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General => General Technical Chat => Topic started by: onesixright on March 24, 2018, 04:47:50 pm

Title: Any risk using a 3 ch power amp as stereo (long term) ?
Post by: onesixright on March 24, 2018, 04:47:50 pm
Hi,

I don't think so, but double checking can't hurt i guess  :-[

Is there any risk damaging a 3 ch power amp for stereo use if the third ch input and output are disconnected?

Thanks!
Title: Re: Any risk using a 3 ch power amp as stereo (long term) ?
Post by: NiHaoMike on March 24, 2018, 05:32:20 pm
Should be just fine.
Title: Re: Any risk using a 3 ch power amp as stereo (long term) ?
Post by: Zero999 on March 24, 2018, 06:25:18 pm
Why would you think not?

If the output has nothing connected to it, then no current will flow and the output stage will not do anything, other than pass the usual quiescent current.

It will be fine, just leaving both the input and output of the third, unused channel, disconnected i.e. open circuit.
Title: Re: Any risk using a 3 ch power amp as stereo (long term) ?
Post by: onesixright on March 24, 2018, 08:25:24 pm
Why would you think not?

Couldn't think of something that would causing a issue, yet I'm no export. So just wanted to double check.

Thanks!
Title: Re: Any risk using a 3 ch power amp as stereo (long term) ?
Post by: ebastler on March 24, 2018, 09:27:31 pm
It will be fine, just leaving both the input and output of the third, unused channel, disconnected i.e. open circuit.

I assume we are talking about a transistor amp, not tubes and outut transformer, right? In that case, yes, it should be fine. I would probably bridge the unused input to avoid coupling any spurious noise, but I guess that's optional.

A stereo amplifier with a built-in backup channel always at the ready if something fails -- great!
Reminds me of this: http://throx.com/home.html (http://throx.com/home.html)  ;)
Title: Re: Any risk using a 3 ch power amp as stereo (long term) ?
Post by: onesixright on March 24, 2018, 09:36:41 pm
It will be fine, just leaving both the input and output of the third, unused channel, disconnected i.e. open circuit.

I assume we are talking about a transistor amp, not tubes and outut transformer, right? In that case, yes, it should be fine. I would probably bridge the unused input to avoid coupling any spurious noise, but I guess that's optional.

A stereo amplifier with a built-in backup channel always at the ready if something fails -- great!
Reminds me of this: http://throx.com/home.html (http://throx.com/home.html)  ;)

Yeah (transistors) its a DENON POA-T3 (built like a tank), nice power  amp. Used in my old surround config, but since I changed the stuff I wanted to use it in a other room for stereo. So the "center" channel, will be unused.

https://www.avforums.com/threads/denon-poa-t2-poa-t3-power-amps.1955696/ (https://www.avforums.com/threads/denon-poa-t2-poa-t3-power-amps.1955696/)

Sorry, bridge ???
Title: Re: Any risk using a 3 ch power amp as stereo (long term) ?
Post by: Edison on March 24, 2018, 09:56:32 pm
Nothing will happen \$\Omega\$
Title: Re: Any risk using a 3 ch power amp as stereo (long term) ?
Post by: ebastler on March 24, 2018, 10:27:29 pm
Sorry, bridge ??

I simply meant to short-circuit the unused input, so it cannot pick up any noise. Amplifying input noise or hum will not damage the unused amplifier; it just "feels wrong". Probably just obsessive-compulsive disorder on my part.  ;)
Title: Re: Any risk using a 3 ch power amp as stereo (long term) ?
Post by: Edison on March 25, 2018, 12:19:45 am
they are three monoblocks, for your obsessive compulsive disorder - disconnect the unused degree source - each stage has its own  \$\Omega\$
Title: Re: Any risk using a 3 ch power amp as stereo (long term) ?
Post by: Brumby on March 25, 2018, 02:29:32 am
Short the input of the unused amp.  Leave the output open (not connected).
Title: Re: Any risk using a 3 ch power amp as stereo (long term) ?
Post by: ebastler on March 25, 2018, 07:15:02 am
Short the input of the unused amp.  Leave the output open (not connected).

Didn't I say that, like, twice?

they are three monoblocks, for your obsessive compulsive disorder - disconnect the unused degree source - each stage has its own  \$\Omega\$

Now it's my turn to add the question marks -- "degree source" ??  :-//
Title: Re: Any risk using a 3 ch power amp as stereo (long term) ?
Post by: Edison on March 25, 2018, 09:49:32 am


they are three monoblocks, for your obsessive compulsive disorder - disconnect the unused degree source - each stage has its own  \$\Omega\$

Now it's my turn to add the question marks -- "degree source" ??  :-//

the amplifier consists of three monoblocks
each monoblock has its own power supply
Disconnect the power supply unconnected monoblock
no power = no noise, no consumption
Title: Re: Any risk using a 3 ch power amp as stereo (long term) ?
Post by: ebastler on March 25, 2018, 10:11:12 am
the amplifier consists of three monoblocks
each monoblock has its own power supply
Disconnect the power supply unconnected monoblock
no power = no noise, no consumption

Thanks; that's what I had guessed.
I was just wondering about the "degree" part -- maybe a translation issue?
Title: Re: Any risk using a 3 ch power amp as stereo (long term) ?
Post by: Edison on March 25, 2018, 10:29:00 am
My English is not good, Google Translator is helping me and it looks like it sometimes .....  |O |O |O ..... :-DD
Title: Re: Any risk using a 3 ch power amp as stereo (long term) ?
Post by: Watth on March 26, 2018, 05:29:12 pm
With the homeopathy-related debates over here, I read it as a 3CH amp. Like the sound is diluted to a millionth.

Holly smoke ! I found a new product for audiophiles and homeopaths ! Homeopathic audio amplification (tm).