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What makes a high quality plate choke?

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Posted on October 6, 2020 at 06:14:07
Deke609
Audiophile

Posts: 48
Location: Toronto
Joined: January 11, 2019
 Hi all - I am in the early planning stages of an interstage transforner coupled parafeed amp using the EML 45B (high power 45) as output tube and, likely, the EML 30A as driver.

There are lots of things I need to figure out, but what's currently puzzling me is the plate choke (PC). To date I've chosen PCs solely on the basis of inductance, voltage ratings, and DCR -- and by default used Lundahl PCs simply b/c of their reputation.

But are there other things I should be looking for?

For example, does the core material matter? In my limited experience with output transformers, I've found that core material matters a lot. To my ears, silicon steel (e.g., M6) is punchier but less detailed than amorphous, and that Finemet combines the best of both. What I don't know is whether the core material is only relevant to "translating" signal on the primary to secondary -- in which case, it really doesn't matter for a PC.

Is there a type of winding I should be looking for?

Are there other important considerations that I haven't even thought of?

Any and all guidance/insight is appreciated.

MTIA,

 

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Having someone competent wind it., posted on October 6, 2020 at 07:16:11
Chip647
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Posts: 2649
Location: The South
Joined: December 24, 2012
 Like in life, how is more critical than what. The great things about separating the output transformer into a choke and step-down is that it is easier to optimize each one. It takes skill to wind a good audio choke.

However, there is no answer to your general question of the absolute best combination of metallurgy. That is circuit dependent, system dependent and hearing dependent.

Look for the choke with the widest, flattest bandwidth at your tube impedance and current requirements. You can convince yourself that only Nine 9s Silver wire and amorphous cobalt cores are the best, however if the winder is just a bobbin spinner you might as well use a Hammond.

You could have someone like Dave Slagle wind you one.

 

You could use a plate choke instead of the interstage as well, posted on October 6, 2020 at 09:04:12
andy evans
Audiophile

Posts: 4378
Joined: October 20, 2000
 Have you thought of replacing the interstage with a plate choke and a really good coupling capacitor?

I've always had better sound out of plate chokes on the driver stage than interstages. I use teflon FT-2 coupling caps, very transparent. I like amorphous - haven't tried finemet.

If you're ordering 2 plate chokes you may feel like ordering 4.

 

RE: What makes a high quality plate choke? .... Better yet ...., posted on October 6, 2020 at 13:26:58
drummerwill
Audiophile

Posts: 965
Location: St Louis Mo.
Joined: January 7, 2003
 Use a Single strand of 14ga Solid Silver wire and go Direct Coupled ..


Willie

 

He was asking about parafeed output transformer arrangement , posted on October 6, 2020 at 13:42:22
Chip647
Audiophile

Posts: 2649
Location: The South
Joined: December 24, 2012
 Can't get away from the output cap!

 

RE: What makes a high quality plate choke?, posted on October 6, 2020 at 17:41:42
je2a3
Audiophile

Posts: 308
Location: PA
Joined: July 15, 2003
 I've been experimenting with plate chokes on med-mu triodes (76, 6SN7, 7193, triode'd 6C6, etc) this past year. I started with a pair of James JS4120N which have been in my parts bin for almost twenty years. They are nickel 200H @ 15mA. I've used this with excellent results in driver stages and also as a plate load for my 76 line stage.

The 2 x Hammond 156C (300H) are very nice for the price as long as I don't exceed 8mA but not quite as transparent in the mids as the nickel JS4120Ns. Still, 156C x 2 sounds better than the Allen-Bradley plate resistors they replaced.

By far the best results I've had so far were from a pair of 250H @ 15mA nickel plate chokes from dave slagle. These sounded best to my ears, great mids with the most extended frequency extremes. The square waves from dave's chokes were also the best looking on the scope which confirms their wide bandwidth.

 

RE: He was asking about parafeed output transformer arrangement , posted on October 6, 2020 at 21:09:39
91derlust
Audiophile

Posts: 1101
Joined: December 25, 2014
 Or the cathode bypass cap (well, you can, but it is a bit more challenging in directly-coupled maps).

Then there are the stacked voltages of such an amp: the EML 30A is a high-voltage input tube and the EML 45B is also a high-voltage device, if Deke wants the power increase. You could be looking at 800V+ for this amp...

And some folks prefer transformer-coupled amp... or just want to try one... or...




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

 

Thanks all - but still wondering about potential effect of core materials, posted on October 7, 2020 at 05:33:54
Deke609
Audiophile

Posts: 48
Location: Toronto
Joined: January 11, 2019
 Many thanks all -

I should clarify that I am treating the interstage-trafo coupling as an experiment (albeit, an expensive one). For comparison, I will also build a 45B amp with cascode CCS-loaded driver and cap-coupling but using a different driver tube. My Bottlehead Kaiju uses the 5670 (with one half as driver and other half doing shunt regulator duty) and I am very pleased with the sound. Better, to my ears, than a 12AT7.

Direct coupling is another possible experiment - thanks.

I will definitely go with a quality winder - most likely Monolith Magnetics. They recently made me some parafeed output trafos that I am very pleased with. I will trust in the winder's expertise as to winding structure and technique.

But I am still wondering whether core composition is even relevant, provided it, in combination with the winding, can generate the desired inductance. je2A3's experience suggests that core composition may make a difference.

Any other experience with different plate choke core materials?

Or theory-based speculations about how they might affect things?

many thanks,

 

RE: Thanks all - but still wondering about potential effect of core materials, posted on October 7, 2020 at 06:22:42
kobasa@xs4all.nl



I use low capacity chokes with amorphous cores or nanocrystalline cores, sometimes in HiB, never in M6

 

RE: What makes a high quality plate choke?, posted on October 7, 2020 at 07:14:15
andy evans
Audiophile

Posts: 4378
Joined: October 20, 2000
 http://jamestransformer.com/en/transformer/index.html

Is this the correct site for James? The stock looks different. If not where do you buy James plate chokes?

 

RE: What makes a high quality plate choke?, posted on October 7, 2020 at 09:26:49
je2a3
Audiophile

Posts: 308
Location: PA
Joined: July 15, 2003
 My source for James iron was Euphonia Audio in NJ back in the early 2000s. Euphonia is long gone and I don't think James caters to the audio market anymore. :(

 

RE: What makes a high quality plate choke?, posted on October 7, 2020 at 10:37:31
kobasa@xs4all.nl
 I don't think the James are low capacity chokes

 

RE: What makes a high quality plate choke? .... Better yet ...., posted on October 7, 2020 at 12:23:53
deathtube 667
 "Use a Single strand of 14ga Solid Silver wire and go Direct Coupled .. "

DC to ZERO FBK SE KT88 tetrode finals if you are one of the MLP elite.

