Forget the so called mistake. My tired head hooked up on this idea yesterday. THe goundpad is referenced to ground and it's all what's needed. It doesn't need any jumper, it's what I think now! 
My DMM specs. say DC: 400mV +-(0.7%+1). My voltage is dancing around +40mV, - 40mV on both boards. I don't have a second meter. Maybe I should change the batteries to be sure.
My DMM specs. say DC: 400mV +-(0.7%+1). My voltage is dancing around +40mV, - 40mV on both boards. I don't have a second meter. Maybe I should change the batteries to be sure.
Pin 3 of Q9 is the Source pin on schematic
Assuming R is 10, then you have about 4,2 mA through that jfet
right board is a bit higher, 6,5 mA, refer to higher IDSS of the jfet maybe
jfets Q6 to Q9 should idle at about the same current if well matched (IDSS)
Jfet drains (pin 1) should be around 9V above Ground
8V to 10V will be in ballpark though
nAr
EDIT
4,2mA seems low for BL grade jfet. Can you check the other jfets currents in 1st stage (measuring parallel to 10R and using ohm law)
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Forget the mA measurement, talking rubish...
Drain voltages Q6-Q9 (if I'm measuring the corectly):
Left board: 304.9 mV
Right board: 03.85 mV
Now for aditional vertigo, I'm questioning the direction of jFets. I've have mounted them according to board markings. But if I believe this document:
K170 pdf, K170 description, K170 datasheets, K170 view ::: ALLDATASHEET :::
and then look at the board, then the drain is a closer leg to source resistors the way it's mounted now.
All the same
Drain voltages Q6-Q9 (if I'm measuring the corectly):
Left board: 304.9 mV
Right board: 03.85 mV
Now for aditional vertigo, I'm questioning the direction of jFets. I've have mounted them according to board markings. But if I believe this document:
K170 pdf, K170 description, K170 datasheets, K170 view ::: ALLDATASHEET :::
and then look at the board, then the drain is a closer leg to source resistors the way it's mounted now.
All the same
From pics you sent seems the jfets are mounted OK ... DGS seen from face, left to right.
Drain voltages are not correct from what I see. Measure taken between jfet drain and Ground.
This probabley means sub regulator and cascode don't work properly.
You should do a check to this points too !
Best,
nAr
Better pic too show how it's mounted. Have I marked the letters correctly?
http://i48.tinypic.com/34e7yf7.png
If it's OK. The way I see in data sheet is the opposite, isn't it?
PS. And yes it was measured Drain to ground as it stands now.
http://i48.tinypic.com/34e7yf7.png
If it's OK. The way I see in data sheet is the opposite, isn't it?
PS. And yes it was measured Drain to ground as it stands now.
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Correct pinout and mounting
I don't understand how you wired the PSU ... You have one board shunt reg for plus and one for minus ? How does it work ?
Which is PSU output pinout and voltage arrangements ?
EDIT / never mind wiring seems perfectly OK
Best,
nAr
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Yes one +24V and a -24V board. Both of them have additional pair of remote sense wires. 8 wires going out from two shunts in total.
I've tied +DC IN pads of L & R boards together with a bridge wire, same for Ground pads, and -DC IN pads. At the middle of +DC IN bridge I have attached a +Vout and a + sense wire, same for the negative, and two ground wires from both shunts and their sense wires to the middle of the Ground bridge.
I've tied +DC IN pads of L & R boards together with a bridge wire, same for Ground pads, and -DC IN pads. At the middle of +DC IN bridge I have attached a +Vout and a + sense wire, same for the negative, and two ground wires from both shunts and their sense wires to the middle of the Ground bridge.