18VAC transformer, what to do with it?

[asbus]

Hi,
I found a transformer lying around on my attic, so I thought I could build an amp with it.
I see there's only one AC secondary output, could I get +/- rails with that?
If so, I could use some tips on nice solid state amps running with +/-25VDC.

I understand I won't get much power out of 25VDC, but it would be fun to do something creative with it instead of throwing it away!



Cheers

[leadbelly]

That trans is only 45VA, which is VERY small for a power amp. Also, with full wave rectification and no centre tap, all you'll get is +25VDC, forget about -25.

You CAN build a power amp with it, say something like a single-supply gainclone, but I would recommend you think along the lines of preamp or headphone amp.

[paulb]

Use double half-wave rectifiers to get +/- 25V. It will power an LM1875 amp very nicely. Look at the datasheet to see what power you can get. You'll need a heatsink.

[Geek]

Seems like a good transformer for making a tube amp with 18V (PLxx for european) heaters to me

Cheers!

[Pano]

That Gregg - he has toobz on the brain!

Since I have T-Amp on the brain - how about an AMP9 from www.41Hz.com ? Easy to build, sounds nice. Just right for your 18V tranfo.

[gain-wire]

How about a variable power supply, either discrete (Pass transistor and op-amp feedback) or LM317?

[Geek]

Originally Posted by panomaniac

That Gregg - he has toobz on the brain!

Hehehehe, as usual!

Since I have T-Amp on the brain - how about an AMP9 from www.41Hz.com ? Easy to build, sounds nice. Just right for your 18V tranfo.

Or a "FIWA"... five watt version of the SEWA

Cheers!