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Tube preamp question

Hello all,
I've recently been looking to possibly add a nice tube preamp to use with my spectron musician ii (hybrid upgrade/no V cap upgrade) monos and Anthony Gallo ref 3.1 speakers. I am currently using a Lexicon MC-12B preamp, bybee power filters with wireworld power cables, cardas balanced xlr and spectron remote sense cables. (I am also using lexicon rt-10 universal player and Oppo bdp 103). I love the Lexicon preamp and mostly watch movies but have been more and more appreciating music on my system. I'd love to add the warmth of a tube preamp but is there anyway to use both or would a tube buffer between the universal player and preamp be the way to go (a happy medium). Basically I want to use the Lexicon for movies and a tube preamp for mostly 2ch music. Is there any way to "pass through" the lexicon and use a tube preamp when I want to listed to the tubes?
I would also need a balanced tube preamp due to the fact the spectrons must be changed internally from balanced/unbalanced.
Any help/input/ideas would be very greatly appreciated as always
duckdownman
jmcgrogan2's avatar
jmcgrogan2
6,346 posts
 
Well the difference is that the BAT is a fully differential design, whereas the Cary only has balanced inputs and outputs. What this means is that Cary is not a truly balanced design, you could use any single ended preamp design with RCA to XLR adapters and have the same results.

Now this has nothing to do with sonics at all. I have owned a few BAT preamps, and I am currently using a Cary SLP-98P preamp. Yes the balanced BAT preamps were a bit quieter, but I prefer the musicality of the 6SN7 tubes in the Cary over the BAT 6H30 tubes. You pays yer money, you makes yer choices.
duckdownman OP
17 posts
 
Thanks for the input Jmcgrogan2 , I appreciate it.
Right now I run full balanced from my av pre to my mono amps and I love it. If I were to add a tube pre with a ht bypass that was non balanced would this now make my system unbalanced since it's connected in line? I might be overthinking this a bit but your point makes me wonder. I absolutely love the sound of Conrad Johnson but all of their models are single ended.
swampwalker's avatar
swampwalker
5,138 posts
 
Duckman- Not to complicate matters but according to this poston AVS Forum, the MC-12B is not "a 'truely' balanced circuit as Lexicon feels that is the wrong way to build a product. The DACs (on both the MC-12 and MC-12B) are run in dual differential mode, then their outputs are summed right at the output of the DACs. This gives you the maximum S/N increase from running dual differntial DACs. From there the signal is sent out the single ended outputs and to the balanced line drivers." so you may be making an issue out of something that is not really there. There are lots of products w XLR connectors that do not have dual differential circuitry, so you would not need to change all of your ICs but you could widen the field of possibilities.
jmcgrogan2's avatar
jmcgrogan2
6,346 posts
 
12-02-13: Duckdownman
Thanks for the input Jmcgrogan2 , I appreciate it.
If I were to add a tube pre with a ht bypass that was non balanced would this now make my system unbalanced since it's connected in line?

Yes, a break in the chain in any spot is still a break in the chain. To run a fully differential system the signal must remain fully differential throughout, from beginning to end (source, preamp, amp). Some feel that this is a big deal, but not me. Some of the best systems I've ever heard are single-ended. Whatever floats your boat though.
pdspecl
254 posts
 
The Doge 8 (1st version) had noise issues with the phono section. The more current 'Clarity' version is absolutely dead quite - line stage and phono section (even when using Moving Coil carts). My friend has the preamp running a Bel Canto amp and Maggies. I've heard the preamp many times through different amps. No noise issues assuming you have decent tubes.
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