Gibson EH150 Amp Repair

Nice custom made case!Nice custom made case!DSC_0348Lovely and she smells vintageLovely and she smells vintageDSC_0350DSC_0380DSC_0381DSC_03775U4G, 3x 6C5 and a 6P55U4G, 3x 6C5 and a 6P5DSC_0394DSC_0378Speaker connector nice...Speaker connector nice…All sockets etched with the valve the amp was design for for that slotAll sockets etched with the valve the amp was design for for that slotDSC_0386DSC_0387Fairly neat layout and wiring (all cloth covered) nice sheilding on sensitive wiring in the preampFairly neat layout and wiring (all cloth covered) nice sheilding on sensitive wiring in the preampAll electrolytics have been replaced and some resistors..All electrolytics have been replaced and some resistors..Does the jobDoes the jobMmm one 47K resistor here should be 100KMmm one 47K resistor here should be 100KDSC_0392DSC_0393After going through eliminating all the possible causes of crackling it turns out this "mod" capacitor added across the output transformer inputs was causing the problem! removing her and we are back to his and crackle being well under the general hum level! Always look for mods to find where problems may be coming!After going through eliminating all the possible causes of crackling it turns out this “mod” capacitor added across the output transformer inputs was causing the problem! removing her and we are back to his and crackle being well under the general hum level! Always look for mods to find where problems may be coming!All Resitors more than 20% out in value have been replaced and a decoupling capacitor added to the microphone stage (as was originally there)All Resitors more than 20% out in value have been replaced and a decoupling capacitor added to the microphone stage (as was originally there)All together and tested good. Little more gain niow in the microphone input that sounds great for guitar ;-)All together and tested good. Little more gain niow in the microphone input that sounds great for guitar 😉 Gibson early 40s tube amp… simple and lovely is crackling a bit quietly…

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