Hammond Power Transformers Upgrade

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David Root
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Hammond Power Transformers Upgrade

Post by David Root » Wed Apr 18, 2012 3:38 pm

Anyone knowledgeable about transformer design/construction care to opine on these newer Hammond PTs?

They also come in an upgrade using M6 steel laminations instead of the original material, M19, M27 (???). Quite significant $$ adder.

Is this worthwhile in a guitar amp application, and is there any downside for a vintage-correct build?

jestaudio
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Re: Hammond Power Transformers Upgrade

Post by jestaudio » Wed Apr 18, 2012 4:01 pm

I,ve used hammonds before and have no complaints about them, its about the only reasonably priced transformer on the uk and definatly good quality

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roberto
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Re: Hammond Power Transformers Upgrade

Post by roberto » Wed Apr 18, 2012 4:34 pm

I've not used new ones, but you can take a look here:
http://www.jensen-transformers.com/an/A ... hapter.pdf

It's a very useful link.

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Re: Hammond Power Transformers Upgrade

Post by John_P_WI » Thu Apr 19, 2012 3:59 pm

David,

I have used a number of their older 272JX / 372JX power transformers and their "twin" replacement power transofrmers in builds and have never had any issues with heat, except when a rectifier tube was in close proximity - and still was not an issue. These were the older Canadian built transformers.

One would assume that if the POWER transformers are still built the way they were, the M6 upgrade would be money wasted.... Sorry I can not answer in more specifics...

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renshen1957
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Re: Hammond Power Transformers Upgrade

Post by renshen1957 » Sat Apr 21, 2012 3:30 am

David Root wrote:Anyone knowledgeable about transformer design/construction care to opine on these newer Hammond PTs?

They also come in an upgrade using M6 steel laminations instead of the original material, M19, M27 (???). Quite significant $$ adder.

Is this worthwhile in a guitar amp application, and is there any downside for a vintage-correct build?
Hi David

M6 Steel is supposed to run cooler, better quality steel, etc.

It depends on the amp you plan to build, clone of a famous model or just a better built than the MBA cost cutters would allow.

The Hammonds are (at least that's my experience) very well built.

However, in the US with the dollar on its downward spiral to doom or some factor like the stupid CE, the Hammond Xformers have increased quite a bit in price with the OTs.

Also, I have made purchases of other hammond smaller xformers (not guitar PT amp) which when they arrived labeled made in China but with Hammond Canadian prices. The Filament Transformer and the 164F12 weren't as cheap as they could have been.

When I make my next purchases Edcorusa.com will get some attention (hand made in New Mexico, USA) They have a wide variety PTs available, open to custom builds, some comparisons as best as I can below.

Edcor Power transformer xpr 120-137 for a 120V, 60Hz. line to 600V (300-0-300) at 450mA center tapped and 6.3V (3.15-0-3.15) at 10A center tapped at $76.66 (no 5V) compares very well to Hammond 272JX at $83-85, 250 mA, 8A 6V3 and does have a 5V (but if you SS it's just taped off).

For PT XPWR179-120 by Edcor USA has the more expensive (M-6 laminations) Power transformer for a 120V, 60Hz. line to 700V (350-0-350) at 200mA center tapped, 6.3V (3.15-0-3.15) at 5A center tapped and 5V at 3A, $60.95 compared 273BX at $71.00 same specifications.

You might want to check out the toroid PT for guitars at antekinc.com .

It is usually the OT that get the attention about being overbuilt.

However, I agree with John_P_WI, the old Hammond Xformers would be considered over engineered/full-bandwidth compared to the usual transformers used in Guitars which were only barely adequate at best.

The full bandwidth has its advantages for powerscaling, better bass response, a more open tone. The original Bluesbreaker and AC30/4 used better quality transformer Radio Spares, than their successors, had.

However, there are those that state that the limitations of the cheaper transformers a play a significant role when pushed outside of their design specifications and are part of the sonic signature.

I will be making purchases from Edcorusa.com (hand built M-6 laminations) as replacements for Hammond OT.

http://www.edcorusa.com/p/448/cxpp60-ms-4_2k

60W 4200 ohm $70.10 compared to

Hammond http://stf-electronics.com/Page0104.Html 1650N 60W 4300 ohm at $102.00 at STF (free shipping USA) and CEDist is 105.90


My $2.00 USD worth (about 2 cents).

