PT with no HT center tap

[Baxtercat]

Hello guys [and gals],
I finally started my next amp project w/ these two trannies [maybe from a Leslie? I've forgotten].
I just noticed there's no orange/yellow CT tap to ground from the PT.

Dang, I can't just follow my old Fender-type wiring scheme this time.
What do you do in these cases?

Here's a pic. of the PT wires:
2 black; 2 green, 2 yellow [5v?], 2 red, and 1 6.3 CT
[the black on the right is to the choke]



Thanks in advance.

[txstrat]

Are you aiming for a diode or tube recto?
With a diode bridge rectifier you don't need a HT center tap.

[Baxtercat]

That's it...
I forgot. I must've skimmed over those pgs.

I've got a nice little bridge assembly in my cigar box of parts somewhere.
I'll be back w/ pics when this gets close to done. Hopefully I won't be back w/ too many questions. [You probably see the same ones over and over.]

Thank you txstrat.

[txstrat]

Hopefully I won't be back w/ too many questions. [You probably see the same ones over and over.]

That's what this forum is for. (maybe not to be repeated over and over but to answer those questions)

[Baxtercat]

Well, I got this scavenged pile put together and have been gigging it out all weekend.

Figuring it out has been a pretty roundabout process but I used a bridge recto for a while, then realized I could [should!] do better than 200+ volts. I webbed around till I found info for making a voltage doubler, got it up to 440V.

I didn't have a winding for fixed bias and was worried about the 6P3S's so I hooked it up K bias [now about 370-375 between K and the plates].

A friend found me four anodized TV legs...which called for this 'Marvin the Martian' motif. I made a box from leftover shelves, Mod-Podged some Tiki textile around it, and added an old 12-inch EV Force speaker. [I think all I spent was $10 for the handle, $7 for the white piping, and $6 for fabric.]

The chassis originally ran two 6973's plus a bunch of other tubes. Even with the four Sovtek wannabe '6L6's now, the amp only sounds like 30 watts. I guess the limitation is the OT in that case. Nothing is running hot though. In fact the tone is great.

The large radio knobs spin but that's about it. The real controls are accessed from the back, where I wired up a preamp, pilot light, on/off switch, input jack, and so forth.

[txstrat]

I'm impressed. Looks great.

[Enzo]

I love the grille cloth.

[gsr]

I love it! Very creative.

[Chuck H]

+++
Not one detail looks fudged. It's like a perfect "Jetsons" cartoon amp. Love, love, love it.

Chuck

[Baxtercat]

Thanks all, I appreciate it.
It's been a hit amongst our fans [err, barflies, Hah!]
Some think I used an old TV set [as if!]
Here's another angle, and also a shot showing my barbarous layout and soldering...



Neat looking potted tranny. I'm still not sure I used it right.

[txstrat]

The first pic looks like Marty McFly of 1955 would jump right out of the picture. Great. Got some sound clips?

[loudthud]

I don't think too many people will want to set their beer on that amp!

[Baxtercat]

Hey, maybe the anti-drink-skid feature will help me cut back on ales.


Clips? I don't know how to do that, but I usually twist the knobs on every rig until it sounds the same—kinda Fendery.

Hate to kill the thread but here's a recent instro through another homebuilt amp: [I'm on the right]

[tubeswell]

That's one helluva cool amp Bob. I like that anti-beer-can feature - In the original shot I was fooled by the camera perspective into thinking it was a square box - nice one. You've inspired me to make my next cab with ABC.

[Chuck H]

That's a really great tone. Are you using a compressor? There's some nice sustain and a soft attack but no muted treble and it rings real clear. I like your tone better than the guy on the left (but don't tell him I said so )

Chuck