 

RE: Thanks all - but still wondering about potential effect of core materials, posted on October 7, 2020 at 12:35:00
91derlust
Audiophile

Posts: 1101
Joined: December 25, 2014
 Not really my area Deke... I do think core materials matter for plate chokes, FWIW. Quality nanocrystal would be my first choice, followed by one of the really Hi-B types. This based on Dave's comments here and elsewhere and those of some engineers in SE Asia that have been winding on a range of cores for 20+ years. On balance, in the hands of good winders, I found in favour of nanocrystal. I've had chokes and output transformers made from it and been very pleased. But I think a really nice, if a bit different flavour, amp can be made with nickel too.



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

 

RE: He was asking about parafeed output transformer arrangement , posted on October 7, 2020 at 12:47:38
drummerwill
Audiophile

Posts: 965
Location: St Louis Mo.
Joined: January 7, 2003
 Yeah 91,
I understand Deke wanted a I.T. coupled device....

I was just saying..... and yes an I.T. coupled device would be
easier to build than a DC device..

The EML 30A is a sweet tube, perfect for your 2 Stage EML 45 amp.

Deke if you've ever built a 2 stage DC SET amp, you would know
difference in sound between different coupling methods........
.... or maybe you already do.

Just another option.

Have fun building anyway !

Willie

 

RE: What makes a high quality plate choke? .... Better yet ...., posted on October 7, 2020 at 15:29:27
Tre'
Industry Professional

Posts: 17297
Location: So. Cal.
Joined: February 9, 2002
 The KT88 has too much harmonic distortion, even in triode, to use without feedback.


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

 

RE: Thanks all - but still wondering about potential effect of core materials, posted on October 7, 2020 at 16:05:25
Sidewinder
Audiophile

Posts: 254
Joined: April 13, 2001
 Hi,
Could you tell us the source for those chokes and $$ ?
Thanks,
David

 

RE: What makes a high quality plate choke? .... Better yet ...., posted on October 7, 2020 at 19:39:44
elblanco
Audiophile

Posts: 3486
Joined: August 20, 2004
 what if you use a driver tube with equal but opposite distortion on other end of swing?

of course with the nasty result of increased higher order.

 

RE: What makes a high quality plate choke? .... Better yet ...., posted on October 7, 2020 at 20:05:54
rivervalley817
 I think you get a guitar amp

isn't that the Dumble recipe?

be well,

 

RE: What makes a high quality plate choke? .... Better yet ...., posted on October 7, 2020 at 20:33:56
Tre'
Industry Professional

Posts: 17297
Location: So. Cal.
Joined: February 9, 2002
 "..driver tube with equal but opposite distortion on other end of swing"

Where do I find one? It would have to "track" at all amplitudes otherwise the mess it would make might be it worse than ever?

In my SE 300b amp I am currently using a driver tube that is less linear than others I have used in the past. The system sounds good but somehow less pure to my ears.

In the past I have always tried to make sure each stage is as distortion free as possible.

BTW I have tried SE KT88 without feedback. Without a doubt, it's not for me. Something like that might benefit from the "distortion cancellation" technique. "a really distorted driver stage feeding a really distorted output stage with the hope of it all coming out in the wash". I don't really have a problem conceding that something like that could work.

I think you would have to find a tube, and an operating point for that tube, so it does have "equal" distortion and distortion that "lines up" with the distortion of the output tube and maintains that relationship as the amplitude changes. That sounds like a tall order to me but WTFDIK?

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

 

RE: What makes a high quality plate choke? .... Better yet ...., posted on October 7, 2020 at 20:34:43
drummerwill
Audiophile

Posts: 965
Location: St Louis Mo.
Joined: January 7, 2003
Nope I'm strickly Triode, no multi-grid tubes for me !


Willie

 

RE: What makes a high quality plate choke? .... Better yet ...., posted on October 8, 2020 at 05:14:17
deathtube 667
 I learned a bit more about how the MLP uses multi-grid tube recently.

Of course, I am sworn to silence by MLP leadership.



 

RE: What makes a high quality plate choke? .... Better yet ...., posted on October 8, 2020 at 06:06:08
dave slagle
Manufacturer

Posts: 5430
Location: NYC
Joined: April 27, 2001
 There was a momentary trend when the 6C45pi came on the scene as a WE 437A replacement some 15-20 years ago to use it with a pretty heavy resistive load at currents below 10ma to get maximum "undistorted" power from a 300B. Indeed the numbers were impressive but the sonics always improved to me when the 6C45 was inductively loaded and juiced to 20+ma.

A FFT of the distortion spectra quickly pointed to the cause of this behavior. At 20ma the THD was higher and 2nd order dominated the THD. The higher harmonics declined with order for the "fairly benign" distortion spectra we attribute to single ended triodes. At the output of the resistively loaded sub-10ma case the even order distortions were markedly reduced giving a slight rise to the 3,5,7 which made the THD meter happy but had a sincere impact on the "toe-tappin" ability of the music.

Looking closer at this behavior It was clear that the low current and chosen load-line for the 6c45 was such that lots of even order distortion was generated. This distortion was 180° from the distortion generated by the 300B and when summed together you effectively created a PP distortion spectra. It certainly sounded that way. At the time I was reasonably convinced that this practice is what gave the 6c45 its reputation for being bright and aggressive and have yet to be convinced otherwise.

dave

 

RE: What makes a high quality plate choke? .... Better yet ...., posted on October 8, 2020 at 06:49:05
Deke609
Audiophile

Posts: 48
Location: Toronto
Joined: January 11, 2019
 This is fascinating and timely information. It was recommended that I try the 6C45P as driver b/c it's combination of relatively low plate resistance and low current requirements makes it an ideal candidate for both inductive and CCS loading. I was going to run it with 10mA plate current for low THD. Rethinking that now. I will have to try running it with more current.

And @Dave Slagle: do have any thoughts on the virtues, or lack thereof, of fancy core metals in plate chokes?

cheers and MTIA, Derek

 

RE: What makes a high quality plate choke? .... Better yet ...., posted on October 8, 2020 at 06:54:50
Tre'
Industry Professional

Posts: 17297
Location: So. Cal.
Joined: February 9, 2002
 "Of course, I am sworn to silence by MLP leadership."

That is very cult like behavior.

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

 

RE: What makes a high quality plate choke? .... Better yet ...., posted on October 8, 2020 at 08:17:32
dave slagle
Manufacturer

Posts: 5430
Location: NYC
Joined: April 27, 2001
 Well without getting into specsmanship of the various core materials and topologies I can offer up my opinion. This is based primarily on the sonics of direct comparisons with nickel, nanocrystalline, and amorphous materials in volume controls, LCR inductors, MC SUT's, plate chokes, interstage transformers and output transformers. I have wound, built with, measured and listened to all of the various possible combinations to form these opinions so take them fwiw.

For low level signals found in Phono and Line applications 80% nickel is hands down my favorite since it gets out of the way and lets the emotion of the music through. As the AC levels increase beyond the capabilities of 80% the 49% is my next choice. Nanocrystalline gives a different sound (cleaner if you will) and is readily available in larger core sizes so it becomes my choice for higher powered output situations and finally amorphous is my choice for the really high power situations (just did some 50W amorphous for parallel SET 845's). All of this takes into account a balancing act between availability cost and sonics. In a perfect world I would use silver wound 80% nickel for everything but ultimately economic concerns tend to dictate these decisions. For my 8W 50/300b amps I use 80% nickel and the silver version i did for a customer is sublime. That said, if someone wants nanocrystalline LCR inductors I will happily wind them.

