Would someone please please help!? I want to make the internal TVR1, TVR2, TVR3 and TVR4 pot settings adjustments after changing the 4 tubes in my SRM-007tII without blowing anything up. I am not an engineer but I am capable of following step-by-step instructions. I have 1 question. Is KG’s outline all I need to do? It seems simpler than the JimL11 + ColoradoTom outline. Many thanks in advance!
KG Outline
- Start with control pots set to the middle
Repeat the following a few times over 30 minutes
- Put voltmeter probes between TP1 and TP2 and adjust TVR1 for zero
(if you have to turn tvr1 more than .25 turn in either direction, stop and get new tubes)
-Then put a voltmeter between either TP1 or TP2 and Ground and adjust TVR2 for zero
-Then put a voltmeter between both TP1 and adjust TVR3 to zero
-Then put a voltmeter between both TP2 and adjust TVR4 to zero
end repeat
JimL11 + ColoradoTom outline
1. TVR1 adjusts voltages between + and - outputs for each channel
a. Insert positive probe into slot labeled “L+” and insert negative probe into slot labeled “L-”.
b. Adjust potentiometer labeled “TVR1” for the left channel. The potentiometer is EXTREMELY sensitive and the meter reading will have a tendency to drift around a bit. The goal is to get under 1 volt.
2. TVR2 adjusts the voltages of the outputs to be close to zero volts with respect to ground
a. Leave positive probe in slot labeled “L+”
b. Remove negative probe from slot labeled “L-” and attach to ground at back of amp. The goal is to get under 1 volt.
3. By alternating negative probe between ground at back of amp to slot labeled “L-” recheck and adjust TVR1 and TVR2 respectively
4. TVR3 and TVR4 - they adjust the plate voltages for the two sections of each 6CG7/6FQ7 to be equal to each other. Connect a voltmeter between both TP1 points or both TP2 points and adjust TVR3 and TVR4 so that the voltage between the two is zero.