Advice for restoring an older twin reverb

[RBHan]

I'm looking to refurb a 73 Twin. Any recommendations on Cap and Tube Kits? I'm not looking for anything esoteric or super high performance...just get it back into shape. IT's never been retubed or capped....though aside from some very scrtchy pots..doesn't really sound too bad. How involved is re biasing? It does have a output tubes balance and hum balance adjustment pots on it. I've checked E-bay for kits and they all seem about the same.

[tyguy335]

Originally Posted by RBHan

I'm looking to refurb a 73 Twin. Any recommendations on Cap and Tube Kits? I'm not looking for anything esoteric or super high performance...just get it back into shape. IT's never been retubed or capped....though aside from some very scrtchy pots..doesn't really sound too bad. How involved is re biasing? It does have a output tubes balance and hum balance adjustment pots on it. I've checked E-bay for kits and they all seem about the same.

Depends how much electronic experience you have really as it should involve rem oving the tube balance and hum balance controls.The amp can't be biased correctly with this setup and will sound remarkably better with the blackface setup.In fact the whole amp should be set up to blackface specs.The wiring layout is horrible in these amps and the power tubes have 2000pf supression caps(supresses highs)to ground which allowed sloppy wire layout!You might open a can of worms removing these caps or you might get lucky and have no parasitic oscillation!My advice find a tech to blackface it for you.If you do decide to tackle this make yourself a current limiter.Simple and cheap as it's a light bulb in series with your amp.How to build is online and Gerald Weber is one source.If you do not use this tool,more than likely, you will smoke:transformers,speakers,tubes,all the expensive stuff and then blame whover for your errors!I have a souped up '73 Super Reverb that was same as your twin with all the nasty parasitic suppression parts.Mine sounds great as has Mercury Mag transformers and other great sounding mods!!The Best to you!Oh Yes,by all means be aware of deadly dc voltage and work with one hand in pocket!Just get a tech to do it!!!

[nedorama]

If you're familiar with electronics and understand the schematic layouts on Ampwares, you can look into doing it. It's not that hard.

If you are at all uncomfortable, I'd go to a tech. by asking about how hard is re-biasing, I'd suggest you go to a tech -- they'll be able to tell you what parts are out of spec, and if you do want to return it to blackface specs, great; you also may be very happy with the clean nature of your amp.

For filter caps, I've used a combo of Sprague and F&T in my Showman rebuild for theand am very happy. For tubes, Groove Tubes 6L6 GE work great. Treat yourself to a Mullard CV4024 in the Phase inverter preamp slot - it's a great upgrade and makes a big difference.

Let us know where you are and we can suggest Fender amp techs that we've had luck with; I've had very good luck with my guy in the South Bay CA.

[RBHan]

Thanks much for the responses. I'm fully comfortable with component replacing and general mechanical end of things... but I'm not savey with the electrical engineering end. I do have a good resource near by though. I was thinking that it was straight up replacement soldering and cleaning sockets and such, but I think that if I'm putting a few bucks into it I might as well take it up a notch. Too bad that I used to live in the South bay years ago, and this amp was dragged back and forth across country a few times.

[nedorama]

Still a great amp, and definitely worth the time, effort and dollars to keep it running in top condition. Think of it as your 100,000 mile checkup.