Supratek Owners Thread


Greetings All - 
It appears that the 26-million-plus view, multi-decade "Preamp Deal of the Century" Supratek thread has been removed. I'm not sure why, but suppose there must be a reasonable explanation.
In any case, on that thread I recently asked whether there might be interest in a "Supratek owners thread" and received some interest. 
The purpose of this thread is for Supratek owners to share the details of their system, ask questions, share information about any tube-rolling they have done, and so forth.
I'll kick us off here with a few details about my system -
ancient Linn LP12 with Ittok arm, Dynavector 17D3 cartridge into Cortese LCR phono stage
Power amp is a fully serviced Innersound Electrostatic amplifier
Quad ESL63 speakers (not USA monitors) or JBL 4430 studio monitors
Digital sources are immature and evolving - ancient Fostex CR300 cd player/burner
DacMagic 100 DAC
Nordost Blue Heaven 75ohm interconnect
Due to the fairly long lengths of speaker wire required in the new listening room, speaker wire is Belden 12 gauge wire designed for low-voltage outdoor lighting systems. 
Next steps - dedicated circuit, new power cords, new interconnects, new wires.
128x128markusthenaimnut
I spoke with Mick and he said his best line stage was built around the 6J5GT and the circuit he designed. 

It's called Grange Signature. It s a four month wait but looking forward to it.
Gloss black with chrome. 

If you go to his 2021 blog from his website you can read his thoughts. 
Funny, I was about to do a search on the Audiogon forum for the Supratek Chardonnay, and bam, saw this thread!

I’m currently auditioning preamps. My amp is a JE labs simple 2A3/45, powering Omega Compact Alnico Monitors. I have the Primaluna EVO 100 pre, which uses 12AX7 and 12AU7 tubes. Not that the EVO is not good, but I like the tube glow of the Schiit Freya Plus, which uses 6SN7 tubes, better. Also in house is the Conrad Johnson Classic 2 SE using a single 6922 tube. I may try an older CJ for more of the tube sound.

I have not read or searched this thread yet, but hope to learn about the Supratek preamps.
"Whats the benefit of doing the 12v?"

Just the cost really. The price difference between 6sn7 and 12sn7 can be dramatic especially considering that they are the same tubes other than the heater voltage. The data between 12j5 and 6j5 probably isn't as stark. I don't think Tungsol ever made round pate 6j5 tubes but Sylvania made their most sought after tubes in single triode versions. 

Oh, and I suppose I enjoy rescuing abandoned tubes lol. I get a kick out of using tubes that would otherwise languish. 
I'm a novice at best when it comes to tubes but I was under the impression that the 6J5 uses half the current/power as the 6sn7 hence why they last forever. 
In the Grange Signature Mick uses two 6J5 for each 6sn7.

Andy at Vintage Tube Service said the circa 1930 RCA 6J5GT are the ones to get.
The 6J5 pulls half the heater current (.3ma) of a SN7 (.6ma)..   BUT, you have 2 of them per channel vs 1 sn7 so the total heater current draw is the same.  This does not effect the longevity of the tube provided it is being run at or close to the 6.3V spec.    In regards to the circuit and how the tube is driven/operated (ie, B+/bias),  it will be very similar as to how Mick runs the SN7 based pre's.   All in all,  they are all run very conservatively.    You'll find that any NOS tube stock (generally speaking),  especially that from the 60's and before to have very long life in Mick's pre amps,.. Tubes just aren't made like they used to be.   Newer Chinese manf. stuff,  not so much.  They can die (and do) with very few hours on them (comparatively speaking).