Standby switch vs. leaving amp in run position vs. turning off

[Gravedigger Dav]

I would add information that gives some perspective on tube care. In the cold war era B57 bombers were always parked ready to launch quickly. In those days, all the electronics were tubes. All the B57s were kept with the electronics on at all times. Here is why. When does a light bulb fail? How often do you see a bulb just go out? Notice that it is most likely it fails when you turn it on. To avoid a tube failing when launching for a mission, they were kept on. The sudden surge of power to electronic components puts a tremendous load on them and causes the failure.
I always turn my amp on and leave it on for the duration of the event. On break, i just turn the bass volume all the way down.

 

[agedhorse]

I just remembered a product I designed that uses an automatic standby circuit.

On the Streamliner, there is a standby circuit that disables the power amp while the tube preamp stabilized during warmup.

This is not necessary because on a tube power amp, the delay of the power tubes is longer than the preamp tubes, but on the class D power amp used in the Streamliner, a time delay standby circuit is used to allow the preamp tubes come to quiescent operating conditions before enabling the power amp. It’s all done automatically.

This is a different application of a standby circuit, similar yet different.

 

[tchristian]

For what it's worth, here's an excerpt from my Traynor YBA300 owner's manual:

"1. The Power and Standby Toggle Switches.
Due to the nature of vacuum tubes, we suggest the YBA300 be powered up for a few minutes prior to using. This will allow the tubes to warm up. The pilot
light glows red when the amplifier is engaged; it glows amber when in Standby mode.
Note: Before powering up and disengaging the Standby switch make sure speaker cabinets are connected to the output jacks. When the amplifier is warmed up, disengage the Standby switch and get ready to experience the classic tone of a Traynor Bassmaster All-Tube Amplifier.
Note: It’s also recommended to leave the amplifier powered up during set breaks, The Standby switch cuts all output from the power amplifier."

 

[Bent77]

Aren’t most modern all tube amps all equipped with a relay in the start circuit? Re: if you turn on both switches, no sound until the telltale “boink” of the relay cycle

So for example an SVT, when did these relays become integrated?
Kind of implies that the standby switch isn’t necessary on start up?

 

[Omega Monkey]

It's my understanding that the reason some studios choose to leave their equipment on is to avoid the repeated heating up and cooling down of the solder connections. Over time, that makes the solder become grey and less conductive and it doesn't pass signal as well. I was also told by an engineer that the very large mixing consoles take a long time to warm up and they don't want to mix on a cold console.

I don't know about you, but if I bought a $100k SSL and it failed any time in the first few years due to a cracked solder joint just because I turned it on and off once a day, I'd be furious, and that would DEFINITELY count as a manufacturer defect. What kind of crap are you putting out if your gear is going to fail just from being turned on and off, let alone actual usage?

Again, we're talking about gear that is designed for probably a minimum 1000s of power cycles.

Many TVs and radios used the same tubes found in amps, did your old TV have a standby switch? No.

Yes, and as proof just take a look at all the 50-70 year old radios and TVs! Oh wait...

I think in this thread we're learning that common sense is not as common as it could be.

Imagine if companies actually put stuff like that in their marketing? The new XQ 75000! Sounds fantastic and will get you loads of birds. But just be aware that if you turn it on one too many times, it will die! So DON'T EVER TURN IT OFF!

How many of you would buy that item? That would not be a compelling sales strategy for me, personally. Is Dennis Hopper going to call me once I get it home and warmed up and make threats to me and Sandra Bullock? I don't get the paranoia.

 

[DrThumpenstein]

I posted a similar thread a few months ago. On, Off, or Mute
My practice is to put it in standby if I’m returning in an hour or less and turn it off otherwise. My WD800 uses around 15 w or less when muted so minimal energy consumption, but why use any power if not needed?

I’m lucky in that the designer of my amp has weighed in on my specific question. I’m sure best practice for any specific amp has everything to do with design/topography, environment, and intended use.

 

[Wasnex]

Edit: Pardon me; what I meant to say is I don't believe either of these concepts is rooted in fact.

