Liverpool 2x el84 PT question

[M Fowler]

Yes those should do the trick.

Haltron are rebranded tubes so hit and miss on those.

[Tabula Rasa]

can anybody tell me what i should change in the powersupply? (R31 to R34) for a 2x EL84?

[dcribbs1412]

Here's a link to a build Fishy did a while ago
has some info you might find helpful
https://tubeamparchive.com/viewtopic.ph ... highlight=
also a link to one I did a while back
https://tubeamparchive.com/viewtopic.ph ... =halfwreck
pretty sure using 9.1k's and a 1.5k 25 watt sag resistor will get you close(R31-34)
you will have to adjust the PI node...I think Fishy used a 22k there

Darin

[fishy]

The power tranny in that build was from MusicalPowerSupplies. I think it has been upgraded these days but it was a decent transformer for the money. Edcors are great too.

I gave that build away as a graduation gift some time ago. Forgot how good that thing was. The person I gave it to is still pretty chipper about that.

[Tabula Rasa]

Please help! I´m halfway through the build and i have a problem with the Edcor OT.

The schematic shows 3 connections at the OT: A B+ and pin 7 of both sets output tubes.

The transformer has 5 cables (1 B+, 2x screen en 2x plate). Can't figure out what to do with 5 wires and 3 connections

[lego4040]

You have the diagram for the OT? One of those extra wires could be a center tap. I have extra wires on my OT that I'm not using, use the ones you know that are for your build and cap others, but verify with your diagram

[ampgeek]

The 2X screen wires from the OT are most likely for ultra linear (UL) operation of the output stage.

If UL operation is not your intent, they can be carefully rolled up, taped off, secured and ignored.

Yes. A OT schematic would be most helpful to confirm the above suspicion.

Good luck,
Dave O.

[Tabula Rasa]

Think Ampgeek is right:

https://www.edcorusa.com/content/images ... ms_10k.png

[M Fowler]

I haven't seen an Edcor transformer without the wiring info glued to the bottom of each transformer?

[Tabula Rasa]

damned! it's already mounted on the chassis with the board under it. It's a lot of work to remove it. Can't remember having seen that. There was a piece of paper that came with it. Lost it.

[M Fowler]

I was just about to mention if bought directly from Edcor they send a wiring diagram in sticker format with each transformer.

This shows only one thing your not thinking ahead.

[M Fowler]

Yup UL taps (screens) clip the bare ends, shrink wrap each wire and then larger shrink wrap over both and stow those wires away.

[Tabula Rasa]

Yup UL taps (screens) clip the bare ends, shrink wrap each wire and then larger shrink wrap over both and stow those wires away.

Thanks, that was the answer is was looking for.

And yes, not thinking ahead.

[M Fowler]

Yup UL taps (screens) clip the bare ends, shrink wrap each wire and then larger shrink wrap over both and stow those wires away.

Thanks, that was the answer is was looking for.

And yes, not thinking ahead.

lego4040 and Ampgeek both said the same thing as I did in their above posts, so 3 answers is good.