Tube Amp Do's and Don'ts

kissmybASS01 · #1 12-29-2008, 09:58 PM

Along with several others, I am a brand new owner of my first tube head, a Peavey VB-2. This thread is not intended specifically for this amp, but rather pure tube amps in general.

I'm looking for advice from those of you who eat, breathe, and while sleeping dream about tubes.

Can you list (from your experience/mistakes) some do's and don'ts. The only few I know are:

Do: Let the amp warm up for a short period of time (?) before flipping the stand-by switch.
Do: Let the cool off in stand-by before switching the mains off.

Don't: Turn the amp fully on without a cab (load) connected.

Whether or not my VB2 is classic in the making (or like GM's Aztec), I'd like to make sure I get a "lifetime of enjoyment." What else should we tube virgins know?

rbonner · #2 12-29-2008, 10:02 PM

Dont take it from the back of your car and turn it on when the amp is -32 degrees C... BOB

Matt Dean · #3 12-29-2008, 10:07 PM

Don't sell it for the latest and greatest SS amp... you'll regret it!

B-string · #4 12-29-2008, 10:08 PM

The warmup before going off standby should be at least 30 seconds some will say 2 minutes.
The amp will not cool off in standby, just I recommend switching to standby before power off so you will already be in standby at next power on.
After using the amp (practice or gig) turn the amp to standby, then power off and let the amp cool in power off for 15-30 minutes before moving the amp. Moving a hot amp is not a good thing.
Have the amp checked every once and a while even if it seems fine, a good tech can keep it glowing and may see something happening that has not caused a failure yet.

Ampeg SVT · #5 12-29-2008, 10:23 PM

Quote:

Originally Posted by B-string

After using the amp (practice or gig) turn the amp to standby, then power off and let the amp cool in power off for 15-30 minutes before moving the amp. Moving a hot amp is not a good thing.

Not sure if thats possible for some people as some of us are playing with several bands at a gig so we have to tear down for the next band to set up.

BbbyBld · #6 12-29-2008, 10:24 PM

Always check the impedance switch.

Here's what I do on all my tube amps...

Let it warm up for a couple minutes. Before you switch it on, check to make sure all the power amp tube heaters are glowing. Watch the power tubes while you switch the standby. Keep watching for 10 seconds or so to make sure one of the tubes is not starting to glow red. If one does, you can switch the amp off quickly and just try replacing or re-seating that tube. I check every time even though I've never had a problem...I also treat my gear nice!

JimmyM · #7 12-29-2008, 10:30 PM

Quote:

Originally Posted by Ampeg SVT

Not sure if thats possible for some people as some of us are playing with several bands at a gig so we have to tear down for the next band to set up.

Well, you have to do what you need to do to make the gig happen, but if you can give it at least a couple minutes before you do any serious movement, it will prolong the life of your tubes.

Ampeg SVT · #8 12-29-2008, 11:01 PM

Quote:

Originally Posted by JimmyM

Well, you have to do what you need to do to make the gig happen, but if you can give it at least a couple minutes before you do any serious movement, it will prolong the life of your tubes.

If taking the head off the cab (I may not even put it on the cab, it looks ridiculous) and walking it to my car and putting it in my car is bad then I guess I should start investing in some tubes.

**Kelly Lee** · #9 12-29-2008, 11:56 PM

Don't mess around inside of a tube amp unless you are fully competent to work on them. There is high voltage in there that will KILL you! BTW, this even applies to some tube amps that have been sitting for a year unplugged.

JimmyM · #10 12-30-2008, 01:24 AM

Quote:

Originally Posted by Ampeg SVT

If taking the head off the cab (I may not even put it on the cab, it looks ridiculous) and walking it to my car and putting it in my car is bad then I guess I should start investing in some tubes.

Eh, exercise reasonable care if you have to move it when it's hot and you will probably be fine for a good long while. Don't jar it, don't shake it, stuff like that. Tube amps aren't as delicate as people think they are. Best to let it cool down when possible, but bands all over the world strike tube amps in a hurry all the time and they're not having to replace their tubes very often. Might want to keep a spare preamp tube in the cable bag, but you need to have power tubes biased when replacing them so there's no real benefit in carrying spares around.

