Question: Doesn't higher gain, "in many cases," also mean decreased negative feedback and that also happens to affect/adjust stability of an amplifier?

Question: Why, when the gain setting is compromised in favor of all other factors, does the gain usually arrive at an average figure of 40? This is too much gain. But reducing it to half (20) or less, "in many cases," seems to make either too much or not enough of everything else.

My first thought on this seems to be fairly important (and isn't): Facilitating clipping with too much available gain (your choice with the volume knob), is a far out different thing than exacerbating clipping by design (most often seen in power amplifiers with line level input). But, I think that its nonsense, because the first problem is voltage and the second problem is current, so like an "apples and oranges" comparison.

Thank you for your low gain illustration involving the high current output buffer to use along with a preamp or flea-power amplifier.
I see two major effects:
1). The preamp can more easily deal with gain, possibly because all of the current is low current.
2). The high current output buffer is sister to the capacitive multiplier and its clean effect on audio applications is well known.

So, Kudos!! Keeping the big current jolts far away from the gain device really does seem like a fine idea. Its similar to avoiding using the recording studio during earthquakes.

It would be nice to see a chart or photographic demonstration of amplifiers that use different gain structures, along with some footnotes for the audible consequences of each (via averaged historical usage data, if necessary). Both theory and application together is the only time it makes sense to me.

---------- cart before horse? --------
It doesn't seem to do a lot of good to work so hard on gain structures if perchance the input circuit doesn't have the same scrutiny.

Problems when applying the volume control are persistent and commonplace in both production and diy amplifiers. So a supplementary article on "how to apply the volume control and not goof" would be a great thing for the entire industry.

And why on earth didn't Pioneer put resistors in series to a potentiometer for a control won't facilitate clipping no matter how far the knob is turned? Although not really line level spec, Technics of the same production time-frame always regulated the volume pot. So, that Pioneer example is the carelessness typical of retail products--Its similar to modern digital examples that just plug in a chip assuming a total solution, even though that assumption doesn't usually work as well as advertised.

Another terrible trick with the volume pot happens when its (wrong) resistance goes in series to your input cap, often causing a dull presentation except for when the volume is "almost all the way" up.
Four fixes:
1). (crude) Put the input cap and rf filter capacitor load all on the RCA jack along with a small additional resistor load onto the RCA jack.
2). (more elegant) Buffer the volume pot.
3). (weird) By reputation, succeeding where potentiometers don't and also giving an "almost buffer effect," that's Lightspeed Attenuator; however, I'd rather see a documented and plausible method of operation that's do-able without either pixies or opto-isolators.
4). Either a different value of potentiometer load or adding or subtracting a resistor load to one side or the other of the existing potentiometer.

Know what I'm saying? While low gain might be fine for many reasons, running low gain to have less of wrong series resistance at the potentiometer isn't a good enough reason but rather its a problem at the input circuit that needs to be repaired before working on amplifier gain.

So, although I like your article very much, it does seem to need a "prequel" article. Please assume that all of this post is either an observation or a question. And, thank you for the fine article.

Thanks.

Well I like to run a pretty strong line level signal, as AUDIODH has mentioned above. That comes from my live sound days in very electrically noisy environments. Even then, I find that the power amps have too much gain, they have to be dialed way back.

Keeping that line level signal high means that it will ride far above all the noise found in the circuits and cables. That's a good thing.

In a home rig, cable runs are short and levels are lower but keeping the level up still helps. Most sources these days can supply 2V as a nominal line level. That's great. Unless you attenuate it by 20-40dB because your power amp has too much gain! If your speakers are efficient, you may not need more than 6-10dB overall gain. Of course a little more wouldn't hurt headroom.

The design and sonic merits of low gain amps are outside the scope of this article. I just want readers to be aware of level matching and the ways to keep a clean signal path. Turning it way down before it hits the power amp in not a good way.

My mixer has a gain stage before the main amplification stage.
I found if the pre-gain is down the sound tends to be washed out.
I have to turn it right up for my guitar to see right.

I would like to add a quite simply "pain-free" way to solve the gain problem, a way which is compatible to standard hifi configurations.

vinylsavour, also a member of diyaudio.com, uses a linestage which has the gain block before the volume pot. This way no low level detail gets lost, because it is amplified first, then attenuated. Of course it is necessary to have very big headroom for the amplification stage. vinylsavour uses a 801 tube/valve for amplification.

Hartmut

The main advantages to good gain structure are:

1. Maintaining a high S/N ratio.
2. Preventing overdriving that causes clipping and distortion

By keeping you signals at the "correct" levels, you can keep them well above the noise floor, but not overdrive the circuits. That's the golden rule. The more devices you have in the signal path, the more you need to pay attention to this.

My rule of thumb is to keep the signal about 6dB below clipping. That can often be impossible or impractical, but it's a goal to shoot for. You don't want to go above that level - unless you're looking to add distortion. Dropping too far below that means you'll pick up noise.

That's it in a nutshell.