DAW > Tube Pre > DAW...Problem

[mark4man]

Crew,

I'm having troubles interfacing a UA 2-610 stereo tube pre with my PC DAW's Audio Interface (Layla 24/96.)

What I was trying to accomplish was...to take a previously recorded vocal track, loop it out of the DAW, through the 2-610; & re-record it back into the DAW (to apply a high shelf EQ to the track; & also see if the 2-610 can give the track a little realism...make it a little more "expansive" sounding.)

No matter which channels I use (going out of the Layla, thru the 2-610; & back into the Layla), or no matter how my gain staging is set up (relative to the Layla's nominal I/O voltages & the 2-610's Gain/Level)...when I push my levels up to where they should be for recording, I experience a hollow, high-pitched ringing sound...like the track's audio material is whistling around inside a bottle.

Could there be something wrong with the 2-610 (as opposed to the routing matrix inside the AI causing a feedback loop)?

The reason I ask is...I can do esentially the same thing with a hdwe. effects processor I use...a Lexicon MPX 500. I routinely send tracks out of the Layla's (Analog) Channel 3/4, thru the Lexicon for FX processing; & back into 3/4, to be re-recorded into an adjacent track in the DAW (Sonar XL 2.2.) This is what makes me suspect of the 2-610.

Any thoughts as to what I may be doing wrong (or exactly where the problem may lie)? This shouldn't be a characteristic flaw for a quality tube pre, should it? Could it be the AI?

Any help from the pros 'round here would be appreciated.

Thanks very much,

mark4man

[Kev]

Lets try ...

DAW output .. CABLE
remove the UA 2-610 ...
CABLE DAW input

this will check you signal routing and your two cables.

If that works OK then it will be something about the cables you are using and they way there interface with the UA 2-610

The line level will need to attenuated before the UA 2-610.

[tubes4tone]

I don't own one of these units, but from looking at the manual I would say make sure you are using the "Line" input on the rear and have the input switch set to "line" on the front. Otherwise the pre is expecting a low-level mic signal and may be amplifying the signal too much and causing the feedback/ringing.

Just a thought. I'm not calling you stupid; as for myself, sometimes I can't figure out why a piece of equipment doesn't work while the power switch is in the OFF position :roll: .

[bmf]

are you sure you muted the input thru in the Echo console? otherwise you'll feed the recorded signal back into the DAW's output... sounds like...

[mark4man]

kev, tubes4tone & bmf,

Thanks for the input (pardon the pun.)

Originally posted by bmf:
are you sure you muted the input thru in the Echo console? otherwise you'll feed the recorded signal back into the DAW's output... sounds like...

Tell me what you mean by the "input thru". In the Echo console (by default), whichever Output Bus is selected...all the other channels' Inputs are automatically muted (as is the case with most pro audio AI & sound card virtual mixing consoles.) For example...if I select Output Bus 3/4...the analog Ins 1/2, 5/6 & 7/8 are automatically muted.

I've never been able to figure out this routing scheme...in light of the fact that the Inputs are actually only "input monitors" (even though they're labled as Inputs); & the faders on those strips only control the level of input signal going to the outputs. Since the only control over input level going to the ADC is external (via front end hdwe.), the input signal must get split pre ADC, with one leg feeding the converters & one leg routed to the outputs (as controlled by the input monitor faders.) There is also a Playback Bus, which controls the output of the audio application.

I guess I would really really need to see a flow chart...but what I'm going to try, is to go out of 3/4, (thru the tube pre), back into 5/6; & just mute everything else, save for the Main faders.

Thanks,

mark4man

[bmf]

in the echo console it works like this (but i think you got it):
each input will automatically be monitored for direct listening as long as you don't switch its output to "mute". that means if you are re-recording something from your card's output 1-2 into an input that is also routed to 1-2 you'll get a feeback chain - of course. "playback" has nothing to do with this...
so the fault must be somewhere in your DAW probably. in Logic i'd have to mute the channel i'm recording to or select "no output".
any success?

[mark4man]

Originally posted by bmf:
any success?

Yeah...that worked (muting everything exept for the immediate I/O channels being utilized & the main outs.)

Thanks for the help & the explaination (direct listening/re-recording loop.)

mark4man


BTW - Thinking further on your explaination...the success probably came from the fact that I was using I/O channels for re-recording other than the main outs (1-2.)

[bmf]

well, you're welcome.
but: did it sound the way you expected it to sound ?

i just added 8 more outs (via ADAT optical) to my card to have more analog channels with eq and comps available without the need of re-recording. this is absolutely worth it!

[mark4man]

Originally posted by bmf:
but: did it sound the way you expected it to sound?

Yeah...the high shelf made it shine; & of course the 2-610 adds a beautiful expansive sound to everything it touches (it gets a bad rap...as being to dark...for some reason; which is not at all true.

Nice move on the lightpipe.

mark4man