Gain and level controls on an amplifier-a good thing?

I think it depends on the level of sound quality you are going for. If it is the highest you can achieve, always leave unnecessary controls behind. They add signal path and lower the fidelity. This is why audiophile level equipment generally have one button and no potentiometers. On/off.

But, If you have high gain noise they are a lifesaver.

Do you mean they have independent gain and level controls, or are you calling them the same thing??

A gain control on a preamp can be really great, since most have too much gain to be useful, and therefore too much noise. It could also change the character of the preamp considerably depending on the setting. 

A level control (simple variable resistor) on an amp can help with channel balance issues, it’s more of a convenience feature installers may like to see.

I had the controls on my Parasound HCA-1000a bypassed and it sounded better...

@jl35 Not really surprised.  For most of us, those level controls are just one more component for the signal to go through.

I think there is nothing wrong with having a volume control, as long the circuit is properly designed. My power amp has one and the manufacturer said some people prefer to not use a preamp, so they are glad to have it. His design is such that if you use a preamp, as I do, and wish to eliminate the amp volume control, to turn it all the way up. This effectively removes it from the circuit. I can verify this as there is a noticeable difference in sound if I don't turn it up fully, it is then obviously engaged. Even though I don't normally utilize the volume control, I am glad to have it as there are some recordings which sound better when I do use it.

Handy if you have very hi efficiency speakers and the ability to dump gain from a preamp can be useful. other than similar reasons it just adds another volume pot to the chain. 

Should have been more clear.  Installers love them because it gives them the chance to balance speakers in different rooms, so this is really, IMHO more of a whole home audio kind of feature than it is something the average audiophile would use.

Good if you have a use case.

Not good otherwise.

Good if you have a use case.

Not good otherwise.

Perfect answer here by @fuzztone 

Since two-channel means two speakers 😀, very few of those in this forum - er, site - have ever wanted for gain control. So as fuzztone states, few folks on this site have a use case.

For those of us who utilize four speakers (because the room is of the size that requires it), gain settings are a must. 

For reasons just stated (minimal amount of use case) many mfg do not include a gain knob. IMHO, there may be a declining need for this feature in AV amps due to the fact that DSP can equalize multiple speaker setups that would be similar to manipulating gain controls. I would prefer the manual ability to match speaker volume- rather than introduce signal processing to equalize- but as technology advances this will become much more arguable. 

Both my NAD amps have gain. I have found that the NAD C298 sounds better when gain is in fixed position (full 29db gain). I have read where others have found their amps to sound better when in the fixed position. However, when you add a second pair of speakers, the interest is in either raising or lowering the sound in the second pair to match the first pair, so the gain in my NAD 275BEE (both amps have 29db total gain available) is set to about 1'oclock on the dial and thus is adding about 17-18 gain. While there is no discernible volume level coming from one speaker to the other, there is however, a differing sound signature coming from the towers and bookshelfs..of course!

The simple logic is this. One pair of speakers (LM Motion 40's) crossover at 500 & 2600 Hz, while the other (LM 35Xti's) crossover at 2200 Hz. Hence, the midrange is boosted (where most of the music I listen to is located) creating louder passages at lower amp volumes. Think of it as a tone control. 

NOTE: Many Parasound amps have gain knobs for each channel. As Erik stated, this can be useful for balance or multiple room setups. NAD amps only have one gain knob for both channels.

Also, it would be preferable to have the gain knob in the front of the chassis, rather than the rear, which means I have to perform yoga in order to get to it.

@goodlistening64 

Awesome comment. I guess in a biamp World, the amplifiers in use would greatly benefit from gain controls

I am not using a bi-amp setup. Simply using two sets of speakers with each pair powered by a different amp. They share the same preamp. 

That is unlike most others here..

But like others here, I have a separate 2-channel setup from my AV setup, so we still have a lot in common!

Does anyone bi-amp anymore? Maybe that is a bit off topic but an interesting one when it comes to gain control...in theory one would have a true treble and bass control through gain settings, right?

@goodlistening64 

You have a lovely basement space and the point of egress with those double doors is very interesting I guess you don't have any water issues. 
 

@emergingsoul 

Thanks! No water issues yet but the doors (threshold) needs to be replaced. Not going to be cheap..

I’ve tried bi-amping a few times now, and even with the SAME two stereo amps I end up with a nagging feeling it’s robbing some of the musical coherence. Always end up going back to a single stereo amp in those cases. That was with solid-state amps, and horizontal bi-amping. I’ve also (briefly) tried with vertical bi-amp, and just felt there wasn’t much of an improvement to justify the expense.

Also tried bi-amping briefly on VAC tube amps - again same 2 amps each swappable from mono/stereo mode - and mono mode was so much better there was no point to stereo biamp.

If the 2 stereo amps are different, you would absolutely need gain controls (at least on the higher gain one) to match them, but even THEN I have to guess I wouldn’t like the result based on prior experience. So I think the problem boils down to: bi-amping with 2 of the same stereo amp doesn’t justify the 2x cost. bi-amping with 2 different amp is a Frankenstein approach, and you should just buy a single better amp.

I’ve had the Parasound Halo amps before (A23, A21, JC1) and the dual gain pots are nice to offset any L/R channel imbalance you have in your system. BUT that issue bugs me so much I prefer to address it in other ways (find the problem and fix it). But if the imbalance is due to acoustics (asymmetric room), THAT is hard to resolve and the dual gain pots could be your savior. 

@mulveling

Amazing looking system you have and that alpine height turntable is really cool. I was thinking about Vac a while back. But incorporating it into the home theatre environment didn’t seem right.

For biamping I am trying tubes and solid state and the results are very good. I’m trying out mc901s and it is achieving what I was pursuing. Being able to change the gain controls it's definitely necessary. I'm not sure if it interferes with signal path quality all that much although it is a concern.

The gain control on my AricAudio amp is useful for when I switch to ultralinear.Then it can be increased just enough so the preamp volume operates efficiently.