Seems the A992 @ 9mA is just right to produce neg phase H2, other part will require other operating point to have intended H2 phase.
Good morning indra1,
I think so too. The ONSEMI KSA992 seems to be happy at around 9mA. Perhaps a kind of 'sweet spot' for this device?
https://www.firstwatt.com/pdf/art_sweet_spot.pdf
But if anybody wants to experiment with this beutiful circuit and other active devices, there is a lot to do and find out.
I can say, that it sounds really great in its original configuration of Mr. Pass.
If anybody wants to experiment and wants to have some kind of 'special fun' (perhaps frustration) - go for it!
Cheers
Dirk
I think so too. The ONSEMI KSA992 seems to be happy at around 9mA. Perhaps a kind of 'sweet spot' for this device?
https://www.firstwatt.com/pdf/art_sweet_spot.pdf
But if anybody wants to experiment with this beutiful circuit and other active devices, there is a lot to do and find out.
I can say, that it sounds really great in its original configuration of Mr. Pass.
If anybody wants to experiment and wants to have some kind of 'special fun' (perhaps frustration) - go for it!
Cheers
Dirk
Yup. Interesting is the region where the active device (no matter if JFet, MosFet or BJT) goes from the more ohmic to the more saturated region -
near the 'knee'. 🤔
https://www.firstwatt.com/pdf/art_h2_v1.pdf
The complete article is interesting - but especially page2 - for me...
On page 6: something about the pinchoff-voltage of JFets (J112 in this case).
Cheers
Dirk
near the 'knee'. 🤔
https://www.firstwatt.com/pdf/art_h2_v1.pdf
The complete article is interesting - but especially page2 - for me...
On page 6: something about the pinchoff-voltage of JFets (J112 in this case).
Cheers
Dirk
So truly worth doubling up using 2sk170 at the input if you have plenty of those laying around?
This was my intent anyway but good to know where to best mess around with the circuit.
What logic? Especially a waste of money for those who are desperately looking for a good price and can't find any more. Or have fakes. Too bad some don't really need it and have their drawers full of it.
For smd soldering a stereo microscope can also be a good thing.
I purchased several years ago a vintage Meopta DM23 stereo microscope (a classic model) for such purpose. Works very well. High quality and not that expensive. It has very good optics.
Eschenbach makes good head lupe but probably even the cheap ones works well.
I purchased several years ago a vintage Meopta DM23 stereo microscope (a classic model) for such purpose. Works very well. High quality and not that expensive. It has very good optics.
Eschenbach makes good head lupe but probably even the cheap ones works well.
I swear by the OptiVisor at work and home. I use the 1.75x Magnification, 14" Focal Length (#3 lens). I wouldn't be able to function without it.