Audio Research REF 3 and REF 5 Tweaks

I've been told by a trusted friend that removing the covers from the ARC preamp and the phono stage is a significant improvement. I'll try it tomorrow and report back. I have a couple of audio enthusiasts coming over for a listening session so we can compare notes. By the way, placing a VPI brick on top of the phono stage helped a little too. With the cover removed, that eliminates that option. We'll see.

My Ref 5 tweaks: GNS 'Statement' upgrade, Nordost Valhalla power cord supported on maple blocks, Gingko Mini Clouds under feet. Plexiglass cover with Note Pad damper.

Oreganpapa,
So what did you think when you removed the covers?
Scousepasty,
What did GNS do to your preamp and what did it cost?
One thing I've noticed about my REF3s is that the sound which is usually open, dynmamic and has great bass, tends to fade away, I at firts thought this was worn out tubes, but I've found a good cleaning of the tube pins with Caig DeOxit and the magic comes back. I've also found that anytime you move or reposition the preamp, the 4 6H30 tubes toward the back of the preamp tend to loosen and hang down just a little bit overtime. The cleaning process and restoring them to their 90 degree horizontal position brings the sound right back without having to retube. I'd not be surprised if this is where the discrepancy between ARC's claim for tube life and other audiophile's findings comes to life. Because of course a person putting in new tubes would probably clean them before inserting and they would be inserted correctly into the tube sockets. And viola, the the spectacular, natural sound is back.
Thanks,
Steve

I tried various tubes, like classic Mullards in the PH-7 and found the stock tubes sound best.

Never tried Mullards, but 6DJ8 Orange Globes or USN white label 7308 Amperex were a substantive enhancement over the stock Sovtek 6922 in my PH7. Nicely extended top end, considerably more detail and improved tonal depth across the frequencies.

Be that as it may, I agree that ARC optimally outfits their Reference components with tubes. The NOS 6H30-DR do offer improvement, but since that tube has really shot up in price the relative value equation may not be their favor. Never tried the NOS Tung Sol 6550 but the GE6550A is not a good choice in the power supply.

Upper echelon Shunyata power cords work very well with ARC Ref - try the Anaconda, Python or King Cobra.

Oreganpapa; The plexiglass top covers can be ordered as an alternative to the 'tin plate' originals. They [plexi]don't ring or rattle, as I've experienced with the earlier material.
Cost for GNS Statement upgrade was $3000+ plus return shipping from UK. New high grade components & piggy backed extras added, wiring shielded and lots of anti-vibration padding can be seen.
Sound is superb and has improved steadily over about 500 hours break-in.
Soon to be replaced by a 40th Anniversary, so we'll see what that brings to the party!
I've always checked tubes if I move any equipment and have often found some do loosen-up during moving.