gusser
Audiophile

Posts: 3649
Location: So. California
Joined: September 6, 2006
 The Dyna MK2 used a 50ohm resistor IIRC. So depending on the DCR of the C354 choke used in the MK3, it's probably close enough. And in those days people didn't worry that much about running tubes hot. Most good old American tubes could easily take it and replacements were cheap and plentiful.

P.S. I see below that Mr. Lowmu has indicated the stock C354 is 55 ohms. So there you go, it's a perfect DCR for that circuit, they probably wound to that DCR for that reason. But yes, if you lower the DCR of a replacement choke, you have to be careful with too much B+. And the Dyna MK2&3 ran high anyway plus the line voltage in the early 1960s was more likely to be 115v. One solution is a Variac (expensive) or buck transformer (cheap) on the primary.

 

Almost all 'de "Usuals" have replied !!! , posted on March 11, 2015 at 11:13:54
drlowmu
Manufacturer

Posts: 9730
Location: East of Kansas City
Joined: January 10, 2005
 None intelligently. Very unfocused. ( Probably just like the amps they build for themselves !! )

LMAO.

JM

 

RE: and what of the self-made designer whom winds his own transformers with NO lacquer on the wire; better still?, posted on March 11, 2015 at 11:23:31
dave slagle
Manufacturer

Posts: 5430
Location: NYC
Joined: April 27, 2001



having priced enameled silver wire, I have considered doing this with bare silver. You need to layer wind and then use a monofilament (or insulated copper wire) with about 40-50% of the wire diameter to set the wire pitch.

dave

 

Two questions:, posted on March 11, 2015 at 12:41:52
The Bored
Bored Member

Posts: 2996
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Contributor
  Since: March 1, 1999
 Jeff,

1. Are you referring to PakProtector? Even obliquely?

2. Are you commenting in a manner that impugns PakProtector?

Fax mentis incendium gloria cultum, et cetera, et cetera...
Memo bis punitor delicatum! It's all there, black and white,
clear as crystal! Blah, blah, and so on and so forth ...

 

RE: Two questions:, posted on March 11, 2015 at 13:53:35
drlowmu
Manufacturer

Posts: 9730
Location: East of Kansas City
Joined: January 10, 2005
 Golly, I hadn't thought about that. Yes and yes it seems, but I thought I was responding to mach 1, but my wording covers them all. Not good at all. What about Triode Kingdom responding to my post "Hi Bas "??

What are the consequences now ?

Jeff Medwin

 

RE: Two questions:, posted on March 11, 2015 at 14:22:53
The Bored
Bored Member

Posts: 2996
Joined: July 28, 2000
Contributor
  Since: March 1, 1999
 >>but my wording covers them all.

It's easy to see it that way.

>>What about Triode Kingdom responding to my post "Hi Bas "??

I don't see that. Provide a link, please.

However, if you are referring to this:
http://www.audioasylum.com/forums/tubediy/messages/23/238601.html
you calling out 'de usuals' is much more direct than him calling out an entire forum of lunatics. For the latter, I might give a warning; for you, I think we're looking at two-weeks, minimum.




Fax mentis incendium gloria cultum, et cetera, et cetera...
Memo bis punitor delicatum! It's all there, black and white,
clear as crystal! Blah, blah, and so on and so forth ...

 

RE: and what of the self-made designer whom winds his own transformers with NO lacquer on the wire; better still?, posted on March 11, 2015 at 14:26:22
Cleantimestream
Audiophile

Posts: 7551
Location: Kentucky
Joined: June 30, 2005
 There is a guy in Greece... Petragavis? over @ DIY whom winds his own for 801A's {16.3 primary... @ 530 volts biased with 1k, rather hot don't you think? whom uses NO varnish but did not elaborate as to how. Stated he chose that scheme for sound, not for distortion.

Yes Sir, Dave; I paused to include the info above but was too lazy to go looking for proof as some guys would think I was talking out of my hat.

The zinger was for Tube Wrangler and Jeff so they might understand there are better ways in our hobby to achieve results.

One CAN make an OTL that can drive a 1 ohm load, Let's start the Insanity!

smile~


The Mind has No Firewall~ U.S. Army War College.

 

RE: Two questions:, posted on March 11, 2015 at 15:03:04
drlowmu
Manufacturer

Posts: 9730
Location: East of Kansas City
Joined: January 10, 2005
 So be it, I will abide by thy decision, and I apologize to cause you this extra time and trouble.

I will have to THINK before I post, and be much more careful in the future.

Have a great day yourself, whomever you are. Good job !

Jeff Medwin

 

RE: Also....., posted on March 11, 2015 at 15:09:15
Al Noakes
 What I usually do is more or less go for a critical inductance input choke (sometimes slightly under the calculated numbers) and an additional (usually 2.5-5H) filtering choke for SE . I always place a small value cap after the rectifier . Neither of the chokes have anything like a 20 ohm DCR but have a much higher F.O.M of your Stancor chokes , no matter what you do to the leadouts :) In terms of relative DCR that F.O.M thing has a lot going for it . Have you just distorted the requirement for inductance that your first mentor used and just gone to low mass like your current mentor uses ? You know , the one with the cowboy hat , cowboy logic and the mudpumps...

