Need technical assistants on 69 build,

redozzman · Post by **redozzman** » Sat Mar 10, 2007 12:17 pm

Amp has sounded fantastik the last week but last night the amp started sounding thin losing bass response. I started checking the voltages against my first readings and everything is in line except pin 8 on V3 all my readings are about 10/15% higher than the base line readings that are provided by Metro, I am getting 38 on that pin when I first took readings I was getting 43. Could this be causing my problems with bass response. Could I have a bad resistor. The power tubes are new and I swapped out all pre amp tubes to make sure one of those was not causing the problem. All my other readings seem to be inline with the metro voltage chart it seems to be pin 8 V3 only.

The amp has been sounding great and I want to keep it that way. ANy suggestions ?

Wicksy · Post by **Wicksy** » Thu Apr 12, 2007 8:58 am

Have you checked your bias? New stock power tubes can drift a lot if they ahvent been burned in then matched.

Flames1950 · Post by **Flames1950** » Thu Apr 12, 2007 6:36 pm

I would doubt it has anything to do with V3 pin 8 either. The tubes or the bias.........