All ok ? Trannies specs,Bias, Power tubes specs

[espinete]

Are you sure that the red wire to terminal 3 isn't actually red/orange?
It's just that you've already got 2 red wires from your PT going to the silicon diode tagstrip.

Sorry, the pin 3 red wire has a very small orange line i didn't see last night.

I've just tested green wires again with new tester cables. Same results, 2.7v each. Could be the fan ?

[Stevem]

Please note that when you do that Tremolo mod ( disconnect the wire) that the signal level hitting the phase inverter goes up like 6 db so I think part of your issue is overdriving that stage and the output stage very early!

[espinete]

Thanks but the problem was already before trem mod. As i think i said before, my two last super reverb style amps had same mods as this one. I mean: trem mod,disconnected normal channel switch, rectifier switch , nfb,.. except the fan and the vibrato channel brigth switch ( 2 modes of punch )

[pdf64]

I've just tested green wires again with new tester cables. Same results, 2.7v each. Could be the fan ?

Try putting one probe on to terminals 4-5 of V6, the other probe on to terminal 9 of V6.
Or across the 2 resistors at V4.
Expecting about 6.3Vac from one green wire to the other. Be careful that the probe tips don't slip off the terminal and short things out.
I suppose that the fan may be loading down the voltage but there's no evidence; what are the fan details, what is that green pcb I keep asking about?

If the red/orange wires were swapped for the red wires at the rectifier switch, then the HT and power tube plate voltage would be reduced about 30Vdc, eg to about 450Vdc.

Be aware that there are a few errors in your 1st sketch, of the power transformer and rectifier layout and wiring, eg red/blue wire should go to the bias supply board.

[espinete]

Thanks, now i'm going to do all that. The pcb looks like it is for the fan

[espinete]

Ups!! Now i hope it's correct

[espinete]

The pcb looks very odd. I asked the builder by mail.

Fan is 12v . One red and one black wires come from the fan and then they go to the fan switch and pcb circuit along with a yellow wire coming out from the switch.

[espinete]

Builder's answering about the mini pcb circuit :
"Yes, that's just a circuit of very low power that I made, it transforms the 6.3 volts AC of the filaments into 9 or 12 volts DC, to power the fan, nothing that affects the sound"

[espinete]

I've just tested green wires again with new tester cables. Same results, 2.7v each. Could be the fan ?

Try putting one probe on to terminals 4-5 of V6, the other probe on to terminal 9 of V6.
Or across the 2 resistors at V4.
Expecting about 6.3Vac from one green wire to the other. Be careful that the probe tips don't slip off the terminal and short things

5.9v

[pdf64]

OK the pcb mystery is cleared up now.

5.9V seems a little bit low but is within 10% of 6.3, so should affect tube operation.
It's best to measure at the actual terminals that the wires from the power transformer connect to; that's usually the front panel lamp.
It would also be useful to measure it with all tubes removed.
And also to measure your mains Vac at your wall outlet, eg 230Vac; just put the meter probe tips into the the 2 smaller holes of the outlet.

[espinete]

OK the pcb mystery is cleared up now.

5.9V seems a little bit low but is within 10% of 6.3, so should affect tube operation.
It's best to measure at the actual terminals that the wires from the power transformer connect to; that's usually the front panel lamp.
It would also be useful to measure it with all tubes removed.
And also to measure your mains Vac at your wall outlet, eg 230Vac; just put the meter probe tips into the the 2 smaller holes of the outlet.

*Pins 4-5 and 6 from v6 with fan off : 6.0v
*green wires from front panel lamp with or without fan working : 6.1v
*green wires from front panel lamp with no tubes : 6.4v
*wall outlet: 237v

[espinete]

I don't know if caps could be part of the problem or not. Anyway i'm gonna remove all 715's and i'll try tad mustard, Mallory, Sozo,.. but i don't know about smaller ones like treble tone stack 250pF cap. Suggestions are welcome

[pdf64]

I don't know if caps could be part of the problem or not. Anyway i'm gonna remove all 715's and i'll try tad mustard, Mallory, Sozo,.. but i don't know about smaller ones like treble tone stack 250pF cap. Suggestions are welcome

I really doubt that will be beneficial, and if you're not competent with doing such work, it risks causing problems.
A good tech should be able to investigate and analyse how the amp is working, so it may be best to leave it till then.
The builder may be able to advise why the amp's HT voltage are somewhat higher then you requested. As noted previously, the lower voltage red/orange HT taps will bring it down a little, but still likely will be way above 400Vdc.
The mains (slightly high) and heater (slightly low) voltages make the picture even more confused.

[espinete]

So, main ssues you're talking about are :
1. Plate voltage 485v when power tubes can handle 400v at maximum.
2. Green wires from lamp 5.4v instead of 6.4v.

????

I want to tell this to the builder. Then, if he can't fix it, i'll call the only good technician ( so far from home and very expensive. )

[espinete]

Should there be an union between these two points? Where the red line is.