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Hammond Power Transformers Upgrade

 
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David Root



Joined: 04 Aug 2006
Posts: 3078
Location: Chilliwack BC

PostPosted: Wed Apr 18, 2012 3:38 pm    Post subject: Hammond Power Transformers Upgrade Reply with quote

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?
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jestaudio



Joined: 12 Mar 2011
Posts: 577
Location: UK

PostPosted: Wed Apr 18, 2012 4:01 pm    Post subject: Reply with quote

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



Joined: 27 Nov 2007
Posts: 848
Location: Italy

PostPosted: Wed Apr 18, 2012 4:34 pm    Post subject: Reply with quote

I've not used new ones, but you can take a look here:
http://www.jensen-transformers.com/an/Audio%20Transformers%20Chapter.pdf

It's a very useful link.
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John_P_WI



Joined: 15 Aug 2007
Posts: 1091
Location: Wisconsin

PostPosted: Thu Apr 19, 2012 3:59 pm    Post subject: Reply with quote

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



Joined: 20 Feb 2009
Posts: 464
Location: So-Cal

PostPosted: Sat Apr 21, 2012 3:30 am    Post subject: Re: Hammond Power Transformers Upgrade Reply with quote

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



Joined: 04 Aug 2006
Posts: 3078
Location: Chilliwack BC

PostPosted: Sat Apr 21, 2012 4:08 am    Post subject: Reply with quote

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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diagrammatiks



Joined: 27 Mar 2011
Posts: 558

PostPosted: Sat Apr 21, 2012 4:19 am    Post subject: Reply with quote

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



Joined: 04 Aug 2006
Posts: 3078
Location: Chilliwack BC

PostPosted: Sat Apr 21, 2012 2:07 pm    Post subject: Reply with quote

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



Joined: 26 Apr 2009
Posts: 2880
Location: East Coast

PostPosted: Sat Apr 21, 2012 4:57 pm    Post subject: Reply with quote

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



Joined: 04 Aug 2006
Posts: 3078
Location: Chilliwack BC

PostPosted: Sat Apr 21, 2012 9:56 pm    Post subject: Reply with quote

Thanx TM, I didn't know any of that before. That would account for the recent price increase I think.
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pula58



Joined: 26 Jan 2010
Posts: 398

PostPosted: Thu May 03, 2012 8:41 pm    Post subject: Reply with quote

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



Joined: 16 Jan 2008
Posts: 11202
Location: MN

PostPosted: Thu May 03, 2012 8:54 pm    Post subject: Reply with quote

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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surfsup



Joined: 29 Nov 2010
Posts: 1511
Location: Chicagoland

PostPosted: Thu May 03, 2012 9:48 pm    Post subject: Reply with quote

I have two edcor tranny amps here. Both run cool. Dont even get warm.
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renshen1957



Joined: 20 Feb 2009
Posts: 464
Location: So-Cal

PostPosted: Sat May 05, 2012 5:57 am    Post subject: Reply with quote

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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