This is not another Lovoltech. I think that SemiSouth is potentially
destined for big success. They've got lots of patents, apparently their
own fab equipment, and Silicon Carbide process that makes for better
switching in converters for solar cell arrays and electric cars.
It is a coincidence that it makes for such a good audio part.
The SJEP120R063 samples for around $60.
😎
destined for big success. They've got lots of patents, apparently their
own fab equipment, and Silicon Carbide process that makes for better
switching in converters for solar cell arrays and electric cars.
It is a coincidence that it makes for such a good audio part.
The SJEP120R063 samples for around $60.
😎
New JFET
That's still cheaper than plenty of 300B tubes....
and if it sounds better..even better.
Nelson Pass said:
That's still cheaper than plenty of 300B tubes....
and if it sounds better..even better.
Nelson Pass said:
Nelson, how about a pair of those devices as the main prize for a lucky winner at the next BAF?
Vix said:
Nelson, how about a pair of those devices as the main prize for a lucky winner at the next BAF?
naah .....
Papa already sent all redundant ones to Serbia ....
Nelson Pass said:
This is great!
These are jfets...At $60 each can we please keep the ancillary circuits Mosfets? Please...
ok waiting the info for buy this device, I can build a decent psu for the new F2 , Vout are standard Pass 2x +24Vdc ?
I wonder if the new F2 will look something like "Magnified J-fet Boz."...
just slightly more complex...
just slightly more complex...
Another direction
Another direction that I have tried in the last 2 days was to look at smaller devices. It appears that these devices might have a better chance to have a "flat" transconductance vs Drain current characteristics. For example, I found that for IRF9610, the gm curve is rather flat between -1.2A to -1.8A (Max rating), giving us a +/-0.3A swing possibility.
Assuming I need 5W into 8 Ohm for my F2, the current swing will be +/-1.2A. If I can parallel 4 IRF9610, I will be able to get this swing. Of course, there are many other things to be thought through - like reliability of IRF9610 biased to such a high current (1.5A), total dissipation, input capacitance etc.... Still a lot to think about...
But these device are much cheaper and more readily available. Hope after some more digging, something pops up.
Another direction that I have tried in the last 2 days was to look at smaller devices. It appears that these devices might have a better chance to have a "flat" transconductance vs Drain current characteristics. For example, I found that for IRF9610, the gm curve is rather flat between -1.2A to -1.8A (Max rating), giving us a +/-0.3A swing possibility.
Assuming I need 5W into 8 Ohm for my F2, the current swing will be +/-1.2A. If I can parallel 4 IRF9610, I will be able to get this swing. Of course, there are many other things to be thought through - like reliability of IRF9610 biased to such a high current (1.5A), total dissipation, input capacitance etc.... Still a lot to think about...
But these device are much cheaper and more readily available. Hope after some more digging, something pops up.
Papa:
Those JFETs make me think it's time for a direct drive electrostatic (headphone) amp. Call it the FkV1 🙂
Those JFETs make me think it's time for a direct drive electrostatic (headphone) amp. Call it the FkV1 🙂
Will F2's be upgradeable to the new version?
Dear Mr. Pass,
I know it is not likely but my curiosity got the best of me.
Will cloning be encouraged for the new version? Offering these new JFET's to the DIY'ers could help absorb some of that minimum order (or we can only hope such might be helpful).
I can see this device being used in multiples for the PASS line, also. Even then, if matching was required maybe we could help absorb some of the devices that do not make the grade?
Nothing more desirable than unobtanium!
Thanks for keeping the hobby EXCITING!!!
Rick McInnis
Dear Mr. Pass,
I know it is not likely but my curiosity got the best of me.
Will cloning be encouraged for the new version? Offering these new JFET's to the DIY'ers could help absorb some of that minimum order (or we can only hope such might be helpful).
I can see this device being used in multiples for the PASS line, also. Even then, if matching was required maybe we could help absorb some of the devices that do not make the grade?
Nothing more desirable than unobtanium!
Thanks for keeping the hobby EXCITING!!!
Rick McInnis
This question addresses some of the issues I am preparing for a
missive to Srajan at 6moons. There is not likely to be further delay
once he receives it.
😎
missive to Srajan at 6moons. There is not likely to be further delay
once he receives it.
😎
Can this be an interesting alternative?
I found BUZ905 rather interesting.
A P-channel MOSFET, with fairly stable transconductance. If biased at 2.5A and expecting a +/- 1A swing, the transconductance seems to vary from ~0.97 to ~1.2. Power and current handling are OK as a direct drop-in to F2. Linearity looks much better than IRF.
Certainly some changes needed as this is a P-device. The N-channel complementary BUZ900 is good but not as good as the P-one.
I found BUZ905 rather interesting.
A P-channel MOSFET, with fairly stable transconductance. If biased at 2.5A and expecting a +/- 1A swing, the transconductance seems to vary from ~0.97 to ~1.2. Power and current handling are OK as a direct drop-in to F2. Linearity looks much better than IRF.
Certainly some changes needed as this is a P-device. The N-channel complementary BUZ900 is good but not as good as the P-one.
F2 question
Hi,
Could someone please answer this question:
From the F2 schematic, it looks like the Source of Q2 (the current source device)
is connected to the Drain of Q1 (the gain device) . Is that correct?
I want to make sure that this is the case because in the orginal Zen amp, the drain
of Q2 was connected to the drain of Q1.
Thanks
Hi,
Could someone please answer this question:
From the F2 schematic, it looks like the Source of Q2 (the current source device)
is connected to the Drain of Q1 (the gain device) . Is that correct?
I want to make sure that this is the case because in the orginal Zen amp, the drain
of Q2 was connected to the drain of Q1.
Thanks