A few years back, a term was coined for this sort of information: "Alternative Facts"

 

[Deleted member 165050]

I would add information that gives some perspective on tube care. In the cold war era B57 bombers were always parked ready to launch quickly. In those days, all the electronics were tubes. All the B57s were kept with the electronics on at all times. Here is why. When does a light bulb fail? How often do you see a bulb just go out? Notice that it is most likely it fails when you turn it on. To avoid a tube failing when launching for a mission, they were kept on. The sudden surge of power to electronic components puts a tremendous load on them and causes the failure.

The MIG-25 uses vacuum tubes and is still in service... I wonder if the pilots swap out tubes to get the plane to fly nicer

 

[seamonkey]

Sweetwater's take:

The Great Standby Switch Myth | Sweetwater

"
The actual reason for standby switches

It’s all about the capacitors!

As the public asked for louder amplifiers, Leo Fender began to build amplifiers with higher power supply voltages. When first turning on the amplifier and before the tubes are warm, tubes do not conduct high voltage, so there is no “load” on the power supply. This phenomenon would allow voltage to rise above the maximum voltage rating for the large capacitors used in the circuit, putting them at risk of shorting out from the stress. This was especially true when Fender started to use solid state rectifier diodes that provided power supply voltage instantly when the mains power was turned on.

While the tubes are warming up, the standby switch removed the high voltage from the circuit until the tubes filaments were warmed up to operating temperature and the power supply voltage would be loaded down by the tubes to the nominal safe operating voltage for the capacitors.

Sure, Leo could have installed much higher voltage rated capacitors that could safely handle the voltage rise, but these were very expensive back in his day. His company’s goal was to produce high quality, but lower cost amplifiers (and guitars), so keeping the price down was important to him. Therefore, the standby switch was a cost-saving design feature much cheaper than the alternative very expensive capacitors.

"

In the battery powered farm radio days standby turned off the high voltage vibrator. The vibrators hummed. It probably also helped when high powered tube amps were not able to use huge filter caps - less hum from the amps on stage between sets.

And when/if you change caps, push the guts out of the cardboard tubes and replace them with a new cap in the tube. They'll look more authentic. It's something many amp restorers do these days. Even for SS amps.

 

[frankie5string]

I have never heard of studios leaving their consoles, tape machines, and outboard gear on 24/7 if there is no work being done in the studio. Studios can and do operate 24/7 to pay the bills, though.

One studio I used to work at had a tape machine that was very poorly maintained. We knew we had to start it up 4 hours before the downbeat or it wouldn't be speed-stable. We finally convinced the boss to get it serviced. After 4 hours of work on it, it never needed to be "warmed" before use, again. The boss got the hint.

Our Westar console drew so much power that we were reminded to shut it down at night when we were done or the boss would yell at us for drawing power for nothing.

We had an old Electrodyne console that sounded really weird and grainy for about 10 minutes after it was turned on. That was fixed by sending the power supplies to some wizard in LA who recapped and tested them.

But I love having a MUTE control on an instrument amplifier.

 

[40Hz]

My daughter used this argument on me with suggesting that I let my computers run 24/7. But I found that if I left the computer running all the time, it just meant I had to take it apart and clean and/or replace the fans more often. Had to replace a video card because the fan got linted up and I didn't catch it in time.

You’re correct (IMO coming from 30+ years in enterprise level IT) that there’s no benefit to be gained by leaving a workstation running 24/7.

A lot of that “always on” lore came out of the days of “big iron” mainframes. Mainframe shutdowns and restarts were a moderately complex and time consuming process. That, combined with the fact they usually did need to operate 24/7 to get their work done, was two of several reasons why mainframes (and to some extent their later successor: the server) were seldom taken down except for hardware repairs or required maintenance reboots.

And these days many hardware replacements and fixes can be done while the machine is still running. So hardware component failure is far less an issue than it used to be in the IT world.

But none of that applies to personal computers. So if you won’t be using them for awhile, shut them off. Especially laptops. They’ll last longer.

 

[Plain Old Barry]

But none of that applies to personal computers. So if you won’t be using them for awhile, shut them off. Especially laptops. They’ll last longer.

