Article - Sony VFETs part 1

[permaneder]

JT-112 LCF

PCB is a nosense

Ahhh, really???

 

[mctavish]

PCB for amp circuit is maybe silly

PCB for power supply is not silly

+1 for PS PCB

 

[dady]

Not only bandwidth, Distortion is a little worst. Is a compromise.
I consider 100kHz is a lot for better but dog and instruments could distinguish. Maybe in the papers.
This is a concept, I.E. Lundahl rise the 150KHz and also is good.

Call the Godfather. Please padrino tell us a little info that is crucial for these poor mortals from the audio aficionado world.

 

[dady]

Power supply SMPS. Little, cheap and ecological.
Or Am I talking heresies?

 

[mctavish]

Power supply SMPS. Little, cheap and ecological.

Real easy to make go BOOM!

Runs on magic smoke.

Trafo and caps PS is like an old ford, I can work on it.

SMPS is like a new Maserati; the old McTavish cant get a wrench on it!

 

[dady]

Connexelectronics?

 

[flg]

Hello
...Last thing original Papa JT-112 LCF have band wide<450 kHz
PCB version JT-112 FLPCH band wide is 270 kHz max at high frequency response... ???

JT-112 LCF Specs are with a 1:2 configuration and BW is 370kHz.
JT-112 FLPCH Specs are with a 1:1 configuration and BW is 270kHz.
These are not equivalent test conditions.
Just Sayin

 

[PKI]

I would ask Nelson to tell us at least how many SITs we will need for the part 2 amp.

 

[dady]

I would ask Nelson to tell us at least how many SITs we will need for the part 2 amp.

Do it tonight or as soon as you can.
There are many people waiting for build.
The best for you

 

[Nelson Pass]

I was intending that single pairs, unmatched, would be covered by pt 2.

 

[PKI]

Oh, for some reason I thought that it would be for a bigger amp with paralleled devises. I don't know why... Maybe because I wanted it

 

[dady]

Bit to bit, step to step.
The question number two, The transformer, Which one?
Thanks in advance and specially for share your knowledge.

 

[Zen Mod]

that will be Part 5

 

[Michael Rothacher]

I see the hand-wringing has begun.

 

[R-K Rønningstad]

that will be Part 5

I was about to propose part three

 

[Soundhappy]

Bit to bit, step to step.
The question number two, The transformer, Which one?
Thanks in advance and specially for share your knowledge.

Hi Dady
Transformers from:

Transformers - AnTek Products Corp

output voltage 24V
output power 300VA or more <

No doubt other brands be ok
Best regards

 

[permaneder]

Papa suggests the use of an input buffer in his article. The published sample shows supply voltages of +-12V. Is that mandatory or do the +-24V main supplies fit aswell?

 

[Soundhappy]

Papa suggests the use of an input buffer in his article. The published sample shows supply voltages of +-12V. Is that mandatory or do the +-24V main supplies fit aswell?

Hi Permanender

This CS1 version must have other transformer with 12V outputs

I like very much PCB you made for SIT CSS with
IXYS transistors together with SK82.
For VFet Papa one it be very elegant solution to menage PSU and
regulated with signal at 2 or 3 distinct PCB´s version CSX2 or CSX2
with buffer or without for one mono chanel.

Cheers

 

[permaneder]

This CS1 version must have other transformer with 12V outputs

Cheers

I don’t talk about the biasing circuits, but the input buffers…

 

[Zen Mod]

simple RC in each 24V rail , to shave 10-12V , will do the job

say , for 7mA Jfets , 1k8+1mF will do the job