Question about Edcor output transformer

[Captain archer]

Hi i am planning to build an el34 10w single ended amplifier.
But it is not so much a quality depended project so the output transformer must be cheap.
With this in mind i found Edcor electronics and they have the GXSE15-8-2.5K
transformer witch is great for the el34 and cheap but it is an guitar output transformer with an freq range of 40hz to 18000khz

Now they also have another series of cheap output transformers the XSE Series with a freq range of 70 to 18000khz witch is intended for normal low quality Hifi applications

http://www.edcorusa.com/products/class_x.html

but in this series they dont have the right impendace for the el34
so is it posible to use the GXSE guitar series witch has better specs on paper than the XSE series in my amplifier design.
Or do these guitar transformers have something special so that i cant use them.

Another option is the Hammond 125ESE (input about the sound please)
but i prefer the Edcor since the have an super linear tap

So to make a long story short, WHAT should i do


Many Thanks Captain Archer

[Boris_The_Blade]

For $30, you can get a XSE25-8-2.5K. It is not listed on the website but they have them for no engineering fees. Just ask Phyllis I have a pair, they work great. The listed frequency range of their transformers is often very conservative, so going to 20Hz with 10 watts outta be a piece of cake for the 25 watt SE transformer. I'd say maybe 30 Hz at 10 watts for the 15 watt transformer. I'm sure they have a XSE15-8-2.5K available too and already designed if your really strapped for cash.

[lochness]

I wouldn't call EDCOR low quality just because they're cheap. They have better performance than many other transformers I've used. They are very customer friendly and if you explain your needs and provide a schematic you'll get exactly what you need in a transformer.

remember quality != $$$$.

[Boris_The_Blade]

Originally posted by lochness
I wouldn't call EDCOR low quality just because they're cheap. They have better performance than many other transformers I've used. They are very customer friendly and if you explain your needs and provide a schematic you'll get exactly what you need in a transformer

right on


some square waves of a XSE25-8-2.5K with a 6JM6 in triode with no feedback or compensation circuits. Pretty dang good for $30. I checked around for other SE amp square waves...most are right on par with the edcor.

http://picasaweb.google.com/Gregory....nd6JM6InTriode

[lochness]

I think thats actually better than hammond square wave performance. Hammond's square wave...really isn't to square...more curvy...Thats not to say they don't make great enclosures and chokes.

[NICKEL]

A tube newbie here!

Here's something on Edcor's guitar line

http://www.audiotransformers.net/for...hp?topic=165.0

Can someone tell me how far you can overspec OPT to get the low notes, without losing the highs?

I need a 10 watt OPT for an EL84 based amp, so what would I lose using the 25 watt OPT?

Many thanks

[Boris_The_Blade]

I'd say any are fine. They are good enough transformers (have enough interleaves) to allow great high extension. The XSE25 I have goes to 45KHz -3dB @ 1watt. About the same at 5 watts. (So it is probably circuit dependent and not transformers)

[Captain archer]

Thanks, well i have found some beautiful transformers on ebay and they have verry good specs
20hz-100khz @ 1 watt, and that for 99$ thats just over 65 euro's and with postal costs its almost 100 euro's and this is the price for a pair.
i made a decision to not cut the budget on the output transformers.
especially since they are the most important factor in a tube amp design.

[lochness]

i made a decision to not cut the budget on the output transformers. especially since they are the most important factor in a tube amp design.

First price has NOTHING to do with the quality of an output transformer and just because something is old or vintage doesn't mean it is good (most transformers I see on ebay are pulled from old equipment or are old NOS).
And the transformer being the most important part is VERY arguable...especially to the OTL guys...they could give a rats *** about transformers except for power ones.