Liverpool 2x el84 PT question

[Tabula Rasa]

You Guys helped me out with finding a good OT (Edcor)

But now i'm stil in doubt about a suitable Power Transformer.

I have read a lot of topic about the Liverpool en have read that the PT should have a secundairy between 260 and 280 volts.

I've downloaded the schematic (normal Liverpool 30 with 4 EL84 tubes) and i see, at the power section 234VAC, rectified that is about 331 accordingg to the schematic.

i'm thinking that a PT with 275-0-275 secundairies wil give me a B+ of about 385V DC (275x1.4)

Why do i read 260 - 280 secundairy al the time and the schematic tells me different (or do i forget something?)

Keep in mind that i want to build a 2 EL84 Liverpool so, about 1600mA less current on the B+.

[Zippy]

RJ was telling me just last week that he's doing more work on the Liverpool 2-holer (15W). Give 'im a call to see what's up with trannies.

[Tabula Rasa]

I've read RJ's topic on the 2 outputtube Liverpool, and as far as i remember he used something like 260 - 280v AC sec.

[RJ Guitars]

Yeah I've settled in on a 270-0-270 power trans for the LP builds and I'm very pleased with it. I'll be using it for a 6V6gt version of the LP that I have in the works... We'll see how it works out. This seems to be a good voltage for getting the sound and not taxing the tubes too much. Best thing about the 15W Wrecks is that they have the big sound with half the weight... I am thinking this makes it an ideal choice for little combo amps as well. For my protoypes I usually have EDCOR wind the transformers but I suspect you could use anybodies 18 watt power tranny and get a good result, although I think 290-0-290 is a more common voltage for those trannies. Let us know what you end up using...

[Tabula Rasa]

Okay RJ, you used a 270v transformer. What was yhour B+? I'm finding the 234 v AC in the schematic, here at this forum a little bit low, since everybody is saying you should use 260 -280 trannys.

what did Ken Fisher had for B+ in his Liverpool moddels? I'm realy confussed about the schamatic and thad 234vac, 331vdc.

if 275 would be okay, i'll probably buy a Hammond 370fx to use with the 10k 30 watt Edcor i bought last week.

[Ken Moon]

I've used this Edcor 275-0-275/150mA several times now with great success, and it's much more reasonably-priced than the Hammond. You just have to be patient, because it usually takes about a month to get a tranny from Edcor.

https://edcorusa.com/xpwr163

[Tabula Rasa]

I've used this Edcor 275-0-275/150mA several times now with great success, and it's much more reasonably-priced than the Hammond. You just have to be patient, because it usually takes about a month to get a tranny from Edcor.

https://edcorusa.com/xpwr163

here in the netherlands it is pretty difficult to get Edcor. I was lucky somebody mentioned Don Audio in Germany for the OT. The PT you just mentioned is not one they have in stock. But if 275v is okay, i'll probably buy the Hammond. That one i can get easily over here (although a bit pricy at about 90 euro).

Still don't get the ratings in the schematic, but everybody uses 275, so i'll try that.

[lego4040]

I will follow this thread as I am thinking about a 15watter LP after Im done with my AC15 build. A 15watt express would be just as nice

[Tabula Rasa]

Thanks for the advice.

This is the set transformers i'll try to build the trainwreck with.

I'm happy (and broke now )

[IMG768]http://i60.tinypic.com/oppi5z.jpg[/img]

[IMG768]http://i57.tinypic.com/iekw7p.jpg[/img]

[lego4040]

Sweet build, you make the cab yourself? Hammond trannies jumped up in prices here as well but compared to Mecury it's a no brainier. I'd like to build the version that is Brown sounded like Early Van Halen. I believe it was the ver. 4 one. Keep us posted please, especially gut shots

[Tabula Rasa]

Yes, together with a friend i build 2 headshells en 2 matching oversized 1x12" cabs in the same style. The are made of old dutch pine cheeseplanks. They used them to store cheese to let them age.

[lego4040]

Keeps costs down, boards funky smelling? Or nice aroma?

[Tabula Rasa]

Keeps costs down, boards funky smelling? Or nice aroma?

Doesn't smell at all. And it's cheap, but if you want to keep costs down, than better not build amps at all.

[lego4040]

That would be no fun at all.

[Tabula Rasa]

found some very affordable tubes, with good measurements (tested, just before i bought).

Don't know if they are the right choice for a TW LP

2 Haltron NOS El84
1 Mullard ECC83 (12ax7/ecc83 Gt. Brittain, IEC Mullard 1022-852)
2 Brimar Rochester CV4004 ECC83