The truth about handling a tube amp

[emperor_black]

oh, the sarcasm! I dont care much for my tube-amp. can i just switch it off after playing? ...and if the amp dies because of my actions, can I come in and get a quick confession?

[Cygnus X1]

Bill. good, but that's overkill.
Most people here have it it right. You want the standby enabled on power up
to allow the voltage to only go to the heaters on the tubes. It takes less than a minute for them to warm up. Then power up fully, let it warm up a couple of minutes more with no signal.

Power off, enable standby, then power off, then, (this is different). flip the standby again to bleed off the caps a bit.

The reason we don't want to apply power directly is cathode stripping. A tube that has
shocked this way can appear cloudy for a while just before it "blows". Light bulbs don't usually fail until you turn the power on them. A tube acts in a similar way.
The popping sound when slamming the power off is the caps discharging large amounts of DC voltage through the output tranny. Not only is it bad for the speakers,
it's hard on the transformer, also. When you do that, you are removing the star ground (I think), and the caps have to do something with all that voltage, since it no longer sees a ground. This is also why I flip the standby again after power off, to dissipate that voltage which will hang around until the next time you power up, then POOF.

[lynchfan6]

Okay,,,here's a related question. When experimenting with different speakers/cabs, should you completely power off the amp before yanking your speaker cable out of one cab to plug it immediately into another? I always do, but some people have told me that you can leave the amp on standby when doing this. What do you think?

[randyrhoadsguitar]

I do it like this and everything is perfectly fine.
I turn the power switch on and the stand by switch off and let it set there for at least 2 mins. When powering down I turn the stand by s switch off and let it sit there for 2 mins then Ill through the power switch off. It simple really. Just dont go throuhging both switches at once or youll go through tubes and possibly damage the amp.

[shreder13]

why does everyone feal the need to repeat the same thing
I think this question has been answered.

[SlasZ]

Indeed, thanks

[horns666]

why does everyone feal the need to repeat the same thing
I think this question has been answered.

I dunno..but just in case.

Ok, here's how you do it. Before you play your amp..turn the power on stand by. Let the the tubes within the amp's interior warm up for approx 20- 30 minutes to about 140 degrees. You could get an egg timer and meat thermometer to assist you know when it is safe to turn the switch from stand by to the ON position. This will allow you to safely play your guitar for double the time it took for it to warm up. Let's say you need to play your guitar/amp for two hours. This will require you to warm your amp up in exactly on half the actual playing time..in this case a one hour "warm up" is warranted. It takes that exact time to let the amp cool down slowly do that it will not "shock" the system. Let the tubes cool to body temperture..98.6 degrees before turning the amp OFF. It's like stretching before you run or get off the computer chair to go to the bathroom. Tube amps are much like the human body..they both require constant care and maintenance to live a healthy life. Make sure that your amp has a steady diet and at least 8 glasses of water per day..so that the tolex will remain supple and will not crack with age. I will keep this short so it will not be confusing. It's simple math really. The actual amp warm up time is exactly one half of actual playing time..then cool down time is the same. Remember, let the tubes heat up to 140 degrees, and cool down to 98.6 degrees. If you program yourself with good habbits such as this..your tube amp should bring you years of joy..until it's quality of life is compromised. Then, at that time it will be put down and join the many amps of years gone by..in tube amp heaven...where players like Jimi Hendrix and Keith Richards could jam on them for eternity and then some.

Amen.

Rev. B Fuggums

[horns666]

Indeed, thanks

Sven, I Wuv U..You Uberinian maniac you!

[Dave L]

Okay,,,here's a related question. When experimenting with different speakers/cabs, should you completely power off the amp before yanking your speaker cable out of one cab to plug it immediately into another? I always do, but some people have told me that you can leave the amp on standby when doing this. What do you think?

Well, I´m thinking you´ll be fine with it on standby as long as you make sure NO signal is going to the input of the amp. But I´m no authority on this, does anyone else know for sure?

[horns666]

Well, I´m thinking you´ll be fine with it on standby as long as you make sure NO signal is going to the input of the amp. But I´m no authority on this, does anyone else know for sure?

Yes, I am Dave..would you like me to explain?

[Shawn Lutz]

I heard your supposed to turn every knob on 10 leave the guitar plug'd in next to the cab for about 10 minutes feeding back at extreme volumes...that cleans the shit out or something, then just yank the power cord from the wall socket. What does stand-by mean? is it because you have to stand by your amp to hit the switch? Which way is on or off..is it up or down? I took me a while to figure out the power switch, I couldnt tell if it was on or off but someone told me the little light thingy comes on when in on mode. Also why does amps have tubes..its not the 60's anymore...pfft

sereious answer is stand-by first power down second. If your carting the amp around after use let it sit for a while before moving it

[horns666]

I heard your supposed to turn every knob on 10 leave the guitar plug'd in next to the cab for about 10 minutes feeding back at extreme volumes...that cleans the shit out or something, then just yank the power cord from the wall socket. What does stand-by mean? is it because you have to stand by your amp to hit the switch? Which way is on or off..is it up or down? I took me a while to figure out the power switch, I couldnt tell if it was on or off but someone told me the little light thingy comes on when in on mode. Also why does amps have tubes..its not the 60's anymore...pfft

sereious answer is stand-by first power down second. If your carting the amp around after use let it sit for a while before moving it

Bravo Shawn..Bravo!!!

I've couldn't explained it better.

Just one thing, When hauling your amp to and fro..what is an reasonable amount of time to make your amp "sit" before moving it?

'Z Bub

[emperor_black]

Well, I´m thinking you´ll be fine with it on standby as long as you make sure NO signal is going to the input of the amp. But I´m no authority on this, does anyone else know for sure?

I think putting the amp on standby disconnects the output stage. It just keeps the heaters on so the power tubes do not cool down and require another 'warm-up' routine. I think you should be fine if you disconnected the speakers/guitars in the interim.

[roodyrocker]

Okay,,,here's a related question. When experimenting with different speakers/cabs, should you completely power off the amp before yanking your speaker cable out of one cab to plug it immediately into another? I always do, but some people have told me that you can leave the amp on standby when doing this. What do you think?

I'm not sure about this but my thinking is that I turn it off completely to switch speaker cables or cabs on a tube head. Reason being that if I accidentally don't have the cab connected to the head and I flip the switch off standby, it could damage a tube head. It needs to see a speaker load on it. Therefore I always have a speaker cable/cab plugged into my tube head unless its in its road case

[emperor_black]

Yes, that is the correct practice. however, when I was talking to the carvin tech on the phone, he was giving me the impression that its ok for the amp to be without a load for quite sometime before it blows its covers.

Also, with regards to impedance mis-matching, it seems tube-amps are designed to withstand a 2:1 load-mis match. So, if you have the amp set at 8 ohms and plug it into a 4 ohm cab, the amp would still be A-ok. In fact, when i was using a 5150 into my weber attenuator as a dummy load, I had at sometime hit the switchable ohm switch to 4 ohms instead of 8 ohms and it was quite a while before I noticed it and switched it back. My amp was just fine.