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 just got a set of Linlai 101D hifi series to replace my older set of TJ 101D Mesh plate. These TJ 101Ds have been on the Supratek Cabernet for more than 10 years which I used very sparingly over the years.

For the price ($100 a pair from aliexpress) they perform very well to my years. They have a very sweet and full sound for vocals and less muddy than the old set (which really should have been replaced long time ago). I like them particularly with voice and the Eva Cassidy album Live at Blues Alley had a very euphoric quality to it. The amplifier I used was Cary Audio 120s by the way. I replaced all the 6SN7 tubes with some RCA and Sylvania NOS on both units. 

Getting the tubes to run at the full potential do take some effort however. TLDR is the tubes archived -70dB THD after tuning the voltages on both channels. If I play at low volume it could even archive -80dB THD wihch mostly 2nd harmonic. This is quite good for a tube design.

I attached an analyzer to the balanced output with 1k input to RCA. I first tuned the 6SN7 bias voltage then adjusted the plate voltage of the 101D and then finally the grid voltage of 101D. There seems to be a feedback in the design and the voltage takes a little while to stabilize after each adjustment. I was watching the FFT of analyzer and voltmeter during the tuning.

After some experiments I found the highest gain setting have the lowest distortion. Lowering the gain will gradually increase distortion for the same output level. I hope this information is useful for those who wonder the effect of the gain on the sound.

Comparing the FFTs of the Linlai and the TJ mesh plate I had the appreciation of the TJ very much. The TJ had very low 60Hz noise and mostly only 2nd harmonic distortion. The Linlai however is quite a bit noiser with 120hz and higher order harmonics of the power noise. The 3rd harmonic distortion is also quite high. I should probably get a set of TJ while it is still available.


Sorry for late response, been busy at work. I think there is something wrong with the umbilical cord for the preamp. I started by turning on the power supply and could not hear any hum coming from it. Then I attached the preamp with umbilical cord with no RCA in or out and I could hear the hum from the power supply. I have asked for a new umbilical cord from Mick and will test it again when I receive it. I also googled the cord and found Revelation Audio Labs makes one. Will also ask them in future to make one for me if it works in resolving the issue. Has anyone tried them?
Brad is supposed to make great cables but from what I have heard on other forums pay no attention to his promised delivery times as they are mostly make believe.
Well Mick says its not the power/umbilical cord so I am left with the hum. I am looking at hum busters. Any suggestions?
Pack it up and take it to a friends house to eliminate your house and neighborhood interference.