Does an amp still draw current

[Good4it]

Evan when a speaker is not attached as long as it’s turned on tha AVR?

 

[Verdinut]

AFAIK, amps always draw current at idle. Any AVR will draw current at idle as well.

The quantity of current drawn will depend on the kind of power supply used and the power output that the amplifier can deliver. Any piece of electronic stuff draws current when running idle.

For example, any of the 2 channel QSC DCA 1222 amps which I use, draw 0.8 amp on a 120V line while running idle. Those are rated at 200w/ch at 8 ohms.

 

[lovinthehd]

From the spec page of your manual:
Standby Power Consumption
HDMI Control Off, Standby Through Off, Network Standby Off
..................................................................................................... 0.1 W
HDMI Control On, Standby Through On (No Signals),
Network Standby Off .................................................................. 1.4 W
HDMI Control Off, Standby Through Off, Network Standby On,
Bluetooth Standby Off
Wired ........................................................................................ 1.4 W
Wireless (Wi-Fi) ........................................................................ 1.7 W
HDMI Control Off, Standby Through Off,
Network Standby On (Wired), Bluetooth Standby On .............. 1.5 W
HDMI Control On, Standby Through On, Network Standby On
(Wi-Fi), Bluetooth Standby On ................................................... 2.5 W

 

[TLS Guy]

Yes, all amps draw power whether driving a load or not. How much depends on the design. In a class A amp, the current draw is the same at idle as being fully driven. In a class B amps the output at power will be much greater and the quiescent current low. However the catch is that in class B operation the operation becomes not linear at lower powers due to crossover distortion. This is very unpleasant. So that has led to class AB amps, where the the biasing moves closer to class A at low signal levels and moves towards B at higher powers. The more the amp is based to class A then the higher the quiescent current and the less efficient it is and so they run hotter.
Class A amps run hot all the time.

Class D, often called switching MOSFET amps, are the most effcient of all and have the lowest quiescent current.

The amps that I use are rare and unusual. They are current dumping amps, patented by Peter Walker of Quad in 1976. In this situation there is a high power output stage, that is biased totally class B. These are the dumpers. There is a very high quality and very linear class A amp that is in a feed forward arrangement to provide error correction to the dumpers. The performance is entirely dependent on the linear class A amp.

So you get class A performance without the formidable disadvantages, which are high quiescent current and high heat output. These amps run very cool and sound superb.

 

[Good4it]

Thanks guys but what I want to know is if there are no speakers attached and I have the amps turned on do they still produce more heat as the volume is increased as if they had speakers attached?

 

[TLS Guy]

Thanks guys but what I want to know is if there are no speakers attached and I have the amps turned on do they still produce more heat as the volume is increased as if they had speakers attached?

Not really significantly. The voltages all the way in the preamp stages will swing higher, and there will be a small increase in power drain, as there will be more power through dropping resistors etc. But you really need to have a load at the output to cause a significant increase in power drain.

If I was planning to use a receiver as a preamp and not as pre and power amp, personally I would disconnect the power amps from the power supply. But I really think if you are not planning on using power amps, you should not purchase them in the first place.