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Old 14th June 2010, 02:39 PM   #3931
Salas is online now Salas  Greece
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Quote:
Originally Posted by Franz Gysi View Post

To design the layout, I use Lochmaster, a handy software.

Franz
Hey, that software is too cool for perfboard planning! Good one Franz.
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Old 14th June 2010, 03:27 PM   #3932
NPower is offline NPower  Portugal
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Quote:
Originally Posted by Salas View Post
Delete the horizontal line from node R17 to Q6's gate. 220uF capacitor's + goes to B+ 37V is the correct polarity of course. The 50pF input load capacitor is not needed. Delete its position or leave it blank for your AT31E that states 100-200pF, so much comes from the TT cable. About double JFET I will check and let you know if it can work with those values around it with proper gain etc.

P.S. I checked it out. Delete the paralleled 2nd JFET in first stage. It will up the trimmer setting adding noise, that will about offset its benefit, plus it will make it lose some gain since it will alter the Vgs point.
Just finished my main PCB according Salas instructions.
I attached files for main, copper and silkscreen in PDF format.
Main PCB layout based on P2P from RCruz (obrigado).
On attached files there are also Gerber and Excellon files. Any modifications on PCB layout are welcome.
PCB made in TCI4 ( free software from French guy Bruno Urbani )
Right now I gonna prepare my self to etch my first PCB.
Dual shunt reg PCB almost ready (only need to perform final check ). I will post that to.
Brgds
Attached Files
File Type: zip SALAS RIAA.zip (73.9 KB, 87 views)
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Old 14th June 2010, 03:31 PM   #3933
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I mind Lochmaster is usefull for the people like me that only want to do p2p.
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Old 14th June 2010, 04:47 PM   #3934
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Here an example of one of my Lochmaster stripeboards: a stereo B1 based on 2SK389 including psu.

Click the image to open in full size.

Today, I had very urgently to solve my hum problem before I can proceed to the V1.2 psu for the simplistic RIAA.

Why?

Because my active crossover got the weakest point in my chain and I urgently had to replace it before I make my phono pre better.

Just to enable me to listen to the differences in my phono preamp improvements :-)))

As you may have seen yesterday, I reactived an old project from me: Rod Elliott crossover with two t-amps in one enclosure.

But it showed strong hum :-(

And as some of you insisted I should use better amps than t-amps I removed this amps, the related trannies and the psu from the enclosure.

It is the more flexible option for the future. When I began build this project, I was not aware, that my low-mid speakers (two Fostex FW250 in parallel) do need definitely more than 8 Watts.

Still hum after removing the amps :-(

I noticed, that the hum goes away, when I shorten the inputs of the crossover.

Then it came to my mind, that I NEVER tried to connect the whole circuit to the chassis ground and the safety earth.

Every hum is gone.

I feel like a complete idiot!!! Please be careful with your answers, as my ego is not in a stable shape right now!

Anyway, I will sleep good tonight and I am looking forward to build the shunt remote sensing psu soon.

Franz

P.S.
The crossover is sounding awesome compared to the IMG Stage Line crossover I used before. Next step: adjusting all three ways with the simple pc-measuring system I have.

Last edited by Franz Gysi; 14th June 2010 at 04:50 PM.
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Old 14th June 2010, 05:02 PM   #3935
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Congratulations for hum noise gone Franz.
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Old 14th June 2010, 05:03 PM   #3936
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Click the image to open in full size.

No comment
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Old 14th June 2010, 05:04 PM   #3937
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@Rcruz

Next step PSU caps test 10.000uF / 63V: Jensen 4 pole vs Black Gate

Click the image to open in full size.
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Old 14th June 2010, 10:46 PM   #3938
Salas is online now Salas  Greece
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Quote:
Originally Posted by NPower View Post
Just finished my main PCB according Salas instructions.
I attached files for main, copper and silkscreen in PDF format.
Main PCB layout based on P2P from RCruz (obrigado).
On attached files there are also Gerber and Excellon files. Any modifications on PCB layout are welcome.
PCB made in TCI4 ( free software from French guy Bruno Urbani )
Right now I gonna prepare my self to etch my first PCB.
Dual shunt reg PCB almost ready (only need to perform final check ). I will post that to.
Brgds
Good clean work. Thanks for sharing.
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Old 15th June 2010, 09:53 AM   #3939
RCruz is online now RCruz  Switzerland
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Quote:
Originally Posted by merlin el mago View Post
@Rcruz

Next step PSU caps test 10.000uF / 63V: Jensen 4 pole vs Black Gate

Click the image to open in full size.
Cool
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Old 15th June 2010, 10:50 AM   #3940
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Test result: winner BG, more punch, more harmonics in the mids, lows focused & articulated without losing body, highs crystal clear, resuming are far the best for PSU, only two problems: are super-expensive & now are NOS due finished production.

Photo with BG & Jensen, BG are exactly double size of Jensen:

Click the image to open in full size.

With BG PSU upgrade now I don't know sure if finally will go to balanced.

Last edited by merlin el mago; 15th June 2010 at 11:00 AM. Reason: add photo
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