I’m fortunate that 10 years ago I was able to acquire two Ampeg Port-A-Flex bass amps for reasonable prices: a 1974 (+/- a few years) B-15N and a 1966 B-18N. I regularly play the B-15 because I like its tone, but I’ve never warmed up to how the B-18 sounds. So the 15 is always ready to use, but the 18 is always in a corner, packed up and covered up. Does it harm a 50+ year old bass amplifier to sit unused for years in a climate controlled environment?
You should drag it out maybe once a month or so and play though it for a while. I agree that there is something special about the B15N but don't lose sight of what's hiding away inside that B18N.
Yes, I think they are somewhat like cars. It is a good idea to fire them up occasionally. I have a V4 and a VT22 which seldom get energized, particularly now with Covid. Tell you what: You could send that B18 to me and I would provide this service to you free of charge.
I tend to bust mine out every year at least, just so I can breathe a little easier and keep the caps in good shape.
I have 28 amps and try to rotate through all of them a couple of times every year. Mainly it's to keep the dialetric in the electrolytic capacitors conditioned. I have one amp that has an output tube that apparently has a slow leak. Every time I put the amp into it's playing rotation, it pulls a little extra current and hums like the output tubes are out of balance. After a couple of hours, it goes back to normal. When I installed the tubes I noticed one of them was extremely drifty... I should have sent the set back . If I let this amp sit unplayed for too long, the current in the drifty tube could potentially get too high; so this amp gets a bit more attention than the others. I always play it on a variac with a built-in ammeter, so I can monitor the total current draw.
My first and only Ampeg was a 1966 B18 because it had a bigger amp than the B15 .. Still didn't cut it with a rock band but I do miss the pant flapping 18.
I deployed over seas for 10 months last year. Guitar amp (jcm800) didnt get touched since I left. Came home, covid happened shortly after. Had band rehersal yesterday and it was the first time that jcm800 got used in a year and half, worked just like normal.
I think it's more important to keep any potentiometer controls (tone, volume etc.) periodically rotated across their full range, than it is to charge tubes or capacitors.
For it's life, that it's gonna be no long any more, i don't think You should turn it on often. Leave it as backup.
I found this on the internet so it has to be true. Of course I am kidding but these kinds of statements are all over the place. "If an electrolytic capacitor is simply unused for an extended period of time, the dielectric will degrade; the longer it is not used, the worse the dielectric becomes. The capacitance is reduced, and the leakage rate increases. If the leakage rate becomes excessive, there will be enough power dissipation in the package to cause the electrolyte to boil, rupturing the package forcefully." I tend to trust Agedhorse so Every year or two is probably good but I personally fire everything up once a month.
My experience is that with reasonable quality caps, this is a greatly overstated issue. it may have been more true 50-60 years ago, but even then when the parts were used within their specifications it wasn’t a big deal. where designs didn’t respect the part’s real world limits, failures would occur but this is more a design issue than a part issue IMO.
I've thought about selling it. If I do, I'll wait until the pandemic is passed and people are rehearsing and gigging.
It isn’t just tube amps that should be used occasionally. It applies to solid state ones as well. Any amp that has electrolytic capacitors.
Decision Made: There is a sound reinforcement company here in Richmond, Virginia that I like, and they have their own recording studio in their building. I’ve loaned them the B-18 to use in the studio. It’s there if I need it, and hopefully it will get used and appreciated. It is a good sounding amp and I’ve done a lot of jazz combo gigs and some recording with it, but it’s always the runner up to my B-15.