"Nick Gorham" wrote in message


If you recorded from a LP, then you will have introduced jitter then.

Just how much, is down to the sound card, I would guess it depends on
many things, the stability of the supply to the sound card I would
guess is important, and how regulated the supplies on the card from
that point.

Virtually every sound card, even the sub-$20 cheapies have their own
regulated power supply(s).

I would guess Arny is the best source of this sort of information.

Thank you. I've tried to measure a lot of jitter over the past 6 years, and
rarely found enough to hear. You're spot on with your concerns over power
supply quality, in that most of the jitter I've found was at the power line
frequency or some harmonic of it. I've got a Delta 1010 that has measurable
but not audible jitter that is obviously due to a well-known problem with a
certain cap in the interface box drying out.

I wonder if anyone has actually done tests introducing various
amounts of jitter to a DAC, and seeing just what the audible effects
are. Similar to the measurements of the effect of various harmonics.

Been there done that several ways. Here are some examples of my handiwork
that you can download and listen to for yourself:

http://www.pcabx.com/technical/jitter_power/index.htm

The easiest way to add jitter that I know involves a little creative work
with Audition/CEP.