Does my Pass amp dislike my Meridian preamp?

Hi Bryon,

Sorry to hear of the further problems.

If I understand correctly, the G68 feeds left and right preamp-out signals into the Pass, and a center channel signal to a separate amplifier which drives the now damaged center channel speaker. And the signal path through the Pass to the left and right main speakers continues to function ok, apart from the intermittent freezeups in the G68.

Given that, my initial skepticism that the Pass could be the cause of the G68's problems is now increased to the point where it strikes me as complete nonsense.

If significant dc offset, or some other anomaly, were to have been fed back from the input circuit of the Pass to the output of the G68, it seems unimaginable to me that it would have caused a problem affecting the center channel speaker, to which the Pass is not connected, without also damaging the output circuit of the G68 that drives the Pass.

With respect to applying your multimeter to the problem, what I would suggest is that you disconnect all of the outputs of the G68, turn off all source components which are connected to it, and see if you can detect significant voltage at its output that had been driving the center channel. Try that with both the dc voltage and ac voltage functions of the meter.

Best regards,
-- Al

If I understand correctly, the G68 feeds left and right preamp-out signals into the Pass, and a center channel signal to a separate amplifier which drives the now damaged center channel speaker. And the signal path through the Pass to the left and right main speakers continues to function ok, apart from the intermittent freezeups in the G68.

This is all correct.

I used my multimeter on the Meridian G68 outputs and the Pass amp inputs, and here are the results:

Meridian G68 outputs:
DCV = 0
ACV = 1V (accuracy of meter is +/- .5ACV)

Pass amp inputs:
DCV = 0
ACV = .7 (accuracy of meter is +/- .5ACV)

Sorry, term I meant was PIC (programmable interface controller).

Bryon, 1.0 and 0.7 volts ac should certainly not be present at those points in the absence of signal, but I'm wondering if those readings might be due to meter inaccuracy.

Is the +/- 0.5 volt tolerance really the meter's specified accuracy, or is it the resolution of the measurement, in which case the accuracy could be and probably is worse than 0.5, and might account for the entire 1.0 volt reading?

What reading do you get if you touch the two leads of the meter to two different points on the chassis? Perhaps the meter is responding to emi being picked up by the leads.

Also, were you measuring at rca connectors, or xlr connectors?

If rca, did you connect the return lead of the meter directly to the ground sleeve of the rca jack being measured, or to some other presumed ground point, such as chassis?

If xlr, did you measure directly between pin 2 and pin 1, and pin 3 and pin 1, or was the return lead of the meter connected to some presumed ground point other than pin 1?

Best regards,
-- Al

Disconnect it from the amp or try a different amp and see what happens.