R15 with 100R at the JFet gate. But CFB is injected at the source, or does both approached work ?
(CFB is new to me)
(CFB is new to me)
The reason I am asking is since Pass and Wayne selected to remove degeneration resistors and use CFM at the source and experienced better dynamics together with better slew rate*, that this would be a good indication of what to do 🙂
But like you have mentioned several times, one have to look at the whole circuit and I understand that. It would be fun to learn the difference of VFB and CFB on the same amplifier, so I guess the only way to find out is to do.
* 100V/mS for INT-25 and XA25 compared to 50V/mS for X and XA.8 series
But like you have mentioned several times, one have to look at the whole circuit and I understand that. It would be fun to learn the difference of VFB and CFB on the same amplifier, so I guess the only way to find out is to do.
* 100V/mS for INT-25 and XA25 compared to 50V/mS for X and XA.8 series
to have it both ways really optimized, it can't be easily "same amplifier"
previous generations of XA amps had it one way, later ones in some other way
and - they are similar amps, but not the same
previous generations of XA amps had it one way, later ones in some other way
and - they are similar amps, but not the same
I'm wondering if I could get away with 4U-sized sinks for the SIT version... Adding some nice and quiet Noctua fans if need be? I think I have some extra fans lying around at the moment lol.
Sorry if I missed it, what's the ballpark ETA on boards? Please count me in for a pair, Mighty ZM! 🙂
Sorry if I missed it, what's the ballpark ETA on boards? Please count me in for a pair, Mighty ZM! 🙂
I have been looking at this while I wait for parts for my Aleph J. Can JFE2140 jfets be used instead of 2SK170BL’s? It might be my next project.
I just want to interject with something.
The Onsemi NSVJ3910 (Vds 25V) is $0.43 per pcs if you order 100 pcs via Mouser. With those prices, you can match to 1% tightness.
That was it, that was all I had to say. Now back to the regular schedule 🙂
Read the full JFet noise test report: https://www.mvaudiolabs.com/diy/modern-jfet-noise-measurements/#setup
The Onsemi NSVJ3910 (Vds 25V) is $0.43 per pcs if you order 100 pcs via Mouser. With those prices, you can match to 1% tightness.
That was it, that was all I had to say. Now back to the regular schedule 🙂
A tiny follow up on post #529. The NSVJ6904DSB6 is a dual package of the NSVJ3910. The NSVJ6904 is a CASE 318BD, this happen to be the same size as the 2SK2145BL in the 2-3L1C package. The difference is the source connection, which is flipped on the NSVJ6904, which is sad since it would have been drop in. Such is life. The fix is easy. Use a 6-pin footprint and create an extra track such that Pin-2 of the Toshiba/LSK part is connected to Pin-5 of the Onsemi part, now both packages have a source trace available.
🙂
🙂
Oh for sure, the Tosh is a no brainer. Yamaha is using those parts (2SK209 single variant) in their top amplifiers and I think Accuphase also use them, but variations is good to have and know about and if we can have yet another FET besides Toshiba and Linear Systems, even better.
Good afternoon. A question for you Zen, The "relative output offset solver" or dc-servo, seen in the XA252 US simple sch. did you manage to add components and simulate that section or is it on your to do list ????
Hope everything is well otherwise 🙂
Hope everything is well otherwise 🙂
XA252 US postponed
mushrooms popping up on the list, that's the reason
when?
ZM plans soon, other ZMs prefer mushrooms
mushrooms popping up on the list, that's the reason
when?
ZM plans soon, other ZMs prefer mushrooms
Oh I see... LOL, no worries .. go attend to your mushroom.
One other thing, your approach to OS-FET CCS is most excellent, I see no issue using that platform on the JFet as well, this should be a very nice upgrade.
One other thing, your approach to OS-FET CCS is most excellent, I see no issue using that platform on the JFet as well, this should be a very nice upgrade.
same as existing one, US (once when finished, ZM eternal optimist) can be made as straight mos, as Schaded mos in upper rail, and with SIT in upper rail
we'll see what goodness each of them would bring
we'll see what goodness each of them would bring