Hi Salas,
No not yet, thanks for asking. One of the problems is that I am enjoying it too much with my amp and loudspeakers! Headphones are getting neglected...
No not yet, thanks for asking. One of the problems is that I am enjoying it too much with my amp and loudspeakers! Headphones are getting neglected...
Ok - listened to the Sennheiser Orpheus HE-1 headphones today. 🙂
Impressive stuff. Science fiction price. 60000$.
Went home - listening to the dcg3 and my own HP just as happy as before and even more satisfied with the dcg3 🙂
Impressive stuff. Science fiction price. 60000$.
Went home - listening to the dcg3 and my own HP just as happy as before and even more satisfied with the dcg3 🙂
Is there an audio show going on at the time in your area? Orpheus is a showpiece normally but I don't know if they have a demo touring their main importers around the world also.
Salas,
I hope you wouldn't mind my intrusion.
I wonder what made you choose a cascoded IRFP9610.
I am sure you must have tried many others before settling on that choice.
But the IRFP PMOS is known to have this strange behaviour as pointed out by Charles years ago.
Did you try e.g. the 2SJ79 as in the Borbely (low capacitance enough to do without cascode) ?
Or even a 2SJ313 which is also quite low in C, and can live with 2V Vgs at 120mA bias.
Thank in advance,
Patrick
I hope you wouldn't mind my intrusion.
I wonder what made you choose a cascoded IRFP9610.
I am sure you must have tried many others before settling on that choice.
But the IRFP PMOS is known to have this strange behaviour as pointed out by Charles years ago.
Did you try e.g. the 2SJ79 as in the Borbely (low capacitance enough to do without cascode) ?
Or even a 2SJ313 which is also quite low in C, and can live with 2V Vgs at 120mA bias.
Thank in advance,
Patrick
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It measured better THD in this circuit even vs Fairchild FQP3P20 cascode. The IRF9610 seems showing more gfs in low current like 0.1A - 0.15A than some others in its light capacitance category from that result. There is gain in the output stage its not a follower so any little crss is bound to be multiplied >>2X. Thus a single TO-220 P-MOS choice would not go far. With such a weak driver stage at least. The discovered kink is for N-Channel of IR original manufacturing only maybe? Post #7 http://www.diyaudio.com/forums/pass-labs/48930-irf9610-matching-manufactures.html
Many thanks for your reply.
For your information only.
According to our measurements (20V Vgs, 40°C case temperature) :
2SJ313 0.46S at 150mA
FQP3P20 0.47S at 150mA
IRF9610 0.33S at 150mA
As far as I can recall, the distortion is for P-channel. See :
http://www.diyaudio.com/forums/solid-state/28853-sound-vmosfet.html#post333923
Cheers,
Patrick
For your information only.
According to our measurements (20V Vgs, 40°C case temperature) :
2SJ313 0.46S at 150mA
FQP3P20 0.47S at 150mA
IRF9610 0.33S at 150mA
As far as I can recall, the distortion is for P-channel. See :
http://www.diyaudio.com/forums/solid-state/28853-sound-vmosfet.html#post333923
Cheers,
Patrick
Incidentally, for the Fairchild, Id varies quite a bit with Vds at fixed Vgs.
In this respect, Toshiba and IR are both much much better.
Patrick
In this respect, Toshiba and IR are both much much better.
Patrick
I did not encounter such a gfs kink in IRF9610 Vishay (IR is part of Vishay for many years now)
> VDS is 8.5V across each in this circuit btw
When there is no output, correct ?
As already mentioned, both the Toshiba and IRF are almost perfect "Penthodes", down to about 3V Vds.
No real influence on the Yfs values.
Patrick
When there is no output, correct ?
As already mentioned, both the Toshiba and IRF are almost perfect "Penthodes", down to about 3V Vds.
No real influence on the Yfs values.
Patrick
DC conditions yes. For some reason (probably the Id variance you discovered) the Fairchild cascode THD result was inferior to the Vishay 9610 cascode
Yes, not many choices for TO220 PMOS.
Too bad 2SJ313 is increasingly difficult to get these days.
With 2SJ313, you can cascode at quite a low Vds and hence won't lose too much headroom or output swing.
Patrick
Too bad 2SJ313 is increasingly difficult to get these days.
With 2SJ313, you can cascode at quite a low Vds and hence won't lose too much headroom or output swing.
Patrick
Very expensive NOS parts. 5x 2SJ313 Y and 5x 2SK2013 Y TOSHIBA Audio Power MOS-FET, $90 for legit looking ones. Ciss Coss Crss 210pF 90pF 45pF
In production Vishay IRF 9610 Ciss Coss Crss 170pF 50pF 15pF
In production Vishay IRF 9610 Ciss Coss Crss 170pF 50pF 15pF
Good to hear the Vishay ones are fine. Someday I will replace my stash of 20 year old International Rectifier versions with the Vishay.
Jim
Jim
Spring time and my job needs me twelve hours per day... But I had some progress. Top cover is almost finished! Believe it or not, I' ll have to install two more leds inside the box. I'm going to power them directly from DCSTB output. Would this affect performance soundwise? Should I preffer the positive or the negative rail for some reason? Or put one led on each rail for symmetry? I guess this is another annual award question😀
