Yamaha RX-V850, the front left / right channels are imbalanced.
The balance and volume pots are not the cause, they measure proper.
The Amp section is fine as well.
The pre-amp outputs have very different peak-peak voltage, I forget the values but recall the overpowered channel clips at around half volume.
not sure it matters since amp is fine, but bias is okay and nill dc.
I figure somewhere in the pre-amp section on the spoiled channel there are out of spec components causing excessive power to flow through.
But yea, do those symptoms indicate any leads as to the cause / possible causes?
The balance and volume pots are not the cause, they measure proper.
The Amp section is fine as well.
The pre-amp outputs have very different peak-peak voltage, I forget the values but recall the overpowered channel clips at around half volume.
not sure it matters since amp is fine, but bias is okay and nill dc.
I figure somewhere in the pre-amp section on the spoiled channel there are out of spec components causing excessive power to flow through.
But yea, do those symptoms indicate any leads as to the cause / possible causes?
If the "bad " channel clips at half volume but everything else works okay --as you say--- then as Rayma says the power supply feeding that channel must have increased its voltage in respect to the input active devices ---still balanced etc but higher than the designed voltage making it more sensitive .
I take it the actual input signal voltage is identical on both channels ?
Of course there could be other faults causing it and its supposition until you make a few tests and post the results.
I take it the actual input signal voltage is identical on both channels ?
Of course there could be other faults causing it and its supposition until you make a few tests and post the results.
On these complex units, it could be a wrong setting rather than a hardware problem.
Can you easily restore it to the factory setup?
Can you easily restore it to the factory setup?
Thank you all for the replies so far.
I've not yet pulled the unit out for more testing but will this evening most likely.
regarding input yes is same level of input, the amp has a built in tuner as well that has same level imbalance.
I'll try and determine where the power supply voltage is for the preamp and measure it. If that measures proper then I suppose need to follow it along to see which component isn't doing it's job.
For electronic/solid state volume / settings it looks like only the center, rear / front surround channels have solid state volume control in addition to the pots, and they seem to have equal output. But I need to double check that. Thanks for the tip!
I've not yet pulled the unit out for more testing but will this evening most likely.
regarding input yes is same level of input, the amp has a built in tuner as well that has same level imbalance.
I'll try and determine where the power supply voltage is for the preamp and measure it. If that measures proper then I suppose need to follow it along to see which component isn't doing it's job.
For electronic/solid state volume / settings it looks like only the center, rear / front surround channels have solid state volume control in addition to the pots, and they seem to have equal output. But I need to double check that. Thanks for the tip!
Below image of measure / channel comparative; pre-amp. And a yt vid as well.
https://www.youtube.com/watch?v=kYad11C_Sq4
https://www.youtube.com/watch?v=kYad11C_Sq4
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