You'll have to spell it out to me, I don't see huge differences with regards to capacitance.
At least certainly not worse than the differences between IRFP240P/IRFP9240P
I think your selection is equally valid.
Added a table showing candidate IXYS parts and well known complimentary parts for comparison.
* Transconductance of IRFP240/9240 measured between 10A and 20A from data sheet (at 25C)
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It seems that main differences is flat Ciss of the miniblock devices, compared to curvy IRFP.
In follower application Ciss is dominant.
"big Class A envelope" probably mean no degeneration.
> "big Class A envelope" probably mean no degeneration.
Read the link in Post #1.
Tells you a lot more.
Patrick
Read the link in Post #1.
Tells you a lot more.
Patrick
I am in bed with the flu.
Mostly you are wrong. The Villars photo showed a mock up of the circuit
I used as an illustration of cascoded performance that I showed at BAF,
and is not related to the XA25.
The XA25 has an RCA input and not balanced outputs. It is a very simple
amp that had surprising performance, however it is the intellectual property
of Pass Labs, and so remains under wrap.
I will tell you this so that you can reverse engineer it:
Three stages, DF is about 700, high current, high slew, .00x% distortion,
40 uV output noise, big Class A envelope, 25 watts into 8, 100 watts into 2.
And it sounds great.
Now back to bed.
Damping factor = 700 ?
If it's not typo of 200 it's huge.
On the first, I was read that, but it was strange for me that diler has spec, wich is steel unavailable on the official Passlabs site.
If we can belive to that description, than more-less topology is clear.
Only to find gain structure in 1st and 2nd stage.
2nd is probably with high drain load. (if it is without degeneration)
when it is simple as Nelson says, it could be something like the "Le Monstre"
instead of one SK170 two, same for SJ74 to allow higher bias for the J-Fets.
At the output something with the higher transconductance Monster hockey pucks, complementary.
only difference Nelson made a real MONSTER out of it!
No Monsters in your dreams Nelson!
😀😀😀
oh no three stages.....!
instead of one SK170 two, same for SJ74 to allow higher bias for the J-Fets.
At the output something with the higher transconductance Monster hockey pucks, complementary.
only difference Nelson made a real MONSTER out of it!
No Monsters in your dreams Nelson!
😀😀😀
oh no three stages.....!
Attachments
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I am drowning..... 🙂)
In the first description it looked like a 2 stage system with a double buffer at the input.
In the first description it looked like a 2 stage system with a double buffer at the input.
My guess is same as XS or XA.8 front end but without balanced X circuit and obviously biased more aggressively at output stage.
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What I assumed to be the front end (that I could see through the vent holes in the cover) was indeed very simple. It included 14? pin DIP devices, a sprinkling of resistors and a few diodes. The hockey pucks and power resistors dominated the heatsinks along with what looked like soft start or another control circuit. I don't recall seeing any 3 legged critters at all. Very limited view though, so your guess is as good as mine.
Most likely the three legged devices were hidden from view.
"The simple front end circuit uses uses two pairs of NOS complementary Fets in common-source mode"
"The simple front end circuit uses uses two pairs of NOS complementary Fets in common-source mode"
I initially thought that as well, but "two NOS pairs" more likely means 2SK170/2SJ74 driving 2SK2013/2SJ313 in an F5-style arrangement like half the front end of the supersymmetric amps.
You forgot that I was a telepathic alien hybrid.
If I got it completely wrong, just call me a dumb alien hybrid. Hahaha
?