help me decide: VTL 7.5 or ARC Ref 3

I purchased a 7.5 Mk2 in August and use it with a CAT JL-2 Sig Mk2. It is the best combination that I have heard with my Eidolons. It is curious that the 7.5 works better with the CAT amp than the latest CAT Ultimate Mk2 does on the Eidolons. I used to own ARC (SP9, LS-1, PH-1) in the early 90's and switched to the CAT because I felt that it sounded much better, but at that time I had Martin-Logan CLS IIz's and 2 Vandersteen subs. I have not heard the Ref 3 in my system so I can't comment on your question specifically.

Well I have owned Ref 3 for almost a year then I switched to the VTL 7.5. My 7.5 is the original not the new Mk2. The Ref 3 did some amazing things that were pretty impressive, especially in the area of detail and transparency and I really had no complaint with it. However when I switched to the 7.5 I then rcognized some weaknesses in the Ref 3. I had everything I had with the Ref 3 and more. Better dynamics, pace, musicality, transparancy and most of all soundstaging/ imaging. This has really peaked my interested in the whole VTL company. My vote is for the 7.5 over the Ref 3.

I have compared them side by side (with several audiophile friends): 1st/2nd and 3rd (latest) version of ARC Ref 3 , VTL Ref 7.5 (older version) and Cary SLP-05 .

Overall winner is : 3rd version ARC Ref 3 which is much more dynamic , more transparent & detail than older version. (most natural , musical , more "you are there feeling)
2nd : 1st/2nd version ARC Ref 3 with NOS National 6L6 upgrade on power supply section -> most warmth , very pleasant on ears .
3rd : VTL Ref TL 7.5 Series I (most dynamic , a bit forward)
4th : Cary SLP-05 (most transparent & detailed , a bit cold)
5th : 1st version ARC Ref 3 without any tube upgrade ( original comes with 6L6 tube as stated on tube positioning sheet)
6th : 2nd version ARC Ref 3 w/o any tube upgrade : 6550C tube on power supply but tube positioning sheet state as 6L6 ( sounds worst , congested , very weak on low frequency , confused) .

Also in my experience : I couldn't find any after market power cord suits ARC Ref 3 better than original one.
Power cord tested : Nordost Valhalla , Transparent Powerlink MM & Kimber Palladian PK-10 .

It was test on system : Musical Fidelity KW SACD , Cary CAD-211M Anniversary , Vienna Acoustics Mahler .

Opinions may vary on different system .

Cheers..

I owned both, and the VTL 7.5 first version was so superior compare to the Ref 3 that it makes me hard to believe how other audiophiles prefer the Ref 3, there was no comparison. I wonder in what hi-fi systems they have been hooked up.

Though I have not personally heard either, from the available data, the VTL *should* have better pre-amp performance, namely better noise performance. From the known literature, the VTL has a shorter signal path, which is in-line with the typical audiophile desires. I believe the Achilles' heel in the ARC topology is the choice of integrated circuit for remote volume control [These devices are readily available from Digikey for a few bucks. These IC's contain numerous active elements (op amps), of which are in the signal path]. The VTL has only a "95-step 70dB discrete relay attenuator for all attenuation functions" - ripped from the website.
I would think for a $10k unit a more robust solution would have been implemented for the actual signal attenuation. The chosen design is quite inexpensive, and is a poor choice IMHO, and as always YMMV.