Pioneer M-90 draws 100W+ when idle !

[Tiberio]

Hello.
I am working on a Pioneer M-90. The unit operates ok, just needs some minor fixing.
I noticed that even without input signal it gets kind of warm.
I have connected a power meter on the AC plug and it draws more than 100 Watts.
Is this normal ?
I find it quite.... excessive. Maybe it was not built to be "green" but still... !!!

BTW: There are no adjustments (bias, DC) that can be made on this unit. There is a dedicated chip for that. There is no significant DC on the output of the amplifier (i.e tens of mA).

Any idea ?

 

[Aeshna]

Hi Tiberio.

Bumping this thread.

Stumbled on this forum discussion (external).

Idle power consumption of amps?​

https://www.reddit.com/r/audiophile/comments/47e6c8

Kind regards,
Mikael

 

[Pioneer.user]

Mine pioneer m90a draws 300 watt righ after switching on, and around 111 watt on idle.

This is due to the way the amplifier circuit works, which sets a high bias current and stabilizes it to avoid distortion.
pioneer m90/m90a/m91 operates close to class A amps .Its Non switching type 2 circuit.
It runs hot and its normal.

 

[painttoad]

i would not believe reddit if they told me water was wet.

just sayin'

 

[Aeshna]

i would not believe reddit if they told me water was wet.

just sayin'

I think the content in the reddit thread is credible info. Several posts from people who had measured the power consumtion of their own gear and shared the results.

 

[larryderouin]

Toad; Just get some of this.................

 

[Matt03221]

Mine pioneer m90a draws 300 watt righ after switching on, and around 111 watt on idle.

This is due to the way the amplifier circuit works, which sets a high bias current and stabilizes it to avoid distortion.
pioneer m90/m90a/m91 operates close to class A amps .Its Non switching type 2 circuit.
It runs hot and its normal.

Good info- thanks for posting! This thing does appear to have quite the current draw and made me a bit nervous.