Parasound Halo A21 amp gain setting?

[cameron paterson]

I will be using my Denon X-4400H receiver to run rcas to my Parasound Halo A21 amp. I was wondering what level do I turn the gain up to on the back of the Parasound amp before I run audyssey? You can look at the back of the amp close up if you click on the pic on the link below.

Model Halo A 21 « Parasound

 

[j_garcia]

 

[cameron paterson]

So having it up that high won't blow anything?

 

[ban25]

So having it up that high won't blow anything?

The volume will be dictated by the pre-amp (i.e. Denon in this case).

 

[j_garcia]

The Denon will determine the appropriate levels for the speakers and takes into account the setting on the AMP, so the amp should be at 100% gain. You won't be using 100% of the amp's power at any given time in normal listening.

 

[cameron paterson]

So everyone agrees to have the gain set at 100%?

 

[lovinthehd]

I tend to try and lower gain on the amp as much as possible without introducing other issues. I tend to set gain on the power amp so it doesn't clip with my highest level signal. Full gain setting shouldn't be a problem particularly, tho.

 

[PENG]

I tend to try and lower gain on the amp as much as possible without introducing other issues. I tend to set gain on the power amp so it doesn't clip with my highest level signal. Full gain setting shouldn't be a problem particularly, tho.

I would too but not with those two knobs on the A21.

So everyone agrees to have the gain set at 100%?

The A21 has two knobs iirc, so it is better to turn them to maximum. Otherwise you will have to take some measurements to make sure the left and right channel has the same gain.

The Denon avr-x4400h can output more than 4 V so if you really want to turn the gain down a few dB you can do it, but again, you then have to take measurements.

 

[cameron paterson]

PENG: what do you mean not with those 2 knobs on the A21? You also said that the amps gain should be at 100%? Sorry I got a little confused there.

 

[PENG]

PENG: what do you mean not with those 2 knobs on the A21? You also said that the amps gain should be at 100%? Sorry I got a little confused there.

At the back, there are too round shap knob, like a small volume control dial, but they are for gain adjustment.
There are no markings, no clicks either when you turn them. So if you adjust say, the left channel by 10 degrees anticlockwise to lower the gain, you end up with the following:

1) can you be sure you could turn the one of the right by exactly 10 degrees? I doubt you can, even if you can, there is no guarantee the two channel's lowered gain will match.

2) you don't know what the gain is vs the dial's position, you only know it will be 29 dB when set to maximu.

You can of course take various measurements, or use you PC, REW etc., to try and level match the left and right channel using the controls on your preamp and make further adjustments to those knobs (better to have one fixed, just move the other to match the output) while measurement the output voltage with a good multimeter and/or mic, spl meter etc. It then becomes basically a trial and error process.

That, to me, is a lot of work for nothing in your case. If the gains are selectable via switch/relay (just an example), such as 29 dB, 26, dB, 23 dB, then in theory there may be benefit to lower it to say 26 dB in your case, to minize noise. The A21 is not silent, neither is your AVR, but in my experience they are closely matched, the A21 seems a little noiser but that's only because of the large toroidal transformer that will hum as long as you have the amp powered on. You may hear it from 1 inch, or up to a couple feet depending on how sensitivity your are to the 60 and 120 Hz hum from the transformer. The AVR-X4400H's small power transformer is not audible when your ears touch the chassis, in a very quiet room. Speaker hiss should be inaudible unless you turned the volum close to +18.

The bottom line is, you have nothing to gain by turning down the gain. If you have one of those AVRs that measured with low SNR, low SINAD dominated by noise, then you may want to turn the gain down but it still depends.. There is really no clear one size fits all answer to your question, but in your case the answer is, leave them at maximum.

 

[ban25]

The Denon AVRs also have a volume limit that you can set if you're concerned about accidentally overdriving your speakers with the amp at full gain. This is from my X3700H:

 

[Trell]

The Denon AVRs also have a volume limit that you can set if you're concerned about accidentally overdriving your speakers with the amp at full gain. This is from my X3700H:

View attachment 60683

I’ve done that with my Denon AVR for many years, and quite handy when having young children to avoid accidental very loud playing.

I’ve set it to -10 dB and that works well for most content.

As I’m using a Harmony remote each activity is using its own QuickSelect on startup with volume set to -40 dB, but that can be set otherwise as well in Denon.

