Questions about Tubes?

  • Thread starter Thread starter xpunkskaterx
  • Start date Start date
X

xpunkskaterx

New member
I bought my first tube amp this week. Its a Traynor Custom Special 50H head. I run the head through a vox cab and it sounds very nice. Anyways, I was wondering if you have to treat a tube amp any differently than a normal amp. Some of my friends were telling me that you have to let the tubes warm up before playing and turning it off. Other people told me that it doesn't matter for guitar, just bass. I dont want to ruin that amp... or anything like that. So any help would be sweeet.
 
I bought my first tube amp this week. Its a Traynor Custom Special 50H head. I run the head through a vox cab and it sounds very nice. Anyways, I was wondering if you have to treat a tube amp any differently than a normal amp. Some of my friends were telling me that you have to let the tubes warm up before playing and turning it off. Other people told me that it doesn't matter for guitar, just bass. I dont want to ruin that amp... or anything like that. So any help would be sweeet.

I have heard that you should let the tubes warm up until the amp (bass or guitar, it makes no diff) will play at full volume before playing on it, something about boiling away metal from the anode/cathode if you push signal through the tubes before the heaters bring them up to temp.

Also, the heater filaments are tungsten, just like in a light bulb. You know how a light bulb filament can break easily if you knock the bulb around while it is hot? Tubes are the same way, let the amp cool off for a few minutes after you've shut it down before moving it around.
 
It's all a matter of opinion.

Some feel they wouldn't produce amps without standby if it really mattered, others say you should leave it on standby for about 10 minutes when turning it on, then at least 10 seconds on standby before turning it off.

I've also heard that when an amp is on Standby, not as much voltage is sent to the heaters, making it safer for tubes to warm up via standby. I have no idea how true that is.

Your safest bet is to do it the 2nd way I mentioned: Throw it on standby before turning it on, and let it sit for at least a few minutes. Then turn it back on for a few seconds before shutting it off.
 
Yeah, I would also like to know the proper way to take care of ones tube amp, i'd hate to blow tubes in the first week if i didn't have to.
 
Tubes are not nearly as fragile as you'd think. Just use the amp as it's intended use and you'll be fine.

The only "care" they really need is just be sure of what you're replacing them with when it comes time to replace them. Check for voltage bias and stuff like that.
 
I've always let my tube amps warm up, on standby, for around 15 minutes before I start playing through them. I was told that doing so helps get a warmer sound from the start as opposed to just turning them on and playing. I also like to have them off for about the same amount of time before I move them. I don't know about the electronics involved with this and it may be purely psychological on my part.

But, I have a few tube amps (3) and I've never had to had to change the tubes due to failure. The oldest of these is a Peavey Deuce that I bought in 1976. Maybe there is something to the warm-up/cool-down theory. What ggun posted seems to make sense to me. I'm sure some one who knows the actual theory behind this will post and enlighten all of us if it is different than already posted.
 
.... Some of my friends were telling me that you have to let the tubes warm up before playing and turning it off. Other people told me that it doesn't matter for guitar, just bass. I dont want to ruin that amp... or anything like that. So any help would be sweeet.

It is not a matter of the type of instrument rather the type of tube circuit.

Here is a link to an article from someone who seems well informed
http://www.hsga.org/learning/win2000_techtips_standby.html

He basically says it depends on the amp, and that some circuits can cause tube degradation if not allowed to warmup in standby for a minute or so.
 
You MUST let the amp warm up in standby mode before playing it. If you apply voltage to the plates before the tubes are at operating temperature it can cause cathode stripping, which will shorten the life of your tubes by a lot.

Cool down is a different thing. You can turn everything off all at once just fine, but it is a good idea to wait a few minutes if possible before you move it, as hot glass is more prone to crack, but it's not a big issue. If you can wait, do, but if you need to move it don't sweat it. On some amps, it is a good idea to leave the standby switch in the on position when you power down, depending on where the bleeder resistors are (if your amp even has them - many amps do not).


Light

"Cowards can never be moral."
M.K. Gandhi
 
You MUST let the amp warm up in standby mode before playing it. If you apply voltage to the plates before the tubes are at operating temperature it can cause cathode stripping, which will shorten the life of your tubes by a lot.

I have never done that; I just flip both switches together. I have always done that since my first amp, a Fender Princeton I bought in 1968 (which I wish I'd held onto). Some of my tube amps don't even have a standby switch. I haven't noticed any premature tube death; my Fender Super that I bought in 1969 still has the original tubes in it.

What I have heard about cathode stripping is that it happens when you try to push signal through cold tubes. I don't do that.
 
It is not a matter of the type of instrument rather the type of tube circuit.

Here is a link to an article from someone who seems well informed
http://www.hsga.org/learning/win2000_techtips_standby.html

He basically says it depends on the amp, and that some circuits can cause tube degradation if not allowed to warmup in standby for a minute or so.

I've been told by techs that it doesn't make a difference on at least my Ampegs (B-12N and B-25B). I don't know if that's because they use 5AR4's which the author of the article says minimizes the damage or because of an issue of scale in these amps.

When I worked for a Chief Engineer at a couple radio stations years ago, we couldn't turn transmitters on in a single step. They had interlocks to prevent the plate voltage from being turned on if you tried to before the tube(s) were warmed. The one RCA transmitter had a transformer the size of my B-12 amp and a couple tubes the size of my head.

So, on the transmitters it mattered, but when considering my bass amps, I believed techs when they said it didn't matter, or that the effect at that scale was negligible. I tend to believe it as I haven't had any particularly short-lived tubes in various amps over the years. I believe that it's an issue at larger scales, but whether that includes larger instrument amps, I don't know.
 
Back
Top