>=20
> Input or not, there seems to be some significant high frequency noise (no=
t
> the obvious 60Hz) that doesn't seem to be coming from the guitar. My regu=
lar
> amp is completely noise free (as far as I can hear at the volumes I use, =
and
> I can hear very well).
>=20
> It's not a deal breaker, but it's still there and it's annoying to use on
> some amp models/pedals/effects that tend to boost those frequencies.
>=20
>=20
> I think I have two options now: either buy a better quality guitar
> interface, or make my own.

Or just change out the op amp in the existing amplifier for one with a=20
much better noise figure. One MEANT for low noise operation, rather than=20
cheapness.

There are op amps designed specifically for ultra low noise audio=20
operations with low internal bias currents and low shot noise as a=20
result.  LT1115 comes to mind, AD8597 series, OPA827, etc.

Saves a lot of time is all you do is swap out the noise maker for one=20
that isn't so intrinsically noisy.
Have you looked at what is in there currently? I'll bet its a general=20
purpose, super cheap, op amp.


R

--=20
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