a friend of mine had put a fender bassman to repair on local guy. but he didnt check the amp properly. he retubed it and changed all the power supply caps fixed the bias section and bla bla bla but now it has LOTS of gain. it distorts BADLY i0m tring to get the gain better but that new ( sovtek ) tubes are hungry for gain.
i have about 140 / 150V feeding the preamp tubes and the cathode resistor is now 2K2 ohm. it has less gains but stil has to much.
sould i uze a kind of voltage divider on each gain stage of this amp ? or what kan a go better ? are the preamp tubes 'cold' with 150V ? anr with 2k2ohm on the cathode ?
The schematics are at
http://www.schematicheaven.com/fenderamps/fender_bassman50.pdf
on the last gains stage before the phase spliter i get the cleanest sound that i ever heard.
so the gain problem is before that.
please help
i home i'm clear enough.
tankx in advance ^^
i have about 140 / 150V feeding the preamp tubes and the cathode resistor is now 2K2 ohm. it has less gains but stil has to much.
sould i uze a kind of voltage divider on each gain stage of this amp ? or what kan a go better ? are the preamp tubes 'cold' with 150V ? anr with 2k2ohm on the cathode ?
The schematics are at
http://www.schematicheaven.com/fenderamps/fender_bassman50.pdf
on the last gains stage before the phase spliter i get the cleanest sound that i ever heard.
so the gain problem is before that.
please help
i home i'm clear enough.
tankx in advance ^^
bassman 50 head, 1973
obviously missing a resistor to ground or a wrong value's been fitted, could be a faulty capacitor or bad valve. you can't really go wrong these are such simple circuits.. you can e mail a close up of the amp i'll have a look, or send it to me with the valves and case removed and i'll fix it. (you pay carriage both ways though..)
obviously missing a resistor to ground or a wrong value's been fitted, could be a faulty capacitor or bad valve. you can't really go wrong these are such simple circuits.. you can e mail a close up of the amp i'll have a look, or send it to me with the valves and case removed and i'll fix it. (you pay carriage both ways though..)
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