Preamp Deal of the Century

You may want to contact Michael Samra at Audio Asylum. He did some mods on a Supratek, and seems familiar with it.
It may just be a loose connection. I also did these mods to mine and my preamp sounds much better. Better than anything I have owned. Hope that helps.

Here's the mod thread and his name to email him.
http://www.audioasylum.com/cgi/t.mpl?f=tubediy&m=148308

Plutos - I tried the Promitheus TVC. Super clean, nuanced sound with a tube like warmth to it. I enjoyed it, but it did not have the dynamics and openness of active preamps. Though I'd bet it was one of the most transparent preamps available for the price. Promitheus has a preamp with an active tube stage in it that probably does the dynamic thing also (haven't heard it). Back to Supratek. One of the best preamps I have owned, and I have been through many. No glare on my system, running a Pass Labs X-150 Eminent Technology speakers, a ESound CD player. I am loving the sound. I have the Tungsol tubes as well as other NOS tubes. I actually like the stock 6SN7s on it best. I trust my ears. Not to boast, but I play piano professionally (1 of my professions - need to do other things to get by in the music business :) Jazz is my love. I know what live music is suppose to sounds like (amplified and unamplified) and attend acoustic concerts- yes classical music. Lang Lang is one of my favorite young pianist) I went through about 5-6 preamps before this one to get that "you are there sound". Those that own one should be proud. Those that have purchased others and have moved on, great. This is a hobby! You have to trust your own ears. Doesn't make the Supratek a bad preamp.
Thanks for listening. On a side not, please support your local musicians. You are missing out on some great talent, even if the sound isn't perfect and the acoustics stink. I don't know how many times I have invited audiophile friends out to listen to some great jazz, and they would rather sit in front of their systems at home - all the time. To bad - nothing like the real thing baby! Sorry going off on another topic. Selah!

Chardonney. The "low end" of Supratek. I have had more expensive preamps, and like it better. Mates great with the Pass amp because you can adjust the gain which is rare on a preamp. No impedance problems either. - Jeff

I did the same thing to my Chardonney, only I used motor run caps. Definitely made the preamp better. Tighter bass, cleaner, more dynamic, better soundstage. I also replaced the stock caps in the linestage with Mundorf Silver/Oil caps - big improvement. I did not have the Auricaps there but, some square blue caps. I tried replacing the other square blue caps near the rectifiers and it messed up the sound. Emailed Kevin Covi about this and he said those caps are not critical and just leave them in. I put them back and the preamp sounds tremendous.

I bet the Duelunds are more linear not as warm. I emailed another Supratek owner that upgraded to Vcaps from Mundorfs and he likes the change. He GAVE me his Mundorf caps! What a saint! Gotta love him for being so generous! I have read that one reviewer did not like the Vcap upgrade over the Auricaps. Enjoy listening I know I am!

Hey Fiddler! Thanks for the caps they sound great! I bet your Supratek is sounding incredible. I will have to try the 7193 tube mod sometime. I actually think the stock EH 6sn7 tubes sound best most extended although the Tunsol Black Plates are a little more nuanced and tubbie sounding. Think I should sell these since they command a high price and are all but gone. I have 6f6 Sylvanias in the regulator position and the 6106 Bendix tube as recitfier. I wonder if a 5ar4 tube would give me a little more warmth in the mids and a little more snap (snare and the like) in dynamics. Not sure.
I still have a Modwright SWL 9.0 preamp which betters the Supratek in dynamics. Different sound. Gotta sell one preamp. I think I'm going to keep the Supratek can get them anymore! The Modwright is a great preamp also but they are selling for so cheap right now. I'll get killed on it! Everything is going cheap now!

I am not aware of any of the parts coming loose from any inmates that own Supratek. Opened mine up to upgrade some caps and all was intact. The caps I replaced should not have come loose in shipping unless the unit was really banged around meaning probably damaged. It took some effort to remove the glued caps. I don't see them coming loose. If you were to buy one used as it looks like not to many are being made now, it wouldn't be a bad idea to open up the bottom and make sure everything is tight. I used "goop" to glue in the new caps. They are not going to move with this stuff! It appears that Supratek is still up and running on a smaller scale. Good to know. Love my preamp.

Thats corect

Believe it or don't!
Ever heard or sympathetic vibrations. Websters dictionary.
* Main Entry: sympathetic vibration
* Function: noun
* Date: 1898

: a vibration produced in one body by the vibrations of exactly the same period in a neighboring body.
Your ears are more sensitive than you think.
Ever hear tubes ring, speaker cabinets vibrating at frequencies affecting sonics. Room acoustics. One cable manufacturer actually uses metal shot in their power cables to damp resonances. I was like you and didn't think any of this stuff made sense, but I became a believer. I even used bicycle tubes under my equipment (gonna try this on the Supratek.) I it sounded much better. I didn't think a power cord made a difference in sound quality, but they do, even sometimes more than speaker and interconnect cables.
Hearing is believing. Those metal tops and bottoms on the Supratek sure look great, but they sure do vibrate more than wood or heavy aluminum etc. They need to be damped some way!

Agreed I was thinking of getting some marble cut or some corian. That's a little over the top though. I will purchase some speaker dampening material for the insides of the unit, and try my bike tube underneath
I really love my Supratek. Have had many preamp other than this one, and no one preamp is necessarily best, but this one does it for me. I hope the dampening deepens the soundstage, that is the only weakness (& it is very minor) that my Supratek has. Still sounds better in my system as a whole than any other preamp I have owned. Killer tone!

It is just like a 6sn7 spec wise. Here is a more detail.

http://www.tnt-audio.com/accessories/shuguang_treasures_cv181_pt2_e.html

They call it a cv-181 because of the way it looks but it measures like 6sn7 so you should have no problems.
Let me know what you think of it - I also own this preamp.