Audio Research Ref: CD8

Tlg. Audio Research turned my unit around in 3 weeks. Door to door.

Actually a point of clarification. The CD8 has a new power supply. Which the CD7 can be retro-fitted to real close. ARC tells me it's a rather large sonic improvement.
But the DAC in the CD8 is totally new. The CD7 can not be retrofitted with the new DAC.
I'll report here once I get my CD7 upgrade back from ARC, next week.

My CD7 was to ship Wednesday (yesterday) back to me with the power supply mod.
I will let everyone know what I hear different; next week.

All,

This is turning out to be quite a lively and interesting discussion/debate.

My CD7 shipped from ARC last Wednesday, so hopefully I see it mid-end of this week.
I will report on the sonic differences when the unit returns.

The cost of the upgrade/modification was $100. I can't comment nor be quoted to ARC as "the cost", but that was the charge to me.
The mod involves replacing the 2 of the 3 6H30 tubes in the power supply (the ones side by side providing regulation) with a 5881. (5881 is a more "industrial" 6L6).
The 3rd 6H30 in the power supply section remains.

ARC also brought everything in the unit up to spec. ie. My unit turned on by itself when plugged in. (not suppose to do that). They also performed a full lab, and listening test.

I think it was a very good unit before this upgrade/mod. I suspect it will sound better when it returns.

I have had or listened to Krell 505, krell Ref64 with MD10, Rega. The CD7 with regard to high frequency transparency, lack of edge, and midrange detail bettered all of the above.
The Ref64 with MD10, is still in my opinion an incredible combination, wish I did not sell.
But I still think overall for musical enjoyment the CD7 is quite a bit better.

When I spoke to Leonard, he did say that this mod was a sonic improvement. I will also be interested to in hearing how so. I suspect the CD7 with the 5881 will run hotter. Though, actually I wish ARC went with a 6550 for regulation. The CD8, and newer Ref3's use a 6550 for regulation. I think I have to wait a few more days for delivery.

I received my CD7 back from Audio Research yesterday. I listened to it last night, and then again this afternoon. Total "break in time" about 5 hours.
The difference from before the mod till now is:
Air. The sound stage and music are riding on air. On top of this when an instrument is highlighted in a band (snare drum, trumpet), or vocal piece (soloist) its like the performer steps up. I have not heard that quality before.
Also the level of micro detail is increased by quite a margin. In particular in the midband, and high frequencies.
I now truly believe Leonard was accurate with his statement that the sonic level improvement was large. Though I must say, overall it sounds like the midrange is boosted up slightly. Before I thought maybe the bass was too much.
My associated equipment is Ref2, D400 Mk2, Wilson watt/puppy 7.
The new tube; 5881 tube is installed horizontally, slightly forward, and to the right cabinet edge of the old 2 power regulation tubes. The older power regulation tube holders are "capped off".
Audio Research also ensured my unit was fully up to spec (turn on mod), greased, lubed the transport.
Again another very satisfying experience from Audio Research.
I am not a dealer, not in the audio business, nor associated with Audio Research in any way.

No, what I am saying is. My CD7 was somewhat lifeless even though I had the replaced tubes. Now my CD7 with the power supply mod is:
The sound stage and music are riding on air. On top of this when an instrument is highlighted in a band (snare drum, trumpet), or vocal piece (soloist) its like the performer steps up.
I do not believe the overall tonality has changed. The midrange is now alive with more detail (not harsh, not aggressive). It just somehow sounds flatter.
For me the improvement is quite remarkable.
I realize it's hard making decisions like this to mod a component, I took the gamble based on Leonards advice, and the sound that my CD7 had. I am estatic over the improvement. I do not know if ARC would characterize the change I hear as what they would expect.

Any other impressions: CD7 5881 Tube upgrade ?
Of the others folks who have had their CD7 upgraded/modified. What are your impressions?

Probably people who are upgrading to the CD8.
Anyone else besides me have input on the CD7 power supply modification ?

The only "part" added is the 5881 tube, which replaces the 2 power supply regulator tubes.
Mine seem to sound great once it was returned from ARC.

I have internal pictures of my CD7 as modified by Audio Research with the 5881 tube. I toook these when I receivced my CD7 back from ARC.I have already emailed them to a few folks here.
Who else would like a picture? Send me an email I'll forward off to you.
Bill

Weiserb,

Does your CD7 have the power supply modification ? ie. we have been talkng about it here for a couple of months.