I did not include any of the silicon and cobalt steels in the above since I swore off them the minute I heard the beauty of a Nature Sound nickel power supply choke 25 years ago. I have been a nickel junkie ever since.


dave

 

RE: What makes a high quality plate choke? .... Better yet ...., posted on October 8, 2020 at 09:30:28
cpotl
Audiophile

Posts: 1002
Location: Texas
Joined: December 6, 2009
 '"Of course, I am sworn to silence by MLP leadership."

That is very cult like behavior.'


It is indeed! And a little strange, in a tube DIY forum, where one might expect people to be sharing their ideas?

Admitting my ignorance, who or what is "The MLP"? I googled a bit, and two of the less implausible possibilities seemed to be the More Light Presbyterians, or the Marxist-Leninist Party. Is it one of these, by chance?

 

RE: What makes a high quality plate choke? .... Better yet ...., posted on October 8, 2020 at 10:29:25
Tre'
Industry Professional

Posts: 17297
Location: So. Cal.
Joined: February 9, 2002
 It's a group of true believers in the Dennis Fraker (Serious Stereo) way of doing things. I believe it stands for Montana Listening Panel.

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

 

RE: What makes a high quality plate choke? .... Better yet ...., posted on October 8, 2020 at 10:37:16
Deke609
Audiophile

Posts: 48
Location: Toronto
Joined: January 11, 2019
 Many thanks Dave. This is useful experienced-based info from someone who's wound a ton of iron.

I'll be in touch with you and your company about winding options once I get closer to a final plan.

cheers,

 

RE: What makes a high quality plate choke? .... Better yet ...., posted on October 8, 2020 at 10:41:40
kobasa@xs4all.nl
 My interpretation of what Dave Slagle says about core types is that if you like a colored sound, sound what is not live in the real world you have to select nickel cores.
If you are smart the nanocrystaline cores are a better choice and for really low level signals there are some amourphous core wich are even more better.

If the nikkelcores are E I cores then i am pretty sure that the level of performance are 2-3 steps behind the c-cores and 3-4 steps behind toroids (or the ultra expensive nanocrystaline c-cores from Vacuumschmelze)

 

RE: What makes a high quality plate choke? .... Better yet ...., posted on October 8, 2020 at 11:02:47
rivervalley817
 I joked that it could be a 'My Little Pony' group

it actually seemed more apropos and far less pompous

sadly, it's probably far less humorous if humorous it was

regards,

 

RE: What makes a high quality plate choke? .... Better yet ...., posted on October 8, 2020 at 11:19:54
cpotl
Audiophile

Posts: 1002
Location: Texas
Joined: December 6, 2009
 "It's a group of true believers in the Dennis Fraker (Serious Stereo) way of doing things. I believe it stands for Montana Listening Panel."

Ah, OK. So probably a bit like a cross between the More Light Presbyterians and the Marxist-Leninist Party, in fact...

 

RE: What makes a high quality plate choke? .... Better yet ...., posted on October 8, 2020 at 11:35:08
Tre'
Industry Professional

Posts: 17297
Location: So. Cal.
Joined: February 9, 2002



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

 

RE: What makes a high quality plate choke?, posted on October 8, 2020 at 14:28:34
griboon
Audiophile

Posts: 449
Location: Lynchburg Va.
Joined: October 14, 2003
 I will add that I installed a pair of Dave Slagle's output transformers on a customers Chalice Audio Grail amplifiers and found the results beyond satisfactory. They easily whipped the snot out of the Bertolucci's! Dave is my go to man.

 

RE: What makes a high quality plate choke? .... Better yet ...., posted on October 9, 2020 at 13:34:32
Stuben
Audiophile

Posts: 669
Location: Guber Ohio
Joined: December 30, 2005
 I'm running SE K88 with cathode feedback across the Output secondary. The input is 6sn7 cascade with second stage CF - RL coupled. Haven't made any real measurements but the sound is very palatable.

Had fun getting there.

Stuben

 

RE: cult like behavior ?, posted on October 9, 2020 at 14:23:16
deathtube 667
 "That is very cult like behavior."

Drummerwill might be able to speak to that comment since he seems to be the ranking MLP member on AA.

Any elite organization makes membership requirements rigorous and holds secrets from the public at large for various reasons.

I would assume that the MLP operate in a similar fashion as they represent the highest level of LOW DCR SE tube amp builders in the industry today.

My review of comments posted below seems to indicate a general lack of understanding of the MLP and its functions.

Rather sophomoric attempts at humor that fail to find the mark as usual.

DT 667

 

RE: cult like behavior ?, posted on October 9, 2020 at 15:48:19
Deke609
Audiophile

Posts: 48
Location: Toronto
Joined: January 11, 2019
 Perhaps foolishly, I had hoped that this thread would be about plate chokes and things related to them.

Maybe the mods (if there are any) could break this other stuff out as a separate thread about audio alchemy societies and their closely guarded arcanum. Better yet: a dedicated secret society subforum with a secret password so that only initiates can read and post in same. On the flipside, I suggest that said initiates be restricted to posting only in the secret society forum.

Who's with me on this?

cheers,

 

RE: it was tried in the past ..., posted on October 9, 2020 at 16:26:58
deathtube 667
 A separate forum for "LSES" and related SE tube amp builders was suggested and implemented on another platform years ago but never took off.

You can always report your concern to the moderators and maybe they can take appropriate actions to restore order to your thread.

 

RE: cult like behavior ?....Wait A Minute !!!, posted on October 9, 2020 at 17:16:46
drummerwill
Audiophile

Posts: 965
Location: St Louis Mo.
Joined: January 7, 2003
 I didn't say anything about a following.


I just Suggested trying DC and my perferrence for Triodes


Willie

 

RE: cult like behavior ? Ahh... DT you are too kind..., posted on October 9, 2020 at 17:32:46
drummerwill
Audiophile

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

You give me way too much credit for something I was just on the tail
end of..

As for as the secrecy of designs. Well i can only say I try to honour
a designer's right to I.P.

So there you are.!

Willie

 

RE: What makes a high quality plate choke? .... Better yet ...., posted on October 9, 2020 at 18:01:21
Tre'
Industry Professional

Posts: 17297
Location: So. Cal.
Joined: February 9, 2002
 I didn't try a KT88 with feedback. I'm happy with the 300b.

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

 

RE: What makes a high quality plate choke? .... Better yet ...., posted on October 11, 2020 at 13:36:43
dave slagle
Manufacturer

Posts: 5430
Location: NYC
Joined: April 27, 2001
 If nickel gives a colored sound (whatever that is) then I am fine with it. I'll take better sound over better material specifications any day. It is pretty easy to have a preference and then find specifications that justify that preference. It is equally easy to dislike something and then find some technical detail to justify that belief.

