6g2 Brown Princeton, PT?

[gtrrich]

Anyone know what Power Trans to use for a Brown Princeton 6G2 Clone? The schematic shows a 125P1A, but I cannot find anything on this. Any help is appreciated. Thanks!

[loudthud]

I'm finding equavalents of the 125P1B at Antique Electronic Supply and the specs look adequate.

[tubeswell]

I can't see it at AES, but with those low voltages I'm guessing the HT is around 290-0-290 (or 300-0-300 for slightly more headroom) @70mA (which I'd spec at 100mA for a bit less sag). 2CW

[RichardBM]

Anyone know what Power Trans to use for a Brown Princeton 6G2 Clone? The schematic shows a 125P1A, but I cannot find anything on this. Any help is appreciated. Thanks!

Hammond 290AX.

Hammond Mfg. - REPLACEMENT & UPGRADES - Tube Guitar Amplifier - Power Transformers

[gtrrich]

Thanks everyone for your input. I've been doing some more checking on this, and I found that Mercury Magnetics has both PT and OT for this amp. No specs on their site though. I would like to make it versatile by being able to use 6L6s as well as 6V6s. I'm considering:

for Power Trans:
Hammond 272DX 300-0-300 144mA
6.3 @4A
5.0 @ 3A
I might have to knock down the B+ with zeners as I have seen others do in other posts.

Output Trans:
Hammond 125E
15W (not sure if thats enough with 6L6s)
selectable output imp.

I'm starting to think it would be easier to stick to the schematic and not try the tube swapping thing. Any thoughts appreciated!

[JoeM]

Allen Amps has some good Heyboer transformers that would work well in this. Probably a lot cheaper than MM too.

Allen Amplification - Parts Order Page

[Bruce / Mission Amps]

Allen Amps has some good Heyboer transformers that would work well in this. Probably a lot cheaper than MM too.

Allen Amplification - Parts Order Page

Unless Dave specifically says the transformers are Heyboer then I would not publish or suppose they are Heyboer.
Yes, they are superior/excellent quality transformers and very well priced... etc.
When upgrading some amps to heavy duty use, (like a Princeton Reverb or Deluxe Reverb) I always call on Dave and have him send one of his HD PTs rather then reinvent the wheel.
Depending on the rectifier chosen and what you want to bias the power tubes at, anything around 300vac to 320vac@ 90ma-120ma will work fine for a Brown Princeton clone.

[andrew_k]

I used the MercMag. BFPR PT and the Triode Electronics Deluxe OT (6.6k, paper bobbin) in my 6G2 clone. Sounds good to me, and to everyone who's played it.

[JoeM]

Unless Dave specifically says the transformers are Heyboer then I would not publish or suppose they are Heyboer.

Quite true, some he refers to as "Allen/Heyboer" others as Hammond. Others are not stated.

[Howlin' Mad Mac]

Please tell me if I'm incorrect but I was imformed that most Champ, Princeton (non-reverb) & Bronco models used the same PT. I believe the 6G2 uses 2-7025/12AX7's, 2-6V6's & a GY3 rectifier so should supply enough current. I only ask cause I've ordered up parts as I've been wanting to build one myself.

[gtrrich]

From what I have seen, the single ended amps (champs, bronco, some princetons) use the 125P1B. There are plenty of PTs out there to replace it. However, the Princeton 6G2 circuit uses the 125P1A. I could not find specs on this one. I ended up using the Hammond 272DX power trans, and the OT20PP output trans (from musicalpowersupplies.com) for the output trans. If you're building a 6G2, I'd be curious to know what your using.

[Howlin' Mad Mac]

Yes the A was replaced by the B or at least that is my understanding however the differences are considered so minor as to not make any kind of sonic difference or at least enough of one to worry about it. Use the B & it'll sound fine... that's what everyone else does.

[RichardM]

Mercury Magnetics Princeton:-

"FBPP Early '60s Brown -- #125P1A"

or

"FBFPP Blackface -- #125P1B "

[Howlin' Mad Mac]

Yeah for my build I ordered my transformer from Antique Electronics Supply. I forget what brand it is although I know it's not a Hammond as it was made in Chicago, not Canada & it's the one with a "B" in the part no. As for the Mercury Magnetics trannies I'm sure they're quite good & all but they're still just laminated iron & magnet wire & I'm just not willing to pay big $$$ for some orange paint & a slick advertisement... I believe in buying quality American (or Canadian) made parts whenever possible & paying more for them. Over-paying is a different story, I'm too frugal for that.