Parasound Halo A21 amp gain setting?

[mtrycrafts]

The back panel has a dot where THX reference is. Use that dot on both channels. Any small differences will be taken care of when you level match all the channels either manually or by Audyssey

 

[PENG]

One other reason why I stopped playing with those knobs was, a few times (got up on wrong side..) I thought I lost one channel or both, ready to box the 60 pounder for repair, then I realize I might have forgotten to turn it back up. I am kidding, but it was no joke at the time.

The OP has absolutely no need to adjust those things, not a single reason!!

 

[Alex2507]

The back panel has a dot where THX reference is. Use that dot on both channels.

And that looks like it might be the max anyway.

My THX hash mark is at the 2 o'clock position on the dial.

I keep it turned to the 12 o'clock position because I don't need 200 watts @ 8 Ohms launching any of my drivers into space. YMMV.

 

[highfigh]

Hold my beer-

 

[Trell]

Hold my beer-

Sure, but the glass will be empty even I hand it back.

 

[highfigh]

Sure, but the glass will be empty even I hand it back.

You're gonna need a bigger glass.

 

[Trell]

You're gonna need a bigger glass.

That’s up to you.

 

[highfigh]

That’s up to you.

Would the large beer boot work?

I have always enjoyed seeing people drink from a boot when they haven't learned how to do it without being doused at the end.

 

[mtrycrafts]

And that looks like it might be the max anyway.

My THX hash mark is at the 2 o'clock position on the dial.

I keep it turned to the 12 o'clock position because I don't need 200 watts @ 8 Ohms launching any of my drivers into space. YMMV.

Well, you do have a volume control, so it doesn't get into an orbit let alone into deep space.

 

[mtrycrafts]

One other reason why I stopped playing with those knobs was, a few times (got up on wrong side..) I thought I lost one channel or both, ready to box the 60 pounder for repair, then I realize I might have forgotten to turn it back up. I am kidding, but it was no joke at the time.

The OP has absolutely no need to adjust those things, not a single reason!!

Maybe he just likes to play with knobs?

 

[TLS Guy]

Yeah I would set to 100% also.

I believe Parasound also recommends 100%.

I think if Parasound likes to include these Gain Knobs, they should place these knobs in FRONT so people can use them as Volume Controls in case they don’t have a preamp.

They should also put the 2 handle bars in the front, not back. They have things backward.

That is a bad idea. I will tell you why. Unfortunately that do not publish the circuit, but since this units has balanced and unbalanced inputs, I can be certain those volume controls are not at the input. They are almost certainly at one of the early voltage gain stages. Modern practice is not to use straight variable resistors.

Modern practice works by altering the gain at an IC voltage amp. When you follow this practice, as you reduce the gain you improve the S/N ratio. So you want to set the preamp to the highest level where it won't clip and then set the two trim controls to where the output is in the comfortable useable range. That is the correct procedure and will optimize S/N.

 

[AcuDefTechGuy]

That is a bad idea. I will tell you why. Unfortunately that do not publish the circuit, but since this units has balanced and unbalanced inputs, I can be certain those volume controls are not at the input. They are almost certainly at one of the early voltage gain stages. Modern practice is not to use straight variable resistors.

Modern practice works by altering the gain at an IC voltage amp. When you follow this practice, as you reduce the gain you improve the S/N ratio. So you want to set the preamp to the highest level where it won't clip and then set the two trim controls to where the output is in the comfortable useable range. That is the correct procedure and will optimize S/N.

You believe that decreasing the voltage gain of the amp (like from 28dB to 22dB) and increasing the gain of the AVR to compensate will SIGNIFICANTLY increase overall SNR?

And increasing the Gain in the AVR won’t decrease SNR as much?

Has anyone ever published the SNR results of these scenarios?

 

[TLS Guy]

You believe that decreasing the voltage gain of the amp (like from 28dB to 22dB) and increasing the gain of the AVR to compensate will SIGNIFICANTLY increase overall SNR?

And increasing the Gain in the AVR won’t decrease SNR as much?

Has anyone ever published the SNR results of these scenarios?

As usual there is no circuit published. However it is now common practice to use circuits where you are not using a straight variable resistor, but put the control in the feedback loop of an op amp. This improves S/N ratio as you reduce the gain. This was a huge advance when it appeared during the eighties, and improved mixer panel performance enormously. Not only does this approach improve S/N but it increase the voltage over head of that gain stage. This approach has been adopted pretty much universally, and is a huge improvement over the old padding potentiometer. However, it does change how you look at gain staging over former methods. Under old engineering your approach would have been correct, but not now. So now by using the a different approach you can optimize S/N and signal overload margin at the same time.
In my live recording days, I was a very early adopter of this approach. I think I ordered the first mixer board with this technology, and I never ever had a crescendo of a live recoding clip the mix panel again. It increased confidence to not gain ride manually, and also not to have to put line attenuators on the mic inputs to prevent clipping the first stage.

 

[PENG]

That is a bad idea. I will tell you why. Unfortunately that do not publish the circuit, but since this units has balanced and unbalanced inputs, I can be certain those volume controls are not at the input. They are almost certainly at one of the early voltage gain stages. Modern practice is not to use straight variable resistors.

Modern practice works by altering the gain at an IC voltage amp. When you follow this practice, as you reduce the gain you improve the S/N ratio. So you want to set the preamp to the highest level where it won't clip and then set the two trim controls to where the output is in the comfortable useable range. That is the correct procedure and will optimize S/N.

Agreed, that's why I said I would use a lower gain too, except in this case his preamp happens to be a good match with the power amp's 29 dB gain. The little improvement from reducing to gain to, say, 26 dB, does not outweigh the also negligible loss in left/right balance if the adjusted gain introduces difference between the left/right channel outputs. Yes, one can adjust the knobs with the help of a good voltmeter, spl meters, REW/mic etc. but why bother. Just leave them at maximum, given the preamp.

I happened to have both the AVR-X4400H and A21 that the Op is asking so I know their specs very well.