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Changed all four(4) preamp tubes. Volume increased but still no compressor. 
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The tube for the compressor is supposed to be a 12AT7/ECC81, was there one?
Does the compressor light come on when playing hard and compressor turned up?Originally posted by Enzo
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There was an ecc81, replaced it with a 12ax7 and the light does not come on when playing hard and compressor turned up.Originally posted by g1 View PostComment
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12at7 ok to replace with 12ax7 on a compressor driver?Comment
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I would think it should work for testing purposes. At least you know which position is the compressor tube.
If it didn't work with either one, put the 12AT7 back in. Are it's heaters lighting up? If so,check DC volts at it's pins 1,3,6,8.Originally posted by Enzo
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V1-pin1/3/8(MVDC) pin6(+12.4vdc)Originally posted by g1 View Post
V2-pin1(MVDC) pin3(-1vdc) pin6(+12.4vdc) pin8(-1vdc).
V3-pin1/3/8(MVDC) pin6(+49vdc)
V4-pin1(MVDC) pin 3(+184vdc) pin6(+36vdc) pin8(+120vdc).
Didnt pay attention that there was an ecc81 mixed in so dont know what position it is. Maybe the voltages will point to it?Comment
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Compressor tube is supposedly 2nd from left when looking at front of unit. Is that the one you are calling V2 ? Do they all light up and feel warm?Originally posted by Enzo
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Yes, they all light up and feel warm. Yes V2 is 2nd from left when looking at front of unit, labeled V2 on board.Originally posted by g1 View PostComment
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Not a lot can be done with this having no schematic. Pin 1 of V2 seems to have no voltage going to it sot that may be somewhere to look. Normally I would expect a resistor there connecting it to some supply voltage.
Might be worth trying a re-solder of the V2 socket in case it's just a bad solder connection causing the problem.Originally posted by Enzo
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