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A challenge to you all

73.25.118.98
Posted on January 19, 2017 at 20:22:49
SteveBrown
Audiophile

Posts: 2454
Location: Portland, OR
Joined: November 14, 2002
 You know, there is so much bickering here - it's the reason I left rec.audio.tubes years ago. But no matter what, I think a place where us "old timers" can help others is not so much in debate about specific topologies and philosophies, but in practical things like actual amp construction. I see few pictures and advice on things like how to create grounding schemes to minimize hum. I'd love to see more pictures of actual amp builds (not breadboards) and preamp builds with a clear layout of how you handled grounding and reduction of hum. I know many have discussed this, but it still gets confusing. So let's see your real world builds and how you addressed this - but only builds that actually resulted in good performance! For example, we talk a lot about star grounds, but if you look at old JE Labs posts you see preamps and even phono-pres that used the ground lug on terminal strips as a way to do this - really? Did that work? Yeah but, major manufacturers used the same approach, so how did you build your greatest noise / hum free amp? And show actual pictures if you can because words can be really confusing. And yes, I'll take some photos soon and post them, I don't want to be left out. My goal? Let's leave micro discussions of insignificant things behind and help newer folks find some audio build success!!

 

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RE: A challenge to you all, posted on January 19, 2017 at 23:39:16
91derlust
Audiophile

Posts: 1101
Joined: December 25, 2014
 Thank you for having the courage post Steve... not that I would have thought you were ever lacking in courage. :)

I agree, generally. I'd like to see more photos of others' builds and some narrative of how and why builders went about their builds as they did. Actually, I'd like more narrative similar to what was found in Sound Practices. Jeff is one of few - perhaps the only - persons attempting this at present, but frankly, that skews the available information and I am not comfortable with...

Your post is the most recent, and most significant, in giving me a kick up the proverbial arse to get moving on my next build - I have been procrastinating for 18 months... not that I think I have heaps to contribute... more that I can learn and share.

Now, to star grounding. I don't use it. It may be okay in some applications - and it is relatively fool-proof in most cases due to the separate wire runs - but seems not the ideal way to do 0V signal grounding for tube amps. I prefer a multiple star approach because it keeps local current loops short and separate when done well. But, done well is critical - if you stuff it up, you'll get noise.

BTW, I have only built one amp and it has been relatively silent, except a while back when a source was not connected and I put my hand near the input tube... the issue was an unshielded cable running near the output TX - fixed now. But, the amp otherwise, with AC filaments, has noise at circa 2mV or less, depending on the tube used. I recall posting the build under the moniker rcdaniel... he was a shit, so I changed the moniker, BTW.

I am looking forward to my next build and posting the pix - it is great to share and great for others (and me!!!) to learn.

Sorry for the lack of proof-reading; work calls - gotta run.

Cheers,
Ray
"Confusion of goals and perfection of means seems to characterise our age." Albert Einstein

 

DIY Audio for builds, posted on January 20, 2017 at 00:45:11
andy evans
Audiophile

Posts: 4378
Joined: October 20, 2000
 AA and DIY Audio fulfil different needs. Here it's discussion around various topics. On DIY Audio there are a lot of threads on actual builds with lots of photos and build information.

Rather than duplicate the functions of either group, I'd suggest using DIY Audio for builds.

 

RE: DIY Audio for builds, posted on January 20, 2017 at 01:18:47
91derlust
Audiophile

Posts: 1101
Joined: December 25, 2014
 I can't be sure of your assertion, but I dislike the general paradigm in play and DIYaudio. I remember Kofi - funny dude - and his builds, well questions, not so many pix... but that was rare.

Generally I have found DIYaudio to be measurement and technically-driven - an internal validity focus - often trivialising the importance of emotional connection with music (external validity). There are some exceptions that prove the rule, but they are rare. Each to their own, but not my scene... Before you ask, I did invest some time over there and I learned a lot from Thorsten and a few others, but I don't care for it now and moved on. So did they.

I'd like this community post their builds: their purpose, guiding principles, desired outcomes and results in preference to enduring the DIYaudio Tube forum. I am not suggesting it become insular though!.. just clear with what it is trying to achieve (and tolerate).

I think the members of this forum can make it great(er) again.

I need to go to bef... er, bed.

Cheers,
91.