On a side note I have a humungous new old stock 3H choke . 4 ohms DCR 1A rated . It weighs 15kgs .

Try fitting that on a chassis . Work out the F.O.M of it :)

Al

 

RE: Also....., posted on March 11, 2015 at 15:37:17
drlowmu
Manufacturer

Posts: 9730
Location: East of Kansas City
Joined: January 10, 2005
 Dr. Halijak was brilliant, and I am GLAD you kept his contribution which I shared up here. Hey, someones paying attention. Dennis is alive, Messers . Fulton and Halijak are gone, and, I have the pleasure of Dennis' company for 30 years, and, heard his LOVELY amps at RMAFs, for maybe 8 years. What I hear of his impresses me Al.

 

Thanks, posted on March 12, 2015 at 02:43:02
1973shovel
Audiophile

Posts: 10117
Location: Greenville SC
Joined: February 25, 2007
 I'm still curious how much of the sonic improvement would be due to the increased voltage, as Jim McShane speculated about different brands of rectifiers.

I suppose the only way I'll know is to try it for myself. Xaudiomanx often posts that he preferred the sound of his Dynaco amps with the choke removed, with a resistor substituted. I never got around to trying that either, mostly because it defied my logic of what should be the better power supply configuration.

Probably not the best methodology on my part.



 

Thanks for the reply Gusser, posted on March 12, 2015 at 02:55:54
1973shovel
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Posts: 10117
Location: Greenville SC
Joined: February 25, 2007
 The point I was attempting to make, or more accurately, what I was attempting to learn was if any subjective sonic improvements were simply due to the increased voltage caused by the substitution of a low DCR choke.

A bucking transformer, as well as NTC limiters are a wise choice for these old amps.

Thanks.

 

RE: Thanks for the reply Gusser, posted on March 12, 2015 at 11:08:29
gusser
Audiophile

Posts: 3649
Location: So. California
Joined: September 6, 2006
 Yes, swapping out legacy chokes with low DCR parts can certainly make sonic improvements. As you will be pushing the B+ up a significant amount, most amps will sound better when operating at higher B+.

But the rub is you are now possibly stressing tubes and other components. And especially the 50 year old components that can be fragile.

My advice is to measure the B+ and make sure you aren't stressing anything with your new low DCR chokes.

 

RE: A Mercedes and a bus..., posted on March 12, 2015 at 13:33:04
rage
Audiophile

Posts: 793
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 Dennis,

Having seen the picture posted of your amp from years ago.. I'm curious to how dramatic an improvement you heard after you started replacing leadouts on power transformers and chokes?

I'm also curious if Jeff had heard your amp prior to making that change... honestly after seeing that picture I became more comfortable with terminating the factory leadouts in to a terminal strip and then using the fancy leadout wire from there. A few more inches of bad wire perhaps, but definitely idiot proof.

 

RE: A Mercedes and a bus..., posted on March 12, 2015 at 14:29:07
Tre'
Industry Professional

Posts: 17306
Location: So. Cal.
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 "Wire INSIDE the laminations behaves differently than wire OUTSIDE the lam-stack."

That can mean a lot of different things.

WRT the resistive losses, inside or outside it's all the same.

Tre'
Have Fun and Enjoy the Music
"Still Working the Problem"

 

RE: A Mercedes and a bus..., posted on March 12, 2015 at 14:56:16
Lew
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 I don't want to take a position in the debate, because I don't feel qualified, but is it not fair to say that the impedance of the wire inside the inductor is very very much more reactive in nature, compared to the wire that comprises the leads, made so by the fact that it's coiled? I think that's all Tube Wrangler meant to say. Yes, WRT its resistance, there is no difference between wire inside vs outside, but TW would advocate low DCR inside and low gauge outside, so as to ameliorate that factor as much as possible. The wire inside, however, is there to create inductance specifically. Just a thought.

 

RE: A Mercedes and a bus..., posted on March 12, 2015 at 15:08:27
Tre'
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 I didn't mean to imply anything more than what I said.

The same as you said. "Yes, WRT its resistance, there is no difference between wire inside vs outside".

Tre'
Have Fun and Enjoy the Music
"Still Working the Problem"

 

RE: A Mercedes and a bus..., posted on March 12, 2015 at 15:37:21
PakProtector
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 The wire inside is of course interacting with the magnetic field it is wrapped around. This does NOTHING to its resistive properties. If there is nothing wrong with this stuff, why not just use it for the lead outs? Eliminate a solder joint, eh?
cheers,
Douglas

Friend, I would not hurt thee for the world...but thou art standing where I am about to shoot.

 

RE: A Mercedes and a bus..., posted on March 12, 2015 at 20:34:10
Steve O
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 I've run across vintage chokes and PTs "terminated" in the very manner you describe: the enameled magnet wire becomes the leadout with the addition of insulating spaghetti. And I always thought this was a money saving trick.

