Recently, I've only had amps that have an automatic standby mode - turns on when it detects a line signal and goes into some standby mode when the signal is gone (after a certain period of time). I guess it saves power and extends life (although I thought I read somewhere that it's better to keep amps on to extend the life of capacitors; capacitors preferred to be on rather than cycled on and off - not sure if true and to what extent).

Anyway, I'm looking to buy another 2ch amp. Slim pickings on local ads. But I found one that sounds decent (good reviews although early 2000 model) but it doesn't look like it has auto standby.

In this case, do I just leave it on all the time? How much (ballpark) power does it consume when I'm not using it (it's rated for up to 100W 8ohm when active; it has a toroidal transformer). Is it on the order of a few watts? Or ten's of watts?

Even though it sounds good, if I need to turn it on/off each time I want to use it, I'll probably pass. I'm too lazy and will just look for a newer model that has auto standby.

Generally they are not standby but 'remote' turn on.
Usually 12v triggered.
Turn on the or a main device and it turns on the acellery device, turning off when the main device is off.
For amps sans the trigger there are power strips to do the same albeit getting scarce due to lack of demand.

Car stereo or home stereo?

8 ohms… home stereo.

quote:

Originally posted by smschulz:
Generally they are not standby but 'remote' turn on.
Usually 12v triggered.
Turn on the or a main device and it turns on the acellery device, turning off when the main device is off.
For amps sans the trigger there are power strips to do the same albeit getting scarce due to lack of demand.

The amp I'm using now has 12v or line signal triggers (also rs232?). Line signal is convenient - I'm hesitant to plug an amp into the receiver to control power.

I have two choices in the listings:
1. Made in USA amp (early 2000 model) - but no trigger. I'll probably just keep it on all the time but would like to find out how much power it'll consume when I'm not using it - I assume less than 10W which would be okay for me (solar) but not sure.

2. USA company but made in prc (I believe). Decent brand, good reviews. Has the signal/12v/rs232 trigger. But made in prc.

Trying to decide..... Or maybe just wait longer for a listing like #2 but not made in prc.

quote:

Originally posted by Beancooker:
Car stereo or home stereo?

8 ohms… home stereo.

Sorry, yes, I should have been more explicit.

quote:

Originally posted by konata88:
Recently, I've only had amps that have an automatic standby mode - turns on when it detects a line signal and goes into some standby mode when the signal is gone (after a certain period of time). I guess it saves power and extends life (although I thought I read somewhere that it's better to keep amps on to extend the life of capacitors; capacitors preferred to be on rather than cycled on and off - not sure if true and to what extent).

Capacitors at T0 (time zero) look like a dead short when you turn them on, so they take a lot of current when you turn the device on. That causes a voltage spike followed by a short damped oscillation on the power bus. That's why startup capacitors on A/C tend to be one of the first things to go in your HVAC system. The voltage spike caused by this is what caused the "thump" sound on turn on and what prompted designers to do a soft start circuitry years ago.

Leaving the amp on eliminates that, though, but you still have the current required to run things with no signal. I'd have to guess the current draw and it'll vary with the type and manufacturer of amp you've got but probably somewhere between 50 and 100 watts. Check your owner manual and it might tell you.

Thanks. Good to know. Will definitely keep the amp on.

A lot of browsing and scanning is suggesting that I should expect (for non-class A amps) about 20-40W (I don't think the amps I'm considering are class A (which would be in that 60W+ range) but trying to confirm - I can live w/ that given my annual net metering from solar; won't cost me any money for electricity as it's noise level to baseline usages (I'm using about 1.5KWHr, 5.5KWHr when the AC is on).

I think I'll go for the made in USA amp and just keep it on....

My amplifier is an NAD C372 and it's been doing it's bit since around 2005. It does feature a standby mode that draws almost nothing and powering it up from standby does not generate any noise in the audio circuit, just the relay for the source clicks. IIRC it's a class AB amp that produces 150 watts of audio for 8 ohms, 340 for 4 ohms, and current limited 460 W into 2 ohms. I'll also note that it was a rather expensive amplifier when I purchased it but it wasn't Macintosh expensive.

Note, class A amps generally don't exceed about 20 watts because the current draw in a class A amplifier is high. I suspect that for 100 watts from class A would require wiring it to a 230 Volt/30 amp circuit. I also suspect that some type of cooling tower would be needed to control the heat. Klipshorn speakers were originally designed as corner loaded horn speakers capable of producing a lot of volume from a 3 to 5 watt tube type class A amplifier.

