Hello all,
I've just installed a VTA-70 on my ST-70. I'm not getting the voltages I should and I'm not sure why. Can cap is brand new 80/40/30/20 with the 80 at the back of amp.
Here's the numbers with rectifier tube installed power on:
Rectifier tube pins 2 & 8 480v pins 4 & 6 360v
Can Cap: All lugs are 485v even after the 2.2k resistor! Which I've checked numerous times and desoldered and re-soldered twice.
So if I install just the rectifier and the 2 EL34 right side tubes and check the bias which is suppose to be .60v it runs away from me and I have to shut it down. I've triple checked the wiring against the schematic and everything is correct. I've checked the diode that replaced the selenium and it checks out good. I'm lost.
Here's the picture from tubes4hifi's of the diagram.
Any help is appreciated.
I've just installed a VTA-70 on my ST-70. I'm not getting the voltages I should and I'm not sure why. Can cap is brand new 80/40/30/20 with the 80 at the back of amp.
Here's the numbers with rectifier tube installed power on:
Rectifier tube pins 2 & 8 480v pins 4 & 6 360v
Can Cap: All lugs are 485v even after the 2.2k resistor! Which I've checked numerous times and desoldered and re-soldered twice.
So if I install just the rectifier and the 2 EL34 right side tubes and check the bias which is suppose to be .60v it runs away from me and I have to shut it down. I've triple checked the wiring against the schematic and everything is correct. I've checked the diode that replaced the selenium and it checks out good. I'm lost.
Here's the picture from tubes4hifi's of the diagram.
Any help is appreciated.