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

Len Ovens len at ovenwerks.net
Tue Aug 13 15:56:36 UTC 2013

On Tue, August 13, 2013 8:08 am, Rusty Perez wrote:

> 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?

That would make sense. The more costly delta 1010, comes with a breakout
box where all the inputs are balanced line level inputs. My delta 66
allows setting them to -10 or +8 (I think) through SW. The LT has
unbalanced and mic. level. That is the use it is made for. I do not even
know what "line level" for the LT is, but from the connector type I would
think -10. Anyway, if the unit I am looking at on the ART web site is the
one you have, there is also an unbalanced output. I would first try
connecting that to one of the unbalanced inputs of your 1010lt. unbalanced
is not all so bad as you might think so long as your cable is short and
the environment is not too noisy. Remember that a lot of radio stations
sit right under their transmitter tower where noise is a lot harder to
deal with. Clean connecting surfaces do make a difference.

> 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.

Maybe maybe not, it could be a transformer. The power filtering after that
could still be ok. The level difference would still be the first thing to
correct. Using a mic input for line levels is never a good idea. You are
adding an extra gain stage you just don't need with all problems that
gives. The hum may actually be coming from the 1010 in that case.

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

I personally think the ART USBDualTubePre (yes they push all the words
together like that) is a great deal. It is USB 1.1 which means 16 bit
audio, but it also means it just works. It does mean being more careful
with input level to get the best out of it, but the tube
compression/limiting is quite helpful for that if used gently. I found it
has less noise than the cheaper ART "USB Dual Pre Project Series" and a
little more gain. But the USB Dual Pre Project Series is quite good too.
The USBDualTubePre does have a S/Pdif output at 24bit which I use with my
delta 66. It gives me a) two more mic preamps b) a different sound from
the mic preamps in my Mackie mixer. The downside is that it becomes the
master clock because it has no s/pdif or clock in. That and it's
16bit-ness kind of removes it from the "pro" side of things... but then
the delta series interface is mostly considered high end amateur anyway.
(even though almost any 16 bit sound card out preforms any of yester-years
pro tape machines.)

You can make good music with only a sound blaster as input... though the
SB Live! has sync problems. The Ensonq PCI is quite good though. Probably,
the HDA internal audio line input with a good external mic pre would do
well too.... though I have found internal audio IFs tend to have much
better output quality than input. Input is kind of hit and miss.

Use your ears. Start making music now with what you have. Everything you
learn now will help you when you upgrade. (Len wants yet another mic :)

Len Ovens

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