Hammond transformers - any good?

[Aurora]

Hi folks...
What is the opinion on Hammond transformers vs Edcor, Heyboer and the brands usually used by folks around here..???
I'm planning a Rocket build, and the trick is that there's a local importer of Hammond over here......

[SteveG]

Hammond have been manufacturing transformers for a very long time, and if they haven't figured it out by now, they never will.

They used to have rather strange secondaries, but I think they have recently started making models aimed more specifically at the guitar amplifier market.

Steve

[jcat5503]

They are good and very affordable IMO

The only thing is their PT's are sometimes a little under rated. I've seen 15-20 volts over on the hot taps

[Aurora]

They do have a "Guitar series" of transfomers, but I suspect that the OT cores are somewhat smaller, as the lower freq. is listed around 60-70 Hz.
I'm thinking of using the Vintage HiFI series of OT, as those have a lower low freq. limit, which I think have a larger core.

[Super_Reverb]

I have had good results with Hammonds, both SE and PP designs. Their guitar series are easier to configure with a variety of spkr impedances without crazy interconnection.

BTW, the bass E string concert pitch for guitar is ~82 Hz

Mouser carries alot of Hammonds, you can order various trannies from rjguitar from this forum and you can order direct from Edcor.

cheers,

rob

[Cliff Schecht]

I have had good results with Hammonds, both SE and PP designs. Their guitar series are easier to configure with a variety of spkr impedances without crazy interconnection.

BTW, the bass E string concert pitch for guitar is ~82 Hz

Mouser carries alot of Hammonds, you can order various trannies from rjguitar from this forum and you can order direct from Edcor.

cheers,

rob

Transformers will start to saturate when a PA is distorting hard and the manufacturers specified frequency rating, even at full power, will mean less and less as the core saturates more. Having a bit of headroom will keep the bass response as an amp is pushed. I'm sure you know this though Rob .

[rocketeer]

For what it's worth .... my last Hammond transformer was a 291FX which is the upgraded Twin transformer. The pdf sheet on their site says 640v secondary at 518ma, got the tranny and it says 670v and 450ma on the label. After SS rectifier I got a whole 410v out of it at idle in the twin circuit. Bummer.

I've had Edcor build me some custom power and output metal and they are noticeably heftier than Hammonds of near the same ratings. Edcor Specs were spot on with voltage and current ratings.

[rfgordon]

I've used iron from Weber, MPS, Hammond, Edcor and Allen, all with good results. I like a particular Hammond PT for a low wattage model I build. The only complaint I have with many Hammonds is a low filament current rating. For many models they offer, adding another amp of filament current could increase the possible applications.

I will say that the Edcors are really nice, and priced well. A PT/OT set from Edcor makes a killer Trainwreck Rocket.

[Alexo]

I love Hammonds. Rock solid power transformers, ime, but I haven't used any of their "guitar amp replacement" pt's, just their bread and butter 200-300 series, which are virtually unchanged since the 40's.

Their 1600 series OT's are also amazing, the weird secondary taps ensure equal performance no matter which impedance you've selected. It's a bit of a nuisance, but it's a 'no compromise' design.

Their transformers are just the kind of part you know you can count on to do their job for the next several decades. At least that's the feeling I get from them.

[Ken Moon]

I think the Hammond 300 series is significantly better than the 200 series, at least in the voltages I've tried.

I used the 276X 320-0-320 PT in the first Talon amps, but they run very hot - I can keep my hand on top of the PT, but just barely.

The 376X runs nice and cool, and doesn't seem to bleed as much heater noise through to the HT winding, possibly because of a superior winding technique on the 300-series.

I don't have anything to do with them, but stf-electronics is having a sale right now, with free shipping on all Hammond orders over $80. This can save at least $15 on shipping, and stf has very low prices already.

I've also bought Hammond trannies from Angela, fairradio and radiodaze.