Gibson GA8T Output Transformer ?

[GR1950]

While I'm waiting for some parts to arrive to complete my GA18 build, I thought I'd make a start on a GA8T. This GA8 version uses two 6BM8 / ECL82 tubes. Info here ....... http://www.tubebooks.org/tubedata/HB...6BM8_ECL82.PDF

Can anybody direct me to a suitable after-market OT please ?

I've enquired of MM and been advised that they make a GA8T replacement OT that has an 8K primary. It doesn't seem that, given the tube data, that's the right OT.

Assistance would be greatly appreciated.

Thank you.

Gary

[loudthud]

What makes you think an 8K primary is not right? The tube data sheet doesn't specify operating conditions for a push pull amp. The GA8-T has them idling at 35mA with a plate voltage of 255V. That's a little on the hot side but not red-plating. You might expect something a little higher like 10K or 12K but the B+ is prettly low.

[GR1950]

Thank you ( yet again ! ) LT.

The answer to the question is simply, limited knowledge !

[GR1950]

Loudthud, one more question if you would indulge me please.

Found two suitable OT's at Antique Electronic Supply.

Antique Electronic Supply > Transformers & Chokes > Hammond > 1600 Series Push-Pull.

There are two models here that I'm assuming would be suitable. P-T1650E and P-T1615 .

Which one should I opt for please ?

Thank you,

Gary.

[loudthud]

IMHO the P-T1650E and P-T1615 are overkill. Too much iron for a pair of 6BM8 or even 6V6 in a guitar amp. This amp is only going to produce 8 to 10 watts and those transformers are capable of very strong bass at 15W. I would look at P-T1750E or the low cost P-T291.

[GR1950]

Decisions, decisions !!

Thank you LT.

Gary

[misterc57]

I know this is an old thread. What did you end up using for the OT and how did it work out? Thank you. MC