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You are not reading my posts!

Posted by Bambi B on August 15, 2010 at 20:45:58

In Reply to: RE: My understanding of the Audio Research SP10 tubes' function posted by wheezer on August 15, 2010 at 15:49:48:

wheezer,

If you'd read my posts to this thread, you'd know:

1. I never wished nor mentioned in this thread wanting to lower the power to the tubes in the Audio Research SP10- if you'd read my reply to Michael Samra, both ARC and Bob Hovland told me in this case, that action was more detrimental to the SP10 sound (loss of liveliness, frequency extension, soundstage, etc) than staying with Sovteks. Their advice was to find rugged, great sounding, non-microphonic, quiet NOS- which if you's read my original post, included warnings of the difficulties to obtain these reliably and reasonably.

2. Accordingly, as above, if you had read my retubing story- I do not need assistance to use NOS tubes in the SP10- as mentioned, because all 15 tubes in the SP10 are models of NOS that were proven to operate optimally for a long time in the SP10: 4 Amperex E188CC / 7308 (1962 and 1964) phono stage, 2- Valvo E188CC line stage gain, and 6- (3 matched pairs) Tungsram red label E88CC (1969 to 1979) for the other control chassis tubes, and a Siemens triple mica E81CC (12AT7WA) and 2- Sylvania 5881's in the power supply chassis.

3. Given the above history, I would not describe myself as a NOS tube "newbie" as I've owned the SP10 since 1985 (uses 2- 6922's), the SP10 since 1987, along the 11 other pieces of tube gear- ARC, McIntosh, Scott, Fisher, and etc., listed at the bottom of my reply, plus about 600 NOS tubes of 34 types purchased over the last 19 years.

4. I never made a comparison of the SP10 and AI Modulus preamps except that by reputation and factory recommendation, the AI's seem to need tubes that are quiet and rugged similarly to the SP10's. I've been a long admirer of the AI Modulus as an excellent entry-level high performance tube preamp. Your experiments reveal an interesting aspect of that level of the high end that such dramatic improvements apparently can be made with component changes- it can sold reasonably and work at an acceptable level, but if the person has the ear and technical knowledge, the budget preamp can become outstanding. Michael Samra says you've gotten great results with the Modulus.

The SP10 though had a different development approach and ARC tried to create a no-compromise design solution for LP playback that was as refined as possible from the factory. This is the root reason Bob Hovland advised against trying to modify the SP10-it had state of the art components already. Further, ARC was always making revisions to refine it further- oddly, some people seem to take exception to ARC constant upgrades as though that's a negative!

4. You mention that I didn't contribute anything to the OP's query. The OP began the thread wanting to know the advantages and how to go about using NOS in an AI. My replies eventually veered off the point to a broader conversation about NOS in general, but my original reply contained the story of how experimentation and a warning that buying before studying the subject was a recipe for over-spending too much and owning unusable tubes. I believe that these comments are to the point and useful to the OP to help guide towards effective and economical NOS tube purchases- mainly by avoiding the haphazard, "bargain" hunting way I did it! As mentioned, the bargains are incredibly expensive if only 25% are useful,..

5. Tube economics: If you'd read my posts in this thread you would have noticed that I comment on the cost of the NOS tubes in the SP10 and that the only reason I could retube the SP10 in this way was that those NOS tubes that today would be $1,200 cost me about $350 because I started in 1991, RE: "most tubes (6DJ8's) were $12-15". In fact, the 109 6DJ8 family tubes I have did probably cost in total $1800-$2,000 over nearly 20 years, but I can sell about 60 of the unneeded ones today for probably near that original amount- meaning the remaining 50 tubes have been nearly free . Similarly, after 23 years use, the SP10 is worth 90+% of it's costs. I figure the SP10 so far has cost me about $20 per year to own. The SP8 I bought used, freshly upgraded in 1985 is worth exactly today what I have into it after 25 years' ownership. You see how clever we 19- year "newbies" can be?

6. I didn't understand the "flame war" comment and now do not understand the, "Some folks get offended rather easily. :-)" comment. Why do you believe that I was or am upset or offended? Am I need of a 90 degree punctuation smiley face? If anything, I'm only a bit perplexed that my communications have not been clear to you.

Perhaps I'm woolly-thinking tired- I've been working 16 hours per day on 4 draft Patent applications for a solid month- writing the detailed technical descriptions, and doing the CAD drawings in that peculiar style required by the USPO. One design needs 16 drawings -plus filling all those damnable forms- they're a test to see if applicants are clever and patient enough to become a government cubicle codger!

Anyway, I hope this has been a satisfactory clarification.


Cheers,

Bambi B

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