Stock 68 spec W/2"OT and such...

[BAinFL]

fuckin' AWESOME tone strat78 !

+1 your clips sound great!

It's amazing how these 12000 can cover so many tones well. Mine sounds nothing like yours (probably due to more things than just the amp itself) but I love the sound of your tone. Your build has that classic VH spot on. Mine sounds like a totally different beast altogether...less brown, but voiced darker. Does a great Sabbath tone dimed on the normal input (and Zep back on about 6-7) and AC/DC great through the bright input. It's amazing how this circuit covers so many things so amazingly well.

[Strat78]

I can't measure sag with my meters... but I can see it on the oscilloscope... the right way to do it is to inject 1-2khz tone into the amp input... as you crank it you will see the sag get greater and greater. I can see it just fine banging on the chords though.

Hitting an open A chord kind of hard, didn't we get someting like a 60v sag with your scope on this amp?

[vh junkie]

I can't measure sag with my meters... but I can see it on the oscilloscope... the right way to do it is to inject 1-2khz tone into the amp input... as you crank it you will see the sag get greater and greater. I can see it just fine banging on the chords though.

Hitting an open A chord kind of hard, didn't we get someting like a 60v sag with your scope on this amp?

Yup... 60v to 70v of sag with the ****** PT...

[YMI5150?]

man, that last clip was amazing! it seemed like it all the sudden just fell into place from the prior clips. i thought to myself, well, those are close and I'd be happy with that tone. then I listened to that clip and it has the magic! awesome job persisting. hopefully you box it up and call it good...

think the diode change was huge? seems like the old school bias change made a difference. or it could be just break in time. thoughts?

[vanhalen5150]

STRAT78, What the thing you have holding the unused wires bundled up against the chassis wall from the PT?

[YMI5150?]

it looks like one of those stick on tabs that have a loop in it to allow a zip tie to go through it. cool idea.

[vanhalen5150]

Something he scavenged from R.Shack I have been told.

[vanhalen5150]

Where does the brown wire of the OT primary go?

[Strat78]

Where does the brown wire of the OT primary go?

Here is the wire hook-ups for the -132
PRIMARY:
WHITE= plates (pin#3 for V6 and V7)
RED= plates (pin#3 for V4 and V5)
BROWN= Center-Tap (goes to the B+)

SECONDARY:
ORANGE= GROUND
YELLOW= 4 Ohms
GREEN= 8 Ohms
GREY= 16 Ohms

Hook the brown wire up to where the red wire (to the HT fuse) and choke wire are souldered to that corner turret. Unlike my pictue, keep the primaries and secondaries away from each other.

[vanhalen5150]

Ok, these trannys with different colored wires is really easy to make a mistake.

Also, the black and blue on the PT just go to the bottom of the Standby correct? Why are they colored different?

[vanhalen5150]

Where did you ground the Green bias winding wire from the PT secondary? Larry ground #5?

[Strat78]

Where did you ground the Green bias winding wire from the PT secondary? Larry ground #5?

run the green and white wires neetly around to the center of the chassis ( a sharp right against the chassis and another sharp right at the edge of the plate thingy and then a left turn down the middle of the chassis), twist them together after the left turn right up to ground #4 where you will attach the green wire. The white wire goes on to the bias tap. The black and blue wires respectively (on either side of the yellow Center Tap wire) go to the standby switch (attach to the two lugs closest to the chassis). Group the wires together like the two PI wires and the white bias and green ground right next to it, so you can identify them further down the chassis. Also, this picture shows a chassis with a 1998 OT, so don't go by those wire colors because they are different from the 132, but it has the same PT as yours.

[vanhalen5150]

Ok, so #5 has the rectifier(diodes). I don't understand it's other 2 connections, "1st filter ground" and "output cathodes".
I assume the 1st filter ground is the diodes as they are connected under the power board anyways?

Output cathodes ground? Aren't they already grounded via the tube sockets? Or is that just a suggestive variation?

[vanhalen5150]

Strat78, what were your voltages before adding power tubes? With just the preamp tubes in, where you getting pretty high voltages on V1 pin 1?

[Strat78]

Make sure it is not on standby. I got 157 on the last build and 137 on Ben's amp, but 550vdc is way too high!