Using transformers not meant for Aleph 5 for Aleph 5

[Possum]

I have two 300 VA transformers with 35x35 secondaries that I was initially planning on using for the Low TIM Leach amp, since the Aleph 5 looked to be too hard to construct with my limited tool skills. However, now that I've completed training at one of my school's machine shops, I have free access to milling machines, lathes, drill presses, saws, grinders, and more, and the training to use them. So construction of an Aleph 5 doesn't look impossible anymore.

Since I already have the two transformers mentioned above, would they be sufficient each for one channel of the Aleph 5? The Aleph 5 uses much lower voltages (25x25, right?) - how would I go about lowering the 35x35 secondaries to 25x25, and if that can be done well, would there be enough power from the transformers to power one channel each?

Thanks,
Greg

 

[PedroPO]

I had a similar problem and i solved it with a lamp 220V 150W in series with the primary of the transformer. the voltage dropped to half. you get a lamp and an amp for the price of one😀

I think you can also unwind the transformer, but I dont know exactly how to do that.

I think someone did that in the forum.

try a search on "unwinding transformers".

 

[UrSv]

I think you could do well by regulating the supplies to the Aleph 5 level (34 VDC I think). Try the Zen V4 article on regulation. You would get a drop of roughly 12-15 V in the regulator at 2 amps per rail per channel meaning that you would have another 50-60 W of heat giving you a total of some 200-220 W of heat to dissipate. If that is too much I suggest choosing some other amplifier as the transformers would be too small for an Aleph with higher rails.

/UrSv

 

[Nelson Pass]

I like the lamp idea, but for 120V use I would recommend
120 Volts at 300 watt bulbs in series with the AC line, and
parallel them until you get the secondary voltage you want.
Because the Alephs have a constant average draw, this
works out pretty well.

Of course another fine alternative is a big fat inductor in
series with the AC line.

 

[paulb]

Of course another fine alternative is a big fat inductor in
series with the AC line.

A big fat Greek inductor?😀

 

[Possum]

Looks like this is going to be more trouble than I thought, having to deal with the extra heat and... light bulbs? I hate incandescent light bulbs and would rather not deal with having to change them every time the filaments burn out or break off.

I'll just sell my transformers and buy the proper ones. 🙂

Thanks for all the help though.

 

[PedroPO]

don't be so pessimist!

look at my amp with the lamp on
hope that cheer you up