 

RE: A Mercedes and a bus..., posted on March 12, 2015 at 20:39:17
Steve O
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 Maybe there are paramagnetic/diamagnetic effects to consider here. Based on my limited knowledge of this subject matter, I'd expect the effects to be infinitesimal. OTOH, perfectionist audio revels in the infinitesimal.

 

RE: A Mercedes and a bus..., posted on March 12, 2015 at 20:49:39
Tre'
Industry Professional

Posts: 17306
Location: So. Cal.
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The older style ElectraPrint transformers are done this way for the secondary.

Edit, I should say apparently done this way. The lead out wire is solid core, enameled magnet wire.

Tre'
Have Fun and Enjoy the Music
"Still Working the Problem"

 

RE: A Mercedes and a bus..., posted on March 12, 2015 at 21:35:48
tube wrangler
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 Improvements in anything come with time.

The original design was a clean sheet of paper, with no preconceived notions, prejudices, or favorite designs or building methods.

The reason for this is that I had some very good push-pull amps. When I first got into S.E. amps, I bought several 300B amps that were highly-rated.

Those things really bought it. They couldn't do ANYTHING right! Those included the Model 91 non-performing Western Electric 300B amp-- a real loser.

They couldn't get the highs right, or even deliver the needed bandwidth. Bass was "impressive", but loose and had no relationship with the music being played. They were slow-sounding and they couldn't even hint at catching the leading edge of a musical attack. Decay was also screwed-up, but the S.E. "magic" that reviewers liked WAS there--- music played more directly and was less processed-sounding-- even though the amps in question couldn't play it right, they didn't change it fundamentally like push-pull does.

I should mention here that this is about amps used for playback because push-pull, "balanced" circuitry is, and for the most part-- should be, used for recording music. .

There are some reasons: balanced is necessary in venues where lead lengths are long enough to pick up too much room-induced noise and hum. Balanced operation of mikes, feeds, etc., benefit from Common-Mode spurious signal rejection.

Does the studio's use of balanced circuits change music? Yes, it does, and that is why the best recording studios are single-ended wired. Unfortunately, S.E. wiring will not work in most real-world performing venues... it is only used commercially where studio conditions are well under control.

Balanced works well for recording real-world music because of another factor: a recording studio is making and selling a PRODUCT. If balanced circuitry is changing music in subtle ways, a good studio can PUT BACK much of the lost "magic" into the final product-- which is really engineered to please all of us anyhow.

Playback, however, should be accurate because most of us want to hear the studio product, not something that's been changed.

This is where Single-Ended amps are mandatory-- they don't CHANGE music. They may fail to reproduce parts of it, but they won't change it's character.

Realizing this fact is what justified to me-- the necessity (and hard work) of designing a S.E. amp that could really get with it musically.

So the whole thing was very carefully thought out-- what it had to accomplish, and ways were devised to allow it to do those things.

The very first one really kicked-ass bigtime, and soon replaced all my other amplifiers, both commercial and HomeBrew. It had dynamics, speed, and a very wide speaker reproduced usable bandwidth, and it kept-up with music's timing cues in every way.

Over the years, every time more of them were to be built (I always built them 10 or so at a time, and then didn't do any more until more were wanted)...., with each new batch a new assessment was made of the whole thing-- how to improve it--- whatever I could think of that would improve.

That is where better, shorter, and more metallurgically correct materials came into practice. Power supplies, and tube op. points were also scrutinized and assessed to see if any of those should get changed, but every time, those looked excellent..

Of course, common-sense, not dogma, was what was applied every time.

The fact that leadouts from chokes, transformers, and capacitors are not up to the jobs required of them-- in stock forms-- became rather obvious when they were changed for better materials, and sound quality then took another leap forward.

Those same kinds of improvements also became very obvious when I started applying the same methods to speakers, their wiring and crossover networks.

Since I normally operate speakers at 8 or 16 ohms, the changes wrought from better wiring and materials in them produced even greater dividends than they did in amplifiers.

Improvements come about as the curious find better ways to do things as they go along. Every once-in-a-while, it becomes necessary to "re-invent" something-- that is, to change it in major ways.

If that is what something is telling you that it needs, then it is desirable for you to do just that.

---Dennis---

 

RE: A Mercedes and a bus..., posted on March 13, 2015 at 05:05:50
PakProtector
Audiophile

Posts: 12366
Joined: May 14, 2002
 It is quite possibly a cost save...:) however, since it is claimed replacing the lead outs helps, and that the coils in the bobbin are perfect as is, using said wire for lead out follows naturally IFF the scheme has any merit at all.

and btw, make the Benz a 6.5 and I'll take it v. the bus anytime...maybe followed by a 115-body, 'C' with a manual and an OM617 under the hood...:)
cheers,
Douglas
Friend, I would not hurt thee for the world...but thou art standing where I am about to shoot.

 

RE: How to butcher a choke in 8 easy steps, posted on March 13, 2015 at 07:32:00
sony6060
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 I did not read all posts. But, if I was concerned about a choke wire lead gage I would also have to address the winding gage as a matter of follow up engineering wise. I view it something like adding a 3/4" water pipe (lead in) connected to a 3/8" water pipe (winding).

