| Author |
Topic: Got a question for your techie's....... |
Ray Montee
From:
Portland, Oregon (deceased)
|
Posted 14 Jun 2008 7:41 am |
|
WHAT is the Standby Switch really for........on an amp?
Specifically for TUBE AMPS? |
|
|
|
Joey Ace
From:
Hamilton, Ontario, Canada
|
Posted 14 Jun 2008 7:59 am
|
|
It keeps the filament voltage to the tubes on, while turning off the high voltage.
This saves tube life.
When turning off a tube amp for the night, I put it in standby mode for a minute first.
Moving to ELECTRONICS |
|
|
|
Jim Sliff
From:
Lawndale California, USA
|
Posted 14 Jun 2008 8:22 am
|
|
The original intent of the standby switch was to allow you to supply power to the tube filaments (heaters - the part the lights up) BEFORE supplying power to the rest of the tube (the recommended wait time before flipping the standby to "on" anywhere from 15 seconds to two minutes - there is no consensus among techs on this issue).
When the tube is warmed up prior to voltage being applied to the plates, in theory it prevents a phenomenon called "cathode stripping" - where, in simple terms, parts of the tube wear off more quickly due to the sudden change in temperature (there's more to it than that, but that's the basic idea). It's also used on stage during breaks to mute the sound, but that was a non-intentional use that just happened to be found to be convenient.
In the last 5-10 years it's been determined that "cathode stripping" is a really minor issue and that tube life is barely, if at all, affected by use of the standby switch. But the switch has become kind of a tradition on tube amps so it's still there on most of the larger ones. Many long-time players just don't feel "right" turning on a tube amp without waiting 15 seconds or so before flipping the standby switch..yet they do it all the time on Champs and smaller amps, and many grossly expensive audiophile stereo amplifiers do not have standby switches.
So - realistically, it's now just a traditional item and unnecessary.
One other point - it has NEVER had any effect when turning an amp OFF. Cutting power to the tubes all at once has no negative effect. Why some players turn switches *off* in sequence is a mystery, as there has never been any reason to do so.
To summarize - when you turn your tube amp on OR off, just flip both switches at the same time.
Hope that helps.
_________________
No chops, but great tone
1930's/40's Rickenbacher/Rickenbacker 6&8 string lap steels
1921 Weissenborn Style 2; Hilo&Schireson hollownecks
Appalachian, Regal & Dobro squarenecks
1959 Fender 400 9+2 B6;1960's Fender 800 3+3+2; 1948 Fender Dual-8 Professional |
|
|
|
Joey Ace
From:
Hamilton, Ontario, Canada
|
Posted 14 Jun 2008 8:28 am
|
|
I believe the Standby Switch should be used when powering down for brief periods, such as between sets.
| Quote: |
| Why some players turn switches *off* in sequence is a mystery, |
Yup. I offered no reason for it.
'Been doing it that way since the 60s, and I'm not gonna change now.  |
|
|
|
Jack Stoner
From:
Kansas City, MO
|
Posted 14 Jun 2008 9:19 am
|
|
My friend Blake Hawkins, who is an EE and retired broadcast engineer, says that the standby really doesn't do anything or at least anything useful.
In essence what Jim has said. |
|
|
|
ajm
From:
Los Angeles
|
Posted 14 Jun 2008 10:00 am
|
|
Also, if the amp has a tube rectifier, a standby switch is not required due to gradual warm up.
Of course, as was said, it's not really required anyway. |
|
|
|
Donny Hinson
From:
Glen Burnie, Md. U.S.A.
|
Posted 14 Jun 2008 10:17 am
|
|
Well, my take is this:
The standby switch let you kill the output of the amp without powering down the filaments. The only real benefits to this were that when you turned the standby switch back on, the amp was ready immediately for use (no warmup), and it also reduced the number of on-off cycles, which was claimed (by some) to be a big factor in filament failure.
I agree with Jim on this one, it's merely a convenience, for the most part. Tubes are only "working" when they're amplifying a signal. The mere presence of high voltage on the screen grid and plate has almost nothing to do with tube life if the amp is properly biased.. |
|
|
|
Randy Reeves
From:
LaCrosse, Wisconsin, USA
|
Posted 14 Jun 2008 10:46 am
|
|
I have done this ritual for years with my tube amps:
Power On and Standby switched active..
fiddle with my cords and effects set up.
tune guitar(s).
plug in to amp.
Standby OFF and I am good to go.
now I need to use another guitar.
Standby goes back ON.
I can pull the cord silently now.
(I have used my volume pedal for this.)
I set my amps volume and tend to leave it there.
band takes a break and I go back to Standby.
to power off for the night I have Standby back on. then flip the power switch off.
when I have simply switched to power off w/o standby on I hear pops or other sounds.
nothing serious, just bugs me.
I have read in tube and and amps articles the the Standby should be used when warming the amp.
cathode stripping etc were the reasons.
I'll stick to my routine, but the information posted in this thread is interesting. |
|
|
|
John Billings
From:
Ohio, USA
|
Posted 14 Jun 2008 12:52 pm
|
|
In my modded Princeton Reverb (20 watts, 12", no stand-by switch) my tech used a 5Y4 ,I believe, cuz it wasn't an instantaneous warm-up rectifier. I think the GZ34 is basically instant voltage. I guess it's not an issue though. Do I have the tube #s correct?
Off topic: I talked to my tech last night, and he was raving about the very short-bottled 5932s that he put in one of his own amps. I had never heard of this tube before. Strange lookin', stumpy tube!
Here: http://tinyurl.com/5jcw2e |
|
|
|