Agreed, but I haven't seen a laptop or desktop in a while that didn't power itself down in various stages as non-use time passes. So, a user has to go out of his or her way to not power it down, and eventually "almost off" when not in use.

 

[Wasnex]

I would add information that gives some perspective on tube care. In the cold war era B57 bombers were always parked ready to launch quickly. In those days, all the electronics were tubes. All the B57s were kept with the electronics on at all times. Here is why. When does a light bulb fail? How often do you see a bulb just go out? Notice that it is most likely it fails when you turn it on. To avoid a tube failing when launching for a mission, they were kept on. The sudden surge of power to electronic components puts a tremendous load on them and causes the failure.
I always turn my amp on and leave it on for the duration of the event. On break, i just turn the bass volume all the way down.

You might be misinterpreting the rationale a bit. These planes were probably kept at a full ready state, rather than in standby, because this sort of instrument of national power requires as close to a 100% Green readiness status as possible.

In the event of a malfunction, I would expect that an alarm panel would immediately show some sort of indication. It's likely a technician would take a quick look and if the problem could not be rectified immediately, a different plane would be brought online.

I would not expect an alarm to go off for equipment that was in standby. So equipment had to be fully powered up so it could be monitored. Sort of a proof of life concept.

Also it's likely that these planes had some backup circuits that were held in standby, so they could be brought online quickly in the event of a primary system failure. In the event of a failure, a technician might swap out the malfunctioning primary circuit with a spare. I would not be surprised if the technician was part of the planes normal air crew. The plane's readiness status might be considered amber until the operations of the replacement circuit had been checked and placed in standby.

Keep in mind, military equipment has regular preventative maintenance intervals to ensure everything is "clean, dry, and serviceable." PMIs are used to clean equipment, take measurements to ensure everything is performing to spec, and also make periodic adjustments to optimize performance. When I worked on tube radios, we did not just check to make sure the radios were working to spec. When certain PMI interval came up, we did a complete alignment of the transceiver to make sure it was working at peak performance.

Since this plane was such a critical asset, I would not be surprised if some of the tubes were metered and swapped out before reaching the end of their expected service life. Keep in mind, the military is primarily focused on the mission, and they go to great lengths to ensure success.

 

[Wasnex]

Aren’t most modern all tube amps all equipped with a relay in the start circuit? Re: if you turn on both switches, no sound until the telltale “boink” of the relay cycle

So for example an SVT, when did these relays become integrated?
Kind of implies that the standby switch isn’t necessary on start up?

No.

AFAIK not even all modern SVTs have a time delay start up. They all have pretty much the same relay circuit, but the circuit that drives the relay varies a bit.

AFAIK, the SVT Classic senses the status of each output tube and puts the amp in Standby when certain a condition occurs. I believe the condition is massive over current in one or more output tubes. AFAIK the Classic does not force a time delay...but I could be wrong. I think there is also an overvoltage sense built into the circuit, but this does not seem to cause much of a problem.

AFAIK, The SVT VR only has a 20 second time delay and voltage sense circuit built into the relay control. So the amp is held in standby for a few seconds until the amp is warmed up, regardless of the position of the standby switch. Also if the line AC voltage drops below about 110V, the circuit forces the amp into standby. A lot of people seem to have a problem with their amp being forced to standby due to low line AC, so it's a common mod to jumper the output of the relay so the amp does not shut down.

 

[40Hz]

Agreed, but I haven't seen a laptop or desktop in a while that didn't power itself down in various stages as non-use time passes. So, a user has to go out of his or her way to not power it down, and eventually "almost off" when not in use.

Pretty much only a problem in the gamer world where “maximum performance” power settings are the norm. For ordinary users who don’t know about or bother messing with power settings your point is well taken since the defaults in most operating systems all do some power conservation.

 

[Plain Old Barry]

You might be misinterpreting the rationale a bit. These planes were probably kept at a full ready state, rather than in standby, because this sort of instrument of national power requires as close to a 100% Green readiness status as possible.

