UNSET is coming?

[TheGimp]

UNSET Schematic from 48.

[Francois G]

Many thanks! (I have downloaded LTspice and will hopefully get proficient enough to do this type of thing myself).

Best wishes with your 6P42S experiments and keep us informed.

[evanc]

Originally Posted by Tubelab_com

I haven't tried the 4D32 in UNSET yet, and tried a 6146 in anything recently.

I did stuff a pair of 4D32's in my Universal Driver push pull test amp.

Look familiar. I believe you have the edcore outputs I had for this project. Hopefully get to see them I use.

[hareynolds]

Originally Posted by Francois G

Hi George,

I’m following this UNSET thread with great interest. For hobby planning purposes, when do you anticipate the PCBs becoming available for purchase?

(a) this is a great phrase,and I have the same question.

(b) Whilst I recognize the artistic merit of Pushing the Limits and Blowing Things Up*, I would be ecstatic with a UNSET that made an honest 10W at low distortion; i.e. a replacement for the TSE 300B (even if it is loaded with SAND. The PowerDrive has made me a Believer.

(c) A Reference Point: if y'all really are getting clean outputs at ~50% of dissipation, this circuit could comfortably get 10W out from select Sylvania 6AV5s (REM those were rebadged as 6B4GAs, and sound pretty good); I am running those right now in uLinear at 400vdc B+ and >22W dissipation with no Embarrassing Redness. (I do know that 6AV5s are difficult to get "overseas", but we Yanks are still up to our gills in them, and it's my Horizontal Sweep Tube of Reference.)

(d) I think this circuit is so promising that TubeLab George could get enough solid commitments for a Beta version of the board, with the advantage that lots of folks would then be Making Mistakes Quickly.
I would be in for AT LEAST a couple. Heck, I still have unbuilt SSE boards with full parts complements, so no worries...

*Blowing Things Up is of course why we all gather 'round TubeLab, like teenagers staring into an engine compartment...

[Parafeed813]

Originally Posted by hareynolds

(I do know that 6AV5s are difficult to get "overseas", but we Yanks are still up to our gills in them, and it's my Horizontal Sweep Tube of Reference.)

(d) I think this circuit is so promising that TubeLab George could get enough solid commitments for a Beta version of the board, with the advantage that lots of folks would then be Making Mistakes Quickly.
I would be in for AT LEAST a couple.

In Europe we have plenty of topcap sweeps: EL36/PL36, PL500/504 (*GB5, not unknown to George) and others.
I also got a bunch of 6CU6 (topcap 6AV5).
And don't forget the Soviet sweeps.
Yes, I'm interested in UNSET

[TheGimp]

Francios,

LTSpice is easy to use, and there is lots of information (and models) in the spice model stickie.

Vacuum Tube SPICE Models

[Francois G]

Thank you, TheGimp! I have bought a book on using LTSpice (albeit for guitar amps), I have downloaded LTspice and I’m rearing to go. How is your progress on the 6P41S amp?

[Francois G]

Is Tubelab UNSET really coming? Tubelab has been uncharacteristically quiet on this thread for several weeks now. I hope George is OK. He posted on a different thread that he had surgery.

[zintolo]

Hi, I've one question: I would like to adapt a cheap chinese SE kit to be used in PSE with EL34 and this kind of design (it is in configuration 12ax7 + octal). Can I reference the grid leak resistor of the output tube to a negative rail instead of ground, and reference the driver Mosfet to ground targeting the output tube cathode to go as close to gnd as possible during peaks? This also would help to keep the grid dc reference stable in case the lnfb plate to grid will be increased to more than 10%.

Thanks

[zintolo]

Originally Posted by Francois G

Tubelab has been uncharacteristically quiet on this thread for several weeks now. I hope George is OK.

Hi Francois, me too I hope George is OK. All the best.