oh, it matters, and quite a lot, actually
and I was about to suggest more gain stages, with att controls
but first, do you have the right mic, and the right mic amp
well, a harmonica have to be a bit special to 'amplify' 😕
I have to side with sreten on this one. You only have a fixed amount of gain in a system before it feeds back. As you increase gain in one section or the other the sections still multiply the signal level. 5 X 10 = 50, 10 X 5 = 50. If you have 2 X 5 X 5 you still get 50.
What is important is that the signal from the harp is greater than the signal from the speaker. The ratio between the acoustic output from the harp and the output from the speaker is the limiting factor.
Now the fly in the ointment is when you clipped the signal. Say you have 100X gain in the system before it feeds back and we have the amp set to a gain of 100 with no section clipping. It is just on the verge of feeding back but it is not yet, it is also on the verge of clipping but is still passing the signal linearly.
So what happens if you give the mic 20% more output from the harp and the amp clips off this 20%? Now you have a 20% difference between what the harp is feeding into the mic and what the amp is. So which one controls whether the system feeds back?
Wow, just clip the signal and we get to increase the volume. Maybe yes and maybe no. While the harp is putting out the extra 20% you can run an increased volume but what happens when you take a breather and the mic picks up the signal from the speaker and not from the harp? I'll let you guess.
Now where the clipping occurs in the amp does not matter. The important time period is when there is no clipping, or at least clipping where the amp is putting out more acoustical power into the mic than the harp.
At least the way I see it.
I guess you are right, in theory
with my present setup it does matter, a lot
I guess anyone using pedal effects, preamps/boosters etc know this too
again, its common to use multiple gain stages, and thats what I suggest to try
and to avoid distorting the signal you may need more speaker and amp power as well
like said, much could depend on what mic(s) you have
Mikkel Simonsen(Dantimax) is using the famous 'THAT IC' in his ThatMic kit
might prove worth a try
and btw, if you are not using a compressor, I suggest to try one
which one will work best for harmonica, mic type or instrument type, I have no idea
the one I use for my bass have additional useful 12db gain switch
admittedly, it does have both positive and negative effects
depends on why or when its needed
dont know
could be a matter of having optimal control
please read Globug's posts
my suggestion here is based on what he says
and its how I do it myself
well, every gain stage seem to have a very small range of optimal gain, set by a dedicated att pot
having only one gain stage, your optimal control range would be very limited
thats my reason for saying it
it was explained to me that lowering the gain on the first triode would make the mic less sensitive, I didn't believe it my self till i tried it, it works no idea why so i use a low mu tube ecc802 and run it thru both triodes the first turned way down round 3 the second I can run wide open and no feedback unless i want it.
I would like to try it myself, I have set up similar experiments when I was not sure on the theory of why musicians got the effect they said they did. I don't have time for this one, too much on my plate for now. Just giving my thoughts on the idea. I have a bit of background on tuning industrial closed loop systems and the whole gain before feedback thing is something I used to spend some time on.
Doesn't make the mic less sensitive just puts less gain in the controller (amp) section. The mic's sensitivity or gain before feedback is pretty much fixed mechanically due to its design. Something going on at the amp stage, interesting question what.
Bingo!
You place a harmonica against a vocal mic and wail through it, you'll clip everything from there to the back wall, starting with the mic diaphragm.
A 12AU7 in the first stage lets the amp be a little more linear, and that means less feedback. But only a little - despite the sizable gain reduction, you can still crunch the power tubes.
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