In the event of a malfunction, I would expect that an alarm panel would immediately show some sort of indication. It's likely a technician would take a quick look and if the problem could not be rectified immediately, a different plane would be brought online.

Back in those days ('58-64), my dad was an Air Force avionics and radio repairman on KC-97 and KC-135 tankers. He even got to work on the original Air Force One at Otis Air Force Base when JFK would go to Hyannis in the brand new airplane, the same B707-based airframe as a KC-135. They did a lot of things that simply don't translate to real, average person life.

Like Wasnex stated, most of the techniques had nothing to do with component life extension, but simply immediate availability when seconds count. Based on the stories I've heard, they had almost a blank check for spares and repairs, it was when in doubt, throw it out, even for expensive items.

 

[Jim C]

I have never heard of studios leaving their consoles, tape machines, and outboard gear on 24/7 if there is no work being done in the studio. Studios can and do operate 24/7 to pay the bills, though.

One studio I used to work at had a tape machine that was very poorly maintained. We knew we had to start it up 4 hours before the downbeat or it wouldn't be speed-stable.

We only know what we know.
I started in small crummy studios like most guys but stayed in it long enough to move up to real studios.

My real studio background was in the 80's in pro studios with 24 track, 2" tape machines and real recording consoles
Everyone left their equipment on 24/7.
My direct experience:
Track Recorders -16 track 2" studio that was Neve and 3M machine; Heart Like a Wheel and Cry of Love was mixed there
Room Ten - 24 track 2" - MCI and MCI; 95% of the DC GoGo scene was recorded there or in a remote truck I also worked at
Omega Studios - 24 track 2" - API and MCI deck
Big Mo Mobile Recording - Twin 24 track 2" - Sony / Sony (while a mobile truck, it "plugged in" to a studio of overdubs, mix downs, and album projects and was booked at least 40 hours per week while parked)
Power Station - Neve or SSL and Studer decks

One studio used a retired tech for service that had worked at The Hit Factory as well as Sigma Sound; his experience was also 24/7

Friends at Media Sound, Criteria, Bearsville, and Sunset Sound all did the same

11 real world examples of pro recording studios being left on 24/7 to include consoles, tape decks, Dolby A racks, & all the effects racks.
Right wrong or indifferent, that's how it was, and is still done when using analog gear.

 

[Plain Old Barry]

11 real world examples of pro recording studios being left on 24/7 to include consoles, tape decks, Dolby A racks, & all the effects racks.
Right wrong or indifferent, that's how it was, and is still done when using analog gear.

I saw it myself locally. Regardless of it's end result, it was done.

 

[frankie5string]

We only know what we know.
I started in small crummy studios like most guys but stayed in it long enough to move up to real studios.

My real studio background was in the 80's in pro studios with 24 track, 2" tape machines and real recording consoles
Everyone left their equipment on 24/7.
My direct experience:
Track Recorders -16 track 2" studio that was Neve and 3M machine; Heart Like a Wheel and Cry of Love was mixed there
Room Ten - 24 track 2" - MCI and MCI; 95% of the DC GoGo scene was recorded there or in a remote truck I also worked at
Omega Studios - 24 track 2" - API and MCI deck
Big Mo Mobile Recording - Twin 24 track 2" - Sony / Sony (while a mobile truck, it "plugged in" to a studio of overdubs, mix downs, and album projects and was booked at least 40 hours per week while parked)
Power Station - Neve or SSL and Studer decks

One studio used a retired tech for service that had worked at The Hit Factory as well as Sigma Sound; his experience was also 24/7

Friends at Media Sound, Criteria, Bearsville, and Sunset Sound all did the same

11 real world examples of pro recording studios being left on 24/7 to include consoles, tape decks, Dolby A racks, & all the effects racks.
Right wrong or indifferent, that's how it was, and is still done when using analog gear.

Fair enough, but I would have figured studios like Mediasound, Power Station/Avatar, and Criteria were actually OPERATING 24/7, either in-session or during downtime for maintenance and the machines would all be on for maintenance. Same thing with Hit Factory and Sigma, they were actually running 24/7.

 

[brianrost]

did your old TV have a standby switch? No.

But it had a tube rectifier