I mentioned I didn't want to get into a discussion based on the technical aspects but there is a fine line between technically correct info and misinformation. I am curious why you think when it comes to audio, nickel EI-cores are 2-3 steps behind nickel C-cores?

dave

 

RE: What makes a high quality plate choke? .... Better yet ...., posted on October 12, 2020 at 01:54:24
kobasa@xs4all.nl
 Dave,

The availability of special heat treatment c-core or even better toroids is a lot better then EI laminations.
How thin are your laminations? Ultra thin laminations for amorophous and nanocrystaline are readily available

Btw the better sound is not for the nickel cores, thats is just your option and very subjective.

In the '50 We would have the same "discusion" Why nickelcores instead of the better "sounding" iron cores.

 

RE: What makes a high quality plate choke? .... Better yet ...., posted on October 12, 2020 at 07:13:02
dave slagle
Manufacturer

Posts: 5430
Location: NYC
Joined: April 27, 2001
 I think I clearly stated that my preference for nickel was my opinion based on listening experience and direct comparisons between the various material in identical designs. I didn't simply buy a nickel transformer and a nanocrystalline one and presume the only difference is core material. I wound the two devices to be as close to each other electrically as possible and then compared them in the same circuit. Same thing with LCR inductors. The situation where things became more difficult for the direct comparison were the MC SUT's and the autoformer volume controls. This is because the minimal gap possible with the cut cores requires more turns for a comparable inductance and this quickly takes a toll on the top end. In the case of small required gaps a toroid could be used but then the winding geometry would need to be different so it becomes a one step forward, one step back situation. I do want to be clear that I will use the nano and amorphous cores if requested and there is nothing sonically wrong with them, I just prefer the nickels for my own designs.

Many times in audio when someone states an opinion and then dives deeply into technical details to justify it seems more like a quest for confirmation bias than a peer reviewed scientific approach. Other times it is simply trolls who assail an opinion with technical facts thinking since their facts are correct, the stated opinion must be wrong. The doesn't take into consideration that it is often the case where the facts simply bear little relevance to the stated opinion.

on to the technical which i said i didn't want to debate ;-)

I presume you are talking about field anneals which allows for a form of "orientation" but the round loop anneals of the 49 and 80% nickels I prefer make them non-oriented materials. This makes me curious as to what special anneal can be had in a nickel C-core over a Nickel EI lamination.

When using the round loop nickels I have not noticed an appreciable difference in sound between 0.014" and .006" lamination thickness. The one place where I can see the thinner lams would be a benefit is when you need a minimally gapped core since the airgap can be made smaller with thinner stamped laminations. Along these lines in cases whee a minimal airgap is required, toroids have the smallest possible airgaps. EI-cores are next and C-cores even if well polished come in at a distant third. There are some C-cores that use a modified surface gap like the uni-core or the duo-core but I have yet to actually see one and I doubt they would be an option for any of the small signal audio sized cores or the 'glass based materials. If I had to guess the 'ultimate' core shape it would be something similar to an R-core with a shell configuration... i'm not holding my breath.

dave



 

RE: What makes a high quality plate choke? .... Better yet ...., posted on October 13, 2020 at 00:18:28
kobasa@xs4all.nl
 Dave,

Your choice is based on your opinion, my choice is based on the physics.

You mentioned the airgap is importent to choise for thinner laminationes, no it's not.
The 0,355mm you use sufferers from serious high eddy currents, the 0,15mm is also a bit thick. You don't want your ac signals starving in the eddycurrents, but i guess you do like that characteristic.

The main choice for not having EI laminations is that the best quality (read: the lowest core losses) nickel iron is not available for EI . Even for c-cores the best quality is not available.
And if you want the lowest losses: avoid nickel too.
Yes Dave, just facts and data and i know you hate it but in the real world this is what counts for a transformer core.
If you are the romantic type, emotional involvement, in god we trust and other irrelevant opinions then take the old cores.

Btw, the special anealing is for Z loop or F loop
Btw 2 the R loop in shell configuration is at least 30y available

 

RE: What makes a high quality plate choke? .... Better yet ...., posted on October 13, 2020 at 04:19:54
Stephen R
Audiophile

Posts: 1428
Joined: January 11, 2002
 Are you able to point us to your portfolio of transformer/choke products and where they are used?

 

RE: What makes a high quality plate choke? .... Better yet ...., posted on October 13, 2020 at 05:59:09
dave slagle
Manufacturer

Posts: 5430
Location: NYC
Joined: April 27, 2001
 I make decisions based on what I hear then look to find the appropriate facts to explain it. I also 'gasp' use single ended directly heated triodes because they sound better and i'm sure physics can point to decades of audio designs that better the lowly SET. We all know facts simply tell us that we like tubes because we like distortion... and i'm OK with that.

I have yet to find any correlation between eddy current losses and sound. High frequency losses in cores are well documented but for an audio core we are looking at variable high frequency flux in the low milligauss range and all of the loss data seems to focus on the single frequency kilogauss range for power usage. I can see where it is really easy to connect the dots from physics to core material but but extrapolating that pattern to what we hear is marketing at best.

dave

 

RE: What makes a high quality plate choke? .... Better yet ...., posted on October 13, 2020 at 06:25:22
kobasa@xs4all.nl
 Dht triodes are highly linear, which is a lot better then Silicon. We also know that most indirectly heated tubes are also worse. But please don't change the subject.

The milliGauss (obsolete, nowadays it's Tesla) range you are talking about is also worse for thick laminations. And better if you use a modern material.
" loss data seems to focus on the single frequency kilogauss range for power usage"
That is rubbish Dave, enough data/articles to find which proof the opposite. Besides, in a core with a crystal stucture* you will have a lot more noise on low level detail.

* smaller crystals are better..

 

RE: What makes a high quality plate choke? .... Better yet ...., posted on October 13, 2020 at 08:41:52
dave slagle
Manufacturer

Posts: 5430
Location: NYC
Joined: April 27, 2001
 Tesla Mode On

what is rubbish is assailing a clearly stated opinion with dubious facts. we went over this a month ago where I asked for low flux (µT levels) loss data and asked for more than just your insistence that it has the sonic impact you suggest. JLSEM came up with some data showing permeability down to 1mT but all of the core loss data I have seen for high frequencies is for levels 100X or more of anything ever seen in audio. the one slight exception would be mc sut's where the riaa curve partially levels the playing field but the flux seen in a mc sut is typically in the µT range to begin with.

you are welcome to your opinion that "better" specifications = "better" sound but I am also allowed my opinion that for low flux signals 80% nickel sounds best. Ultimately who is "right" comes down to if people listen with their ears or eyes.

Tesla Mode Off

dave






 

RE: What makes a high quality plate choke? .... Better yet ...., posted on October 13, 2020 at 10:26:15
kobasa@xs4all.nl
 Dave,

You maybe have noticed that JLSEM data showed you a straight line. We don't go straight to area 51 if we have a lower inductance. What you are doing is just speculate that below that level something special will happen in you favor.
I explained thicker laminations is not a good thing (eddy currents, you will manipulate the signal depending on frequency And inductance ) That is not an opinion but a fact. The same if you use EI instead of a toroid.

