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Conrad Johnson 17LS Stock Tubes

I am about to buy a CJ 17LS from a dealer as a "demo" model. The dealer told me HE threw out the stock tubes and replaced them with "something." He mentioned Phillips, but he couldn't recall. I am using the CJ with Theta Digital gear (transport, dac and SS amp). I would have been happier with the stock Stovtek tubes for a couple months and then started to experiment with rolling, but I guess I don't have a choice. Should I call CJ and ask for a new set? and then go from there? I think it would be nice to hear what the company intended the preamp to sound like so I can make informed decisions on what tubes to try next...right? Is it usual for a dealer to throw out the stock tubes before selling an item? Also, I was reading the Stereophile review and the reviewer states "The Premier's Sovtek tubes themselves are carefully burned-in and matched, and supplied with damping rings to reduce microphonics." What are damping rings and how do I know if he threw those out too? I am just guessing, but a "carefully matched pair" of Sovteks is better then a couple of this and a couple of that? Right? Does it matter if you mix an match with preamps?
busaganashi
8 responses Add your response
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chuck
203 posts
 
B,

Yes you can purchase a set of stock 6922's for your Premier 17LS. I do not know the cost, but I am sure that Knut of CJ would be happy to provide you with that information. When replacing the tubes you must replace with matched pairs, from what I understand. The stock tubes tend to sound a little grainy and aggresive on the high end. Yes I would purchase the stock tubes so that you could get an idea of what the preamp sounds like stock, tube dampners included. Tube dampners are small heavy gauged rubber band circles that fit snugly over the input tubes. They help reduce mircophonic vibrations. They do seem to take some of the "air" away from instruments. One last note, the dealer probably threw out the stock tubes to taylor the sound to the system he was using.

Hope this helps,

Johnny
fatparrot
1,314 posts
 
Do yourself a BIG favor and call Andy at Vintage Tube Services @ 616-454-3467 (www.vintagetubeservies.com) Don't waste money with stock Russian tubes...they just DO NOT have the magic that N.O.S. will give you. Most manufactures will use current production Russian tubes for cost considerations and availibility but THEY AIN'T classic N.O.S. tubes! I just used Andy to retube some Atma-sphere equipment with Tung-sol 6SN7's and the results were more than I would have believed possible!
busaganashi OP
32 posts
 
I'll call CJ on Monday and order some new ones. I read up some on tubes today. I noticed a lot of people are impressed with the Siemens CCa and the Telefunkens. They are about $100 each though. Will the best tubes make the 17LS that much better....especially given that I am using it with all SS gear. Has anyone tried these tubes or any other NOS with CJ preamps? Are there any good Russian 6922's?

Thanks for your replies.
truman
167 posts
 
I'd just like to second Fatparrot's suggestion that you contact Andy Bowman at Vintage Tube Services. I have dealt with him before. He is very reputable and stands behind his products. I have also had excellent dealings with Kevin Deal of Upscale Audio and can similarily unconditionally recommend Kevin to you.
NOS will give you "the best" your preamp can offer. Call them to ask what tubes they would recommend for your equip. I am sure they will both be very helpful. Turner/Atlanta.
busaganashi OP
32 posts
 
I looked at both of the websites. Upscale Audio seems to be limiting their "best" tubes to people that buy gear there (cookie jar). I'll call Andy Bowman at VTS on Monday. I think I will buy 4 of the Telefunkens and four of the Siemens, maybe even some Mullard type 1's. What is the difference between "moving mag," "moving coil" and the other types he lists? How long do these tubes last? Assuming the tubes last a year...it seems we will all be in trouble soon and buying Russian tubes...right? What about his damping rings made of solid brass...probably better than the CJ rubber ones or should I go without all damping rings?

This may be an ignorant question, but since the CJ 17LS comes with stock Sovteks and so does the 16LS..if I buy the NOS tubes like the Telefunkens..wouldn't that make the 17LS sound a hell of lot closer to the 16LS or even ART?
ed_sawyer
588 posts
 
CCa's or 7308s (or even 6922s) should last at least 10,000 - 15,000 hours, minimum. figure on 4-5 years I'd guess of fulltime listening. NOS tubes may make the pre sound better than stock 16ls or ART, perhaps. Agreed: forget the Sovteks, they are ok and not microphonic but are a low common denominator in terms of sound. Suggest some amperex 7308s.

-Ed
artmaltman
769 posts
 
I just put NOS Sovteks from Kevin Deal into my Audible Illusions M3a and am shocked at the level of improvement in sound. There seems to be something to this "NOS" thing.
--a
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