OPA627 + BUF634 Preamp PCB Design

Alcaid · 26th May 2004, 01:17 PM

Hi!

Any comments on my PCB layout and how to improve it?
Is the grounding good enough wth the jumpers?

The pot is a Noble 50K dual log.

Alcaid · 26th May 2004, 01:20 PM

Here is the schematic:

Alcaid · 26th May 2004, 01:23 PM

Read this thread if you want to read more about this preamp and others who have buildt it.

peranders · 26th May 2004, 01:28 PM

I think the layout is fair but somehow I don't like your efforts to create a groundplane. Probably it will work fine but I would still suggest that you have ground under the opamps and two traces with v+ and V-, close to the IC's. I would also suggest compactness and smaller parts if possible.

Maybe you should have the BUF's close to the outputs of the opamps? Try to get the physical layout similar to the schematics.

Why don't you consider a pcb with groundplane? If you are going to make it yourself it's real easy with a groundplane. Just put brown parcel tape on the upper side. Se picture below.

peranders · 26th May 2004, 01:31 PM

Quote:

Originally posted by Alcaid
Read this thread if you want to read more about this preamp and others who have buildt it.

This is more or less the same but with SMD parts.
Schematics here

jan.didden · 26th May 2004, 01:35 PM

Quote:

Originally posted by Alcaid
Here is the schematic:

Hi,

Are you sure you need R5 & R15? It negates the effect of the buffer. What's the value of those resistors?

Jan Didden

Alcaid · 26th May 2004, 01:35 PM

Quote:

Originally posted by peranders
....Why don't you consider a pcb with groundplane? If you are going to make it yourself it's real easy with a groundplane. Just put brown parcel tape on the upper side. Se picture below.

Now that's an easy way to get a ground plane!

Maybe I'll do that, and have all ground on top layer.

Alcaid · 26th May 2004, 01:37 PM

Quote:

Originally posted by janneman

Hi,

Are you sure you need R5 & R15? It negates the effect of the buffer. What's the value of those resistors?

Jan Didden

50R

peranders · 26th May 2004, 01:41 PM

Quote:

Originally posted by Alcaid

Now that's an easy way to get a ground plane!
Maybe I'll do that, and have all ground on top layer.

Did you get how I have done?

tape

etch

drill a bit with 3-4 mm drill

very easy

peranders · 26th May 2004, 01:43 PM

Quote:

Originally posted by janneman

Hi,

Are you sure you need R5 & R15? It negates the effect of the buffer. What's the value of those resistors?

Jan Didden

A OPA627 can't drive a 50 ohms cable at high levels but is this the case?

26th May 2004, 01:28 PM	#4
peranders diyAudio Member Join Date: Apr 2002 Location: Göteborg, Sweden Blog Entries: 4	I think the layout is fair but somehow I don't like your efforts to create a groundplane. Probably it will work fine but I would still suggest that you have ground under the opamps and two traces with v+ and V-, close to the IC's. I would also suggest compactness and smaller parts if possible. Maybe you should have the BUF's close to the outputs of the opamps? Try to get the physical layout similar to the schematics. Why don't you consider a pcb with groundplane? If you are going to make it yourself it's real easy with a groundplane. Just put brown parcel tape on the upper side. Se picture below. __________________ /Per-Anders (my first name) or P-A as my friends call me PA03 LM4780 amplifier group buy, SIGN UP HERE for the group buy 64 boards on the list.

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26th May 2004, 01:23 PM	#3
Alcaid diyAudio Member Join Date: Nov 2003 Location: Klepp	Read this thread if you want to read more about this preamp and others who have buildt it.