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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

Showing 6 responses by klinerm

klinerm OP
80 posts
 
Thanks for your post, Cjfrbw.

I'm going to try upgrading the 7044's, per your suggestion. The Steelhead is a wonderful piece of equipment, as you point out, and it deserves to be "maxed out."

With my ARC gear, I've also replaced the Russian 6L6GC in the Ref 2 Mk II preamp with an RCA Black Plate, with overall improved "liquidity" and "listenability." I'm still a novice at this, but I think this is about as far as I can go with this piece.

I have purchased, but not yet installed, RCA Black Plate 6AS7G's to replace the Russian equivalents in my Ref 300 Mk II mono amps, and have purchased GE 6550A's to replace the the Cryo-Valved Svetlana's in the same amps. From what I read, TungSol 6550's may be better, and Gold Lion KT88's would almost certainly be better, but it could take many months and a big wad of cash to try that experiment.

The only saving grace to this madness is that this seems to me to be a sort of "final frontier" in upgrading. There appears often to be fairly good agreement on what constitutes the best tubes of a given type ever made, so there's (thankfully) nowhere to go after that.
klinerm OP
80 posts
 
Has anyone tried replacing the 6922's in the Steelhead with NOS (1960's) Siemens CCa's?
klinerm OP
80 posts
 
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.
klinerm OP
80 posts
 
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.
klinerm OP
80 posts
 
More updates - keep in mind Cjfrbw's admonition that most of this is probably system dependent, so it may not work for you.

STEELHEAD

1) I've decided I prefer Mullard E88cc's in the 6922 position over grey-plate Siemens CCa's. A little less accurate, perhaps, but more "musical". Go figure.

2) The jury is still out in my mind on whether Bendix 6900's are better (in absolute terms) in the 7044 position than the TungSol 5687's. For the money, it's a "no-brainer"; the TungSols blow them away.

ARC REF 300 Mk II

1) I have decided Tung Sol 6550's have far too much bass, relative to Gold Lions, for my taste. I have gone back to all Gold Lions.

On another note, I have amassed quite a collection of Gold Lion KT88's, ranging from the older "large lion" brown-based ones complete with rotting boxes (which I think are unequivocally real), to slightly smaller "small lion" tubes with black bases and newer-style boxes. Some of the latter have solid plates, and some have holes. I recently saw a thread on Tube Asylum in which the latter, newer style were described as "unequivocal Chinese fakes", identical to current "Shuagang" (or something like that) tubes.

I don't pretend to know much about this, but I understand that MOV did begin manufacturing in China towards the end of their production. I have been conducting A/B tests (not blinded) between the older "unequivocally real" Gold Lions, and the newer "maybe fake" ones. Guess what? If anything, the newer ones sound BETTER, at least in the above system. If the newer-looking Gold Lions are actually current "Shuagangs", then I think there is a real bargain to be had. I have also wondered that if the Chinese companies kept making tubes after MOV went under, then it may not be so surprising if their current tubes look like later Gold Lions. I'm pretty much content to believe what my own ears tell me, but if anyone is really an "expert" in this area, I'd like to hear their 2 cents' worth.
klinerm OP
80 posts
 

mmrkaic,

1) no, and

2) no.

The topic of this (ancient) thread is the sound of different tubes, and respondents' enjoyment or lack thereof of various tubes in the specified equipment. The topic is not about objectively measuring anything. (Almost) everyone posting here clearly believes that they hear very significant differences in different tubes (I know I do), and I doubt that all of us are wrong. We enjoy sharing our impressions with other enthusiasts who feel similarly. No one posting here except you cares one whit about objectively measuring parameters that some people may or may not think are important. We have our systems because we enjoy them, not because we want to measure them.

The human auditory system has evolved over hundreds of millions of years, and it's pretty much a sure thing we will never completely understand it. Who knows what makes music sound "good" or "real?" We'll be asking and attempting to answer those questions for many years to come.

So please mmrkaic, and I say this sincerely. Sit back, chill, maybe get a drink, and just enjoy the music.

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