2. amps-preamps
  3. 1219850650

Supratek Preamp. and 6SN7's impressions

I have had a Chardonnay for over a year now and have enjoyed it immensely. I used to drive a Plinius P8 amplifier with it, which was an overkill (200 w/c) for my Reference 3a MM Decapo's. It was a fairly musical combination, though.

Recently I sold the Plinius and bought a First Watt F4 stereo amplifier. It is a class A, 25 w/c buffer type amplifier,(designed and built by Nelson Pass)which means it does not amplify voltage, it is a current amp. You need to have a high gain preamp to drive it, and the Supratek is perfect in that respect.

This also means that the characteristics of the preamplifier are passed thru the amplifier without any gain or editing -or at least minimal editing-. So, I thought this would be a perfect combination to study the effects of the 6SN7 tubes in the Chardonnay.

I have used the following tubes: EH, NOS Tungsols, RCA's, Sylvania's. Verdict: The EH came on top. More natural sounding in both tone, pace and in soundstaging. More vocal and instrumental body. The others seem to have more energy in the highs -brighter- and do not throw a soundstage as natural and effortless as the EH's do.

Also the same conclusion was obtained with the 6106 rectifier that some raved about in this forum.. It does not really function as well as a GZ34 or GZ37. It gives the impression of more dynamics but at the end makes the preamp sound more "hifi". Soundstage is also constrained compared to the GZ34's. Not recommended if you want your Supratek to work as intended. Mick had informed in an email that the 6106 does strange things to the circuit's operating voltages.

So, what would this seem to indicate, in my opinion, is that Mick apparently voiced his preamps. around this tube (EH and GZ34, etc.)to make it as musical as he intended. That works very well.

Sources: Shigaraki CD transport and DA with 47 Labs Dumpty power supply. Supratek Chardonnay preamp. Interconnects and speaker cables: Jena Labs. Power Conditioning and power cables: Jena Labs
manolo
amandarae
512 posts
 
Agreed 100%

I have a Chenin since first quarter of 2004. Went astray with the tube rolling threads and spent tons of money on the so called "recommended" tubes. Garbage!

I never like the 6106 and have some reservations on the Tungsol RP (still have the tubes) on my preamp. The 6106 does weird thing in my phono section. To me I found my heaven with Raytheon 6SN7 and/or EH 6SN7, Sovtek KT66 or 6L6GC rectifiers, and Mullard M80/Amperex D getter 6922 on phono. For rectifier, nothing sounds better to me than a good old double d or O getter GZ34. Its been almolt two years now since I refuse to roll tubes in my preamp.

The Supratek uses the 6SN7 in SRPP topology, transformer coupled to the output. If you read more about the topology and understand the circuit operation, you will be safe from spending a lot of money rolling tubes IMO. For example, you have to realize that changing the rectifier changes the OP of the tubes because the change is transparent to the B+. The sound changes, as perceived by the listener, not because the rectifier have blackplates, gold pins, and all the BS etc. What I cannot believe on the thread here in Audiogon was that someone posted improvement by changing the umbilical cord. Gimme a break!

Nevertless, I am at peace with my Chenin. I still love it but I do not use it as often but as a back up because the preamp I made sound so much better then the Supratek with the system I currently have. I never tried comparing the two with my other system set up though.

regards
vett93
205 posts
 
Which RCA, Sylvania, and Tung-Sol 6SN7s did you use? Take RCA as an example. Did you use clear glass 6SN7GTB or smoke glass 6SN7GT or VT-231?
dgarretson
2,586 posts
 
I recently went through similar 6SN7 rolling comparing early 1951 Sylvania WGT, RCA Gray Glass GT, Raytheon GT, Russian 1578/6N8S, and recent production EH. EH was only surpassed by Russian and Raytheon, and not by much. EH is very good indeed.
manolo OP
12 posts
 
RCA with clear glass 6SN7GTB from 1956 sold to me by Tube World. A small bottle with black base. Sounds smooth. I know it is not the best RCA there is.

The Sylvanias were also small bottle, chrome top cryod,1960's. Sold them.

The Tungsols where lent by a friend they were NOS, do not have them.

But my theory or point is that we tweakers do not realize sometimes the voicing process in the design of electronics. The better designers listen to their products and optimize them for the parts and or tubes they use.

Sometimes we go ahead and start swapping caps, tubes, resistors... and because it sounds different we think it is better. Sometimes that happens but not always.
More to discover