Steve

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David Root
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Re: Hammond Power Transformers Upgrade

Post by David Root » Sat Apr 21, 2012 4:08 am

Thanx Steve, that's pretty much my take too, in general. That Edcor 60W OT sounds like a perfect BF Bassman OT!

I was thinking particularly of the PT for a period correct build, specifically a first generation ODS, #004 with corrections and maybe a tweak or two. This would be Bassman iron, I have an original '64 OT for it but no PT yet.

Would the M6 be a good option for the PT in this build, vs. the standard material, which I think is M19 (?), in conjunction with the original OT?

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Re: Hammond Power Transformers Upgrade

Post by diagrammatiks » Sat Apr 21, 2012 4:19 am

I understand making stuff period correct, and maybe it's the exchange rate that has me scratching my head..but I can't believe that hammond is only now offering m6 at an upgrade and at a premium price over m19.

even classictone uses all m6 and they are supposed to be a "budget" oriented company.

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David Root
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Re: Hammond Power Transformers Upgrade

Post by David Root » Sat Apr 21, 2012 2:07 pm

Canadian dollar is at par with the US dollar now, almost exactly. Hammond iron at retail is higher in Canada than it used to be when the Cdn$ was less than $1 US. So I think they have boosted their margins. The distributors may have done so too I think.


Who is classic tone? Do you mean Magnetic Components? I thought their stuff was all M19.

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ToneMerc
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Re: Hammond Power Transformers Upgrade

Post by ToneMerc » Sat Apr 21, 2012 4:57 pm

David Root wrote:

Who is classic tone? Do you mean Magnetic Components? I thought their stuff was all M19.
I believe they have recently started using M6 for the power transformers across the board, some of the OT transformers have had the option of M6 steel for several years. I've always been under the impression that Tweed iron was m19 or m27 and BF/SF iron was M6, at least the output iron anway.
In the PT's that I gotten from Heyboer I have always requested M6.

TM

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David Root
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Re: Hammond Power Transformers Upgrade

Post by David Root » Sat Apr 21, 2012 9:56 pm

Thanx TM, I didn't know any of that before. That would account for the recent price increase I think.

pula58
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Re: Hammond Power Transformers Upgrade

Post by pula58 » Thu May 03, 2012 8:41 pm

I have read a number of posts at this sites where users of Edcor Power supply transformers reported that they run hot to the touch. For me, that is something I don't want. Otherwise, I would try some of their power supply trannies.
Last edited by pula58 on Thu May 03, 2012 9:19 pm, edited 1 time in total.

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M Fowler
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Re: Hammond Power Transformers Upgrade

Post by M Fowler » Thu May 03, 2012 8:54 pm

I've read on TAG people saying MC iron ran hot but can't say I remember anyone talking about Edcor running hot.

Either way, I use a lot of Edcor and MC iron and they do not run hot for me?

Mark

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Re: Hammond Power Transformers Upgrade

Post by surfsup » Thu May 03, 2012 9:48 pm

I have two edcor tranny amps here. Both run cool. Dont even get warm.

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renshen1957
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Re: Hammond Power Transformers Upgrade

Post by renshen1957 » Sat May 05, 2012 5:57 am

David Root wrote:Thanx Steve, that's pretty much my take too, in general. That Edcor 60W OT sounds like a perfect BF Bassman OT!

I was thinking particularly of the PT for a period correct build, specifically a first generation ODS, #004 with corrections and maybe a tweak or two. This would be Bassman iron, I have an original '64 OT for it but no PT yet.

Would the M6 be a good option for the PT in this build, vs. the standard material, which I think is M19 (?), in conjunction with the original OT?
Hi,

I've used M6 in PT before (and toroid PT for that matter) in builds. No one could tell the difference. I just figured better quality couldn't hurt. The famous brand companies are just trying to squeak by with the cheapest stuff they can get away with.

There are a few authors (and some posters) who will argue the issue back and forth on original construction material vs. overbuilt components.

If you building with an idea that the amp has to last a lifetime and you are going to keep it and repair it, then don't compromise or skimp on good components.

Building a clone? Very few new PT or OT are built like the originals. Magnetic Components does, the rest use modern materials (for a variety of reasons, some of them safety, some for liability issues). Mercury Mag uses plastic, Edcor uses modern material, but hand stack the core.

Best Regards,

Steve

My two

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