Preamp Confusion

[SimpleTheater]

I’m confused by all the AVR’s, including my Yamaha RX-A3060’s preamp section on the rear panel. In the setup menu, you can tell the AVR you’re using the L/R channels for external amplification, or the rear/front presence speakers, plus there are other configurations. What is confusing me is why have these options at all? Why isn’t the AVR smart enough to know you’ve plugged in an external amp using the preamp outputs? For example, neither the Yamaha’s, Denon’s or Marantz’s have the configuration of using L/C/R (three front channels) using a dedicated outboard amp.

Which brings me to my question, how should I configure my AVR to let it know I’m using a three channel amp for L/C/R and a four channel amp four my ceiling speakers? Will this help or hinder the sound quality since there is no configuration for this setup? Or will it simply just keep the unused amps on, yielding no benefits to the speakers still connected to the AVR?

 

[Chrispy]

Usually the pre-outs are just always on. Some will even use them to duplicate channels. I'd go with your manual for guidance on best setting for your configuration, but it's probably more based on your overall speaker arrangement rather than an external amp being involved. Many avrs keep the amp sections going at all times, too, which has caused some measurement issues, altho not particularly audible ones.

 

[SimpleTheater]

Usually the pre-outs are just always on. Some will even use them to duplicate channels. I'd go with your manual for guidance on best setting for your configuration, but it's probably more based on your overall speaker arrangement rather than an external amp being involved. Many avrs keep the amp sections going at all times, too, which has caused some measurement issues, altho not particularly audible ones.

The manual doesn’t specify but I think you’re right, they’re just on all the time and so are the AVRs amps. This is what bothers me because if you could shut down the internal amps completely (instead of just two), you’d free up the power supply to just the amps actually being used.

It’s funny because I know it wouldn’t sell, but I’d love a 6.4 channel AVR (13.4 processing) designed exclusively to run ceiling speakers only. It could use cheaper amps because it shouldn’t ever be overly taxed. Basically a preamp at an mid-level AVR price, say $1,500.

 

[Chrispy]

The manual doesn’t specify but I think you’re right, they’re just on all the time and so are the AVRs amps. This is what bothers me because if you could shut down the internal amps completely (instead of just two), you’d free up the power supply to just the amps actually being used.

It’s funny because I know it wouldn’t sell, but I’d love a 6.4 channel AVR (13.4 processing) designed exclusively to run ceiling speakers only. It could use cheaper amps because it shouldn’t ever be overly taxed. Basically a preamp at an mid-level AVR price, say $1,500.

This issue has been brought before D&M/Sound United and somewhat addressed by some of the latest avrs as to switching off amp sections when using pre-outs....my old Denon has this but only when I use just external amps rather than a combo. Still, not likely an audible issue.

 

[Chobes11]

similar boat here. I am trying to use a similar Yamaha avr as a preamp but it looks like the internal amplifiers are just always on no matter what. Years ago I thought I remember seeing that leaving channels amplifiers active without drawing power damages the amp. but maybe this isn’t an issue with the newer technology?

 

[raindance]

I'm not sure what damage an amp swinging voltage but delivering zero current into a load could cause. The only amps that aren't happy with this are tube amps that use output transformers.

 

[sergeauckland]

I'm not sure what damage an amp swinging voltage but delivering zero current into a load could cause. The only amps that aren't happy with this are tube amps that use output transformers.

Generally none. A SS amp isn't bothered whether there's a load on or not. As to switching off any amps not being used, there would only be a marginal benefit to this, as an amp left on with no load only draws its bias current and a bit for the earlier stages. Any AVR who's power supply is so marginal it would benefit from switching off this tiny draw will have other more serious problems. Yes, there's some wasted power and excess heat generated, and in these environmentally sensitive times it would be better if that wasn't there, but in the global scheme of things it won't make a lot of difference.

S.

 

[Chobes11]

Generally none. A SS amp isn't bothered whether there's a load on or not. As to switching off any amps not being used, there would only be a marginal benefit to this, as an amp left on with no load only draws its bias current and a bit for the earlier stages. Any AVR who's power supply is so marginal it would benefit from switching off this tiny draw will have other more serious problems. Yes, there's some wasted power and excess heat generated, and in these environmentally sensitive times it would be better if that wasn't there, but in the global scheme of things it won't make a lot of difference.

S.

Great, thank you!