DIY Sony VFET pt 1

[Sidsmith]

It's an active crossover? Wouldn't DSP be superior these days for use as a crossover? That being said, I love old Pioneer gear.

It's a Pioneer D-23 : Pioneer D-23 on thevintageknob.org

a 4-way active analog crossover produced a the end of 70's. This was the heyday of the venture of the big electronics japanese brands in high end audio, which also produced these wonderfull SIT transistors. Another great contemporary was the Sony TA-D900 : Sony TA-D900 on thevintageknob.org

Some, including me, prefer analog crossover. Seems more natural to my ears.

 

[Sidsmith]

nothing extraordinary on mine , panasonic film caps in place of Wima , Nichicon FG for power supply , Nichicon ES NP for the big 1000uf coupling cap . i have also change the stock Rubycon with a Big Elna 10000uf 63V ( only because i have it ) that i put under the card to have more place .

i will try later a 100uf film cap to bypass the output cap but i don't feel the need of it immediatly as the baby amp is getting better and better with time... 😀

This is great news : without esoteric parts, it is nontheless sound good and compete with a good SETriode mature design, with greater reliabilty as a plus.

At what frequency do you utilised it ? I see in the article that the distorsion is pretty constant from 400 Hz to beyond 20 kHz. that made it ideal to drive 2'' or 1'' compression drivers.

Without real probability of winning, I bough a pair of Token THF-51S SIT and hopping that Master Pass will made a version of this design of this transistor.

Did anyone knows, when the other versions of this amp will appear (for other SIT's, and MosFet/JFet), if this particular chassis will be available? I found the aesthetic of it quit modern, beautiful and elegant.

 

[Manolo47]

3 Leds included in kit...

Does it mean I can use any one of these in the front panel?
Thanks!

 

[juanitox]

yes all exept the Blue one it can blind your cat 😀

 

[coolnose]

Or make the resistor 27/33/39/47k...

 

[carsten.witt]

Hi,

what is the minimal voltage rating for the DC blocking cap (C2) in the front end?
I asked because I would like to use my preferred ELNA Silmic II (RFS) with a little bypass in this place?

Thanks.

 

[Zen Mod]

Rail Value

you can go with lower, but only if you're adrenaline junkie



we can go backwards, from amp output to amp input and calc what's sufficient input Vpp to have full blast on output

then sufficient DC rating of cap is Urail/2 + Vin/2

but, I'm always counting on fact that some idiot in my benchroom or living room is capable to blast input with BigBadaBoom

 

[carsten.witt]

Thanks, my first thought was Vin/2 but I think it ist better to leave it as is.

 

[juanitox]

i use a 16V MUSE NP cap here but this can be Kamikaze as the DC volatage here is 14,7V 😀

 

[Zen Mod]

no worries for you. you're wearing Goggles all the time

🙂

 

[juanitox]

no worries for you. you're wearing Goggles all the time

Yes but my Wife hate the smell of explosed Caps😀

 

[nicoch58]

😀😀 a gapped trafo, downgrade your px4

 

[MEPER]

Were all VFET amps back in time push-pull designs?
If not probably not P-channel based?

 

[Zen Mod]

trying to find flaws in actual amps?

 

[MEPER]

No....not at all.....just want to know how rare our SE P-channel amp is......and know a little bit of "VFET history" 🙂

Maybe our VFET amps are the only SE P-channel amps made?

 

[planet10]

Very rare.

dave

 

[pinholer]

Depends on what you mean by "made". Quite a few DIYed.

 

[Zen Mod]

fact is - we know so little about big world of Eastern DIY scene

they were making SET amps, buying everything WE and related, in time when all of that was simply trashed on junkyards

so, while looking at just one small part of World Map, our awareness can't grow big

 

[MEPER]

But no commercial amps?

When I look at curves for N vs. P-channel VFET they look "identical good".....

 

[coolnose]

Jean please leave that body 😀