Problem with CJ Phono Pre and Dynavector MKIIXX2


Have Conrad Johnson Amp and Pre--so decided I would go and splurge on the TEA 2 SE Hi Gain--problem is, the "hi gain" from Conrad Johnson is apparently not enough "gain" for my also expensive Dynavector Moving Coil Cartridge--

What a mess. I was told the Hi Gain choice from CJ would work well with my choice of low gain cartridge---now I have two expensive investments that do not work together.

Next??? apparently the CJ will work well with a moving magnet--but not with the latest moving coil. Not sure which of the two items I can more readily sell on the market, and or if there is other solution?? Ideas welcome.
bluesnbike1954
If it seems like you are not too far away from having adequately high gain and adequately low noise, changing the 12AX7's in the TEA2 to tubes that have been carefully selected by a reputable vendor to have particularly low noise might get you there. Doing that with the tube(s) in the TEA2's input stage would have the greatest likelihood of being beneficial.

Otherwise you could insert a suitably chosen step-up transformer between the turntable and the input to the TEA2, although that would involve significant additional expense. Also, although I'm not sure how much significance this might have, if any, doing that would seem to go against the design philosophy of the TEA2. Based on reviews I've seen it intentionally avoids using a transformer at its input, thereby possibly improving its sonics with higher output cartridges but making it unsuitable, or perhaps marginally suitable, for use with cartridges such as yours that have particularly low outputs.

Bob's Devices offers moving coil stepup transformers that have received a lot of favorable comments here and elsewhere, and cost considerably less than a lot of the competition. He is a member here at Audiogon, btw, screen-name "Bobsdevices."

BTW, although phono stage noise specs tend to be inconsistently and incompletely defined and therefore need to be taken with several grains of salt, given the TEA2's hum and noise spec of "80 db below 10 mv input," and its specified 55 db of gain, and the 0.28 mv rating of your cartridge, I'm not surprised that there is a problem.

Hope that helps,
-- Al
"Next??? apparently the CJ will work well with a moving magnet--but not with the latest moving coil. Not sure which of the two items I can more readily sell on the market, and or if there is other solution?? Ideas welcome."

Correct in that your phono preamp will have trouble driving your low output DV moving coil. I wouldn't be so fast to sell anything, though. Your CJ and DV are both excellent products. I don't see you having any problem getting both pieces to work together if you use a step up transformer, like Al recommends above. I'm not familiar with Bob's Devices myself, but I use a place called The Cable Company. They specialize in lending out cables and components to customers so they can demo the products in their system before they make a purchase. Personally, I find them to be extremely reputable. Its likely that they will have several different options for you to try in your system. Doing it that way will gaurantee you get it all right.
thanks so much for the input--I was not "prepped" for this sort of dilemma-

I will indeed look into the idea of a Step Up transformer.

I only wish vendors were more explicit in regards to informing customers of the limitations of their products, etc.

I am VERY disappointed with both my CJ rep and local rep who I discussed in detail my scenario and installed the Dynavector anyway. And--ultimately the response or lack thereof of both.
Unfortunately the TEA is just not high "enough" gain to run the LOMC Dyna. Don't despair though. The CJ electronics are beautiful instruments (I run all CJ electronics myself) and with the right step-up transformer will sound glorious.
I use the same cartridge and CJ phono pre in Low Gain. Despite what CJ said, my dealer and I always believed that High Gain was not enough for a MC DV and a SUT will be the best path so, Bob Devices Cinemag 1131 enters in the equation... Fantastic sound... Lot of detail, dynamics and soundstage...musical without any doubts...
any thoughts on the "hum" coming through the system? Isn't present when I turn CJ pre on--or when I turn the Oracle on---but put stylus to vinyl---by end of the first cut--ever present HUM --coming from speakers.

Ideas as to how to begin to eliminate? thanks.