Can I just say Nelson, with my boards up and running with tightly matched 2SK170BL's running at a regulated +/-20VDC supply, these sound fantastic - I expect you should have quite a lot of demand for this simple board. Once again you have achieved 110% with an elegant simple circuit - well done indeed.
Hello,
I got a problem.
My audiobug is hungry again...
I gotta do somthing, before he transforms into the monster at the midnight of blue moon..
While awaiting and wondering how can the kit get to EU and not cost an arm and a leg...I woke up and opened the drawer for cookies. Found some 2SK170, but, ah, GR grade.
And some J310 (maybegoodenough as CCSs) Bipolars? Oh, just some BC559 critters...
So, Nelson, can I feed my audiobug with these, and get this pre to work? What currents should I aim for?
Thanks, as always 🙂
I got a problem.
My audiobug is hungry again...
I gotta do somthing, before he transforms into the monster at the midnight of blue moon..
While awaiting and wondering how can the kit get to EU and not cost an arm and a leg...I woke up and opened the drawer for cookies. Found some 2SK170, but, ah, GR grade.
And some J310 (maybegoodenough as CCSs) Bipolars? Oh, just some BC559 critters...
So, Nelson, can I feed my audiobug with these, and get this pre to work? What currents should I aim for?
Thanks, as always 🙂
already answered earlier, you just need to find simple and short calculus what are Iq numbers for each specific current path of circuit
so, GR falls perfectly in, without pulling its gate skyhigh
also - there is a article Pa recently posted, specifically addressing mater of JFet current ranges, regarding Iq in circuit; pardon moi, can't remember where it is exactly, have no time to search right now
ZM, not sure if this is the article you were thinking of? https://www.diyaudio.com/community/threads/beyond-the-j-fringe.370957/#post-6617332
exactly
luckily, Dennis is here, one of Boyz having both brain and clarity and memory (3, I know)
luckily, Dennis is here, one of Boyz having both brain and clarity and memory (3, I know)
How about the other flavor of 2SK170, V grade? I thought I read somewhere that the performance of the jfet is diminished as it is run below its Idss. Does a a pair of Idss 11 or 12mA V grade jfets sharing 3 or 4mA perform worse than the GR or BL grades in this situation?
Thanks ZM, I plan to. Just wanted to understand in general if there is a penalty running them much below their Idss?
Identify the polarity of your capacitors on the silkscreen for when you run out of non-polar caps?
Seems the footprint for some of the transistors is very close?
Aloha Mr Pass, by chancedohave a copy to modify the Soundstream D100ll to a Class A50? Does one exsist for the d200 to Class A100? Anuything would help. Thanks
Quoting Mr. Juma ?
https://www.diyaudio.com/community/threads/f5-semi-turbo-with-lateral-mosfets.209568/post-3067403
(Does not mean I share his opinion)
V-grade best save for source follower use (or if you prefer DC-B1). A waste here.
Patrick
Thanks ZM and Dennis
I had not seen that article... Now I can sleep better 🙂 and use the GR-emlin fet 😉
if JFet is used open loop, everything matters, and 80-90% of Idss is desirable
though, my experience is - when JFet is enclosed in NFB, plenty other factors are in play, and I'm ignoring Idss/Iq ratio
in some cases shooting for specific Idss is important but that's more related to values of accompanying resistors than anything else (say when NFB is folded back to source resistor of said JFet(s))
though, my experience is - when JFet is enclosed in NFB, plenty other factors are in play, and I'm ignoring Idss/Iq ratio
in some cases shooting for specific Idss is important but that's more related to values of accompanying resistors than anything else (say when NFB is folded back to source resistor of said JFet(s))