Why not contact Heyboer Transformer in MI and specify a heavy gage wire throughout the entire choke. If a certain wire lead is wanted, simply mail the lead in wire to Heyboer.

No doubt a few DIYers hear something different with a 'special' lead on a choke, but the choke is electrically distant from the amplifier circuitry. The last PS filter capacitor is much closer.

I am a fan of low DCR chokes for superior load regulation.

My 2 cents.

 

RE: A Mercedes and a bus..., posted on March 13, 2015 at 07:57:22
Tre'
Industry Professional

Posts: 17306
Location: So. Cal.
Joined: February 9, 2002
 " I should mention here that this is about amps used for playback because push-pull, "balanced" circuitry is, and for the most part-- should be, used for recording music. .

There are some reasons: balanced is necessary in venues where lead lengths are long enough to pick up too much room-induced noise and hum. Balanced operation of mikes, feeds, etc., benefit from Common-Mode spurious signal rejection.

Does the studio's use of balanced circuits change music? Yes, it does, and that is why the best recording studios are single-ended wired."

Balanced and push pull are not the same thing.

Very few professional vintage studio units that have balanced inputs are balanced all the way through.

Most of the great vintage studio units use input and output transformers so the cabling between units can be balanced for the sake of common mode rejection but the circuitry in between is single ended.

I have never heard of a professional studio wired "single ended".

Please keep your facts straight.

Tre'

Have Fun and Enjoy the Music
"Still Working the Problem"

 

RE: A Mercedes and a bus..., posted on March 13, 2015 at 08:35:06
tube wrangler
Manufacturer

Posts: 2484
Location: USA
Joined: January 29, 2007
 Two different worlds, obviously.

Different definitions, different conclusions.

That first 1989 amp was built in two pairs. After many years, I got one of them back as a keepsake, Lakerfan has the other.

I know you've had a lot of trouble understanding the Miller-Effect in that kind of amp-- the fact that I can drive it effectively with a low plate-current driver.

I'm not here to argue, but just for understanding's sake, you could ping Lakerfan and ask what the highs are like.

Who knows? You might question something that you formerly believed-- and that could become useful to you?

---Dennis---





 

RE: A Mercedes and a bus..., posted on March 13, 2015 at 09:10:56
Tre'
Industry Professional

Posts: 17306
Location: So. Cal.
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 I have no trouble understand Miller effect.

It's not the limited current. You probably don't push the 2a3 that hard.

It's the 39kHz -3db point that causes measurable amplitude loss down into the audio band and phase shift all the way down to 3.9kHz.

That might sound just fine to some people but that's not the point.

The point is it's bad engineering.

Can you name one professional recording studio that does not use balanced connections between the microphones and the mic preamps?

No? I didn't think you could.


Tre'
Have Fun and Enjoy the Music
"Still Working the Problem"

 

RE: A Mercedes and a bus..., posted on March 13, 2015 at 10:52:04
tube wrangler
Manufacturer

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 You can call Mapleshade recordings at 1-410-867-7543.

Pierre can explain why S.E. is used in his entire recording chain.

Interestingly, Pierre understands what balanced interconnects are processing out of music just like I do. I confirmed this 5 minutes ago by talking with him.

Also, Pierre is using push-pull amps (so far). I think that might very well change someday......

---Dennis---


 

RE: A Mercedes and a bus..., posted on March 13, 2015 at 11:22:49
Tre'
Industry Professional

Posts: 17306
Location: So. Cal.
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 "Sony TC-880 II, wow! This is the Queen of CONSUMER reel to reel decks."

That's not a professional deck.

Now, name one major professional recording studio that does not use balanced connections between the microphones and the microphone preamps.

Tre'
Have Fun and Enjoy the Music
"Still Working the Problem"

 

Mapleshade Audio - LOL!, posted on March 13, 2015 at 11:56:29
gusser
Audiophile

Posts: 3649
Location: So. California
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 Take a look at his products, specifically his biwiring jumpers.

What? Stock brass biwire jumpers no good? Here try some of my cut up scrap copper sheet with directional marking by Sharpie!

This takes the biwiring farce to a whole new level!

 

RE: Mapleshade Audio - LOL!, posted on March 13, 2015 at 12:11:41
Tre'
Industry Professional

Posts: 17306
Location: So. Cal.
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 "All stock, factory-provided jumpers seriously degrade speaker sound."

Well, that seriously fits into Dennis' way of thinking.

There's so much BS and snake oil in this hobby.

It makes me want to puke.

Tre'
Have Fun and Enjoy the Music
"Still Working the Problem"

 

nah..., posted on March 13, 2015 at 12:38:56
PakProtector
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 read the marketing claims of dennis...that will tell you all you need to know. His amps sound different...maybe you like, maybe you won't...but that is up to you if you like his brand of different. The wording of the claims is all the proof you should ever need...LOL
cheers,
Douglas
Friend, I would not hurt thee for the world...but thou art standing where I am about to shoot.

 

RE: A Mercedes and a bus..., posted on March 13, 2015 at 20:33:06
tube wrangler
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 Typical dogfighting contest here-- nothing new that I see.

