Challenging Turn Table Setup - Help Needed


Hello!! I have a homerun which houses all my audio/video equipment for pretty much my entire home. In my family room, I am trying to place a record player there and having some distortion issues with loud sections, large cords and certain tones being played. Sometimes it sounds just fine. After much play and different configurations, here is my setup which I still get distortion when certain cords or hit and with some vocals. It's annoying and I am hoping you guys might have some ideas. My limiting factor is that I have to use my coax line from the record player to the homerun:

Project Record Player -> Project Phono Box MM PreAmp -> Tributaries Analog to Digital Converter -> Coax Line -> Marantz 7010 Digital In via Coax

I also have CAT5e cable that I can use but I tried that with left/right analog balloon but I got way more noise in the line versus the above. I also tried to not use the phono preamp at the beginning and covert the signal back to analog and into the 7010 phono stage but that was worse.

I thought about maybe using a coax line amplifier, line isolator or filter but have no idea which one might help or hurt as I am passing a digital audio signal through and these items were made to fix poor video signal. If this doesn't work, my only other idea is to use a sonos connect but I know that compresses the signal.

Maybe the problem is overdriving the Analog – Digital Converter? but then if I remove it from the equation:
- using the coax input into the Marantz gives bad results as I have to put the volume all the way up to hear, and
- using a DAC on the other side into the phono stage of the 7010 doesn't work either

I really want this to work as I love my setup... yellow project turn table with the white B&W CM10's, the yellow on the record player sort of matches the top midrange dome and those CM10's sound so good... running new wires is not an option as I have spray foam insulation.

any ideas on how to help remove my distortion? I could do an integrated amp with HT bypass in my living room but then my solution needs to be wife approved and I know she'll hate the simplicity of what we are going for (unless there is a tube based integrated amp with HT bypass -- don't know of one...)
dhallag
Are you sure the turntable is free of distortion before you do the ADC?
Curious why you are using an ADC and then connecting to your AVR via Coax? Why not run L/R analog interconnects from your Pro-ject phono stage into any of the 5 line level analog inputs on your AVR? This would be the cleanest, most direct connection from an analog source.
I totally agree with Paraneer. You would do much better going direct from the phono preamp to your 7010's line level inputs. That's why you have a phono pre, so you can use any linestage input.

Regards,

Matt M
"I also tried to not use the phono preamp at the beginning and covert the signal back to analog and into the 7010 phono stage but that was worse."

"- using the coax input into the Marantz gives bad results as I have to put the volume all the way up to hear, and
- using a DAC on the other side into the phono stage of the 7010 doesn't work either"

You need to learn what a phono preamp is, does and how it works. That's the problem. Assuming your TT is set up properly, and your cart is broken in, try this. First, go from your Project Phono Box to one of the analog inputs on the back of the receiver. Use any input except the phono input. You shouldn't have any distortion. You can also try plugging your TT directly into the phono input on the back of your receiver and not use the Phono Box. You shouldn't get distortion that way, as well, but using the Phono Box will probably sound better.
Agree with Paraneer, Mattmiller and Zd542.

Why put an A/D converter (and coax line) in this signal path? Converting a phono signal to digital just forces the Marantz to convert it right back again. This adds complexity without purpose.

Connect your phono preamp outputs directly to line level inputs on the Marantz, using a stereo pair of analog signal cables.

The time to fine tune sonic issues is after the system is hooked up correctly.