"Confusion of goals and perfection of means seems to characterise our age." Albert Einstein

 

RE: DIY Audio for builds, posted on January 20, 2017 at 01:40:34
andy evans
Audiophile

Posts: 4378
Joined: October 20, 2000
 I'd prefer this community post their builds: their purpose, guiding principles, desired outcomes and results in preference to enduring the DIYaudio Tube forum.>>

Well, this is what I mean. Conversation here can be more general - as you say, purpose, guiding principles etc.

But I thrive on DIY Audio. I love the build threads, and they are exactly what you want if you are contemplating building, in the process of building or have built particular designs. There are very long threads on the builds I do myself - 4P1L SET, 26 preamp, 01A preamp, Rod Coleman regulators, various DACs, Mark Audio speakers being examples. These get very detailed - choice of resistors, capacitors, wiring, chassis, connections, troubleshooting, mods etc.

You are not likely to get 600 posts on a particular subject here, but you easily get them on the more popular builds on DIY Audio.

So, as I say, they do different jobs. Both good.

 

DIY vs. Commercial you can do better., posted on January 20, 2017 at 03:52:59
DAK
Audiophile

Posts: 2712
Location: PACIFIC
Joined: August 8, 2010
 I am not sure if bickering is the correct term. It seems to me that there exists here, a base of very tube savvy individuals who can call up information regarding amplifier circuits and tube operating points as second nature. While the rest try to follow along. I think that it is wonderful that they are willing to share their hard earned knowledge with those who are seeking answers to problems. And speaking for myself, i find that while build threads don't seem to have a high priority here as on some other forums, but that doesn't bother me. But i find that whenever i do have a problem with a project, that the inmates give their thoughts and solutions in a manner that is courteous and friendly and sincere. And to me advice that is given in that manner is hard to come by.
But on to practical matters, If you are good at building and soldering then a diy'er can make a better amplifier. Without an accountant to make sure you are only spending X amount of time for each amp and X amount of dollars for each part one can do a much better job. Almost all commercial amps use circuit boards. This is so there are no mistakes and robots can assemble the cb in just a minute at very little cost. The early kit built amps from the "golden age" of tube audio serve as examples of how to build an amp with point to point wiring. There are different ways or styles of wiring an amp. There is the military style with neatly bundled wiring, there is "The Fisher" style which is neat but unbundled, There is the Scott style, not so neat, and the post 1960s oriental style which can be described as an explosion at the "lo mein factory". And the funny thing is they all work, more or less.
As far as posting about your amp projects, Check my last post "fixed problem fixed" which shows my last amp that i just finished building. And i am looking forward to more build stories from other inmates. cheers, Dak

 

RE: DIY vs. Commercial you can do better., posted on January 20, 2017 at 08:14:36
SteveBrown
Audiophile

Posts: 2454
Location: Portland, OR
Joined: November 14, 2002
 So let me get this straight... you're bickering with the use of my word bickering? :-) Just kidding. I love the description of the different styles you mentioned. I look at some of that vintage stuff and I'm just amazed it is as quiet as it is. I think for those new to DIY, doing a close study of existing, working designs is highly instructive. I'm also guessing companies like Fisher, etc. took the time and money to prototype designs to work out bugs.

 

(External validity), posted on January 20, 2017 at 08:47:11
TomWh
Audiophile

Posts: 764
Location: Tucson Az
Joined: August 7, 2003
 How dare you bring a subjective reality of how something sounds to the mad hatters tea party or is that the party the subjective people,who listen to music, belong???

The reality is there is not a lot of building going on like 10-20 years ago. Lots of opinions but not a lot based on (external validity). Even worst is the ones who pride themselves in logic do not even get transistors can look real good on paper and scope but do they sound like DHT's. The other variables like reducing this number only to find out you screwed up 5 variables you can understand or measure yet.

So the moral of this story is you use the information from every one. The math guys can help you not blow things up and sometimes get you in the ball park. The subjective group, if you read between the lines, can help you with (external validity).

Enjoy the ride
Tom

 

RE: A challenge to you all, posted on January 20, 2017 at 09:23:29
TomWh
Audiophile

Posts: 764
Location: Tucson Az
Joined: August 7, 2003
 Steve I agree on let's build more and compare notes vs let's replace 2 inches of wire or blind test those poor naive souls who can play and hear music.

