Peavey 5150 ii SGR Replacement Help

metalfan1212 · Post by **metalfan1212** » 21 Dec 2011, 22:43

I had a tube fail and fry a screen grid resistor in my 5150 ll. I've already ordered the new sgr's 470ohm/5watt and want to replace them all. I'm pretty good with electronics, soldering etc. but I'm not sure of the location of the resistors. I'm a complete noob at schematics but I really want to do this myself so I can learn along the way. I'm aware of the potential danger present without draining the juice. I know I can do it with some assistance. I also want to add a choke as well. Anyone care to guide me in the right direction? Thanks a ton in advance.

metalfan1212 · Post by **metalfan1212** » 22 Dec 2011, 00:30

Nevermind about the SGR's. I found them today hiding under the board. I would still appreciate some assistance with the choke though. Which resistor does the choke replace?

blackbunny · Post by **blackbunny** » 22 Dec 2011, 02:56

The choke replaces the 400 ohm 10 watt ceramic resistor, R210 on the 5150 PCB. May be a different number on the 5150 Mk2.

phatt · Post by **phatt** » 22 Dec 2011, 09:44

You say you had a tube fail and fry a screen resistor.
(I'll assume you mean power tube)

Humm,,, My guess is the Amp has issues ,,, likely due to a design flaw.

IMO,,,Not the kind of Amplifier you want to learn from as it could turn into an $expensive$ learning curve.

Phil.

DrNomis · Post by **DrNomis** » 22 Dec 2011, 11:32

Just be careful to completely discharge the power supply filter caps before you do any work on the amp, otherwise you could be risking death by electrocution....