Mod your Beresford 7520

**chrism** · 25-03-2009, 19:07

Hi Stan,

Beginner but handy with the old iron so happy to have ago. If I wreck it it will give me a good excuse to buy a 7520

Regards

Chris

**rhmjmango** · 25-03-2009, 19:10

Getting warm!
http://search.digikey.com/scripts/Dk...me=399-4328-ND

**leo** · 25-03-2009, 19:12

Originally Posted by Sensimilia

A few beginners have ran into troubles

.

Yes, its easy to end up with a knackered dac

**sponge** · 25-03-2009, 19:16

Originally Posted by rhmjmango

Talking about a 0.1uF ceramic cap. I do not know what to look for on the farnell website. Can anybody help me out? Thanks!

Try part no 114-1775 from Farnell - Good quality Vishay cap at 35p for 5

Ken

**chrism** · 25-03-2009, 19:20

Am I right in thinking that Farnell is £20.00 min order or am I reading the small print wrongly. RS online does not appear to have this though.

Regards

Chris

**leo** · 25-03-2009, 19:21

Originally Posted by sponge

OK, here goes:

Sorry about the photo quality.
Here is the mounted and modded chip installed in the DAC.

Ken

Nicely done there Ken! should help prevent any issues

**leo** · 25-03-2009, 19:24

One thing to remember if others are fitting the ceramics, don't over heat or sharply bend the legs, these caps are pretty fragile

**drumlins4ever** · 25-03-2009, 19:39

As an idea
I think it may be interesting after a month or so when everyone has become acquainted with the various opamps to run a favorites poll.

**HighFidelityGuy** · 25-03-2009, 19:41

Originally Posted by Sensimilia

There is. It's the one marked MLC10 in the picture posted by Ken

. But the specs recommend that the 100nF is as close as possible to pin 4 and 8. So that's what the '0.1mF mod' is all about

. You are adding a 100nF as close as possible to pins 4 and 8. The one on the main PCB is not close enough once you start adding an adapter PCB. The distance from say pin 4 on the surface mount IC and the appropriate leg on MLC10 is now several mm longer. And that extra track increase is suddenly an obstacle/nice short length of RF aerial. Putting an extra cap in circuit and closer to the chip even things out again.

STan

Thanks for taking the time to explain that so thoroughly, it's really helped me understand what the cap is for.

**sponge** · 25-03-2009, 19:46

Originally Posted by chrism

Am I right in thinking that Farnell is £20.00 min order or am I reading the small print wrongly. RS online does not appear to have this though.

Regards

Chris

You are probably right at that - Welcome to the world of DIY electronics!

Ken

Thread: Mod your Beresford 7520

Thread Tools

Display

Tags for this Thread

Posting Permissions