To the point at hand. You may have picked the most complex issue there is. You have even given examples of there is more than one way to skin a cat. There are white papers written on hum that are as long a trashy novel. Twist wires and put them in the corners, move transformers and inductors around, star semi star, balanced interconnects etc ...

The sad reality here that even if you built exactly the same unit with same dimensions and parts you could get some hum. The tubes themselves from the same manufacturer can vary.

In regards to build more and share vs argue, would be a great improvement. This might bring more middle ground people into the fold.

Enjoy the ride
Tom

 

RE: DIY and Good Sound...... not for the short term .., posted on January 20, 2017 at 10:25:16
drummerwill
Audiophile

Posts: 965
Location: St Louis Mo.
Joined: January 7, 2003

My problem is none of my DIY amps are "Truly Done ".assembled , Yes
but not done.

There's always an added cap or resistor change after assembly. Then there's the break-in time for all new parts.

That's DIY if you don't like it you can always change it.

Fun stuff eh!

Willie

 

RE: DIY and Good Sound...... not for the short term .., posted on January 20, 2017 at 10:58:43
vinnie2
Audiophile

Posts: 4481
Location: North Carolina
Joined: September 28, 2013
 That's what I love about bread boards. Put the whole thing together in a couple of hours and change anything you want in a couple of minutes. Try doing that with a fully assembled amp!
I have seriously thought about trying to build the ultimate bread board platform as my next project. Just leave it up full time and have every thing easy to change but a little better than clip leads. I like those European style terminal blocks that let you put a wire in and tighten down a screw in just a very short time. Use universal output transfromers and have adjustable psu and filament voltage capabilities. I might have to start an "amp of the month club" if I do that. : )

 

+1. nt., posted on January 20, 2017 at 11:44:49
91derlust
Audiophile

Posts: 1101
Joined: December 25, 2014
 .
"Confusion of goals and perfection of means seems to characterise our age." Albert Einstein

 

RE: Ground.., posted on January 20, 2017 at 11:50:27
sony6060
Audiophile

Posts: 1465
Location: USA
Joined: August 8, 2014
 Ground is simple, no schematic needed. I place a separate ground wire across the chassis on ceramic standoffs. Connect all transformer leads at far end. Next, I connect audio transformer grounds. Rest of various grounds are next, Then ground this wire at input jacks & chassis. 120 volt power ground is at transformer.

Never had a hum issue.

 

RE: DIY Audio for builds, posted on January 20, 2017 at 12:23:58
91derlust
Audiophile

Posts: 1101
Joined: December 25, 2014
 Hi Andy,

I may not have been clear last night.

I am not suggesting that builders *only* post what drives their builds; more that they discuss the "why" (perhaps link the technical back to the sonic), not just the "what" and occasional "how".

I'd love to see more build threads here, but the branching nature and option for a "classic" view of the threads probably is not helpful. This is especially relevant to my builds, as they may take several months (or years!) and would spin off into other discussions and/or get buried over time.

I prefer the vibe here to the more expert-adherent, superiority vibe on DIYaudio... although, there are a few zealots here in AA... and they build and post more than others.

Cheers,
91.

"Confusion of goals and perfection of means seems to characterise our age." Albert Einstein

 

RE: Ground.., posted on January 20, 2017 at 13:11:14
vinnie2
Audiophile

Posts: 4481
Location: North Carolina
Joined: September 28, 2013
 You posted you're reply to the wrong post methinks. At least I do not see how it relates to my post in particular. You might want to re-post to the correct one and delete this one.

 

RE: A challenge to you all, posted on January 20, 2017 at 13:59:08
xaudiomanx
Audiophile

Posts: 3647
Joined: August 16, 2004



Here is my grounding scheme and the amp is dead quiet. It is a piece of copper tubing that is connected to the chassis on one end only. The rest of the copper tubing is held off from touching any metal using standoffs and wire ties to secure it. Works great and is very neat. This is one of my first tries using it. My other work is a lot nicer. I just don't have any pictures. Because of the size(1/4 inch I think) of the tubing it is almost like star grounding even though wire is soldered at different points of the circuit. If you take an ohm meter and check for a dead short it is doing just that from any solder point on the copper.

