Do you leave your rig switched on?

[John Wentzien]

Some amps can make a nasty pop through the PA when switched on or off. I've seen people actually blow the horns out in the mains and moitors when they forgot to mute the channel at the board.

 

[deaf pea]

...(most) failures occur during switch-on...

In my 37+ years working in "professional" recording studios, I've noticed that the consoles are NEVER tuned "off" (except for scheduled maintenance) for just that reason . . .
When I have asked various maintenance guys "why?", thay ALL have said the same thing!

"Most failures happen when you turn something on".

FWIW, I was also taught that you SHOULD turn "off" tube equipment if it's NOT going to be used for 10 hours (or more) . . .

 

[seanm]

at Bass Emporium when they get a new head, they hook it up to a random cab and just turn the thing on and leave it on all day to see if anything will happen. i don't quite now why they do this, but if they leave these things on for at least 8 hours, then i don't see the harm in leaving your stuff on for a half hour. yeah, fuses blow, but they could do it at anytime. can't help that.

It's called a burn in. It *should* be done at the factory, they obviously have found otherwise.

 

[hbarcat]

Tubes are thermally stressed by being cycled off and on and this shortens their life span. They're also stressed (though to a much lesser extent) by simply being on. It's generally considered better to leave a tube amp powered up, even for several hours, than to turn it off and then back on. Most recording studios leave their tube gear on all day and only turn it off at night, and some even leave their solid state gear on perpetually, although they always have sophisticated protections on their regulated power supplies.

I can't vouch for the wisdom of this as I'm not an electrical engineer, but I've heard several engineers say this is their practice and I've read interviews with engineers and studio technicians who say this as well.

Maybe QSC Bob has an opinion on this.........

 

[SteveC]

On and muted - Neo-Pak.

 

[A9X]

Tubes are thermally stressed by being cycled off and on and this shortens their life span. They're also stressed (though to a much lesser extent) by simply being on. It's generally considered better to leave a tube amp powered up, even for several hours, than to turn it off and then back on. Most recording studios leave their tube gear on all day and only turn it off at night, and some even leave their solid state gear on perpetually, although they always have sophisticated protections on their regulated power supplies.

The filaments in tubes are similar to incandescent light globes. There are always microfractures in them during manufacturing, and these areas get slightly hotter than the rest of the filament and so it stretches slightly and thins out. Eventually as this gets worse over time with on/off cycles the necked section will get too thin and fail, going open circuit. Filaments have the lowest resistance when cold, and therefore draw more current; that's another reason for failyre at turn on. There is a name for this but it eludes me at the moment.

In some tubes, because of design and/or manufacturing tolerance, suddenly applying the HT to a cold tube can cause enough deformation in the physical structure that there can be a short or breakage caused in an element, therefore failure of the part and sometimes the surrounding circuitry. Do this enough over time, and there will be a failure. There's lots on both these issues in the old military reliability data.

All my hifi tube amps have tons of solidstate in the; to slowly bring the cathodes up to temperature over 2 mins or so, the slowly bring the B+ (HT) up, then the biassing. The tubes get a very gentle time and long life. None of this is hard to do, but to do it well is expensive enough for the modest scale of construction of tube power amps that it would likely add a decent amount to the sale price. Besides, a lot of 'purest', who usually don't have a clue, don't like any SS in amps, even if it's not in the signal path.

My new tube hifi preamp will likely never be turned off, but the poweramps will as sometimes I don't use the system for a couple of days, and it's quad-amped, with all but the sub (<60Hz) tube.

 

[jokerjkny]

for tube stuff, i just leave it on standby...

for SS stuff, i'll leave it on, cause i learned the hard way that sometimes, the DI will make that annoying fizzying, "air escaping a balloon" like sound.

btw, anyone know why that happens with some amps and their DI's?

 

[Nakedfish]

I like to have my amp switched on/muted for at least an hour before the first set.

To my ears it always sounds richer if I do this rather than simply switching on right before I play. It's solid state so as far as I'm aware there isn't a technical reason for this, but I can definitely hear the difference.

 

[Brad Maestas]

When I had tube amps, I would try to power up well before soundcheck and let it warm up if I could, then leave it on standby when I wasn't playing through it. I would also make it a point to let the amp cool before moving it around.

