Well, in principle you can use Patricks variant also with laterals as the 2SK1530 has already really low VGS.
However, don't forget that laterals have much less transconductance, which translates into lower gain and higher output impedance. You need about a pair to get the same values as a single vertical fet; in that case gate capacitances are about the same again (though more linear).
Go for it, if you want.
Have fun, Hannes
However, don't forget that laterals have much less transconductance, which translates into lower gain and higher output impedance. You need about a pair to get the same values as a single vertical fet; in that case gate capacitances are about the same again (though more linear).
Go for it, if you want.
Have fun, Hannes
balanced version
Sorry 'garborbela' (?), forgot to add this...
There is balanced design started by Tino on post 130 (p6) and further taken up by EUVL on #1186 (p48).
TimS (NZ) also did a design on #135 and continued... (he also did a rather good one for headphones)
Hope this will get you started in the right direction.
Sorry 'garborbela' (?), forgot to add this...
There is balanced design started by Tino on post 130 (p6) and further taken up by EUVL on #1186 (p48).
TimS (NZ) also did a design on #135 and continued... (he also did a rather good one for headphones)
Hope this will get you started in the right direction.
Hello,
Thanks everyone for your answers! I will try to take a look for some other solutions. At the moment I am using this product:
http://www.falco-systems.com/High_voltage_amplifier_WMA-300.html
However, it is only up to +- 150V.
Anyway, thanks to all.
Cheers
Thanks everyone for your answers! I will try to take a look for some other solutions. At the moment I am using this product:
http://www.falco-systems.com/High_voltage_amplifier_WMA-300.html
However, it is only up to +- 150V.
Anyway, thanks to all.
Cheers
Using 2SK1058 in the DAP follower
Do bear in mind that the LU1014 is being used in "triode" mode, and thus the characteristics of the cascode device plays a more important role than a "penthode" device like normal MOSFETs. I would encourage you to try this, but be prepared to vary the cascode gate voltage AND the source resistor value. In any case, always try to measure Id vs Vgs of the LU1014 directly until you get a linear operating regime. I would guess that you would need to reduce the value of both to get optimal results, due to the lower transconductance (or higher effective resistance) of the 2SK1058.
Or if you have reliable Spice models for both, that would make the initial optimisation a bit easier.
Patrick
PS I propose that we should shift any further discussion to the follower thread.
http://www.diyaudio.com/forums/showthread.php?s=&threadid=128571&pagenumber=3
Do bear in mind that the LU1014 is being used in "triode" mode, and thus the characteristics of the cascode device plays a more important role than a "penthode" device like normal MOSFETs. I would encourage you to try this, but be prepared to vary the cascode gate voltage AND the source resistor value. In any case, always try to measure Id vs Vgs of the LU1014 directly until you get a linear operating regime. I would guess that you would need to reduce the value of both to get optimal results, due to the lower transconductance (or higher effective resistance) of the 2SK1058.
Or if you have reliable Spice models for both, that would make the initial optimisation a bit easier.
Patrick
PS I propose that we should shift any further discussion to the follower thread.
http://www.diyaudio.com/forums/showthread.php?s=&threadid=128571&pagenumber=3
it could operate lower, i believe, but remember that the sound changes slightly depending on voltage. the amp with the power supply outlined in the user manual/schema says to use a transformer with dual 18v secondaries, if i recall, which gets you something like 24v rails (is that right? its been a while for me)
-J
-J