hammond transformers stink?

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danfrank
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Re: hammond transformers stink?

Post by danfrank » Wed Mar 11, 2015 6:41 pm

Hi,
This is my 1st post on this forum, and I came across this thread.
Hammond transformers are conservatively rated; intended for Hi-Fi use. Their 1650 series are rated for 30-30khz at power;
IE. Their 1650R will pass 30-30khz at its rated 100 watts power output. So for guitar use (lowest guitar frequency @ 80Hz) the transformer should be able to pass around 200 watts without breaking a sweat.
Hammonds are big because it takes a big core to pass 30Hz at the powers they are rated for, not because they use inferior materials. In fact, Hammond cores are made of M6 material, IIRC, which is the highest grade silicon steel used for transformer laminations.
In output (audio frequency) transformers the core is important for the lower frequencies but not important for passing higher frequencies. This is only a guess by me, but after 200Hz or so, the core makes a negligible contribution to passing signal. Above that, signal is passed directly from primary winding to secondary winding through inductance; core not involved so much just the windings.
Now, for the original transformers used in the classic amps; electronically speaking, they were under-rated, cheaply wound with very little interleaving. In a lot of cases they were wound primary first then secondary wound on top of the primary. Not only were they cheap to manufacture this way, the way they were made actually benefits the guitar tube amp as a whole in terms of tone. Little interleaving causes a lot of high frequency roll off in the output transformer which is generally good for an instrument amplifier.
I'm not going to get into a discussion on which current made transformers are best as each person is gonna have their own opinions, but I will say that many transformer makers making product for tubed instrument amplifiers really pile on the marketing hype to try to get people/musicians to buy their product. Fancy terms and a lot of adjectives don't make a superior transformer. It all comes down to an individual's particular taste.
As for Hammond transformers... Yes, I think they can make excellent MI output transformers, but the circuit of the amp may have to be tweaked somewhat to get the tone one wants from the amp, just like for any other transformer

charles anthony
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Re: hammond transformers stink?

Post by charles anthony » Sun Mar 29, 2015 6:56 pm

Welcome to a great place,and thank you for the insight regarding Hammond tranny's. Best regards, Charles.

awangotango
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Re: hammond transformers stink?

Post by awangotango » Sat Feb 16, 2019 6:15 pm

the insight regarding hammonds slight rolloff of high frequency, also jives with experience. another reason it may blend well with jubilee (or any marshall circuit really) as the circuits have plenty of treble and upper mid presence....but one does need to watch out for hammonds excessive treble rolloff, as it can be an issue if one does not use a Vol brightcap or uses a bass spec circuit etc.....but the jubilee i built had a bright cap

crumb
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Re: hammond transformers stink?

Post by crumb » Sun Sep 22, 2019 4:05 pm

Hammond transformers are high quality, well built transformers.
Do they sound good?
I dont know what your ears tell you, mine tell me, yes, sometimes too good, sometimes perfect.
An example of perfect?.....1750j hammond transformer for fender 35w ( bandmaster etc)
This transformer in this application sounds ' better' than the original.
Why?...because the original one has a slight ' raspy' flavour to it ( ive tried several original ones, I still have them here ) the hammond clone is simply killer, sweeter frequency response, slightly fatter...superb.
An example of ' too good' is an old hammond c1998 output transformer( plexi) knock off Im now using as a doorstop..this thing wont saturate early enough, and theres too many tops.
There are so many different models of so many transformers its hard to just say, yeah, they all sound magnificent.

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neikeel
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Re: hammond transformers stink?

Post by neikeel » Fri Sep 27, 2019 4:42 am

I've had no issues with the Hammond stuff I have used either 8)
Neil

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