Tube Amp Warm Up

[oldguy]

Ditto......... plus my old Fenders always sounded better when the tubes got hot and stayed hot, IMHO.

[Stormrider]

I'm a new member; I'm not much for big introductions, and this thread isn't the place anyway... Hello all.

Anyway, if you take a look at the old data sheets for tubes you'll see most of them state the proper warm up time. A 12AX7 for instance needs 12 seconds or so, bigger tubes will take longer. I think a 6L6 is something like 30 sec, but I'm not sure. Large rectifier tubes take about the same, but some are quicker than others depending on the model. The standby switch comes after the rectifier in the power supply line so, depending on what type of rectifier your amp uses that will delay the B+ by itself, even if you switch off standby immediately after you power up the amp.

Smaller amps with lower B+ voltages don't even have or need standby switches.

Basically, I say that 1-2 minutes is a long enough warm up time depending on the amp. Of course, you should always follow what the manual says.

[mrmudcat]

Welcome and indeed 2 minutes is enough to warm up the tubes...I give them 10 -15 minutes as stated ........Ill just keep doing what has worked for me but thought id offer my opinion.

Just looked at my manual for the vintage/modern marshall and it states to turn on without standby on and after two minutes warmup you are good to go then you can hit standby if not playing.: Exactly opposite of my fender hrd manual:

Also I have seen personally the HT fuse,main fuse and tubes go bad when somone has turned on their tube amp with the stanby switch on and within a minute or two flip the switch to play just to hear a pop..of course there is a delay for a few seconds while the HT or Main fuse does the slow burn


Anyways to each his own

[msteeln]

...is turning the volume full bore helpful in getting things all warm and fuzzy, or does it not, and, does it hurt the amp any to do this (or not) with the guitar cord not plugged in the amp?
Stupid minds want to know!

Q #2 - doesn't the standby mode do quicker damage to the amp, maybe the tranny? I heard long ago that stand-by mode was injurious to the amps internals.

[Plank_Spanker]

...is turning the volume full bore helpful in getting things all warm and fuzzy, or does it not, and, does it hurt the amp any to do this (or not) with the guitar cord not plugged in the amp?
Stupid minds want to know!

Q #2 - doesn't the standby mode do quicker damage to the amp, maybe the tranny? I heard long ago that stand-by mode was injurious to the amps internals.

Diming out the amp without an input will do nothing to futher warm the amp up. Without an input, the tubes are idling. It won't hurt the amp as long as you remember to turn it down or put it in standby before you plug your guitar in..............................speakers don't react well to that loud ground hum thump you get when you plug / unplug a guitar with the volume up.

As for standby, it will not damage your amp, either. It's there for a reason - to allow the tube filaments to warm up and the high voltage power supply to stabilize before you throw the coals to the amp. Some tube gurus argue that leaving the amp in standby for long periods will cause cathode stripping in the power tubes (perhaps tung or some other tube gurus here can chime in on this). Personally, I've never experienced any ill effects from going to standby at breaks and whenever I'm not playing the amp for short periods but want to leave it warmed up and ready. I use my standby switch like a mute switch.

As for the output transformer, the best way to fry it is to play with no speakers or grossly mismatch the speaker's impedance to the amp's. It's the Achilles Heel of tube amps, and you need to protect it with careful use of the amp. Output transformers are a very expensive component to replace.

[markb]

As for the output transformer, the best way to fry it is to play with no speakers or grossly mismatch the speaker's impedance to the amp's. It's the Achilles Heel of tube amps, and you need to protect it with careful use of the amp. Output transformers are a very expensive component to replace.

As a friend found when his AC50's impedance selector plug jumped out of its socket in mid-set. Great stage effect but thunderflashes are so much cheaper