Major studios range in the thousands. I even like some of the best products from them.

You asked, however, for one studio that uses S.E. wiring. I gave you one-- there are several more in L.A. alone. That's irrelevant.

What is relevant is that both balanced and push-pull circuits have Common-Mode rejection, which reduces noise and hum.

Unfortunately, a lot of music is exactly like-- momentarily, of course-- exactly like the CM items that both balanced and push-pull circuits are cancelling out.

The so-called "magic" of S.E.-- is that it either conducts, or amplifies everything. It's up to the builder and venue wiring expert to decide what he wants to accept, and what hum & noise he may decide to reduce.

For most Majors-- as you call them-- it's academic, it's already decided by their Banking firms. They don't spend the time and won't spend the extra money and man-hours to optimize a recording system every time it's moved to somewhere else. They'll simply design everything balanced and push-pull, and be done with it. Plug it in and play. Convenient, cost-effective. Just like Canned Soup!

---Dennis---

 

RE: Mapleshade Audio - LOL!, posted on March 13, 2015 at 20:40:48
tube wrangler
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 I don't subscribe to the thin-wire theory-- it simply doesn't work.

As you should already know, heavy silver multistranded conductors outperform everything available.

You asked me to name a S.E. studio, not recommend wiring!

---Dennis---

 

RE: A Mercedes and a bus..., posted on March 13, 2015 at 21:32:44
Tre'
Industry Professional

Posts: 17306
Location: So. Cal.
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 "Unfortunately, a lot of music is...exactly like the CM items that...balanced....circuits are cancelling out."


You don't have an understanding of what "common" means.

BTW Balanced and push pull are not the same thing.

Dennis, you are clearly very confused. I don't think I can help you.

I don't think anyone can say that I haven't tried over the years.

Tre'


Have Fun and Enjoy the Music
"Still Working the Problem"

 

RE: A Mercedes and a bus..., posted on March 14, 2015 at 06:01:17
cpotl
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 " What is relevant is that both balanced and push-pull circuits have Common-Mode rejection, which reduces noise and hum.
Unfortunately, a lot of music is exactly like-- momentarily, of course-- exactly like the CM items that both balanced and push-pull circuits are cancelling out."

This statement seems to indicate a very basic misunderstanding of the principles involved.

Chris

 

RE: "most amps will sound better when operating at higher B+", posted on March 14, 2015 at 07:16:10
1973shovel
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Posts: 10117
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 Which was my point.

So I should be able to get the same sonic benefit by increasing B+ and leaving the choke alone.



 

RE: A Mercedes and a bus..., posted on March 14, 2015 at 08:36:57
tube wrangler
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 YMMV.

---Dennis---

 

RE: A Mercedes and a bus..., posted on March 14, 2015 at 10:41:36
Tre'
Industry Professional

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Location: So. Cal.
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 No. There's no varying when it comes to the principals involved here.

This is not subjective or just someones opinion.

You clearly don't understand Common Mode Rejection.

You also don't understand audio signal.

When a microphone is in the presents of sound there will be an output signal.

If the microphone is single ended the signal will be represented by a voltage potential difference between ground and the one signal wire. If the microphone is balanced the signal will be represented by a voltage potential difference between the two signal wires.

Common Mode Rejection is the rejection of any signal that is common to the two balanced wires.

That can never be the audio single generated by the microphone because, as I have already explained, a balanced microphone's audio output is represented by a voltage potential DIFFERENCE between the two signal wires.

CMR does not reject voltage potential differences between the two signal wires, CMR rejects only voltages that are the same in each of the two audio signal wires.

I don't think I could have made this more clear.

Tre'


Have Fun and Enjoy the Music
"Still Working the Problem"

 

RE: A Mercedes and a bus..., posted on March 14, 2015 at 12:37:36
tube wrangler
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 Correct, and I have never disagreed with this-- as far as it goes.....

That same microphone's two balanced output leads would normally be encased in a cable that has a shield around it.

That shield would be grounded-- in some cases, one of the two "hot" leads would also be grounded.

True balanced would have the two leads "hot". S.E. would ground one of the two "hot" leads to the shield in most cases..

In the case of balanced, with a shield NOT connected to either lead, Common-Mode rejection takes place between the two "hot" wires, and to the grounded shield.

In the S.E. example, where one lead is also grounded to the shield, there is no longer a Common-Mode. There's only one "hot" wire. The loss here is "hot lead" energy being absorbed into the shield, and into the grounded lead.

The energy loss in the two balanced "hot" leads with a shield example-- is to load the Common-Mode that is between the two "hot" wires-- into the shield. The Common-Mode is thus attenuated into the shield.

You have losses either way-- into the shield, etc. In the S.E. example, loss is broadband, but not totally-- that depends on what the wire's characteristics are.. In the balanced example, loss is both into broadband and into attenuating the Common-Mode between the two "hot" wires in the shielded cable/interconnect.

Some users prefer to wire the mike as S.E.-- that is, with one "hot" pin grounded with the shield also as ground. For short runs, this sounds more real.

