cviller said:
Please let me know before you etch my fish... I have a few updates to for it.
Papa is the one teasing as all! I would love to see the aleph j too!
http://www.passlabs.com/np/AlephJSerM.pdf
And I guess cause it's a Zener picture???
zener diode
You might have guessed it from the diode arrow symbol orientation.
Some manufacturers avoid the confusion by using +/- notations instead of cathode and anode.
Welcome to Solid State.
You might have guessed it from the diode arrow symbol orientation.
Some manufacturers avoid the confusion by using +/- notations instead of cathode and anode.
Welcome to Solid State.
Different point of view on F4 amplifier PCB 
Ground connected in only one point.
schematic
PCB top view
PCB bottom view
Ground connected in only one point.schematic
PCB top view
PCB bottom view
Not yet, but I will probably order few to make sure, that there are no mistakes (schematic and layout is very easy so there shouldn't be any surprises). I have 200mm high heat-sinks and they will feat just fine
If somebody want to have less problems with matching FETs - IRFP240/IRFP9140 should work better in output stage (I was using such pairs in Dracula amplifier). I added RA,RB and CA, CB components on this PCB but they can be skiped (just place jumper instead of RA and RB).
3D view of this board:
If somebody want to have less problems with matching FETs - IRFP240/IRFP9140 should work better in output stage (I was using such pairs in Dracula amplifier). I added RA,RB and CA, CB components on this PCB but they can be skiped (just place jumper instead of RA and RB).
3D view of this board:
Attachments
mpmarino said:
Right.....
Hey, would it be a big deal if the ZENERS were 6.2v as a sub for the 6.8v in the circuit?
Oh, are Jfets wicked static sensitive?
you mean crippled 2N4736.......
they're there just for protection- just put what you have in drawer or don't put anything if you are confident that you wouldn't have short circ between headphones during connecting cables to amp
mpmarino said:
When we adjust bias voltage, e.g. TL431, we could make a
mistake by accident. If the bias voltage is too high,
the power mosfets would suffer from excessive current.
If so, when we have no spare parts, hmm . . .
Meanwhile, the input jfets are formed with self bias. As long as
the rail voltages are under control, the jfets are safe. In my
opinion, the probability for us to use wrong rail voltages are
ignorably low.
My first etching 
Thanks to Nelson Pass for sharing the schematic
Thanks to Veteran for sharing the layout
Thanks to Tom Gootee for the 'how to etch' instructions
Thanks to Nelson Pass for sharing the schematic
Thanks to Veteran for sharing the layout
Thanks to Tom Gootee for the 'how to etch' instructions
An externally hosted image should be here but it was not working when we last tested it.
