Old Fender Amp Maintenance

Kevin Bullat · Post by **Kevin Bullat** » 11 Nov 2005 9:53 pm

My father gave me a early '60's Fender Delux amp. I replaced the tubes and the speaker (as it was damaged), and it plays fine for about a half hour. Then it starts to make popping sounds and other noises.

I'd heard about something called 'biasing' the amp. Is that what I need to do with this one?

P.S. It also has no ground on the plug, only a polarity switch. Should I install a ground plug?

Thanks for any info.

Jerry Erickson · Post by **Jerry Erickson** » 11 Nov 2005 10:42 pm

Kevin,
Your amp is in need of some routine maintinence. A grounded plug would be a good addition. Also having the electrolytic capacitors replaced in the power supply,bias supply and on the cathodes of the preamp tubes would be a good thing to do. Having these replaced will let you find out if there are any other components that also need replacement. Is it brown or balck tolex covering?

Al Carmichael · Post by **Al Carmichael** » 11 Nov 2005 11:45 pm

Kevin--You want to probably get the amp to a tech who knows these amps. I second all Jerry says and would add that there are probably some resistors that drop the voltage that go to the preamp tubes that are probably needing replacement. As the amp warms up some of the components are experiencing fatigue I bet.

That old deluxe is a real nice vintage amp and its definitely worth taking to a pro who works on Fender tube amps.

Jim Sliff · Post by **Jim Sliff** » 11 Nov 2005 11:48 pm

What Jerry said is essential, plus adding a 3-prong plug for safety reasons. The ground switch should be completely bypassed if done properly.

Retubing a vintage amp without checking/replacing filter and bias capacitors and proper biasing is a great way to blow an output and power transformer - the most expensive...and heart and lungs...of the amp.

ALL...repeat ALL...tube amps 20 years old or older should have had those caps replaced. If it hasn't been done, get it done now before the amp is damaged...and it almost assuredly will be.

Kevin Bullat · Post by **Kevin Bullat** » 12 Nov 2005 9:39 am

Jerry,

It's brown tolex. My step-father was a country-western guitarist in Tucson when I was a kid.

He bought the amp in '63 and a '56 Gretch Silver Jet. He gave me both as he knows I'd take care of them.

Thanks for all the information folks!

Jon Light · Post by **Jon Light** » 12 Nov 2005 9:46 am

think of the electrolytic caps like the oil in the engine of a 40 year old car that has been sitting in a garage. Even if it has zero miles on it, you would never crank it without changing the old oil out and refilling with fresh stuff. Even old caps with no playing time on them have a limited lifespan, whether on the shelf or in an amp.
that ought to be a fine sounding amp when it gets its maintanence. Nice score.

Jerry Erickson · Post by **Jerry Erickson** » 12 Nov 2005 10:46 am

Nice rig Kevin!!! I'm sure there are a few of us who'd like to see some pics of those two.

Papa Joe Pollick · Post by **Papa Joe Pollick** » 12 Nov 2005 4:06 pm

Yes Kevin,,all the above.Be sure the work is done by someone who knows TUBE amps. Have them clean and tighten the contacts on the tube sockets too.Then replace the speaker with a newer design quality speaker..[save the orginal to retain the vintage value].I have a 62 Deluxe,so I've been there.After getting it all tuned up,the speaker sounded like crap.Replaced it with a celestion and now it's a ball buster amp..Great for blues and traditional rock & roll..One of the best tremolos I've ever heard..I'm takin mine with me when I go.
P J

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