DIY Sony VFET pt 2 (N-Channel Build)

[Zen Mod]

just replace them and chill

or, send everything back and ask for refund

 

[TungstenAudio]

That is unfortunate, but easily corrected. Replacement with another 1% metal film resistor is sufficient. The diode should be replaced as well.

 

[Analogico]

Thank you guys. I'll replace them both.

ZM you are a funny fellow.

 

[kannan_s]

you can measure it as the leads are fine

 

[Nelson Pass]

I would have to have gotten smacked after testing....

 

[Zen Mod]

blame Variac

he's resident Forum's Gremlin

 

[Nelson Pass]

I have a feeling that Nelson Pass put that double pole switch in the circuit design and on the PCB layout, because he felt it was essential. I have a feeling he carefully considered the idea "maybe I could omit the second half of the switch" and after thorough examination, decided he could not.

Yes, you can just short where the 2nd pole goes and use it - it will just
have a larger turn-off thump, but not a turn-on thump. This was simply
the simplest approach.

More sophisticated approach would add two transistors and two more
resistors...

 

[Analogico]

No big deal. Like ZM said I'll "just replace them and chill".

 

[Zen Mod]

Sissy

scared to send it back

 

[Analogico]

You nailed it!
ZM, besides being funny, is a mind reader!

 

[Zen Mod]

channel module evidently got banged - there is indent in edge of T profile, above VFet

be sure that side going on hsink is flat (no indentation and similar bruises), with prescribed screws there is no torque force to overcome even slightest deformation of surface

not likely the case, but worth saying

 

[Analogico]

Although at first glance everything seems to be fine, I'll take your advice into consideration and check the bracket's surface flatness.
Thanks.

 

[HelmutHolz]

I saw the M3 srews for the fastening of the T profile on the heat sink, my decision is to scale up to M5 for a better feeling.

 

[thompsontechs]

It's an amplifier not a bridge span Helmut.

 

[RafaPolit]

…I've reversed the FE board mounting and opted for just two stand-offs rather than loop the various connections…

I did this exact same thing on my P version with the FE. Everything felt more natural, no wires crossing from front to back and back to front of the board. Shorter input path. But putting the third screw was really hard, and, after some tests, not needed.

Looking forward to your pics.

Regards,
Rafa.

 

[nicoch58]

HI Nelson there is an error on pcb board the R1 is after the C1

 

[nicoch58]

real pcb too

 

[Zen Mod]

that is not error, really

call it Artist's Freedom

or you can call it - another Thinking Trap for Greedy Boyz

observe - R5 is still outside, to bleed C1

 

[chede]

Yes, board and schematic do differ. But I think the way it is implemented on the PCB makes more sense - capacitor C1 as first element in the signal path, and R1 being able to function as gate stopper, connected directly to the gates of the JFETs.


Best regards, Claas

 

[nicoch58]

the really Thinking Trap for Greedy Boyz are C4&R6