[Don Pearce[_3_]]

On 10 Feb 2019 09:22:28 -0500, (Scott Dorsey) wrote:

James Price wrote:
What's the differentiating factor between digital clipping at the input sta=
ge, and its effect on the end result, compared to how an analog guitar ampl=
ifier sounds when boosted?

This is not a digital vs. analogue question. You are asking whether clipping
the analogue input of an ADC is different than clipping the analogue input of
a guitar amplifier.

And... the answer is.... it depends a lot on the ADC and on the amplifier.
In both cases you're creating a lot of odd harmonics, but the actual
spectrum varies a lot. You can likely assume both are nonlinear but
time-invariant (although there used to be some ADCs that would stick to
the rails when clipped).

To refine the question, if I'm recording guitar using a digital amp / guita=
r cab simulator into a DAW and the input of the guitar is clipping, how doe=
s that clipping affect the digital amp / cab and what's the end result at t=
he output end (after the amp / cab) compared to an analog amplifier with hu=
ge amounts of input boost?

It will sound different because the spectrum is different.

But you're using this as a musical instrument. If it sounds the way you
want, do it.

But be aware that although most guitar amps are designed with the intention
of clipping them, most ADC designers didn't spent a lot of time worrying about
clipping behaviour because they didn't expect people to use them that way.
So you're likely to find that no two ADCs sound quite the same way when
overloaded.
--scott

If the clipping in an ADC happens after the anti-alias filter (ie
actual numeric digital clipping), you are in trouble, because you now
have high frequency products that are not filtered away, but are right
there and are going to produce alias frequencies in the audio band.
They won't be harmonically related as analogue clipping would be, but
they will instead be dissonant. You really don't want this to happen,
because once they have been produced, there is no DSP capable of
removing them.

d