With my SS amps, I try to let them warm up a bit too before hitting them full on. Since most of my gigs consist of setting up as quickly as possible, playing for an hour and then tearing down as quickly as possible, I usually don't have the luxury of letting them warm up which is fine. I might turn it off when there's more than an hour break between soundcheck or sets. They seem fine either way.

 

[Sean S]

Okay, here's a question I haven't seen in this thread yet. When switching to standby, is there any possible damage/popping/etc. when using a DI from a tube head? For example, I use a Traynor YBA200. If there's a line from my head I usually just hit the mute button. Would I cause damage if I turned to Standby during longer breaks?

 

[pulse]

Tubes are thermally stressed by being cycled off and on and this shortens their life span.

This sounds similar to a recent experience I had, bought a second hand SVT2 (non pro). In my first day of testin being new to tube amps, we were testing it with different cabs and speaker cables, so there was a lot of on / off going on (to protect the load),

At some point the bass amp would start fading wildly in and out volume wise. I leave it for a day, the next day it performs without a hitch for 3 hours straight.

At the end of the session try somemore swopping, problem re-occurs, since then I just leave it on from session start to finish, turning down the bass guitar volume to mute ... and no such problems so far.

Still trying to isolate exactly what was going on in the begining to make it cut in and out like that
cheers

 

[Moe Hickey]

Do people need to stand really, really close to you to hear the bass?

Strike that. During BREAKS. Although sometimes I think people would prefer I play air bass.

 

[T-MOST]

On and muted.

 

[Altitude]

I am almost completely sure that switching the amp on and off between sets and after the soundcheck will create more wear and tear on it than leaving it on the whole time. Unless there is a power surge or something unforeseen.

 

[Bryan316]

Most of my gigs, we set up quickly, DEVASTATE the audience, then pack up and get offa there for the next band. Never have time to leave my gear idling waiting until we play.

Practice, when we take a break or something, I just leave it on.

Block party, between sets, we shut stuff off. No need to waste electricity.

 

[BassmanPaul]

Just a point A9X, the bias voltage has to be there before the HT or your output tubes will run away and draw all the current they can. Just nit-picking, I KNOW you know this,

My system gets powered on as soon as possible and stays on for the rest of the gig. I do mute my pre-amp during breaks. If you have been pushing a fan cooled SS amp hard, it's good to leave the amp on so that the fans have a chance to cool the heatsinks right down. If you don't hot spots could occur which might cause a future failure.

+1 on the damage at switch on. Most light bulbs pop when you turn them on. Same thing.

Paul

 

[A9X]

Just a point A9X, the bias voltage has to be there before the HT or your output tubes will run away and draw all the current they can. Just nit-picking, I KNOW you know this,

Output tubes are biassed to near cutoff during the sequence, then come up to Q. That would have been a better way to describe it.

 

[Ben Clarke]

Okay, here's a question I haven't seen in this thread yet. When switching to standby, is there any possible damage/popping/etc. when using a DI from a tube head? For example, I use a Traynor YBA200. If there's a line from my head I usually just hit the mute button. Would I cause damage if I turned to Standby during longer breaks?

The standby circuit will not affect the preamp section, including the DI. No problem.

 

[bassmodder]

SVT 6 Pro.

On ASAP and stays on between sets. Bass vol all the way down though. And as was states before no pops or weird sounds through the board. It does make some strange sounds through the DI when you turn the power off and leave the mixer hot. So I make sure to take the mixer down to 0 before turning stuff off.

 

[Johnny Crab]

Solid state:
Leave it on with volume pedal in the "off" position(muted basically).

When I used tubes(SVT 1970's~1980's) and after I put a fan on the transformer side of the case:
Turn on about 1 hour before the show on Standby.
Put it back on Standby during breaks.
Turn it to Standby for about 15 minutes after the show(fan cools down internals and XFMR as the power tubes are less hot when on standby) and then off.

PS:
About turning stuff on and off, this is not only true for amps. I work in industrial instrumentation and control systems. A certain additive scale manual said "avoid turning off and on". We turned this controller on for loop test(make sure it works)and then off. When it got powered up again, it cratered. The manufacturer said FOUR WEEK DELIVERY but bosses want it running next week. I opened the POS up and found the power supply capacitors were running at 1 volt below their rating so every time you turn it on(spike voltage) it's getting slammed with most likely a voltage spike higher than its rating and blowing a capacitor out. Replaced the marginal capacitor with one rated at twice the operating voltage. No more problems.