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

Rusty Perez rustys.lists at gmail.com
Tue Aug 13 15:08:38 UTC 2013

Hi folks, Thanks for your thoughts!
I'm sure you all see me for the newby I am. And if not, these
questions will expose me! :-)

First of all though, the hum I am hearing is very faint and is covered
up when music is played. I don't want you to imagine that it's loud at

You've all given me some good info.

Fons, you're right. I'm going from the xlr out on the tube pack to one
of the xlr ins on the delta 1010lt. I kindof figured that was
understood since I mentioned the xlr connections, but one cannot
assume. Anyway, I'll look at the jumper situation. I really don't want
to take my machine apart though. :-)
Do I understand correctly that set on the mic setting, the card gives
the xlr ins a 60 db boost?

Also, when I get really close to my ART tube pac unit, I hear a quiet
humming from the box itself. Is this normal for a piece of equipment
with tubes in it? :-) Could this suggest a problem, and is this hum
introducing itself in to my signal at low levels.

Thanks for mentioning the usb pre Len. I don't see it mentioned when
ever anyone talks about usb interface options on linux.


On 8/12/13, Len Ovens <len at ovenwerks.net> wrote:
> 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
> www.OvenWerks.net

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