If you like a nickel core that's ok for me, because it's still very good material. The best material, no. The best sounding....very subjective and i prefer no sound from a transformer.


By the way, why are you so obsessed with extremely low level and at the same time saying that the small signals are on top of the average signals.

Second, check this out: https://en.wikipedia.org/wiki/Barkhausen_effect

 

RE: What makes a high quality plate choke? .... Better yet ...., posted on October 13, 2020 at 11:44:03
dave slagle
Manufacturer

Posts: 5430
Location: NYC
Joined: April 27, 2001
 In the case of the JLSEM data I know that straight line ultimately bends when you extend it on both directions. For all cores this low level behavior is both non-linear and under-documented. It generally gets simplified to a single initial permeability number and it is pretty easy to make numbers say whatever you want them to.

I have measured some well respected microphone transformers that were called "improved" because the 80% nickel core of the original design was replaced with a cobalt based core. (permandur / hiperco 50) These were intended to be used as mc step-up transformers and when fed with a 1Vac signal from a 50Ω source, the bandwidth was flat to well below 20HZ. When fed with 0.25mv @ 50hz or the signal close to what a Denon 103 would give the response was -3dB @50hz. It was this particular experience that got me thinking that maybe everyone is focusing at the wrong end of the flux range and maybe the known of high level core losses and saturation are not as important as what happens down in the shadows of response.

dave

 

RE: What makes a high quality plate choke? .... Better yet ...., posted on October 13, 2020 at 12:00:40
kobasa@xs4all.nl
 Permendur is a shit material for low level ac level, actually even worse then standard SiFe cores.
Somebody with bad knowledge about core materials did the wrong thing. You not have to measure it to know that it is not suited

About the data, these curves are correct and also measured worldwide by independent technician. Nothing to worry about

 

RE: What makes a high quality plate choke? .... Better yet ...., posted on October 13, 2020 at 17:04:22
dave slagle
Manufacturer

Posts: 5430
Location: NYC
Joined: April 27, 2001
 I have yet to see complete data of core behavior below 1 gauss.... oops sorry 1µT. I'm sure Elmen and later Yensen documented it for the nickels but that info is locked away in the bell labs archives somewhere in New Jersey.

dave

 

I think its Nokia Labs now but., posted on October 13, 2020 at 17:15:43
elblanco
Audiophile

Posts: 3486
Joined: August 20, 2004
 k

 

RE: I think its Nokia Labs now but., posted on October 14, 2020 at 02:49:10
kobasa@xs4all.nl
 Nice to see such an old article.
Probably the materials they used where super good at that time but nowadays......

Anyway, some of the curves shows what Dave is missing, permeability at low level. The core losses then where so huge you can easely show it in the graphs.

 

So there Dave..., posted on October 14, 2020 at 03:33:07
PakProtector
Audiophile

Posts: 12363
Joined: May 14, 2002
 It would seem to me that capacitance is the choke's natural enemy as far as wide bandwidth inductive performance is concerned. Leakage L makes the windings less effective, and thus more are required and then capacitance goes up along with it.

So how far up the audio spectrum can the self resonant point between winding capacitance and end-to-end L be?
cheers,
Douglas

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

 

RE: So there Dave..., posted on October 14, 2020 at 05:03:19
kobasa@xs4all.nl




This is a prototype 12H choke. I tried to measure the impedance, at 100 Hz its about 7500 Ohm and it still above 10000 Ohm at 1 MHz. Probably it's better because of the capacity of my probe (6pF).

 

RE: So there Dave..., posted on October 14, 2020 at 05:49:45
dave slagle
Manufacturer

Posts: 5430
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 I think by definition the self resonance you talk of always needs to be midband. It is the resonance of the two things that limit frequency extremes and typically falls in the 500Hz-2kHz range. This means that up until the resonant point the device is behaving primarily as an inductor. At resonance it appears as a resistor and then at high frequencies it appears as a shunt capacitor.

This resonance is why LCR meters that sample at 1Khz give crazy results on audio signal transformers. The meter is looking for a signal that has current lagging the voltage by 90°. At resonance that lag isn't there so it see the device as a resistor and spits out an incorrect number. I believe pretty much all of the digital LCR meters out there simply measure the Z and then look at the current in relation to the voltage. If current lags it measures L. If current leads it measures capacitance (or gives a - inductance value) if the they are in phase then it sees a resistor.

dave



 

RE: So there Dave..., posted on October 14, 2020 at 05:58:26
dave slagle
Manufacturer

Posts: 5430
Location: NYC
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 that suggests 10pf of capacitance which represents a srf of around 14Khz.

curious as to why you used the poylmide / ML insulated wire? Is it a sonic choice or what you had on hand?

dave

 

RE: So there Dave..., posted on October 14, 2020 at 05:59:20
kobasa@xs4all.nl
 I did not use a lcr, i use a scope and i can measure from below 1Hz to 20MHz

 

RE: So there Dave..., posted on October 14, 2020 at 06:03:45
kobasa@xs4all.nl
 Poylmide ML ?

 

RE: So there Dave..., posted on October 14, 2020 at 07:41:37
dave slagle
Manufacturer

Posts: 5430
Location: NYC
Joined: April 27, 2001
 the high temperature wire insulations. From the color of the insulation it looks to be polymide but it could be another polyester based type.

 

RE: So there Dave..., posted on October 14, 2020 at 08:04:35
kobasa@xs4all.nl
 I never look at the color of the wires, i have seen polyurethan, polyimide, polyamide, polyesterimide wires with almost the same color, from yellowish to red. Even blue and other colors are available

I take the wires i have, i take the wire which is more reliable, i take the wire which can have high voltage.

Usually i not take the polyurethan wires

For this choke i took the wire i had because It was an experiment.

 

RE: So there Dave..., posted on October 14, 2020 at 11:06:16
kobasa@xs4all.nl
 Dave,

I looked at my design overview: the wire i used is a polyesterimide + polyimide wire 0.18mm

I use all kinds of wire, silk (= a polyamide) cotton, teflon, glas and many others. "Sound" is always less important then reliablility

In this case almost every other wire is good enough. The choke is made for the powersupply as the last choke for a line amplifier

 

RE: So there Dave..., posted on October 14, 2020 at 11:55:12
GEO
Audiophile

Posts: 4749
Joined: April 7, 2000
Contributor
  Since: September 9, 2000
 Will you be selling those?

 

RE: So there Dave..., posted on October 14, 2020 at 12:00:51
kobasa@xs4all.nl
 '

 

RE: What makes a high quality plate choke? .... Better yet ...., posted on October 15, 2020 at 02:59:57
91derlust
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Posts: 1101
Joined: December 25, 2014
 Hi Dave. Please bear with me. What follows is a bit of a brain dump... I'm looking at this from the perspective of a pragmatic potential customer that is not an engineer or transformer winder but does have some understanding of what is required to spec a transformer for use in circuit and is willing to invest quality. Because of the unknowns, we rely on opinion and advice and there is an element of trust a customer places on a prospective supplier: perceived motive, competence and commitment matter.

