[LAU] sortof OT -- ART tube pac preamp and compressor noisy?

Len Ovens len at ovenwerks.net
Mon Aug 12 23:45:34 UTC 2013

On Mon, August 12, 2013 8:05 am, Rusty Perez wrote:

> Anyway, I'm hearing a low level hum, sortof like a grounding hum.
> Does anyone else use the ART line of pres? Has anyone had trouble with
> them?

I use an ART dual pre/USB tube box. Two channels. I have not noticed any
hum on mine.... but. Mine does not have a grounded plug. It has a wallwart
:P that puts out ac. Also, I generally use it with S/PDIF out, which may
also affect things. I have yet to try audio in and out.

> The unit uses 2 tubes and I'm sure they aren't high quality tubes.
> Could a lower quality tube cause a low level ground hum?

I don't know enough to comment... but I will anyway. (someone will correct
any really bad ideas I am sure... and I might learn something) I would
expect more noise rather than hum with tube quality, and hum from other
poor choices.

> The unit has a grounded plug, and I can't seem to get rid of the hum
> by unplugging other components, but when I mute the unit through my
> sound card, the hum is decreased.  The hum is audible in silences on
> my tracks, so I know it's not just my playback system.

This is not clear to me. It could mean that if you record digital silence
(all zeros) you hear hum... which is not your pre. If it is you pre, just
unplugging it should remove the hum. (not just reduce it)

Len Ovens

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