Please Help re: Source > DMP 2 Pre > Lucid AD 9624 > MAudio Audiophile 2496

[rontokyo]

Try as I may, using the above setup to record vinyl [the source] to my hard drive is giving me a compressed squared-off waveform where louder passages slam up against an imaginary line. I'm using a coax connector from the Lucid to the S/PDIF on the Audiophile card. I've tried lower preamp levels on the DMP 2 and higher levels on the Lucid analog "sensitivity" knob and visa versa.

Please help! I think I'm in over my head here, though the solution may be something very simple that I'm not doing properly.

 

[mixsit]

Are you not seeing overload levels on the Lucid input meters?
Does a record player feed the DMP-2? Either or any of the analog points could be clipping.

 

[rontokyo]

Gain levels on the DMP2 are *very* low and the levels on the Lucid meter do not indicate overload. The feed to the DMP2 is via my stand alone phono preamp that requires a signal boost [so there's no overload from the source]. But whether I adjust the mic pre very low or higher and the adjust the Lucid in the opposite direction, the waveform as recorded on Sound Forge 6 is squared off. I simply cannot get a natural looking waveform. Does setting the Lucid at either 16 or 24 bit make any difference? I generally record [with my previous Aardvark card] at 32 bit, but should I set SF to record at 16 or 24 bit? Don't know as this could be the source of my problem, though.

I should also mention that whereas the waveform is squared off, it is not clipped. Adjusting either the DMP pre or the Lucid will vary the waveform from -inf to -3dB, but at any level it is squrared off.

 

[Blue Bear Sound]

Re: Please Help re: Source > DMP 2 Pre > Lucid AD 9624 > MAudio Audiophile 2496

Try as I may, using the above setup to record vinyl [the source] to my hard drive is giving me a compressed squared-off waveform where louder passages slam up against an imaginary line. I'm using a coax connector from the Lucid to the S/PDIF on the Audiophile card. I've tried lower preamp levels on the DMP 2 and higher levels on the Lucid analog "sensitivity" knob and visa versa.

Please help! I think I'm in over my head here, though the solution may be something very simple that I'm not doing properly.

I don't see where you've got an RIAA phono preamp in there... you need one to convert phono signals to line level (it's not about gain, it's about the RIAA eq curve used to cut vinyl!)

 

[mixsit]

... The feed to the DMP2 is via my stand alone phono preamp that requires a signal boost [so there's no overload from the source]. But whether I adjust the mic pre very low or higher and the adjust the Lucid in the opposite direction, the waveform as recorded on Sound Forge 6 is squared off...
I should also mention that whereas the waveform is squared off, it is not clipped.

Would it happen to be line level from the phono amp, feeding a mic input?

"...Adjusting either the DMP pre or the Lucid will vary the waveform from -inf to -3dB, but at any level it is squrared off. "

I don't get the difference of 'squared off' not being clipped, but if you can do that, it woud seem to point back to the phono amp or DMP combo?
How about phono amp directly to the Lucid?

 

[rontokyo]

Thanks, mixsit. I've spent more time dicking around with this and have determined that the DMP2 is the culprit--specifically the 1/4" input from the phono pre to the mic pre. It seems that MAudio has configured the 1/4" inputs as high impedance instrument ins, which may be why I'm having the problem I am. What I'll have to try now is using the DMP's XLR inputs, necessitating my converting one end of an unbalanced pair of cables to balanced with XLR connectors. Don't know if it'll work, but it's worth a shot. Things like this happen when you use gear [a mic pre, in this case] for purposes other than for which they were designed.

Oh. Feeding the Lucid with a direct signal from the phono pre is a good idea, but I don't at present have the proper connectors. Going directly from the phono pre to the analog ins on the soundcard results in a very low signal--hence the need for the mic pre.

 

[mixsit]

Is the phono output somewhere between line and instrument level -too hot for the 1/4" in's but not enough to go line-in on the card?
Maybe the s/c 1/4" is balanced and you're loosing 6db going in unbalanced.
Something to consider. If that's the case and the level going direct to the s/c is not too far out of wack, you could bring the gain up in software once it's in. At 24 bit you could throw away many db at the A/D and still have way more s/n than the record does. Or better yet, get the Lucid in there. Wouldn't that be a better front end than the s/c?
Wayne

 

[rontokyo]

Is the phono output somewhere between line and instrument level -too hot for the 1/4" in's but not enough to go line-in on the card?

Yes, I believe that's correct.

Maybe the s/c 1/4" is balanced and you're loosing 6db going in unbalanced.

I can, from the phono preamp, enter the soundcard via unbalanced RCAs--but in so doing I would need someting like 40-50dB of gain to bring the signal up to about -3dB, which is where I'd like it to record.

If that's the case and the level going direct to the s/c is not too far out of wack, you could bring the gain up in software once it's in. At 24 bit you could throw away many db at the A/D and still have way more s/n than the record does.

Oh sure, if it were merely a question of a few dB I could bring the gain up that way [and I often do, in fact], but without the mic preamp in the chain I'd be coming in *way* too low. Most people in my situation have a preamp as part of their stereo system [I'm using an integrated amp] so they can adjust phono gain levels to their s/c using their preamp outs.

Or better yet, get the Lucid in there. Wouldn't that be a better front end than the s/c?
Wayne

Oh sure. My purpose in using the Lucid is to bypass the s/c converters, so with the Lucid in the chain I enter the s/c via the S/PDF.

In any event, I'm off today to get RCA>XLR adaptors and enter the DMP via the balanced ins. *Hopefully* this will solve the clipping problem I'm having.