 

RE: A challenge to you all, posted on January 20, 2017 at 14:25:23
SteveBrown
Audiophile

Posts: 2454
Location: Portland, OR
Joined: November 14, 2002
 Hi Xaudiomanx, thanks for the picture. Where is the AC mains grounded? What input does the amp see? A DIY preamp, commercial digital source, phono-pre? I think when I have issues with hum it is usually from up-stream components or the interaction of up-stream components and down-stream components. I'm thinking that soldering to that "buss" would require some significant heat, yes?

 

Challenge accepted, but..., posted on January 20, 2017 at 19:48:31
91derlust
Audiophile

Posts: 1101
Joined: December 25, 2014
 I am willing to take up the challenge and post details of my pending build to AA. Documenting my mistakes might help others avoid them... and it might motivate me to get it done.

I have a question: how should I post the build stages/progress? If I post to a single thread, it will be lost to folks running a "Classic" view - is this an issue? Or should I start a different thread, maybe with a common prefix in the subject, for each stage of the build?

Or maybe just post the results and answer any questions that others might have?

What would inmates like to see? What level of detail and what types of things would people like to read about? Does it really matter?

Any thoughts?

Cheers,
91

"Confusion of goals and perfection of means seems to characterise our age." Albert Einstein

 

try a blog, posted on January 21, 2017 at 05:04:49
RayP
Audiophile

Posts: 727
Location: Maryland
Joined: June 30, 2005
 I prefer to use a blog and post a link. It puts everything in one place and makes it easier to do a construction narrative and why you made certain choices. Below is a link to one of my early attempts.

But I like blogging so I am biased. On a side note, I travel a lot in my retirement and have found it very useful to blog what I am doing. It makes it easier to remember what I did.

Here is an example:
http://ratbagp.blogspot.com/2016/09/the-quarantine-station.html

But for me, the most amazing blog I follow is one by a woman who is walking around the UK. Check it out.

https://coastalwalker.co.uk/

ray

 

RE: A challenge to you all, posted on January 21, 2017 at 10:09:19
6AS7_6SN7

































Only magnetic coupling hum is a difficult problem.
In all other cases a deadly quiet amplifier is the norm, not an exception.

 

RE: A challenge to you all, posted on January 21, 2017 at 10:41:29
SteveBrown
Audiophile

Posts: 2454
Location: Portland, OR
Joined: November 14, 2002
 Wow, that's an awesome collection of amps! I would think you would have trouble with hum from the long AC wiring from transformers but apparently it works for you. Beautiful wood work!

 

RE: try a blog, posted on January 21, 2017 at 12:11:06
91derlust
Audiophile

Posts: 1101
Joined: December 25, 2014
 Thanks Ray - a blog is probably best.

I had considered one, but my perfectionism kicked in and I could see it being much more difficult and time-consuming than I had the energy for. I could start simple and grow as needed. I will look into it again.


Thanks for links also - I will check them out!

Cheers,
91. (a Ray also)


"Confusion of goals and perfection of means seems to characterise our age." Albert Einstein

 

RE: A challenge to you all, posted on January 21, 2017 at 13:42:30
bwaslo
Manufacturer

Posts: 245
Location: Portland, OR USA
Joined: September 10, 2006
 Hi Steve,

Hum can come in via a lot of different means, as you know. But one kind of hum I ran into was from AC line current riding in the return (shield) conductor of the input wires. You can tell this is your problem if the output is hum free until you connect the cable to the preamp, then it starts humming, or until cables from both channels are connected.

I found a way to cut that kind of hum back to very low levels with just a well placed resistor (and probably some rewiring of the input stage and input jack). John Broskie over at TubeCAD does a similar thing in some of his designs. I wrote a blog about the technique (see link). No need to read all the techie stuff in the article, but do have a look at the schematics to see.
_

Make easy high performance diffusors:-->http://www.libinst.com/diffusers/Depot_Diffuser.html

Horn Design Spreadsheet:--> http://libinst.com/SynergyCalc/

SmallSyns:-->http://www.diyaudio.com/forums/multi-way/292379-s

 

RE: A challenge to you all, posted on January 21, 2017 at 17:14:29
SteveBrown
Audiophile

Posts: 2454
Location: Portland, OR
Joined: November 14, 2002
 Great post, thanks!

 

RE: DIY Audio for builds, posted on January 24, 2017 at 12:11:15
r.crawley@ntlworld.com
Audiophile

Posts: 41
Location: United Kingdom
Joined: November 22, 2005

The post layout here doesn't really lend itself to very long threads on builds. I read all 3800 posts on the type 26 DHT pre before starting mine. It would be a nightmare trying to do that here. And it works, too!