When reading your post, my first question is: "What would winding towards the same electrical characteristics on different cores tell me?" My answer is that I don't really know what the specific electrical characteristics are or whether they are relevant, yet I assume it has been done for reasons of internal validity and reductionism to give a sense of the impact of cores with other conditions controlled. My next question is "Does this tell me what I need to know when deciding which core is for me - what are the cores are ultimately capable of and can Dave wind to that?" My somatic markers (gut feel) say "no." The reality is I don't know because I am now in the realm of my limited understanding, relying on the info available that I can comprehend, uncertainty, seeking answers... and heuristics. Fraught - at the mercy of bias. Aren't we all. But I'm not convinced by the arguments at this point. So I look further...

I've seen posts about Japanese winders compromising inductance to gain high frequency performance or some such. From what I can tell, this is more common in cheaper (more compromised) transformers and less so in more expensive types. I've also had discussions with winders in SE Asia that firmly believe, after experimenting with nanocrystal cores a lot over the last 5 or so years, that approach is not something you want to do if a goal is to achieve a perceived balanced sound and avoid a distinctively (c)lean sound with nanocrystal cores. I have heard their nanocrystal transformers and I would not describe them as (c)lean: more like musically expressive, nuanced and natural. This is in conflict with what you are describing. Their collective experience, especially with nanocrystal, is perhaps greater than yours... their nickel experience is likely not as great, though they wind on a wide range of cores. This does not mean they have it right and you are wrong. It suggests to me that maybe winding towards the same electrical characteristics that have been well-evolved for nickel might not tell the whole nanocrystal story. But maybe I'm conflating and my biases are biting hard?

I very much agree with your comments about confirmation bias. I would add that there are a couple of relevant and related biases: group think, self-interest, and authority biases. There are also the availability biases (over-emphasis on current events, available information, available models - recent successes), and anchoring biases that are relevant to reading forum posts to inform decision-making. I guess my point here is that in making a decision about what cores or transformer to purchase, if I spent my time mostly on AA, that path would likely lead to you and nickel... and I would also like what I paid for. There is nothing untoward in that and I'm not complaining - it is what it is. But it IS. If I frequented European or SE Asian or even UK sites I might come to a different decision.

Enough! I appreciate that you post here - I like your approach and find it informative. I don't mean to criticise; I'm questioning. I've been following your exploits since before reading about you wheeling in a trolley full of craziness at a NY Noise... so a while now. :)

I'm going for oversized nanocrystal cores in my next build... but may slip some nickel in there at some point.

Take care.

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

 

RE: So there Dave..., posted on October 15, 2020 at 05:48:50
PakProtector
Audiophile

Posts: 12363
Joined: May 14, 2002
 And then there is other stuff, to lay it out here:

Gap the core, this sounds better, and works to mitigate the permeability response to varying magnitude signals.

Section the bobbin, in an attempt to drop the shunt capacitance. This follows your, hit the self resonant point at midband.
cheers,
Douglas
Friend, I would not hurt thee for the world...but thou art standing where I am about to shoot.

 

RE: What makes a high quality plate choke? .... Better yet ...., posted on October 15, 2020 at 06:30:23
dave slagle
Manufacturer

Posts: 5430
Location: NYC
Joined: April 27, 2001
 "What would winding towards the same electrical characteristics on different cores tell me?"

I believe there are certain primary design considerations that must be met for all transformers and they involve a selection of compromises that tend to give a transformer a house sound. As you mentioned the japanese transformers tend to put emphasis on the top end of the spectrum (high frequency extension) and the american sound tends to the bottom. This shift can roughly be equated to a choice of inductance vs. winding capacitance. I do not believe there are any certain "technique" one would do for one core type over another. On the most basic level you have choice of frequency range and operational flux which determines the "arena" of the BH loop that the music plays in.

For the case of nickel vs. nano in a 1:1, things were simple. A bifilar bobbin was used of the same dimensions and the cores were gapped to give the same inductance and behavior with respect to DC. The AC behavior of the cores was at a low flux level. Don't take my earlier comments in the in the wrong way, both transformers sounded great and were marked improvements over typical steel. They just had slightly different presentations and for my listening preferences I prefer the 80% nickel.

"Does this tell me what I need to know when deciding which core is for me - what are the cores are ultimately capable of and can Dave wind to that?"

I think this brings us back to the "american vs. japanese" sound. I have observed that the tango iron that I first fell in love with typically had lower inductance and greater top end extension than say a Hammond. The Tamura and Nature Sound transformers were similar to the Tango in their overall acceptance of -1dB @ 20Hz-100kHz rather than -1dB @10HZ and 50kHz. The difference is only an octave on paper but the sonic signature was marked. Taking the cultural appropriation out of it and simply looking at Tango vs. Tamura I gave the sonic edge to Tango. Digging down a bit I found the tango permalloy transformers sounded substantially better than their steel counterparts. Tamura made steel(2000) nickel(7000) and amorphous(5000) series transformers. Amongst the tamradio family of sounds the nickel did not give the huge improvement in sound that the tango did but it did have the decided nickel flavor. The amorphous (5000 series) were a substantial step forward. Since i think it is safe to assume that the basic rules of transformer design were followed in all of the above designs, I think the differences came down to a "house sound" if you will. This involves all of the other minutia of design choices (wire, insulation, impregnation, etc.) and these things do not show up in the measurements but they all have sonic characteristics. Call it the "special sauce" of any design house. This is audio and there are no guarantees. I find the best option is to find and work with people who have similar tastes. If someone points you in the right direction.... continue to follow. If they point you off a cliff, stop short and make note of it for the future. The best you can do is look for a pattern of good sonic results and constantly assess if you are moving in the right direction or not.

I always keep coming back to food analogies and this all should be like eating at your favorite restaurant. Some people like the all out experience of a world renowned chef, others like roadside BBQ and still others crave a home cooked meal from mom. The only way for you to know which one is for you is to experience them all and decide.

dave

 

RE: What makes a high quality plate choke? .... Better yet ...., posted on October 15, 2020 at 09:29:31
kobasa@xs4all.nl
Just one comment, the Tango transformers has a range of transformers with more Inductance, the X series do have the this -1dB at 10Hz under typical triode load. The XE serie has less inductance.

 

RE: So there Dave..., posted on October 16, 2020 at 13:05:44
The Bored
Bored Member

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  Since: March 1, 1999
 Judging from the sequence of this exchange, you are selling product.

Please adjust your registration immediately to reflect your status as a member of the trade.