Others don't have time for that and wire everything balanced. For longer runs, and for frequently moved/disturbed studios, this is the way to go.

You are, however, attenuating the Common-Mode mostly because your wire has a shield around BOTH "hot" leads..

What if it didn't have a shield? Just two wires-- balanced. If they're near each other, or twisted together, then the internally radiated Common Mode is also being attenuated by the cable-- even without a shield because the two "hot" leads are close enough to radiate into each other.

There. You have it.

---Dennis---

 

RE: A Mercedes and a bus..., posted on March 14, 2015 at 12:54:52
Tre'
Industry Professional

Posts: 17306
Location: So. Cal.
Joined: February 9, 2002
 "In the case of balanced, with a shield NOT connected to either lead, Common-Mode rejection takes place between the two "hot" wires, and to the grounded shield."

No.

Ground is only connected to the shield to deflect the hum fields, that the cable might encounter, away from the two conductors.

CMR is between the two "Hot" wires only.

Any hum that gets through the shield is impressed on each of the two "Hot" wires equally and is therefore reject by the CMR of the input. (circuit or transformer)

"You have losses either way-- into the shield, etc. In the S.E. example, loss is broadband, but not totally-- that depends on what the wire's characteristics are..

In the balanced example, loss is both into broadband and into attenuating the Common-Mode between the two "hot" wires in the shielded cable/interconnect.You are, however, attenuating the Common-Mode mostly because your wire has a shield around BOTH "hot" leads..

What if it didn't have a shield? Just two wires-- balanced. If they're near each other, or twisted together, then the internally radiated Common Mode is also being attenuated by the cable-- even without a shield because the two "hot" leads are close enough to radiate into each other."

Dennis, you are mixing two different properties/functions.

The shield will interact with the two "Hot" wires to whatever degree (subject to discussion) but that's has nothing to do with the function of CMR.

All three wires are in close proximity so there will be capacitance and inductance between each of them but again Dennis, that's not CMR.

Tre'


Have Fun and Enjoy the Music
"Still Working the Problem"

 

LMAO..., posted on March 14, 2015 at 14:53:27
PakProtector
Audiophile

Posts: 12366
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 --This statement seems to indicate a very basic misunderstanding of the principles involved.

It is just SE builder marketing. Those who pay attention to such 'explanations' are where the real misunderstanding lies. Or you could be entirely correct. I suspect that it is some Column A, some Column B.
cheers,
Douglas
Friend, I would not hurt thee for the world...but thou art standing where I am about to shoot.

 

RE: A Mercedes and a bus..., posted on March 14, 2015 at 20:13:03
tube wrangler
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 Any signal that is common to both "hot" leads will be attenuated by any grounded shield that is around them.

This is so basic that no further explanation is needed, and none will be given.

---Dennis---




 

RE: A Mercedes and a bus..., posted on March 14, 2015 at 20:29:30
cpotl
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Posts: 1002
Location: Texas
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 "Any signal that is common to both "hot" leads will be attenuated by any grounded shield that is around them.
This is so basic that no further explanation is needed, and none will be given."

But the audio signal is the *difference* between the two "hot" leads; it is not "common" to them. By contrast, a stray signal like hum pickup will be common to the two hot leads, and will be balanced out.

The strange thing that you appeared to be saying was that an actual audio signal could be common to both "hot" leads. This, of course, is not true. Anything that is common to the two hot leads is, by definition, not part of the audio signal, and therefore it should, quite properly, be rejected.

Chris

 

RE: A Mercedes and a bus..., posted on March 14, 2015 at 21:04:42
elblanco
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Posts: 3486
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 He is not looking at it as a system, rather he is focusing on the cable. Signal we want is 180 degrees out of phase and one leg is inverted by circuitry and becomes additive. Anything we dont want will be common mode , in phase, and when the one leg is inverted by said circuitry , it will cancel. This inherent operation will take care of everything we can possibly hear and the shield/foil thickness will take care of stuff cats couldnt even think about hearing. Much more explanation will be necessary. None will be heeded.

 

RE: A Mercedes and a bus..., posted on March 14, 2015 at 23:18:28
Tre'
Industry Professional

Posts: 17306
Location: So. Cal.
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 I hope you were trying to say "Any external hum signal that is trying to get to the two "Hot" wires will be attenuated by the grounded shield"

Yes. That's why the shield is there.

But this is not CMR and has nothing to do with CMR.

Again, CMR is what a input signal transformer (that does not have either side of it's primary winding grounded) does.

Any external hum signal that gets through the grounded shield is impressed upon the two "Hot" wires.

That hum signal will be impressed upon the two "Hot" wires equally.

And because the transformer can only respond to the voltage potential differences between each end of the primary winding, the hum signal that came from an external source (a signal that has nothing to do with the output of the microphone and is therefore not music signal) is rejected.

That is CMR and a quick explanation of how and why it works.


Tre'
Have Fun and Enjoy the Music
"Still Working the Problem"

 

RE: A Mercedes and a bus..., posted on March 15, 2015 at 08:25:35
Tre'
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 "Signal we want is 180 degrees out of phase and one leg is inverted by circuitry..."

