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Topic: Things you should know to maintain a tube amp |
Paul Sutherland
From:
Placerville, California
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Posted 14 Apr 2020 4:41 pm |
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Let me begin by saying I am NOT a qualified amp tech. But if you are going to play steel guitar through a tube amp I believe you should know how to do a few basic things.
My suggestions don't involve modifying anything, soldering anything, or poking your fingers inside the chassis. My suggestions are about as complicated as checking the oil in your car and adding a quart if it's low. Do you really need to pay someone to do that?
There can be a great benefit to knowing a good qualified amp tech, and having him or her give your amp an occasional once-over. I feel very fortunate to have Skip Simmons in my area; a recognized expert on Fender amps. So that's my first suggestion. Find out in advance who you can trust to work on your amp. And while they have the amp, ask lots of questions. Most techs seem to like to share their knowledge, to a degree.
For basic maintenance that you can do:
1) Know how to change tubes. It's really simple. Change preamp tubes one at a time until you find the culprit. When installing new power tubes always replace all of them, preferably with a matched set, and always reset the bias. And recheck the bias again after the new set of power tubes has been used awhile.
2) Read up on the sonic characterizes of different brands and models of preamp and power tubes, and have some spares ready to go if you encounter problems, like at a gig. Become knowledgeable about tubes.
3) Buy a basic bias gauge/tool and learn how to use it with your amp. Biasing some amps requires that you remove it from it's cabinet. Some can be biased without having to remove the chassis. (Thank you Milkman) You'll need to know what value to set the bias at. That's a whole new topic, but once you learn the proper value for your amp it's really a simple process to repeat it every time you reset the bias. You can ask your amp tech or builder for the value they use, then season to taste.
4) Know how to remove your amp chassis from it's head or cabinet. That's usually just four bolts.
5) Have a spare set of reverb cables just in case. You may never use them, but they are cheap.
6) Have some deoxit contact spray for noisy pots, and to spray a touch on the ends of tubes before inserting them in the sockets.
If you don't want to take on these responsibilities I suggest you use a solid state amplifier.
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It don't mean a thing if it ain't got that swing. |
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George Redmon
From:
Muskegon & Detroit Michigan.
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Posted 15 Apr 2020 12:05 am
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This is great advice for the novice, so glad you passed this along for the more inexperienced. So many are overwhelmed by tube amps it seems. Thanks paul.
Valve's Forever. |
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John Limbach
From:
Billings, Montana, USA
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Posted 16 Apr 2020 5:59 am
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| A bit more advanced than novice, but not too much. With most grid biased, push-pull tube amps, a simple circuit modification allows you to bias the output tubes individually thus negating the requirement for matched tubes in almost all cases. |
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Robert W Wilson
From:
Palisade, Western Colorado
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Paul Sutherland
From:
Placerville, California
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Posted 16 Apr 2020 7:34 pm
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I don't know what to make of articles like you've presented Robert. I don't understand most of what he's saying. As I said, I'm not an amp tech.
I use the standby switch when first turning on a Fender style tube amp, and when taking breaks on stage or at home. I was told by Skip Simmons that I only need to give the amp about 10 seconds on standby when first turning it on. Some seem to be saying not to use standby for extended breaks once the amp is up to temperature. Someone on the forum said it's better to leave the amp fully on, but turn the volume off during those breaks. But I really don't know what's best.
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It don't mean a thing if it ain't got that swing. |
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Tony Prior
From:
Charlotte NC
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Posted 17 Apr 2020 1:19 am
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I would just add that if you DO PULL THE CHASSIS you have both AC Line voltage and very HI + DC volts running around, (+435 and higher) if you do not know where those points of contacts are, DO NOT PULL THE CHASSIS, you can get seriously bit. Each leg of those Power Supply Filter caps have HI DC on them, please be aware .
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Emmons L-II , Fender Telecasters, B-Benders , Eastman Mandolin ,
Pro Tools 12 on WIN 7 !
jobless- but not homeless- now retired 9 years
CURRENT MUSIC TRACKS AT > https://tprior2241.wixsite.com/website |
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