Hi guys, what do you think is the safest way to turn a tube amp with a standby switch on and off? I've heard so many different things that I do not know what to believe anymore. This is how I turn my Peavey 6505 head on/off:

On

1st - turn power on
2nd - wait a minute or two
3rd - turn standby on

Off

1st - standby off
2nd - wait a few seconds
3rd - turn power off

Thats the way I do it too but with volumes turned down to avoid any sudden unexpected frights!

CC

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Blackstar HT-5

looks the right method to me

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No no and no

Ditto!

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10-4 good buddy, over and out!

+1

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2010 Guild Gad-F40e

thats how i do it..... i was thinking of getting a 6505 but went with the vypyr 2 (not sure if thats the right name ) and got a sanpera 2 foot pedal thing with it.... LOVE peavey amps

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looks about right but you forgot to stand in a tub of water!!

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I'm not an expert, but I play one on the internet.

Or just keep kicking it until it shuts up.

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No no and no

What???? People, the idea of the standby switch on is to allow voltage to go to the tube heaters only and warm the tubes before going full voltage or keep them warm. The standby does not effect the rectifier tube but turning the standby on then power on warms the tubes, two minutes later standby off and play, if you take a break turn stand by on and keep the tubes warm . Applying full voltage to cold tubes wears them out. Good habit to turn standby on wait minute before turning off that way its on already to power up.

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The strongest reason for the people to retain the right to keep and bear arms is, as a last resort, to protect themselves against tyranny in government.

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I think this is the most times I have seen the forum agree on something.lol

According to Fender ...

http://fender.com/news/index.php?display_article=461

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Then again, what do I know ... I've only been playin' for 6 months ... !

It makes sense to me. Don't need to put the amp in standby when turning it off. I do it this way:

Off
1st - turn power off
2nd - standby off

Turning the amp off the way noted at the beginning of this thread (standby then off) makes my amps go "pop".

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When your are breaking down equipment just turn standby on while still power on and the tubes will start cooling down slowly because heaters still on but tubes are not full power, then just turn power off. Leaving the standby on means the amp is ready for the next time you are going to use it. Turn the power on, the standby will already be on, wait two minutes turn the standby off and play.
What you are doing is heating to tubes up and down at slower rate which prolongs to tube life.

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The strongest reason for the people to retain the right to keep and bear arms is, as a last resort, to protect themselves against tyranny in government.

Thomas Jefferson

This from Lyle Caldwell on the vintage amps bulletin board, and there's been similar discussion on Vox and Gibson forums too -

"Better for the amp if you either just leave it on with the master down or turn it off until 5 minutes before you start playing. Standby offers no benefit but every time you engage the standby switch there is a large current inrush and voltage spike. This gradually damages the GZ34 and eventually the filter caps and output tubes. Nominal B+ on these amps is about 325vdc, and the filter caps are rated 400-500vdc. When you flip the standby switch, voltage spikes of over 700vdc with brief but heavy current surges are common. These put undue stress on the parts mentioned above, as well as eventually causing the switch itself to fail.

Sometimes its a lot of fun when the spike/surge causes the rectifier tube to actually arc weld itself. You get a light show and a funky smell. The light show is over fast, but that smell lingers. And sometimes it takes out other parts of the power circuit! Yay!

And the reason people tell you TO use standby is so there is no instantaneous plate voltage on the tubes until the heater filaments in the tubes are warmed up. Thing is, no B+ (plate supply) flows in these amps until the filaments in the GZ34 have warmed up themselves, by which time every other tube in the amp also has its filaments heated.

So there is no valid reason to use standby, but lots of empirical, explainable, and predictable reasons not to.

Note, for the sake of this argument, I am only discussing amps that use a GZ34 rectifier tube or the Weber replacement. So JTM45, AC30, Bassman, etc. Amps with other tube rectifier types or solid state rectifiers are not part of this discussion.

Though really, unless you're talking about an extremely high voltage amp like an SVT (700+vdc B+) cathode stripping is really not a danger, so there still is no compelling reason to use Standby on a Twin or Marshall either.

Lots of techs "know" things based on what they have been told. That really is not knowledge. That is just a good memory.

Let me put this in less technical terms.

It's rare for you to be sitting in a room reading a book and the light in the lamp just goes off.

But it's common to switch on a lamp and have the bulb die at that point.

In the first scenario, the light has a steady voltage and steady current through it. Unless physically vibrated, that filament inside that bulb will keep on going a long long time.

But that same bulb when subjected to the voltage spike and current increase due to the electricity quickly being switched on will fail. The filament that could withstand hours and hours and hours with a steady voltage and current will fail instantaneously when the voltage and current briefly exceed its threshold of failure.

Now, that same bulb on a dimmer would not fail at power up if the dimmer was all the way down when the switch was turned on, and then you slowly brought the voltage up with the dimmer.

This last scenario is what happens when you let the filaments of the GZ34 control the voltage sent to the rest of the amp, rather than using the Standby switch.

Standby = instant on.

GZ34 = slow dimmer increase.

Hope this helps."

You can find the discussion here
http://vintageamps.com/plexiboard/viewt ... =2&t=75667

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