It can be done with active circuitry but many sources are inherently balanced.

A dynamic microphone is like a speaker used in reverse.

A coil of wire sitting in a magnetic field being moved by a diaphragm by sound pressure.

When the wire is moved, signal voltage is generated because magnetic flux lines are being crossed.

That coil wire has two end, neither end has to be grounded.

A moving coil phono cartridge (or a moving magnet phono cartridge for that matter) is an inherently balanced signal source.

When used with a step up transformer there's no need to ground either end of the coil or either end of the primary winding of the step up transformer.

When we hook it up this way using one "2 conductor shielded cable" for each channel, (looking a one channel)





we get CMR for any noise picked up in the tone arm cable.

Many studio units (micpres, EQs, compressors, mixing consoles, etc) are balanced in and balanced out using input and output transformers.

The circuitry in between is single ended but the primary winding of the input transformer and the secondary of the output transformer are inherently balanced as long as you don't ground either end of the windings.

The secondary of the output transformer on your tubed power amp is inherently balanced and so are your speakers. The only reason to ground them (if your not using global negative feedback) is safety. BTW, I don't ground mine.

Tre'

Have Fun and Enjoy the Music
"Still Working the Problem"

 

RE: A Mercedes and a bus..., posted on March 15, 2015 at 08:35:53
tube wrangler
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 Yours is an excellent explanation of how major studios normally apply CMR.

One can also apply CMR to an operating pair of triodes in push-pull. Simply tie the two cathodes together into ONE common cathode resistor that goes to ground. Common-Mode Reduction will be applied directly, or indirectly to all of the signals present in the two tubes.

Another application is with two tetrodes (or pentodes) operating in push-pull.

To apply VERY effective CMR to the pair, connect a resistor of equal value in series with each G2. Then, tie the two resistors together at their outboard ends. Take this COMMON POINT, and apply G2 bias into it. You have just installed CMR into the push-pull pair of tetrodes, or pentodes.

CMR can be applied in numerous ways in many, many circuits. Another CMR application is to use a center-tapped choke on push-pull grids on a triode pair (or otherwise also).. The choke isn't necessary, you can also do it with resistors, or with a push-pull transformer.

I've been applying all of these and more CMR methods for many years now.

The more places you can find to apply CMR in a push-pull circuit, the better it will perform. It's only open to your imagination.

It only stands to reason that I would find ways to do it with wiring schemes also.

---Dennis---









 

RE: A Mercedes and a bus..., posted on March 15, 2015 at 08:59:53
tube wrangler
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 I understand the theory and agree with it as far as it goes.

Here's the problem: ALL musical signals contain some artifacts that are identical to common (to both leads) signals in some way-- at some time in the musical cascade (for want of a better term admittedly). Difference signals are not the ONLY components in music.

Push-pull operation applies CMR at certain points in the circuitry (it should-- the more the better-- for push-pull). So does balanced signal systems such as studio wiring, etc.

I'm not arguing that this doesn't occur. What I am saying is that S.E. amplifier operation and also S.E. signal wiring cannot reduce the Common Mode.

In MUSIC, that is an ADVANTAGE. In cleaning-up signal, it is a DISADVANTAGE.

No one is arguing how this works. We all agree here. What I am saying is that artifacts of real music have components that are identical with Common-Mode distortion.

The question before us is-- do we wish to reproduce that common-mode signal or do we want it to be attenuated?

Your answer will put you into one of two camps-- S.E. amps or push-pull. S.E. wiring or balanced?

I think that, in practical terms, all of us are using combinations of both.

The item here is that I understand what each is doing musically.

---Dennis---



 

RE: A Mercedes and a bus..., posted on March 15, 2015 at 11:48:25
Tre'
Industry Professional

Posts: 17306
Location: So. Cal.
Joined: February 9, 2002
 "Here's the problem: ALL musical signals contain some artifacts that are identical to common (to both leads) signals in some way"

No, music signal does not contain any signal that is common to both "hot" leads.

By definition, music signal is the difference between the two wires (or the one wire and ground in a SE circuit).

There is no signal common to both wires created by the source (microphone/phono cartridge).

Signal common to both wires is, and can only be, noise generated from an outside source that has nothing to do with the music signal generated at the signal source.

Every time you assert the idea that there is signal that is common to both "Hot" wires, in a music signal, you show your ignorance.

Tre'
Have Fun and Enjoy the Music
"Still Working the Problem"

 

RE: A Mercedes and a bus..., posted on March 15, 2015 at 15:23:14
LinuxGuru
Audiophile

Posts: 582
Location: European Union
Joined: November 11, 2008
 > Every time you assert the idea that there is signal that is common
> to both "Hot" wires, in a music signal, you show your ignorance.

Incompetence, to be precise.

Like other insanely dumb "idea" to bias cable & interconnects with hum to make them respond quickly to musical transients.

 

RE: A Mercedes and a bus..., posted on March 15, 2015 at 16:19:35
PakProtector
Audiophile

Posts: 12366
Joined: May 14, 2002
 I am not sure the exact source of these claims, but consider the marketing required for the amps he sells at the price he commands. There has got to be some stated reason to go and buy his v. something else. Examine the target market. Is it comprised of engineers capable of design and building their own vision? I don't think so.