We welcome the participation of industry members: manufacturers, dealers, designers, engineers, musicians, producers, 'zine publishers, 'zine writers, everybody. But, we have a special set of rules that we would like industry members to follow. Since you appear to be in that group, please review these rules:

RULES FOR MEMBERS OF THE TRADE
Trade Members have a depth of knowledge about audio products that exceeds that of most enthusiasts. The Asylum welcomes your participation and appreciates your insight. There are many technical questions that can best be answered by those who are deeply involved in this hobby and often, only by those who make their living in this business. There are two general conditions:

All "members of the trade" (manufacturers, dealers, distributors, manufacturer's reps, importers, magazine and e-zine writers and others) shall identify themselves as such in the login profile that posters can access by the "profile info" link (M, D or R). That way any reader who wants to know if the poster has any special expertise - or vested interest - in the subject of the post can find that information.

We ask that you observe the following special rules for posting which are designed to maintain the non-commercial, hobbyist nature of the Asylum while maximizing the participation of industry members.

The Asylum is most definitely NOT anti-trade. On the contrary, trade members are a welcome and vital part of the Asylum community; however, the Asylum is not the place for self promotion and advertising of audio products or services.


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: So there Dave..., posted on October 16, 2020 at 15:06:31
Tre'
Industry Professional

Posts: 17297
Location: So. Cal.
Joined: February 9, 2002
 Here is the place on the AA to sell.

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

 

RE: What makes a high quality plate choke? .... Better yet ...., posted on October 16, 2020 at 18:18:30
91derlust
Audiophile

Posts: 1101
Joined: December 25, 2014
 Thanks for the thoughtful and nicely written response Dave. Much appreciated.

I'm still open to the possibility that the "special sauce" of different houses can complement - or could be better suited to - different core types. Drilling into that, I'm open to the possibility that different techniques (materials, winding methods, erring to the side of more or less inductance...) could be used to attain a more desired performance from different core types... that different core types could benefit from different techniques. I don't know this to be so, but I'm open to the concept.

I like the way you described the "special sauce" and house sound and I very much agree with your main point: "The only way for you to know which one is for you is to experience them all and decide." There is no substitute for trying stuff (though some problem solving can narrow down the choices). I reckon that can get costly though! ;)

Thanks again for taking the time to share. Take care.

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

 

RE: What makes a high quality plate choke? .... Better yet ...., posted on October 17, 2020 at 06:30:34
dave slagle
Manufacturer

Posts: 5430
Location: NYC
Joined: April 27, 2001
 I think the blurb by Joseph above comparing what I did for him to replace the James transformers is interesting. He approached me to wind some chokes because the James he was using were no longer available. Even though they were potted it was pretty easy to come up with an educated guess based on physical size and a few assumptions what was going on inside. I chose the biggest core size I had that would fit in that box. Then I started doing calculations to see how many turns of what gauge wire would both fit the winding window and give a comparable DCR. Armed with those numbers I could then look at various gap sizes to see the possible inductance vs current for various air gap lengths. I found that for the given dimensions and specifications a taller stack of laminations would be required to increase the core area while still fitting into the allowed space and ended up with what I think was a reasonable estimation of what was done to match the existing data. Ultimately for his application I felt that the choke he had was right at the "edge" leaving little margin for over current situations. It would not be something I would use in my personal design so how could I build and send it out with my name on it? I suggested to go up a core size to build in some headroom and get a little more inductance in the process and the net result was the choke he is currently using.

I came at the whole magnetic design aspect from being a tube circuit builder first. When I found that I really liked what nickel did to the triode sound it became clear that I needed more. With the only providers being in Japan and the internet in its infancy the telephone was the only option. All of the designers I approached to wind me nickel refused stating technical reasons why it was a bad idea. My offers to take full responsibility for the results and pay a fair price were met with engineering reasons why I was wrong. I eventually took the giant leap of buying some 80% nickel core material and replacing some steel cores on some hammond PS chokes with nickel. After some success with that I gradually proceeded to getting a winder and rolling my own. Winding to meet the needs of a known circuit gave me a perspective on magnetics design that allowed me a full understanding on the best choice of compromise to make for any given design.

The double whammy in all of this is as lovers of tubes we also face engineering backlash from the mainstream audio world. Move that to Single ended Triodes and toss in analog you become a running joke and I think it is fair to say that I take my humor seriously.

dave

 

RE: So there Dave..., posted on October 17, 2020 at 08:51:44
The Bored
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 Thanks for adding that link!


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 ...

 

Thank You Dave, your erudite and cogent response is markedly appreciated.~nT, posted on October 17, 2020 at 13:16:34
Cleantimestream
Audiophile

Posts: 7550
Location: Kentucky
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 !
The Mind has No Firewall~ U.S. Army War College.

 

RE: What makes a high quality plate choke? .... Better yet ...., posted on October 18, 2020 at 16:29:06
je2a3
Audiophile

Posts: 308
Location: PA
Joined: July 15, 2003
 dave pretty much summarized the transcript of our emails regarding the nickel plate chokes installed in the amps I'm enjoying. Great job dave and thanks again!

 

RE: What makes a high quality plate choke? .... Better yet ...., posted on October 18, 2020 at 17:33:07
je2a3
Audiophile

Posts: 308
Location: PA
Joined: July 15, 2003
 Great post dave!

I just want to share my thoughts on output transformers I've handled since the Sound Practices days. I've owned and still enjoy listening to my amps fitted with the Tamura F7002 and Tango NY15S since the late 90s. I've also built an amp for a friend using the Nature Sound NS70SE many moons ago. A very fine unit! I was a bit less enamored by the Tamura F500X amorphous series. Even if they are high resolution with excellent extension in the frequency extremes I find the overall sound a bit mechanical, thus, less musical to my ears.

The nickel transformers from Tango and Tamura portray a more vivid midrange over the regular Si steel core models although these were no slouches either e.g. XE60, XE20, F2007, F475, etc. Although I don't listen with my eyes, these also showed cleaner square waves on the scope.

I'm quite impressed by the entry level Noguchi (now General Transformer) FM6WS Finemet I picked up in Akihabara on a visit in 2015. Given its bonsai proportions, the bass extension was impressive while the midrange + upper harmonics posses the virtues of both nickel and amorphous. Very nice square waves from this petite iron!

Since my training is in music, I can't back up what I hear with technical data. I just know what sounds good to my ears having played the violin professionally for many decades. Besides, if I was after the best specs then I won't be listening to tube amps and talking about iron will be redundant. ;)

Happy listening!

JE

 

RE: What makes a high quality plate choke? .... Better yet ...., posted on October 18, 2020 at 18:11:44
91derlust
Audiophile

Posts: 1101
Joined: December 25, 2014
 "The double whammy in all of this is as lovers of tubes we also face engineering backlash from the mainstream audio world. Move that to Single ended Triodes and toss in analog you become a running joke and I think it is fair to say that I take my humor seriously."

Well said Dave.

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

 

RE: What makes a high quality plate choke? .... Better yet ...., posted on October 20, 2020 at 12:38:54
kobasa@xs4all.nl
 Is it allowed to present here facts?

I recently presented here a datasheet from a top manufacture international accepted facts.
Also an explanation what such facts mean if you make a choke or transformer.

Without explanation this is removed, on an American forum? There is more freedom of speech on a Russian forum.

