Audio Research Ref: CD8

My CD8 is now spinning the Purist Audio Design System Enhancer in repeat mode and I will wait at less 24 hours before listening to it. I just measured it and did a spectral analysis to be sure everything was correct and comparing it to the CD7 could find that the CD8 output level is 3.5dB lower, as I confirmed later from the respective manuals.
When comparing these units one must carefully match the volume, otherwise the CD7 is much louder!

How that translates into volts ?

BTW - 24h is prolly not enough. It took my CD-7 400h of continuos play to fully break-in.

The CD8 output is 1.8V RMS RCA and 3.6V RMS XLR .
The CD7 is 2.7 and 5.4V RMS respectively.

I am using the Purist Audio Design System Enhancer CD for break-in, so I hope that after 100 hours the CD8 will be listenable. I went through two CD7s and I still remember how disappointed I was when I replaced one with more than 1000 hours play by one taken from the box.

My perception after a few minutes listening is that the CD-8 is more detailed and has better bass definition - air moves faster - the fly at track 10 minute4'44'of Paniagua LaFolia is clearly heard!

What I've Learned: I spoke with Leonard at AR and asked him if this upgrade is a sonic improvement. He advised that it addresses a specific issue: if the existing two tubes in the power supply drift apart in their values this can cause noise. By going to a single tube instead of two tubes, this is eliminated. Because AR is covering this at no charge, I would imagine that they see this as correcting a problem.

The two 6h30 problem drift was solved with an upgrade kit that was fitted by my distributor free of charge, after I noticed some hum in the CD output when used in single ended mode. This was traced to a defective 6h30, but after this upgrade I had no more problems. Before parting with the old CD7 I checked the tubes - after 2500 hours they still measured as new.
Although the CD8 is still burning-in, one thing is sure - bass is better articulated and more controlled. Three walls in my room are 2 feet wide solid stone and there is almost no bass absorption. As I am currently using Soundab A1PXs, bass performance is critical and the difference between the two players is easily noticed.