[spurton@gmail.com]

I recently built the MP566-II Tube pre and when I first powered it on I could not get any sound out of it. So I removed it and discovered I had a solder bridge on the back of the header pins to the tube PCB. I fixed the bridge and ran it again. It puts out sound but very quiet, not enough to register signal but I can hear it faintly. It also distorts heavily when I turn up the gain knob or output knob. I know shorting leads can fry the ICs. Does this sound like what I did? If so I will order new ones. Thank you. 

[JPK]

Can you tell me which pins were shorted?
What results do you get from the voltages checks in the test guide steps 2 to 5?

[spurton@gmail.com]

I found 2 bridges which I fixed. 1 was between 2 joints that connect the main PCB to the tube support PCB. The other was on the HPF pot connection. I hooked up a signal generator at 1k 0.020v and used my oscilloscope to trace the signal after I fixed the bridges. I was getting no signal from TP3,4,5,6. TP2 had a slight signal. I replaced the U2 and U3 op amps and no signal. Here are the DC test values. So something is messed up somewhere. 
VO to V+ 16volts
VO to V- 0.817 volts
V- to B+ 13.8v
H+ to H- 18.96v
V0 to TP2,3 14.58v
VO to TP1 -0.003 v
VO to TP4 0.04v
VO to TP5 2.25v
VO to TP6 1.38v

😞