 

RE: DIY vs. Commercial you can do better., posted on January 24, 2017 at 14:43:27
drlowmu
Manufacturer

Posts: 9730
Location: East of Kansas City
Joined: January 10, 2005
 That is funny. I think just the opposite of you.

I think most DIY below-the-deck shots I see photos of are atrocious, and circuit implementations, are a waste of the person's time and money, compared to a good commercial product.

Most DIYers do not KNOW how to lay out an amp really really well ( me included ) and most make horrible choices, by penny pinching, or not KNOWING what is a good sounding or a poor sounding part to use from the onset.

Some are SO amateurish and go so far as to think a bread board is a viable amp...it isn't !! Lay out is huge factor in making a great amp.

I will mention just two products, commercial audio amps. In the solid state realm, a Spectral DMA-200S and in the tube world, my good friend Dennis of Serious Stereo, his latest 2A3 amps. Think a DIYer at home can beat either commercial amp ?? If so, you will be 100% wrong.

Some others come to mind, the people at Berkeley Audio, and the great sounding MBL amps and speakers.

There are many good reasons to do DIY, and I ENJOY it, but don't think for one millisecond, you will outdo the folks in the San Francisco area, and Montana, Germany, etc, the Professionals.

Of course, one must be able to discern, the good from the bad in the commercial realm.

All the names I've mentioned off the top of my head, have superior products, to ANY DIY implementations. Get REAL !!

Cheers,

Jeff Medwin

 

Depends on your goals, posted on January 24, 2017 at 15:26:00
maxhifi
Audiophile

Posts: 584
Location: Alberta, Canada
Joined: August 4, 2004
 DIY audio is a leisure activity into itself. The idea that it's possible to make something in your garage which will compete viably with a highly praised $10k commercial product is of course complete insanity, unless there's a genius at work.

But it's certainly possible to build something which will compete performance wise with gear in lower price categories.

I liken it to people who build cars in their garage. No person in his right mind believes that his home made car is going to be objectively better than a commercial product.. I think that just isn't the point.

It's an outlet to express creativity and enjoy solving some puzzles. And there's a feeling of accomplishment when the end product is satisfying. I strongly suspect that many people in the DIY community enjoy thinking about amplifiers and working on them as much as they enjoy using them... and what's wrong with that?

How to mitigate hum? In my experience, the nastiest, worst, sneakiest thing in an amplifier is the connection between the power transformer and the negative side of the first filter capacitor. If this isn't a direct connection, even a milliohm will introduce hum into the amplifier. And if the capacitor is over sized off a solid state rectifier, it won't be hum, it will be buzz.

 

Comparing dollar for dollar, you are deluded, posted on January 24, 2017 at 18:06:12
DAK
Audiophile

Posts: 2712
Location: PACIFIC
Joined: August 8, 2010
 Sure, a 3000.00 amp better sound better than my 500.00 amp. But comparing my 500.00 cost amp to commercial products? Up to 1500.00 Not even close. Who are you Kidding?
Actually I compared a 3500.00, SE 845 Raphaelite amp to my SE pentode KT90 amp which costs about 500 for the parts, and they both sounded very close with the Raphael amp having a miniscule edge in resolution while my amp was better at bass and dynamics. So i think your statement isn't in left field, not even in the ballpark, maybe in the parking lot, at the end of the row.

 

You are INEXPERIENCED , posted on January 25, 2017 at 07:25:02
drlowmu
Manufacturer

Posts: 9730
Location: East of Kansas City
Joined: January 10, 2005
 **** But I said you have to be able to discern, DISCERN, what is a good commercial product. *****

You have not enough experience, have no clue !!!

Since you are talking tube amps, I referred to Dennis' Serious Stereo, latest 2A3 amp. If you compared your " close " 500 dollar amp, to that much more expensive Serious Stereo amp, you would slink away from the A-B like a doggie, with his tale between his legs. Solid State amp, try a Spectral DMA 200S, or an MBL.

If you WANT the best, you have to first KNOW what it is, then you pay for it. If you are unable to DISCERN, and accomplish either, that is not my problem.

