What exactly is the problem?
Also, sign into SLOCLONE That forum is a bit dead and it might take a day to get a reply, but those guys over there know amps.
This is the email I sent yesterday to fryette support.
Hello sir,
this is my last desperate attempt to get my broken Sig X working. My tech guy has been working on it for a very long time. I had even borrowed another SigX head from my friend and he had made some progress with it. But he could not do more without your help. Here are his notes about the problems with the amp.
He had to replace several resistors in the poweramp section - TIP50, LM317, Zener diode. But there are 3 problems.
1. The high voltage drops cca 100V down every second on R152 and then return back to full voltage when all tubes are in. When he take out both PWR tubes or one - two ECC83s (V1 - V5, doesn't matter which one), the high voltage stays high on R152.
2. There is 180V voltage drop across R150 (22k measured) and only 30V across R152 (3.7k measured, even with 3.9k tried). Only 1V drop between legs of LM317 (new one).
3. The GAIN II boost RED LED stays on all the time and GAIN II boost YELLOW LED stays off all the time. The channels could be switched but the RED boost LED is lit even when the yellow channel or clean channel is selected.
In the e-mail attachement are his notes about measured voltages. He had done over 10 hours of diagnosis, parts replacement, valve measurements, voltage measurements, basic schematics drawing. But he is now at the end with ideas. He would be very glad for your help or partial schematics (power section, output section, channel and boost switching).
Could you please help us? Or do you have any official service center in Europe? I'm really desperate now. If there is a fee for your help I am willing to pay it.
Thank you