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Old 10th April 2010, 10:26 AM   #1421
housing is offline housing  Hong Kong
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Default Simplistic Mosfet HV Shunt

Does any member finish his 5687 I/V stage with the Simplistic Mosfet HV Shunt designed by quanghao? How much current and voltage should it be set?


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Old 10th April 2010, 10:38 AM   #1422
housing is offline housing  Hong Kong
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Default Problematic I/V stage PCB

Hi quanghao,

I looked at ksnider1's I/V stage PCB that's clean with crispy copper traces and examined mine that arrived this morning. Why is mine so dirty and masked by something unknown, and the ground plane near R32/R33 is extremely deformed and distorted?

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Last edited by housing; 10th April 2010 at 10:40 AM.
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Old 10th April 2010, 05:45 PM   #1423
Ekkeri is offline Ekkeri  Finland
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Quote:
Originally Posted by housing View Post
...and the ground plane near R32/R33 is extremely deformed and distorted?

Mine is also deformed in that place, looks very similar.. There have been some other quality issues also, with Salas output pads if I remember right..
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Old 10th April 2010, 10:04 PM   #1424
Jogi is offline Jogi  Germany
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Quote:
Originally Posted by housing View Post
Does any member finish his 5687 I/V stage with the Simplistic Mosfet HV Shunt designed by quanghao? How much current and voltage should it be set?



Very good question, as I am waiting for salas board. As far as I remember, 50V + are required for the shunt to work.
So which transformer secondary voltage do we need, does anyone have an idea?


Cheers,

Juergen
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Old 10th April 2010, 11:33 PM   #1425
Salas is offline Salas  Greece
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15V-25V Will still be OK.
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Old 11th April 2010, 03:22 AM   #1426
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Quote:
Originally Posted by Yunick View Post
Nice work Ksnider1!

Very neat and tidy.
Thanks, I'm waiting for Salas shunt PCB for DAC now. I hope it's on the way by now.
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Old 11th April 2010, 03:47 AM   #1427
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Location: Kaskus / Madiun
Quote:
Originally Posted by erwincantona View Post
Just sharing

Click the image to open in full size.

My friend uses Nelson Pass D-1 (replacement for Supply + IV Stage) for my DAC End 2.
But it hasn't worked well. He said the problem is on D-1.
(He'll find what really happened later)
Sound output ( Right and Left channel) isn't at the same level.
After replacing IRF610, previous problem is gone...
now DAC sings equal volume at right & left channel

After 1 hours play few songs, the result (compare with just DAC+Salas Shunt):

soundtage get wider
thick vocal
low and high get more extend

But..... voice sounds a little bit stiff. Need more time to break in?
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Old 11th April 2010, 08:15 AM   #1428
housing is offline housing  Hong Kong
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Nice. Seems D1's I/V is an alternative to the tube I/V.

Thanks. Would like to hear further progress.


Quote:
Originally Posted by erwincantona View Post
After replacing IRF610, previous problem is gone...
now DAC sings equal volume at right & left channel

After 1 hours play few songs, the result (compare with just DAC+Salas Shunt):

soundtage get wider
thick vocal
low and high get more extend

But..... voice sounds a little bit stiff. Need more time to break in?
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Old 11th April 2010, 09:01 AM   #1429
FRUGIVO is offline FRUGIVO  Spain
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Join Date: Feb 2010
Location: Burgos
Hi Quanghao,I need full board (DAC END, Salas shunt for DAC, I/V stage and PSU for I/V Stage)I will wait until your PCB for PSU for I/V is ready.Thanks.
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Old 11th April 2010, 09:54 PM   #1430
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Location: Davis,CA
I have altered my unit so that it is now using Welborne's PS10 power supply. It is regulated and uses no electrolytics. 267 volts to I/V board with 105V on the plates. I have listened for a couple of hours and believe the DAC has more punch and dynamics. Could me my head playing tricks but I am going to keep it this way for now.

Enjoy

Bob
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