Hermida Audio - Zendrive [ goop-alarm ] [traced]
-
snofla1900
- Breadboard Brother
Thanks for the clue , I'll give it a try.
Thanks all for the incredible insight and info! Apologies if this has been covered already but all my searches have turned up conflicting info...
Has it been confirmed beyond all doubt that the zendrive used mosfet body diode clipping and not true mosfet gate clipping with blocking diodes? I'm curious because all schematics show G+D mosfet clipping with additional diodes in series. However the Tanabe Zenkudo in "zen" mode, which is a pretty close copy appears to use 1n34a's as blocking diodes to create gate mosfet clipping. The Zenkudo is also the only production pedal i'm aware of that uses mosfet gate clipping.
Thanks in advance!
Has it been confirmed beyond all doubt that the zendrive used mosfet body diode clipping and not true mosfet gate clipping with blocking diodes? I'm curious because all schematics show G+D mosfet clipping with additional diodes in series. However the Tanabe Zenkudo in "zen" mode, which is a pretty close copy appears to use 1n34a's as blocking diodes to create gate mosfet clipping. The Zenkudo is also the only production pedal i'm aware of that uses mosfet gate clipping.
Thanks in advance!
-
george giblet
- Resistor Ronker
Diode/MOSFET Connections and Ordering
1) PCB
+--- Sh >|------ Ge >|--- S G D ---+
| |
+--- D G S ---|< Sh -----------------+
Sh = Schottky, Blue
Ge = Germanium, Red ring
2) Years ago someone drew a picture of the MOSFET connection.
It was drawn with G (pin 2) and D (pin 3) connected.
Combining items (1) and (2), we would see the MOSFETs are
being used as body diodes.
3) Direction of the clipper. (Still not 100% confirmed.)
The earliest trace with the most correct circuit shows
the clipper with the two diodes and the MOSFET pointing
towards the opamp output.
So from that the Z-drive schematic in this thread has the whole clipper
flipped tip to tip across the opamp.
Maybe this one is close (pin 1 on Voice and Tone not corrected and then Voice pot pins 2 and 3 flipped),
https://aionelectronics.com/wp-content/ ... tation.pdf
1) PCB
+--- Sh >|------ Ge >|--- S G D ---+
| |
+--- D G S ---|< Sh -----------------+
Sh = Schottky, Blue
Ge = Germanium, Red ring
2) Years ago someone drew a picture of the MOSFET connection.
It was drawn with G (pin 2) and D (pin 3) connected.
Combining items (1) and (2), we would see the MOSFETs are
being used as body diodes.
3) Direction of the clipper. (Still not 100% confirmed.)
The earliest trace with the most correct circuit shows
the clipper with the two diodes and the MOSFET pointing
towards the opamp output.
So from that the Z-drive schematic in this thread has the whole clipper
flipped tip to tip across the opamp.
Maybe this one is close (pin 1 on Voice and Tone not corrected and then Voice pot pins 2 and 3 flipped),
https://aionelectronics.com/wp-content/ ... tation.pdf