I understand with computers that standby saves the state of memory so that code doesn't have to be loaded from physical storage again. I could see this mattering for any digital-controlled component.
For an analog component, is "standby" a thing, and does it matter? I've seen "tube saver" circuits that lower the power level through the tubes when the amp is idle. Would disconnecting power to the output stage(s) but leaving the power supply caps charged up be a type of standby? Does it matter?
For an analog component, is "standby" a thing, and does it matter? I've seen "tube saver" circuits that lower the power level through the tubes when the amp is idle. Would disconnecting power to the output stage(s) but leaving the power supply caps charged up be a type of standby? Does it matter?
Standby from the perspective of commercial amplifiers is shutting the amplifier off, but leaving the remote control receiver on so you can turn it on from the sofa.
Standby mode can vary a bit with the age of the gear and depending on the type of device and application. Consumer type audio amps and HT amplifiers now have an extra, very small power supply that keeps only the control microprocessor circuits, IR remote control receiver and power button awake, 24/7. A touch on the remote control, power button or maybe on any matching unit in the AV system, should then switch on the main power supply via a relay and all systems should then be working normally - power lights on etc.
So standby mode for common types of audio and AV gear, is where only a wake-up circuit is powered 24/7 so it consumes a lot less power, is less of a fire risk if left unattended etc.
So standby mode for common types of audio and AV gear, is where only a wake-up circuit is powered 24/7 so it consumes a lot less power, is less of a fire risk if left unattended etc.
Last edited:
So if I don’t have any sort of trigger or remote function, there’s no reason to concern myself standby. Thanks both of you!
It’s always important to take note of the power consumption when you’re not using it. Standby power is a big contributor to global warming, not to mention your electricity bill. If you can design equipment to minimise this, either through shutting off most of the circuitry when not in use, or just not drawing lots of quiescent power in the first place, then that’s good.
I’ve been working with class-G topologies of late for my amplifiers, as it lets me cut quiescent power significantly.
I’ve been working with class-G topologies of late for my amplifiers, as it lets me cut quiescent power significantly.
What type/model of amp. or other product are you concerned about? We can't simply say that anything with a standby mode is fine, same as any other. A microprocessor based control system will likely have a bundle of extra, integrated features and safety functions that trigger and reset fault states anyway.
I just built a 50W class A amplifier…. That… might be hard. 😱
As far as I can see, I should simply turn my amp off when I’m not using it. Is there any reason to run it at some partial-power state? I asked a similar question before and no one seemed to think warmup time was something to worry about.
EDIT: Ian: It’s a First Watt BA-3 class A push-pull. Nothing fancy.
Last edited:
Err...50W x 2 in DIY class A - push-pull? Well, all bets are off on energy saving and keeping it hot longer than necessary is not going to give the electrons a smoother ride. Yep, I do want a stand-by switch for the main power supply there, as I watch the meter in the fuse box whizz around 😀.
WHERE did you see that "standby" function that is worrying you.
Your question means NOTHING without context.
For me, this is standby, go figure:
but also (check pin 9 😉 ):
Notice NONE of these is a digital device, yet all use "Standby".
Last edited:
What does “standby” do in those devices?
I’m asking because I want to understand if it’s something that would benefit a power amp such as mine, or if it’s only relevant to digital or tube circuits.
I’m asking because I want to understand if it’s something that would benefit a power amp such as mine, or if it’s only relevant to digital or tube circuits.
Standby is different for literally every device.
For tube equipment, it "generally" means keeping the filaments hot, but turning the HV off.
For a lot of integrated amplifiers, "standby" would mean keeping the control circuits and preamp powered up, but shutting down the power amp.
For tube equipment, it "generally" means keeping the filaments hot, but turning the HV off.
For a lot of integrated amplifiers, "standby" would mean keeping the control circuits and preamp powered up, but shutting down the power amp.
1980's portable radio-cassette recorders often had an on-standby rather than on-off switch, so the same cheap switch could be used when it was running on battery and on mains power.
I can't think of any reason to include a bypass mode in your amplifier.
I can't think of any reason to include a bypass mode in your amplifier.
A 20A rated 125VAC mains power switch for the primary side of the transformer would probably do all that's needed. Its better, easier on the contacts to switch AC than low voltage DC which tends to blow cheap switches and relay contacts to smithereens.
Good point. It wasn't an issue at the voltage and current levels of those radio-cassette recorders, but it probably would be at the DC levels needed for a 50 W amplifier.