Triad HS56 vs HS66 vs A57J (new vs old)

[waxstash]

Greetings, all!
I'm modding an old Yamaha M1524 console and looking into trying some different output transformers on the "master bus" (routing is a tad wonky on these boards).

I'm running Flickinger style op amps so thought the holy grail HS56 transformers would be cool. Of course, that comes with a hefty price tag. I want to be careful not to sink too much into a board with a low value ceiling (relative to API, Neve, etc). So I want to explore all my options.

My questions are...
-Are the HS56 and 66 pretty much interchangeable in regards to sound and performance for my purposes?
-How close is the A57J to the HS56/66 in sound and performance?
-Any word on how the new J series stack up against the originals?
-Any word on how the Vintage Windings T56 stacks up against the HS56?

Would be grateful for any insight.

Thanks!

 

[CJ]

56 and 66 are the same turns wise, and core, i think the difference is shields,

 

[waxstash]

56 and 66 are the same turns wise, and core, i think the difference is shields,

Thanks, CJ. I just ordered a pair of 66s. Looking forward to hearing them VS the stock Tamuras and seeing if they live up to their reputation (and price) in my project.

 

[CJ]

here are prints for A57J and HS 56, as you can see, the 57J is pretty simple as far as winding structure,

you can use the 56 print to compare your 66 for DCR , i would be curious to see if they match up,

 

[CJ]

Ok from the catalog

HS 56 P1 shielding

HS 66 P3 shielding

P1: one nickel alloy hi perm shield -45 db reduction in pickup

P3: two nickel alloy shields interleaved with one heavy copper shielding ring -70db reduction in pickup

FYI

P5: three nickel alloy shields interleaved with two heavy copper shielding rings -95 db reduction in pickup.

Note that this extra shielding reduces noise pickup but can degrade frequency response as it adds capacitance to ground to the coils.

 

[waxstash]

Ok from the catalog

HS 56 P1 shielding

HS 66 P3 shielding

P1: one nickel alloy hi perm shield -45 db reduction in pickup

P3: two nickel alloy shields interleaved with one heavy copper shielding ring -70db reduction in pickup

FYI

P5: three nickel alloy shields interleaved with two heavy copper shielding rings -95 db reduction in pickup.

Note that this extra shielding reduces noise pickup but can degrade frequency response as it adds capacitance to ground to the coils.

Thanks for all the info! Massively appreciated.

So it looks like 56 = P1 and 66 = P3. What are your notes about P5 in reference to?

Based on your notes here, it looks like even if the winding and core of 56 and 66 are the same, they may sound different because the extra shielding in 66 could reduce HF response.

I can't escape the feeling that I just need to keep an eye out for some 56s, buy 'em some day and A/B 'em against the 66s.

 

[CJ]

I get it now. You are buying reissue 66 transformers and you wonder if different from old stuff.

Since this is just a 1:1 xfmr, I would not expect any difference since the freq response for the old ones goes out well past 100 kc.

Resonant peak of the 66 I tested was at 273 kc, so as long as the used the same turns and coil structure they should match up with nos.

Only difference might be from type of coil wax they use (old stuff was different). Different wax can alternator (spell check is a hoot!) the hi end a bit as the waxes can have different dialectic contacts.

Lamination differences might alter the low end a tiny bit but this would probably be at 5 hz or below so no big deal.

Looking through my binder I see that I hacked both the 56 and 66. Same coils and lams, just different shielding.

 

[waxstash]

I get it now. You are buying reissue 66 transformers and you wonder if different from old stuff.

Since this is just a 1:1 xfmr, I would not expect any difference since the freq response for the old ones goes out well past 100 kc.

Resonant peak of the 66 I tested was at 273 kc, so as long as the used the same turns and coil structure they should match up with nos.

Only difference might be from type of coil wax they use (old stuff was different). Different wax can alternator (spell check is a hoot!) the hi end a bit as the waxes can have different dialectic contacts.

Lamination differences might alter the low end a tiny bit but this would probably be at 5 hz or below so no big deal.

Looking through my binder I see that I hacked both the 56 and 66. Same coils and lams, just different shielding.

Thanks, CJ! To be clear, I was kinda considering all options including new and vintage units. I wound up going with with a pair (sequential serial numbers) of vintage HS66s pulled from a custom built recording console circa '73. I guess I'm just wondering how close those will sound to vintage 56s.

Thanks a ton for all the info!!!

 

[ranalog]

I get it now. You are buying reissue 66 transformers and you wonder if different from old stuff.

Since this is just a 1:1 xfmr, I would not expect any difference since the freq response for the old ones goes out well past 100 kc.

Resonant peak of the 66 I tested was at 273 kc, so as long as the used the same turns and coil structure they should match up with nos.

Only difference might be from type of coil wax they use (old stuff was different). Different wax can alternator (spell check is a hoot!) the hi end a bit as the waxes can have different dialectic contacts.

Lamination differences might alter the low end a tiny bit but this would probably be at 5 hz or below so no big deal.

Looking through my binder I see that I hacked both the 56 and 66. Same coils and lams, just different shielding.

Hi CJ, off topic of this thread, Can you tell me anything about the langevin 602a ?, I believe it is a repeat coil but no info,
I have come across a half dozen or so , have seen them on the eby, just curious if you know much about specs etc,
Thanks Ray by the bay

 

[CJ]

This is all I know about Langevin
He did work at Western Electric for a while so he might have borrowed ideas from their stuff.

https://groupdiy.com/threads/langevin-transformers.74183/