Audio Research Ref: CD8

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.

For those who made the CD7 upgrade. Mine was already upgraded with a board on top of the two 6H30s slots. I had to change 4 resistors on the board, add one, put the board and installed two new 6h30.

I heard the 5881 upgrade the tube is puted horizontally. Does it have a new board on top of the 6h30 slots to hold the 5881? Can someone send me some pics? I'm not in the US so i have to see if it can be done on field.

I just recieved my CD-7 back from ARC with the upgrade. Will was right on in his assessment.

I only had time to listen to a few "cuts" before I had to leave, so anything I say here was with less than an hour on the player. Its operating on "repeat" until I get home tonight.

The improvement is NOT subtle at all ... in fact, from my limited time listening today, what occured to me was ... this is like going from a mid-grade Grado cartridge to a very good moving coil. In comparison, inner-detail is much improved, like hearing around the notes of a classical guitar. Dynamics are much more explosive ... try the Jessica Williams "Live at Yoshi's" piano trio, both Vol-I and Vol-II. Amazing.

My contact at ARC tells me that the modded CD-7 gets you about one-quarter to one-forth of the way to a CD-8. All I can say is, the CD-8 must be something speciall indeed.

I'd recommend the upgrade mod to anyone who has a stock CD-7. Original owners get the mod for free.

Take care guys and happy listening.