 

RE: What makes a high quality plate choke? .... Better yet ...., posted on October 20, 2020 at 14:27:58
GEO
Audiophile

Posts: 4749
Joined: April 7, 2000
Contributor
  Since: September 9, 2000
 Maybe you should change your designation to "M".

 

RE: What makes a high quality plate choke? .... Better yet ...., posted on October 20, 2020 at 14:34:20
rivervalley817
 as specifically instructed a few days ago by the Bored?

what's the rush?

regards,

 

RE: What makes a high quality plate choke? .... Better yet ...., posted on October 21, 2020 at 00:15:55
kobasa@xs4all.nl
 Technical this is impossible due to legal rights. At the moment that i registrer myself as a manufacture people could think that i really am a manufacture but i am not. Specially in Europe laws are strict.
I just sell once in a while an amplifier or part to get money for a new project, probably many diy do the same.

Secondly, i have no VAT number

 

RE: What makes a high quality plate choke? .... Better yet ...., posted on October 21, 2020 at 09:03:22
rivervalley817
 fair enough, thanks for the clarification

be well,

 

RE: What makes a high quality plate choke? .... Better yet ...., posted on October 21, 2020 at 09:59:34
GEO
Audiophile

Posts: 4749
Joined: April 7, 2000
Contributor
  Since: September 9, 2000
 Ok. I thought you were selling transformers and magnetics. Are you ramping up?

 

RE: What makes a high quality plate choke? .... Better yet ...., posted on October 21, 2020 at 11:54:02
kobasa@xs4all.nl
 no

 

RE: What makes a high quality plate choke? .... Better yet ...., posted on October 22, 2020 at 11:15:33
kobasa@xs4all.nl
 Death of a Salesman

 

RE: What makes a high quality plate choke? .... Better yet ...., posted on October 26, 2020 at 23:23:27
ivan_terrible
Industry Professional

Posts: 201
Location: Ivangorod
Joined: April 26, 2015
 "Since my training is in music, I can't back up what I hear with technical data.
I just know what sounds good to my ears having played the violin professionally for many decades. Besides, if I was after the best specs then I won't be listening to tube amps and talking about iron will be redundant"

What on earth makes you come out with this??
Are violinists supposed to be,- how can I say,
"knowing what is good to your ideas criteria" freaks?

After important measurements I understood violinists subject their LH ear+pinna more or less constantly to SPLs of well over 110db, while the RH is doing something totally unbalanced
Does that make them deaf in one ear?

Does it make a violinist unable to have a scientific training or work as sound engineers??

After traipsing thru this thread all I could get from the mostly unscientific rubbish was hearsay.

Slagle gives us massive generalisations about Yankee v Jap sound, never even mentioning the most important bit which is speakers, which of course are often using yankee designs, often with serious sound coloration, and of course completely forgetting Walker's amazing neutral ESLs.

You also conveniently forgets some of the very best in the business!
Are we Europeans so dumb, all that seems to matter is yankee or jap?

What about the BBC? FM stereo radio more or less invented by them?
What about the British? GEC /Mullard?
What about Partridge, Parmeko, Sowter?

I reckon this so called 'superiority" of Jap transformers and Yankee "sound signatures", is just overhyped myths and legends, easily beaten by a lot of the best old British made stuff.

 

RE: What makes a high quality plate choke? .... Better yet ...., posted on October 27, 2020 at 05:40:00
RPMac
Audiophile

Posts: 377
Location: So. Mississippi
Joined: January 3, 2005
 The end product and reason for this "hobby" is the enjoyment of the music.
Who is better qualified to know if the reproduction of acoustical music from a system is real than a professional musician that makes that music?

 

RE: What makes a high quality plate choke? .... Better yet ...., posted on October 27, 2020 at 06:20:38
kobasa@xs4all.nl
 Death of a Salesman

 

RE: What makes a high quality plate choke? .... Better yet ...., posted on October 27, 2020 at 07:21:06
ivan_terrible
Industry Professional

Posts: 201
Location: Ivangorod
Joined: April 26, 2015
 Because real musicians don't listen to music, they read notes and watch a guy waving his arms around, or they get pointed out in rehearsal and told to behave.

Violinists have such a distorted version of reality, they rarely play perfectly in tune or together, - just watch the guys on desk 5 trying to play pizzicato exactly at the same time as the orchestra leader, if you don't believe me!

Add to this, inside a real orchestra, nobody can really hear even remotely anything objective at all, so they havevn't the slightest idea what the balance is, or whether the guys in the back row on the balcony really give a damn if he is playing at 439 or 442hz...

I did a test on a professional orchestra and was horrified to see, hardly a single musician could actually tell the difference between A-440 and A441 or A442.
How do they tune then?
They use those stupid apps from Apple Iphone etc, cos they are incapable of doing otherwise.

If that scares you, well imagine what the average audiophile is,- a total numpty that can't even come close to that accuracy, but claims he can hear the difference between one cable and another, or a "long plate" this or a "short plate" that.
Call me a cynic?
Nope I just know what people can hear and can't, which means most men over the age of 45 are not even capable of hearing 8khz, never mind 10!

 

RE: What makes a high quality plate choke?, posted on October 27, 2020 at 09:49:16
ivan_terrible
Industry Professional

Posts: 201
Location: Ivangorod
Joined: April 26, 2015
 Or go ask Jack (Elliano) at Electraprint.

He has about 50yrs experience in chokes of all shapes & sizes.
I have many happy arguments with him, and he is anything but stupid.

What he doesn't know about design of plate chokes and autoformers is not worth knowing.
He tends to be a bit "direct", so not to tolerate silly questions gladly.

 

RE: What makes a high quality plate choke?, posted on November 12, 2020 at 23:24:20
sser2
Audiophile

Posts: 2571
Location: Pittsburgh USA
Joined: July 30, 2003
 Combination of high inductance and low winding capacitance. The latter is achieved by highly sectioned winding.
One should keep in mind that at 3-5 kHz,core permeability for EI laminations becomes unity, and inductor behaves as if there is no core. Thinner laminations and nickel-based materials help extending the frequency point at which ferromagnetic inductance collapses. Nanocrystalline and amorphous cores allow extension up to 10-15 kHz and more, because they have very thin laminations, typically 25 microns.
One way to address high frequency inductance collapse is to use a series second choke with ferrite core. Ferrite retains ferromagnetic properties up to 50-100 kHz.
Of course, core materials affect the flavor of sound. 80% Ni is probably the best.

 

RE: What makes a high quality plate choke?, posted on November 13, 2020 at 11:24:09
kobasa@xs4all.nl
 I use for "cheap" but good chokes amorphous cores, 8-16 sections (which is not the same as layers)
The sound of nickel is more based on the low coercivity and the high eddy currents because most permalloy laminations are rather thick. Nanocrystaline surpass the nickel cores easely for sound because coercivity is even better and eddy currents lower.

But anyway I never would use a anodechoke. I like the real transformer a lot more. I just use the quality chokes for filtering the high voltage for my tubes.

 

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