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December 05, 2019, 04:51:30 AM

Author Topic: Single input power amp  (Read 462 times)

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Offline crgolfer

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Single input power amp
« on: April 14, 2018, 01:57:56 AM »
I only need one input and don't need a volume or balance control.  So I an thinking that I would only install one set of RCAs, leave out the input selector, balance and volume controls and then run the RCAs directly to lugs 8 10 and 11.  Since I am leaving out the 100K volume pot it looks like that I would then have to connect 100K resister across each RCA.

Is all this correct?

Online Paul Birkeland

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Re: Single input power amp
« Reply #1 on: April 14, 2018, 05:32:39 AM »
That's the jist of it.  The balance control is still useful with zero feedback amps, as there can be some small channel imbalance. 
Paul "PB" Birkeland

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Offline crgolfer

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Re: Single input power amp
« Reply #2 on: April 14, 2018, 06:44:03 AM »
Thanks for confirming my thinking.  I am not concerned about some channel imbalance as I will be running it from my dac which has volume and balance controls.

Is 100K the right value for the resistors or should I go to 133K to account for the resistor in the existing balance circuit?

Online Paul Birkeland

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Re: Single input power amp
« Reply #3 on: April 14, 2018, 07:08:52 AM »
Any resistor value between about 47K and 470K is going to do the job.  The stock volume pot/balance pot/resistors present something a bit more than 50K IIRC.
Paul "PB" Birkeland

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Offline crgolfer

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Re: Single input power amp
« Reply #4 on: April 14, 2018, 09:09:37 AM »
Ok, thanks.