Tube rolling ARC amps & Steelhead


A while back I decided to try tubes. I have had an ARC Ref 2 Mk II preamp for about 2 years, a pair of ARC Ref 300 Mk II monoblocks for about 1 year, and a Manley Steelhead for 3 months. They sounded great, but it never occurred to me until recently that they could sound better - I always assumed that the manufacturers knew best when they put the stock tubes in.

My speakers are Acoustat Spectra 66 full-range electrostats, and, of course, I wanted more bass. After some investigation, I replaced the stock Sovtek 6550's in the monoblocks (8 per channel) with CryoValve 6550C's (from TubeDepot). The improvement in bass was nothing short of dramatic, and I much preferred them to the stock tubes. Nonetheless, the midrange and treble seemed to be lagging behind. After some more investigation into tube replacement options, I replaced the stock 5AR4 rectifier in the Ref 2 Mk II with a Genalex Gold Lion 5AR4, let the amps warm up a couple of hours, and then listened. I was dumbfounded at the change in sound. There was no "good bass" or "good midrange", everything just fell together with remarkable imaging and coherence, and that was with CD's and the tuner! All from changing ONE tube! I then replaced the stock 6922's in the Manly Steelhead with Mullard E88C's (following the advice of another A-gon member), put on an album, and and watched the bar further raised beyond my wildest expectations. All the sound was in beautiful coherence, rock-stable imaging, perfect balance of frequencies, not a touch of harshness, enjoyable at every volume level, like Neil Young was sitting there in the room pouring out his heart to anyone who would listen. I had a friend with me who has heard my system many times before, and he independently remarked "I can't believe it, everything sounds PERFECT!"

My question is - is this a unique experience, or have others found NOS or other tubes to make such an significant difference? I can certainly see why manufacturers don't include scarce tubes with their products, but it still amazes me that the choice of tube can affect the sound so profoundly. I would be interested to hear if others have had similar experiences.

Other equipment:
VPI Scout / Benz Ruby
Levinson 390S
Luxman T12
klinerm
What ever happened to the days when you could just walk into a store and buy a stereo?

I've purchased 2 1962 S/H CCa's and 4 Bendix 6900's for the Steelhead. I'll post my impressions when they get here. I'm also going to try the TungSol's - it'll be neat if they actually sound as good or better than the Bendix's, for way less money.
My friend would be very interested to hear your results, he's trying a quad of TungSols and a pair of Orange Globes soon after his Steelhead breaks in.
Well, I believe I'm finally nearing the end of the road in tube rolling everything I own.

ARC Ref 2 Mk II:
1 Gold Lion 5AR4
1 RCA black plate 6L6GC

ARC Ref 300 monoblocks:
8 Gold Lion KT-88's per side
original 3 Sovtek 6AS7G's per side (actually sound much better than NOS RCA's which I tried)

Manley Steelhead:
2 Siemens old version CCa's
4 Bendix 6900's

I tried Tung-Sol 5687's first in the Manley - the Bendix seem less "punchy" than the Tung Sols, but a little more accurate and extended. I'm still not sure if I prefer the CCa's over Mullard E88CC in the 6922 position - CCa's seem more accurate, but I think the Mullard is "sweeter." It's going to take some dedicated listening to get this sorted out.

I'm also playing with subbing power tubes (one per side at a time)in the monoblocks. Have just replaced one Gold Lion with a GE 6550A - noticeably brighter and more forward, which is kind of nice, but I already miss that MOV "ultimate smoothness." I'm ready to try subbing a Tung Sol 6550, a Svetlana Cryo-Valve, and maybe some others, to see what kind of effects they produce.
More updates please on the tube rolling for the Steelhead. I just replaced Manley 250's amps with 10 year Jeff rowland Model 6 driving the new Von Schweikert VR-7SE. The change was dramatically better. Manley couldn't produce enough bass or highs. It opened up more possibilites with the steelhead. Leaning toward the above post suggestions on the siemens and bendix. Any thoughts?
I currently use the tung sol 5687's and like them for their warmth and punch. I think tube rolling is going to depend on your system. I have tried the raytheon triple mica 7044's, and they are also better than the stock GE 7044, which can sound soft and bland. You should try some of these, they don't cost that much, and for the 6922
I don't think there are any bad or best choices, but most decent NOS tubes will sound better than the stock soviet 6922's and some improvement is also possible by changing the 7044's. I would like to try the bendix tubes, but have generally heard that they do better in circuits that bring them closer to their higher 600v rating than in circuits that keep them at 250v or 300v, and they are very expensive. Amperex, Mullard and Ediswan tubes are all good choices for the 6922 slot.