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Old 11th March 2010, 03:36 PM   #3111
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Yes
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Old 11th March 2010, 04:02 PM   #3112
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What is the voltage on Q2's drain now?
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Old 11th March 2010, 04:05 PM   #3113
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0.2v

The input voltage at the phono RIAA is between 12.1-12.3V instead 45V
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Old 11th March 2010, 04:27 PM   #3114
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So you got some problem with its individual channel shunt? Try the working's one.
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Old 11th March 2010, 04:38 PM   #3115
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I do the measurements with the same regulator
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Old 11th March 2010, 04:45 PM   #3116
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So something is overloading it or upsets it. What is different to the other good channel where the regulator touches the audio perfboard? Some connection, some small capacitor is there or not, the wires are mixed, something must be different to the other channel.
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Old 11th March 2010, 05:11 PM   #3117
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I have extracted the small 0.1uF cap but still continues the same voltage. I follows looking for bad connections.

Is possible wrong Q6 do that?
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Old 11th March 2010, 05:35 PM   #3118
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Haven't experienced such a failure but Q6 is right at B+ so I would check that out too.
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Old 11th March 2010, 06:12 PM   #3119
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I AM VERY VERY HAPPY.

Only was necessary to change Q6 now I have:

LEDs 7.33V (return original colour: after orange, now very nice yellow)
R17 347mV
R10/Q2 10.06V
R1/Q3 11.5V
R7/GND 10.21V
Drain Q5/GND 21.1V

Now I have only to wait a couple o day the new Tx from Mouser so finally I will hear the heaven
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Old 11th March 2010, 06:25 PM   #3120
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Congratulations. Pictures alight please.

Why don't you just use a single reg for both till then? Most phonos made are not double mono for PSU. Will be near best and you could run it in a bit until you got the extra Tx.
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