Hoffman Amplifiers Tube Amplifier Forum

Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: punkykatt on November 17, 2014, 06:50:06 pm

Title: Ampeg Reverberocket
Post by: punkykatt on November 17, 2014, 06:50:06 pm

Hey guys, got in a Ampeg Reverberocket for service, cleanup , three conductor cord, and cap job. Should I add 470 ohm screen grid resistors to the 7868 power tubes?

http://el34world.com/charts/Schematics/files/ampeg/Ampeg_reverb_rocket_12rt.pdf (http://el34world.com/charts/Schematics/files/ampeg/Ampeg_reverb_rocket_12rt.pdf)

Thanks Punky

Title: Re: Ampeg Reverberocket
Post by: AZJimC on November 17, 2014, 07:04:13 pm

Just my opinion, but I would. I think it adds a layer of extra safety, and no real negative. I use 1K on my 7591 amp, same tube in an octal base. I also have a 10k, across a switch, on screen feed prior to the union of the 1K resistors that allows me to switch in and out a bit of sag and compression.

Title: Re: Ampeg Reverberocket
Post by: moonbird on November 19, 2014, 12:58:18 pm

AZ -


I have a 7591-based Ampeg I need to restore, would you mind posting a quick schematic of the switched resistor you are describing? Can't quite picture it.  :think1: Thanks.