 

[lovinthehd]

I would too but not with those two knobs on the A21.



The A21 has two knobs iirc, so it is better to turn them to maximum. Otherwise you will have to take some measurements to make sure the left and right channel has the same gain.

The Denon avr-x4400h can output more than 4 V so if you really want to turn the gain down a few dB you can do it, but again, you then have to take measurements.

Well that can go for a lot of gain knobs on amps/subs as to accurate, actual results from an approximate physical setting. Too bad the Parasound doesn't have a clipping indicator to help out.

 

[TLS Guy]

I would calibrate it lower. If you turn the gain high you will have a poor signal to noise ratio. What you need to do is set it where the volume on your receiver is about -10 to 1 12 db, and set the amp gain to just before the point of being uncomfortably loud, then run Audyssey. That should optimize your signal to noise ratio. Getting gain ratios optimal is a very important part of set up.

 

[Trell]

I would calibrate it lower. If you turn the gain high you will have a poor signal to noise ratio. What you need to do is set it where the volume on your receiver is about -10 to 1 12 db, and set the amp gain to just before the point of being uncomfortably loud, then run Audyssey. That should optimize your signal to noise ratio. Getting gain ratios optimal is a very important part of set up.

And even one choose not to use Audyssey one can still use the levels and distances found by the Audyssey calibration along with whatever desired crossover.

 

[Trell]

The A21 has two knobs iirc, so it is better to turn them to maximum. Otherwise you will have to take some measurements to make sure the left and right channel has the same gain

But running Audyssey will adjust for any imbalance between left and right channel using those two knobs. As long as they are at a similar gain I don’t see any issue.

Noting which gain he set is useful in case the knobs are later turned by mistake.

 

[PENG]

Well that can go for a lot of gain knobs on amps/subs as to accurate, actual results from an approximate physical setting. Too bad the Parasound doesn't have a clipping indicator to help out.

I has only 29 dB gain, same as that of the Denon, Marantz, Yamaha amps so it is considered a good match anyway.

 

[PENG]

But running Audyssey will adjust for any imbalance between left and right channel using those two knobs. As long as they are at a similar gain I don’t see any issue.

Noting which gain he set is useful in case the knobs are later turned by mistake.

For someone willing to hook up a $2,500 2 channel amp I think he will likely do a lot of direct, pure direct mode.

 

[Trell]

For someone willing to hook up a $2,500 2 channel amp I think he will likely do a lot of direct, pure direct mode.

Not me, even if I were to buy such an expensive 2 channel amp.

 

[AcuDefTechGuy]

At the back, there are too round shap knob, like a small volume control dial, but they are for gain adjustment.
There are no markings, no clicks either when you turn them. So if you adjust say, the left channel by 10 degrees anticlockwise to lower the gain, you end up with the following:

1) can you be sure you could turn the one of the right by exactly 10 degrees? I doubt you can, even if you can, there is no guarantee the two channel's lowered gain will match.

2) you don't know what the gain is vs the dial's position, you only know it will be 29 dB when set to maximu.

You can of course take various measurements, or use you PC, REW etc., to try and level match the left and right channel using the controls on your preamp and make further adjustments to those knobs (better to have one fixed, just move the other to match the output) while measurement the output voltage with a good multimeter and/or mic, spl meter etc. It then becomes basically a trial and error process.

That, to me, is a lot of work for nothing in your case. If the gains are selectable via switch/relay (just an example), such as 29 dB, 26, dB, 23 dB, then in theory there may be benefit to lower it to say 26 dB in your case, to minize noise. The A21 is not silent, neither is your AVR, but in my experience they are closely matched, the A21 seems a little noiser but that's only because of the large toroidal transformer that will hum as long as you have the amp powered on. You may hear it from 1 inch, or up to a couple feet depending on how sensitivity your are to the 60 and 120 Hz hum from the transformer. The AVR-X4400H's small power transformer is not audible when your ears touch the chassis, in a very quiet room. Speaker hiss should be inaudible unless you turned the volum close to +18.

The bottom line is, you have nothing to gain by turning down the gain. If you have one of those AVRs that measured with low SNR, low SINAD dominated by noise, then you may want to turn the gain down but it still depends.. There is really no clear one size fits all answer to your question, but in your case the answer is, leave them at maximum.


View attachment 60678

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.