Tube amp question

[Don W]

I have 2 nice Fender tube amps. A Hot rod Deluxe and a Deluxe Reverb reissue. I love these amps for use with my electrics but have been playing solo acoustic fingerstyle almost all of the time so my amps are not getting much use. Does it hurt the amp to be un-used for a period of time (maybe 6-12 months) ? I don't know much about tube amp maintenance.

[printer2]

It would not hurt sparking them up once a year or two but otherwise no worries.

[rmp]

you should have no worries for this.

as long as they are in a dry environment, should be A-Okay

[Charlie Bernstein]

Your tubes and speakers don't need exercise, but other little components can lose their zest if they don't get used. Printer2's advice is good. Use the amps once or twice a year just to keep the cobwebs out.

Rmp is right, too. A dry room or closet is mandatory.

[Don W]

Thanks all...you put my mind at ease.

[printer2]

Originally Posted by Don W

Thanks all...you put my mind at ease.

The only parts that need "exercise" is the electrolytic capacitors. The voltage reforms the insulating oxide layer in the capacitor. The capacitors should be replaced every 25-35 years to keep the amp running its best. The amps can be played without replacing the caps, some have lasted 50 years. By applying voltage to the amp every few years lengthens the time the parts need to be replaced by.

[Wardo]

What Fred said above.

But turn all the knobs back to O while in storage so that the amps won’t need a reset down the road.. lol

[stokes1971]

If no current passes thru the power filters they dry out and will fail, not a pretty thing when they do. I have been repairing tube gear since 1969 and have built roughly 25 or 30 tube amps that me and my sons have. I make sure to power them up once a month and change the filter caps every 10 yrs or so. Not necessary to actually play the amp, just power it up for a half hour to an hour. While they will last beyond 10 yrs, after 10 they do deteriorate to a degree. Back in the late 90's I posed a challenge on a Mesa Boogie forum that if their caps were over ten yrs old, I would change them and if there wasnt a marked improvement in the bass and overall response I would put the old caps back and not charge for the service. Over the next couple years I got 50 or 60 takers and every one was stunned with the improvement. As the caps begin to lose effectiveness the change is very gradual and your ears just get used to it and you usually wont notice until you change them. Powering it up a couple times a year is probably good enough, I worked for a TV repair shop in my teen years and he told me once a month, so thats what I do.

[Jamolay]

Every so often turn ‘em up to 11.

[printer2]

Originally Posted by Jamolay

Every so often turn ‘em up to 11.

"But the knob goes to 12." (Tweed all the way)

[mtdmind]

I fire up my Princeton Reverb 1 or 2 times a year. I mostly use my Katana or my Yamaha G112 50

[Steve DeRosa]

Originally Posted by Don W

I have 2 nice Fender tube amps. A Hot rod Deluxe and a Deluxe Reverb reissue. I love these amps for use with my electrics but have been playing solo acoustic fingerstyle almost all of the time so my amps are not getting much use...

Why not - IME an old-school American-voiced electric guitar combo (like your DRRI) is just the ticket for a piezo UST-equipped guitar, since its natural response characteristics (frequency rolloff above ~ 5kHz, midrange scoop in the 1-2kHz range) filters out virtually all of the sonic nasties as long as you use the low-gain input...

[edward993]

Originally Posted by printer2

The only parts that need "exercise" is the electrolytic capacitors. The voltage reforms the insulating oxide layer in the capacitor. The capacitors should be replaced every 25-35 years to keep the amp running its best. The amps can be played without replacing the caps, some have lasted 50 years. By applying voltage to the amp every few years lengthens the time the parts need to be replaced by.

Oooh, good read and excellent to know.
Fwiw, I've got a Boogie that is original (minus tubes) from the early 90s and sounds glorious today as it did when I got it, and not given me any hint of trouble, not even a noisy pot, except for one jack that started getting iffy. I play this amp (and another Mesa) regularly. Thanks for the info, I hope I am in the 50-year camp!

Edward

[jseth]

Originally Posted by stokes1971

If no current passes thru the power filters they dry out and will fail, not a pretty thing when they do. I have been repairing tube gear since 1969 and have built roughly 25 or 30 tube amps that me and my sons have. I make sure to power them up once a month and change the filter caps every 10 yrs or so. Not necessary to actually play the amp, just power it up for a half hour to an hour. While they will last beyond 10 yrs, after 10 they do deteriorate to a degree. Back in the late 90's I posed a challenge on a Mesa Boogie forum that if their caps were over ten yrs old, I would change them and if there wasnt a marked improvement in the bass and overall response I would put the old caps back and not charge for the service. Over the next couple years I got 50 or 60 takers and every one was stunned with the improvement. As the caps begin to lose effectiveness the change is very gradual and your ears just get used to it and you usually wont notice until you change them. Powering it up a couple times a year is probably good enough, I worked for a TV repair shop in my teen years and he told me once a month, so thats what I do.

Once a month... that's the same thing that my local "Tube Amp Savant" told me when he worked on my '76 SF Deluxe Reverb... it's also the same thing I have been told by several other men who were BRILLIANT with tube amplifier tweaking and repairing.

Easy enough to do to ensure the continued longevity of my wonderful Deluxe!

[jonfields45]

OK, now you're gonna hear the same thing from a full blown electrical engineer with experience in reliability, in addition to getting stuff designed in the first place.

The insulation in an electrolytic capacitor, between the positive and negative terminals, needs to be (re)formed by periodically powering them up. A couple times a year should be plenty.

When these capacitors fail, they short out, the short burns up, and the capacitor is still there with a slightly lower value. Generally this can go on for quite a while before it is so low in value that you can hear it (I used to refer to it as fart mode if it’s the main power supply caps). They also do less often fail catastrophically (that short doesn't burn up fast enough) which can be quite a show when you look inside the amp.

None the less, this is all fixable and something I never concerned myself with back in the days when I owned tube amps. Just play and enjoy.