A PCB-design for Phono-pre-amp

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Roushon

Roushon

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Joined 2004
#1
Here is a single-sided pcb-design (with two jumpers) for a phono pre-amp circuit based on the National Application Note AN-1651.
I request for suggestions and corrections in the design.

Regards
Roushon
 

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#4
Thanks Joachim. R18 is 38.7R. I corrected it now. I am following the Topology 2 (Active/Passive) in the application note. Half of IC4 is not used, so
I made a unity gain buffer out of it. I know it is not required, but it is not of any harm if added I hope.

Regards
Roushon
 
Last edited:
#7
On the pcb: do not use 90 deg. anles on traces. In the etching process (especially home-made boards) undercutting at the anle could happen). Use only obtuse angles (135 deg. or greater). The star grounding you are employing is not required here. It is used in high power systems where a ground lead could be modulated causing hum and feedback. Not using star grounding can reduce the pcb size. E
 
#8
mickeymoose said:
On the pcb: do not use 90 deg. anles on traces. In the etching process (especially home-made boards) undercutting at the anle could happen). Use only obtuse angles (135 deg. or greater). The star grounding you are employing is not required here. It is used in high power systems where a ground lead could be modulated causing hum and feedback. Not using star grounding can reduce the pcb size. E
Click to expand...

Thanks a lot for your suggestions. I will make the angles smooth. About the
ground connection can I make only one ground connection from the board, meaning, is fusing all the ground end from both upper and lower parts of the
pcb to a single point OK?

Regards
Roushon
 
#9
Hi,

I am also working on the same app note. But, I am using hard wiring with ultra pure silver wires instead of the PCB's. Also, I am using single opamp's instead of the dual version. What is the supply you are using ?

Best regards,
Bins.

Roushon said:
Thanks a lot for your suggestions. I will make the angles smooth. About the
ground connection can I make only one ground connection from the board, meaning, is fusing all the ground end from both upper and lower parts of the
pcb to a single point OK?

Regards
Roushon
Click to expand...
 
#12
Re: Grounding
You can safely connect your PAD11-18 to your main ground or common through a single point to point trace. The traces are to short and the currents to small (and balanced out) to matter. As a personal rule I make the supply traces wider (as you did) and double them for the common.
E
 
#13
Our posts overlapped! I would add a second pad to PAD3(?) GND to take a wire from your new star ground to there and than to the raw DC supply. As you did star grounds all around there is no need for increasing the common trace sizes. Good luck!
E
 
#16
Bugle

Hi Binspaul,
Can you kindly post a Bugle PS circuit? I just searched the net and found one such circuit using 7815 and 7915 and zenner diodes. But I think 317 and 337 are more flexible and reliable. May be you can post something better.

Regards
Roushon
 
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