Audio Research CD6 vs CD9 original and SE versions

I recently had an ARC CD6 in for a demo.  The system is:

Intel NUC --> MSB Analog (USB) --> Krell FBI --> Thiel CS2.7

With the ARC installed it went straight to the Krell.

What I heard was a fabulous top to midbass.  Where it did not sound right was in the bass.  For lack of a better term the bass sound was "rounded".  I tried a few different cables with varying degrees of success however I could not live with the bass.

My question is does anyone have experience with side-by-side listening of the CD6 vs CD9 and or the SE versions?  If so what differences did you hear?  I listen to mostly classical on this system and having poor bass drum, tympani, and double bass performance won't cut it.

To me if both well implemented, it comes down to the type of conversion used, Delta Sigma or R2R Ladder 

The AR 9 uses PCM1792 dac chips which are Delta Sigma, not my favourite, my fav being the R2R ladder dacs PCM1702 and the even better last made PCM1704.

The AR6 I can’t find what dac chips it uses, I looked but there is hundreds to look through, Search "Audio Reseach CD6’ and look for dac chip, dac’s, or D/A converter. If you find it let me know, as it "seems" to be a bit of a secrete.

Cheers George
From another post:

"The Ref CD-8 used Burr Brown PCM 1792 chips configured in stereo mode. By contrast, the CD-6 and Ref CD-9 use the BB PCM 1792A, but configured in quad mono mode."

Does this - in your experience - lead to issues with low frequency issues?
Just curious if you're just wanting to play CD’s why don’t you run a transport into your MSB Dac? Or do you not like the sound of the MSB?

Just curious if you're just wanting to play CD’s why don’t you run a transport into your MSB Dac?

+1 on that.  jond

solobone22 If the CD6 and CD8 and CD9 are all  PCM 1792. wouldn't bother them the MSB should nail them all.

Give me the MSB Analog and a nice CD transport, and feed that Krell direct with the MSB's volume control.

Cheers George
@jond @georgehifi I've looked at the MSB spinners however they use the Oppo transport which may be hard to get these days.

I've run a few different CD players into the MSB however they never quite worked for me:

Denon 1650AR
Primare CD31

The midbass on up was far superior on the ARC CD-6.

Ideally I would like something that I can play discs and has a USB or network input.

I keep re-reading this post and wonder, if, ARC has developed these newer spinner(s) to "bloom" in the midbass/midrange registers?
Possibly a more rounded or softer presentation?

Happy Listening!
@jafant that could be.  I for one would like to hear a few ARC players back to back to back.

I think the ARC had a fantastic mid/high presentation.  A trombone should sound like a trombone and a flute should sound like a flute.  Not all trombones sound the same and not all players on the same equipment sound the same however there is a component of the sound that should identify it as a trombone or a flute.  I think that is what the ARC gets right.  

The MSB on the other hand gives a very clear presentation with a little less of that component of the sound that identifies the instruments.

I will keep you posted as I attempt to obtain a demo of the CD6/6SE or CD9 SE spinners. HiFi Buys Atlanta is the closest ARC dealer/retailer to me.

Happy Listening
The sound of the individual instruments were fuller (some might call this warmer) however the bass was muddy.  I heard the instrumental presentation as closer to what I would hear in the concert hall with the exception of the double bass which was not clear at all.

This was the impression I got from the CD6 (review is of the REF9):

From this thread:

"The Ref 9 might not be the most detailed player in the World, especially at low frequencies where it is a little warm and wooly"

Thank You for the follow up. During my demo sessions, I did not find, the CD9 muddy in lower registers.

Happy Listening!
@jafant what did you listen to during the demo sessions?  what were the other components?
I auditioned the CD9 with ARC gear. Ref5 SE pre-amp, Ref75 power amp.
For fun- Bryston 4B-ST power amp. Transparent OPUS cabling all around.Wilson Audio Sasha and Sophia loudspeakers. A large, rectangular room dimension, tuned by the late Dave Wilson.Audio Advice Raleigh, NC.

Musical selections:Jamie Cullum- Twentysomething (2004) VerveJourney - Greatest Hits (1988) ColumbiaDark Side of the Moon (DSOTM) 1990 EMISRV- Couldn't Stand The Weather (1986) Epic: all CDs are original pressings -not remasters starting after 1994.

then various tunes via a MacBook to demo the DAC section.
Happy Listening!