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Old 12th February 2009, 01:22 AM   #1011
iko is offline iko  Canada
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Ricardo, I put a .15u russian cap in the interstage coupling position, and then another one on the output, in parallel with two 1u (sprague pio).

Hope it goes well for you.
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Old 13th February 2009, 09:32 PM   #1012
RCruz is offline RCruz  Switzerland
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Hi Salas

Can I use a 16v cap in C6 ?

What is the maximum voltage there ?


Almost done...!!!

After all the board does not have a common GND between channels.... Lee left the copper all around the circuit... like a mask... should I ground this "virtual gnd" ?

Regards

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Old 13th February 2009, 09:45 PM   #1013
Salas is offline Salas  Greece
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Yes you can, the Zener is for 8.2V there. So C6 can safely be 16V.

Actual ground traces I would connect from phono channels to the shunt's reg out GND like a Y. And from there, with one cable to chassis. The masks I would connect locally to the ground traces where the cables to reg GND take off. Off course all this may change if you face some GND loop (I wish not).

Photos, first impressions etc. I don't have to remind I guess...
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Old 14th February 2009, 09:51 AM   #1014
RCruz is offline RCruz  Switzerland
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Thank you Salas

My plan was to build a central star GND and then route there all the following GND five wires:

Shunt - one wire to star
Riaa (both left and right GND plus another wire for the screen) - three wires to star
Output rca - two wires to star

I plan to solder the input rca directly to the riaa board.

Is this a good idea ?

Ricardo
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Old 14th February 2009, 10:00 AM   #1015
Salas is offline Salas  Greece
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Yes its a standard star. So it must be good. You must start with something. If you don't get buzz, you will be practically OK. Make it so we know. Final countdown? When ready?
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Old 14th February 2009, 10:27 AM   #1016
RCruz is offline RCruz  Switzerland
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I believe tomorrow I will have everything ready for testing.

I will have to compromise in this first stage because I do not have a metal case.
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Old 14th February 2009, 10:29 AM   #1017
RCruz is offline RCruz  Switzerland
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Underside....
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Old 14th February 2009, 03:10 PM   #1018
Salas is offline Salas  Greece
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I hope that the PIO in the RIAA filter is in good tolerance...
Where is your C3? This one is the most RIAA critical. Must be 15.8nF-16nF measured and matched if possible.
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Old 14th February 2009, 08:34 PM   #1019
RCruz is offline RCruz  Switzerland
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Here you have a pic of C3 ... it reads an incredible +-0.3%
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Old 14th February 2009, 08:37 PM   #1020
RCruz is offline RCruz  Switzerland
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And another of C1.... looks very small to me
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