Ampeg SVT · #11 12-30-2008, 01:27 AM

The Buster has an auto biasing feature but I will eventually put in a bias pot.

Ill probably just put the head right next to the cab or on my guitarist's combo so I dont have take it off my cab.

tareh · #12 12-30-2008, 01:40 AM

Start, turn off bass guitar volume, switch on pedals / effects, make sure bass amp's volume is rolled off, switch on amp, let amp warmup then switch on bass volume, then turn on bass amp volume.

End, switch off bass volume, turn off bass amp volume, switch off amp, switch off pedals.

Blues Cat · #13 12-30-2008, 02:39 AM

Always have a cab plugged in when on.

jokerjkny · #14 12-30-2008, 03:11 AM

learn how to bias. you'll save A TON OF MONEY.

kissmybASS01 · #15 12-30-2008, 05:52 AM

Wow! Tons of helpful stuff guys! I really appreciate it!

A few follow-ups:

At the end of a gig, is it my understanding that I really don't have to put it into stand-by before powering off? Just putting it into stand-by at nights end just prepares it for its next use?

I usually forget to turn the volume down when I flip the stand-by and get that "thump." Tareh suggested to turn all volumes down on bass/effects/crowd volume/cell phones before fully powering up. Is that thgump bad for tube amps? I've seen threads here where SS amps (like SWRs apparently) thump loudly with no problems? A good rule of thumb, or just un-warranted precaution?

Usually at the end of the gig (the dreaded tear-down) we're all in a rush to get outa Dodge. I'll turn off the amp (see above) and while it's cooling off, pack up my bass and gather my cables and such. I'm usually ready to load the head into my truck within 15 minutes or so. Being winter up here (-35C/-30F ) is this a bad idea? Should I leave the head til last?

As for carrying spare pre-amp tubes, it appears all 3 of the tubes are encased in these little metal covers held with a couple of screws. It almost looks like Peavey doesn't want anybody messing around with them.

Keep em coming all! Loads of great tube specific info!

tareh · #16 12-30-2008, 06:27 AM

Quote:

Originally Posted by kissmybASS01

I usually forget to turn the volume down when I flip the stand-by and get that "thump." Tareh suggested to turn all volumes down on bass/effects/crowd volume/cell phones before fully powering up. Is that thgump bad for tube amps? I've seen threads here where SS amps (like SWRs apparently) thump loudly with no problems? A good rule of thumb, or just un-warranted precaution?

on my part, its just a precaution. in my country, my Mesa cost as much as a car

ttyR2 · #17 12-30-2008, 08:51 AM

The metal covers protect the tubes. They aren't meant as a "tamper-resistant" feature.

BassmanPaul · #18 12-30-2008, 10:24 AM

I have never turned any of my tube amps to standby before turning them off. I always kill the power and the residual charges left in the amp are drained as the tubes cool off.

Paul

Bassflute · #19 12-30-2008, 10:56 AM

Quote:

Originally Posted by rbonner

Dont take it from the back of your car and turn it on when the amp is -32 degrees C... BOB

Quote:

After using the amp (practice or gig) turn the amp to standby, then power off and let the amp cool in power off for 15-30 minutes before moving the amp. Moving a hot amp is not a good thing.

I got screamed at repeatedly and called a moron and an idiot for suggesting those very things in another thread by some self-proclaimed tube expert.

But that was the conventional wisdom when I was growing up.

Also, go here for a lifetime of tube info;

www.amptone.com

ostensibly for guitarists, if you dig a little bit there is MOUNTAINS of good info and links.

Cheers,
Cameron

Surly · #20 12-30-2008, 11:17 AM

Quote:

Originally Posted by jokerjkny

learn how to bias. you'll save A TON OF MONEY.

+1

Buy function generator and a working 'scope that's cheap; just good enough to look at a sine wave. If you need, make a voltage divider to make the sine wave (smaller) readable; 2 resistors like a 64K and a 6.4K for example. Get four large ceramic 1 ohm/100 watt resistors to make a 400 watt load. Finally, some cables and a multimeter that does AC RMS (some do average) voltage, also good for ohming out stuff...

I understand that not everyone can actually do this, but with a little effort you can have a test bench for under $50. I do.