As for USA made audio amplifiers, they are out there. One brand I've always wanted is McIntosh, all made in the USA but the price is equal to that of high end shotgun. Another brand I lust for is Mark Levinson. I remember one test on a Levinson amp where they hooked it into a square wave generator and welded some 1/4 inch steel with it. Yeah, an amp that could also serve as a welding power supply, that's one amp that isn't "current limited".

Based on the longevity of my NAD I believe that the most pertinant question is How Old are You? Because odds are that if you purchase a quality amplifier similar to my NAD there is a very real chance you'll never have to purchase another amplifier. BTW, NAD is headquartered in Canada. Have no clue at all about where the hardware is made.

The capacitors on my McIntosh finally went after about 40 years. Other than that, never a problem

Don’t turn off amp with signal going to speakers. Will harm speaker relays, if they exist. I ruint a Sansui AU9500 amp doing this.

quote:

Originally posted by Hamden106:
The capacitors on my McIntosh finally went after about 40 years. Other than that, never a problem

I'll bet that if you sent your McIntosh in for repair they would do a full R&R on it and not charge your for anything except the shipping.

McIntosh provides evidence that buying high end audio can often be the most inexpensive purchase you make. Because after 40 years of use that amp of yours is rather cheap when you consider the alternative of purchasing some cheap Japanese stuff. Prior to my purchase of my NAD I had a "high end" Yamaha that I dumped because it sounded like crap and I got fed up after 3 years.

When I picked up my 40 year old MCS amp from a year at the 'spa" getting reconditioned back to better than new I was told to buy the best surge protecting power strip I could find and use it to turn the unit off and on rather than the power switch on the unit. I also learned about turning the volume to zero before powering off/on.

It's been home for a year now and that's all we ever do.

quote:

Originally posted by Appliance Brad:
I also learned about turning the volume to zero before powering off/on.

It's been home for a year now and that's all we ever do.

So you don't blow your speakers out. It's happened.

Turning volume to zero before power on/off? The pre-amp? Or the amp?

1. Volume to zero before power off the pre-amp?
2. Volume to zero before power off the amp?

#2 may not an issue since I'm planning to just keep the amp on all the time. #1 will be an issue and may be cause to not buy the amp.

But for #1, is this also an issue for my amp which has auto-standby? Seems like it should but I never set volume to zero before powering off the pre-amp. I just turn off the pre-amp and then the amp goes to standby after a period of time. Is this bad?

Turn the volume to zero before turning the power on unless you have a soft start amp.

Is this clearer?

Thanks. Yes; sorry, but this is an important decision criteria for me so wanted to be clear.

So, I need to turn the pre-amp volume to zero before powering on/off the amp. If I keep the amp always on, then issues with the volume control setting when I power on/off the pre-amp.

For amps that don't have auto-standby, I will keep them always powered on. If I need to set the pre-amp volume to zero before toggling power to the pre-amp, that would be a non-starter for me (especially remembering to zero it before turning it off). But if it's not an issue what the volume setting is because the amp will always be on, then that's fine.

On my McIntosh the volume turn knob is the on-off at the low end.

I'm too unfunded to have the equipment I want, so this is what I have now...until properly funded: Rotel RA-1572 120 WPC integrated amp; Adcom GFA-555 200 WPC amp; Apple Mac mini/Apple Super Drve streaming TIDAL, Apple Music, and my ripped CDs; Goldenear Triton 7 tower speakers; and Velodyne F-1800RII 18" subwoofer.

The Rotel has an on button, and it goes to sleep after not in use. I wake it from standby with the remote's power button. Turning it off with the remote button only puts it into standby, and it can only be turned off by physically pressing the button on the front panel.

Also, I have a Denon AVR-S650H which is a 90 WPC 5.1 surround AVR receiver, which I use for general listening. The front stereo speakers are klipsch RP-600Ms, the center is as Sony SSCS8, the two rears are Sony SSCS5s, and the sub is a 10" Klipsch R-100SW. The AVR is also fed by my Mac mini and my Apple TV 4K HD.

I use my Rotel integrated amp as a preamp, using the Adcom to power the Goldenears. When the Rotel goes to sleep/standby, my Adcom remains on.

When my Denon goes to sleep/standby, I can awaken it with the remote, and I can also turn the system power off with the remote, unlike the Rotel, which has to be done by the front panel button.

Also, when I'm using the Denon for general listening, I control it with the HEOS app on my iPhone. I rarely ever use the Denon's remote. The app wakes up the system and puts it to sleep.

I just checked: ADCOM still makes power amplifiers; you can buy their 6002 70-watt stereo amp for $600 new. Or you can find used amps on eBay in good condition. They were a standout in the 80's and 90's for quality at a reasonable price. As far as I can see they are still made in the US.