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Old 5th July 2012, 10:13 AM   #1551
Siberia is offline Siberia  Lithuania
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Now I've used a mA function on my DMM and got these values which I find weird:

Left board: 2.87; 2.85; 2.84; 2.86 mA
Right board: 4.56; 4.51; 4.58; 4.51 mA
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Old 5th July 2012, 10:42 AM   #1552
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mA in series with a voltage leg, V+ or V- ?

nAr

EDIT : can you confirm Q6-Q9 drain Voltage, and R28 and R29 voltage check ?

the R source measure of 1st stage seem fine to me - I assume GR grade for the 1st set of measures
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Last edited by nar; 5th July 2012 at 10:56 AM.
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Old 5th July 2012, 11:14 AM   #1553
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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
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Old 5th July 2012, 11:22 AM   #1554
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Quote:
Originally Posted by Siberia View Post
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. DGS seen from face.

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
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Old 5th July 2012, 11:30 AM   #1555
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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.

Last edited by Siberia; 5th July 2012 at 11:33 AM.
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Old 5th July 2012, 11:38 AM   #1556
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Quote:
Originally Posted by Siberia View Post
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.
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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"... Audio needs the thinnest wire ..." Rowan McCombe ... I hear it !!!
"Just 'cause they can't hear or sense it themselves doesn't mean you can't !" Allen Wright Allen was right ...

Last edited by nar; 5th July 2012 at 11:44 AM.
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Old 5th July 2012, 11:48 AM   #1557
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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.
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Old 5th July 2012, 12:00 PM   #1558
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Q1 measurements on both boards:

http://i47.tinypic.com/2rw54ko.png
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Old 5th July 2012, 12:04 PM   #1559
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Quote:
Originally Posted by Siberia View Post
Q1 measurements on both boards:

http://i47.tinypic.com/2rw54ko.png
Which voltage do you sense at Emiter of Q3 ?

Best,

nAr
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Old 5th July 2012, 12:31 PM   #1560
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Here it is, if I'm measuring the right thing:

http://i46.tinypic.com/2vnnvcl.png
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