NEW! Transcendent Sound SLIDER Tubed Preamp (Kitset $US 549.00 + Tubes!)

Go to Transcendent Sound SLIDER Kitset...

I have previously built TS kitset tubed gear with great success - so this looks very interesting...

While she is definitely no "belle of the ball" the TS SLIDER does tick a lot of my boxes...

Zero feedback
Tube rectified
Variable gain (-13dB to +20dB)
Wide bandwidth (-2 dB at 30 Hz and then flat to 500 kHz)
Common tube compliment (Including new production 6386 tube)
COST EFFECTIVE!!!

Sure the 6386 tube is pricey, but designer Bruce Rozenblit is a very caring dude, who does not drive tubes hard at all. In fact, I ran my last highly modified TS GROUNDED GRID Preamp NOS tubes 24/7 for more than 12-years, before someone paid me big money for it and took it off my hands. My guess is, that those tubes are still running perfectly.

All for $US 549.00 (+tubes) this TS SLIDER preamp has got to be an ideal lock-down project, surely?

Best of all, Rozenblit does not insist on boutique parts for good sound, so there are always loads of parts enhancements the builder can incorporate, in order to add that personal touch.

What does the panel think?

Transcendent Sound SLIDER.jpg
 

Chops54

Junior Member
It's an ugly critter that's for sure. I prefer the look of my GGs with the tubes inside and the old style faceplate though they're no beauty queen either!
 

Chops54

Junior Member
Is there something special about the 6386? Bruce is usually quite thrifty so he must have had a good reason for doing this.
 

paulbottlehead

Active Member
It's generally suggested that remote cutoff tubes aren't really suitable for audio, and there's some truth to that. The 6386 is horribly non-linear, and if you tried to use it as a driver in a power amp where you needed the whole swing the tube could deliver, it would perform terribly.

On the other hand, you could set it up to have different operating points to get different gain, and if you had good confidence that you didn't need much swing out of the tube, the performance in general would be predictable. 80VP-K/5mA looks like a nice low gain area of operation, 120V/5mA a bit higher gain, and 160V/5mA quite a bit higher. A constant current source plate load and a switch that changed the cathode resistance could produce such a circuit. In a linestage, +/-5V peak would be enough signal to get the job done, so you could confine operation to local areas on the plate curve that look to be reasonably linear, but there are a lot of assumptions being made here...

In practice you would aim to operate dead center of the curves so you had symmetrical variable gain, and that is the "compression" aspect of the tube, that the grid voltage curves spread further apart as you move away from the center of the curves as drawn. The first +/-4V of signal you throw in might produce +/-20V out, but going to +/-8V of signal may only produce +/-30V out, and +/- 12V of signal maybe only goes to +/-35V out.
 

Chops54

Junior Member
Thanks Paul. The idea of variable gain is interesting and the preamp must obviously work so I suppose it's a case of waiting for someone to tell us what it sounds like and how it performs.
 
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