Now the entertaining question is( IMO), does dennis actually believe the stuff he is saying?
cheers,
Douglas

Friend, I would not hurt thee for the world...but thou art standing where I am about to shoot.

 

RE: A Mercedes and a bus..., posted on March 15, 2015 at 16:25:17
LinuxGuru
Audiophile

Posts: 582
Location: European Union
Joined: November 11, 2008
 > Now the entertaining question is( IMO), does Dennis actually
> believe the stuff he is saying?

1000% he does.

 

RE: A Mercedes and a bus..., posted on March 15, 2015 at 17:25:51
tube wrangler
Manufacturer

Posts: 2484
Location: USA
Joined: January 29, 2007
 Look-- the difference signal is most of what's left after common-mode attenuation has been applied.

It IS NOT----- ALL of the generated signal.

Your microphone-- let's assume it's balanced, is transmitting accurate total information from it's two equal but opposite outputs.. These two outputs truly are equal but opposite. BOTH contain both Common_Mode and difference signal information.

Some would argue that the mike element itself cancels any Common_mode across it. Theoretically, yes, actually it's only partial cancellation because of the mike's internal generator resistance.

However, when you apply a twisted wire pair (your mike's output cable) to the balanced signal, you have now installed an attenuator-- a Common_Mode attenuator.

Anything that the mike delivered that was common to both output leads is now attenuated-- so that mostly, only the difference signal remains..

We can argue all day about who prefers to listen to this sanitized mostly difference-only signal, or who prefers to have his mike cable not attenuate what Common-Mode existed inside the mike-- before the output wiring was applied.., but we cannot deny that a real difference exists.

There's more than just a difference signal that the mike is generating.

In practice, push-pull amps and balanced circuitry is clean because it's been cleaned-up-- mostly all that's left is the difference signal.

S.E. stuff sounds FAR more "real".

It does this because nothing that occurred naturally in the Common_mode is filtered out, sadly leaving only a difference signal to listen to.

A truly balanced difference signal is the Gold Standard for both balanced and push-pull circuitry. The less of anything else it contains, the cleaner and "better" it is.

The problem is that it WILL NOT convey a sense of reality to the listener. It is fully incapable of it.

That leaves S.E.-- distortions, hum and all the rest-- if you want music to sound real.

---Dennis---







 

RE: A Mercedes and a bus..., posted on March 15, 2015 at 18:19:01
Tre'
Industry Professional

Posts: 17306
Location: So. Cal.
Joined: February 9, 2002
 Dennis, I didn't even read your whole post.

The microphone is not capable of generating common mode signal.

If the two "hot" wires are at the same potential, one vs. the other, you have silence. No signal.

This would happen when there is no signal and at zero crossing. In other words, when there is no voltage potential between the two "Hot" wires it's because, in that moment, there is no signal, nada, nothing.

I think it's OK to cancel nothing.


Tre'
Have Fun and Enjoy the Music
"Still Working the Problem"

 

got it. thanks! (nt), posted on March 15, 2015 at 20:01:59
elblanco
Audiophile

Posts: 3486
Joined: August 20, 2004
 .

 

RE: Mapleshade Audio - LOL!, posted on March 16, 2015 at 10:09:44
gusser
Audiophile

Posts: 3649
Location: So. California
Joined: September 6, 2006
 You know I have to admit, as much as I come down on audiophile snake oil and cables, most stuff is in fact very well made. Even though it does nothing over commodity parts in terms of sonic improvements, most audiophile snake oil at east looks expensive and high end.

But this crap Mapleshade sells is downright shoddy. I mean just look at it! This guy doesn't even have the pride to at least make his junk presentable.

 

RE: A Mercedes and a bus..., posted on March 16, 2015 at 14:05:52
PakProtector
Audiophile

Posts: 12366
Joined: May 14, 2002
 " That leaves S.E.-- distortions, hum and all the rest-- if you want music to sound real."

Total, unadulterated, SE-amp-marketer, bull cookies.
cheers,
Douglas


Friend, I would not hurt thee for the world...but thou art standing where I am about to shoot.

 

RE: "most amps will sound better when operating at higher B+", posted on March 18, 2015 at 10:39:43
gusser
Audiophile

Posts: 3649
Location: So. California
Joined: September 6, 2006
 I would say yes. Because replacing say a 2h 50ohm DCR choke with a 0.35uh 5 ohm choke would elevate the B+. However you have now lost a significant amount of ripple filtering with the millihenry sized choke.

So if more B+ is your goal, reducing the choke DCR is only a good option if you can maintain the same or close henry value.

And again I must stress that bumping up the B+ to get a more dynamic or aggressive sounding amp is not a good practice. Most commercial amps were designed at the optimum operating points. Some even beyond that such as Dynaco because tubes were cheap in those days. And remember that line voltage in the 1950/60s was 110-115v. Today we have 120-125v.

You really need to carefully analyse the circuit before raising the B+.

 

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