Jeff Medwin

 

RE: Comparing dollar for dollar, you are deluded, posted on January 25, 2017 at 09:12:15
PakProtector
Audiophile

Posts: 12363
Joined: May 14, 2002
 DAK, you are on the right track. Commercial stuff is nutty expensive, and if it is making money, it is either even nuttier, or bean-countered.

It does not take a genius to do this; it is for the most part just solid engineering( like any other product ). I've played and A-B'd with some talented folks. That in and of itself is entertaining. Learned a bit from each of them.

As to the traditional insults leveled at this opinion, like 'you just can't tell the difference'...there is no argument to be won. That is why it is used so often...LOL I take its use as an admission of defeat.

That argument is widely used to part fools from their money with techno-babble in a well documented fashion you've no doubt read about and seen in action by salesmen of any sort. LOL...if you are good enough, you will be admitted to the club where you can spend even more money. No thanks.
cheers,
Douglas

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

 

RE: Comparing dollar for dollar, you are deluded, posted on January 25, 2017 at 10:52:52
DAK
Audiophile

Posts: 2712
Location: PACIFIC
Joined: August 8, 2010
 Hi Doug, and thank you for commenting. I will not be baited into a blatant attempt at trying to stir up the pot of controversy over something as obvious as night and day. The doc (sic) should take some of his own medicine. With comments such as "trust your ears" and "have fun, i am". It seems that those terms should be amended with, which can not happen unless you are "experienced" which accordingly, can not be attained without listening to specifically recommended equipment.
I wonder why a person with such beliefs would be part of the DIY community? It is obviously a waste of time for someone with that "experience". sincerely, Dak

 

RE: Comparing dollar for dollar, you are deluded, posted on January 25, 2017 at 17:34:17
PakProtector
Audiophile

Posts: 12363
Joined: May 14, 2002
 Yep...don't get baited. It took me a while to recognize that, 'you aren't good enough to hear the difference' argument as an admission of defeat...LOL

I love some of the Irony presented in the arguments. In one paragraph, they tout some EE PhD, and in the next claim all such knowledge is worthless.

And then there is the techno-babble...'transfer efficiency' indeed.
cheers,
Douglas

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

 

Forget MONEY, .Learn Audio DISCERNMENT , posted on January 25, 2017 at 19:05:09
drlowmu
Manufacturer

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

Neither that amp you compared yours to, nor the amp you built, ( if its an 845 ), would "I" ever want to be stuck with, to listen to.

First of all, there is NO need for an 845 amp on 98 dB or better speakers.

Second of all, there is NO need for a three stage amp, when a well designed two stage, especially Direct Coupled, will CREME it.

You are, thus far, unable to discern that !!

As I have said, in all my posts in this thread, it has NOT much to do with money, but the ability to DISCERN the good from the MANY MANY audio also-rans.

My amp references remain, the four amps I have mentioned. Any 845 amp is KIDDIE stuff compared to those, and low in overall fidelity to boot.

I do commend you for building DIY amps. I enjoy doing that myself. But I try to at least copy the best available. I DISCERNED " what end is up ", what was the best, years ago, by going to CES and RMAF shows, etc. You DAK, need to do that, and learn what end is up, so that you, too, will discern better.

Ever hear a MBL amp, playing their Radialstrayler ( sp ??) speaker?? Oh my goodness. You should !!

Have fun, continue to broaden your audio horizons, I do that myself, all the time. Live and learn.

Jeff Medwin

 

RE: Depends on your goals, posted on January 26, 2017 at 20:32:19
tube wrangler
Manufacturer

Posts: 2484
Location: USA
Joined: January 29, 2007
 Good observation! You want your grounds short, and made from VERY heavy current conductors.

-Dennis-

 

RE: DIY vs. Commercial you can do better., posted on January 27, 2017 at 12:22:16
rage
Audiophile

Posts: 793
Joined: December 17, 2010
 Jeff,

When and where did you hear the "Spectral DMA-200"? On what speakers? What length of time where you able to evaluate said amp?

Have you heard Boulder, the other example you have sited?

 

RE: Depends on your goals, posted on January 27, 2017 at 14:59:09
maxhifi
Audiophile

Posts: 584
Location: Alberta, Canada
Joined: August 4, 2004
 I have achieved decent results paralleling specific circuit board traces on a couple commercial amps which were not that well designed with bare #14 from Romex - not the stuff of high end, sure, but it made a noticible reduction in background noise.

 

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