Salvaged Transformers for 18W Build. ???

[Guitarnut]

Well, the amp bug has bitten and I'm ready for build #2.

I want to build an 18W TMB circuit...not sure which flavor yet. There seems to be large variation on a theme to choose from.

I have an Epi Blues Custom 30 that's pretty much a parts bin. UPS dropped it hard and sheared one of the speakers off the baffle. They paid me for the amp and never bothered to pick it up. I've robbed the speakers and tubes from it already so I'm thinking of using the xformers and choke from it for this build but the specs are more like the Bassman I just finished.

Everything looks good except the AC is 350-0-350. I see 290-0-290 in some of the 18W layouts. Would this be overkill or affect the way the circuit sounds? I seem to recall a Fender Bassman schematic where the AC range was 600 - 700 vac. So, is 60v a big deal in the 18W? Or, should I save these xfomers for another build?

It's interesting that it also has a 11.5-0 ac that is rectified to filtered DC for the 12aXX tube heaters, but the power tubes and rectifier are the usual ac heaters.

[IMG768]http://www.crenshawweb.com/18watt/epi_trans.jpg[/img]

[M Fowler]

Way too much voltage and with 250mA rating is for a 45w to 50w build.

Yoiu need anywhere from 275-0-275 to 290-0-290 @ 120mA to 150mA. for 18w build.

Mark

[Blackburn]

If you need some trannies that are perfect for what you're looking to do, let me know. Brand new Mercury Magnetics PT and OT. PT puts out 285-0-285 with two 6.3v windings. OT is standard 8K Dominator/AC15/18W with an 8R and 16R secondary. Let me know if you're interested, I can probably give you a deal on the pair.

David

[statorvane]

That is a lot of voltage for EL84s, but you may be able to drive EL34s instead. Of course it won't be an 18watt power section, but you could build the TMB preamp from the 18watt..

[Guitarnut]

If you need some trannies that are perfect for what you're looking to do, let me know. Brand new Mercury Magnetics PT and OT. PT puts out 285-0-285 with two 6.3v windings. OT is standard 8K Dominator/AC15/18W with an 8R and 16R secondary. Let me know if you're interested, I can probably give you a deal on the pair.

David

PM sent.

[Guitarnut]

That is a lot of voltage for EL84s, but you may be able to drive EL34s instead. Of course it won't be an 18watt power section, but you could build the TMB preamp from the 18watt..

Good option. I'll think about it.

Peace,
Mark

[Guitarnut]

Way too much voltage and with 250mA rating is for a 45w to 50w build.

Yoiu need anywhere from 275-0-275 to 290-0-290 @ 120mA to 150mA. for 18w build.

Mark

Thanks. Good to know what I'm looking for.

Peace,
Mark

[M Fowler]

Way too much voltage and with 250mA rating is for a 45w to 50w build.

Yoiu need anywhere from 275-0-275 to 290-0-290 @ 120mA to 150mA. for 18w build.

Mark

Thanks. Good to know what I'm looking for.

Peace,
Mark

Also use 8k primary OT rated for around 18w.