Does this 2520 PCB look familiar?

[peterc]

http://www.ebay.com/itm/JJE-2520J-DISCRETE-OPAMP-SOCKETS-API2520-REPLACEMENT-UPGRADE-2520-FORMAT-/231151336089?ssPageName=ADME:B:SS:US:1123

The solder joints look pretty suspect as well........

 

[JohnRoberts]

Yup, not good solder wetting on some of the leads, but with double sided plated through holes, if the the bottom solder joint is good it doesn't matter what the top solder joint looks like.  While this does suggest that the bottom solder joints may need to be checked.

JR

 

[fum]

If that is your artwork, and it's not for profit, report the auction to ebay.

 

[okgb]

curious

" 30 day money back Guarantee.  All opamps are fully assembled and tested and come with a 3 year warranty.
1731J and 918J discrete opamps are also available. "

Actually appears to be a few other " products " including full units
http://www.ebay.com/sch/jjelecllc/m.html?item=231151336089&ssPageName=ADME%3AB%3ASS%3AUS%3A1123&rt=nc&_trksid=p2047675.l2562

 

[Meathands]

FWIW I've corresponded with JJ Electronics a couple times over the last few years. Seemed like a nice guy using his DIY skills to make some money.

If he copied someone's layout without credit, that's not cool. But I thought I'd chime in.

 

[abechap024]

That urei 530 eq pcb is a great idea. Saving eqs from the landfill!

 

[SSLtech]

I've got 530 main boards out the wazzoo... (Personally I wouldn't give you a button for them!)

The only thing you typically need to replace to get a 530 working is the sliders... are drop-in replacement slide potentiometers not available? -I've never sought one out...

 

[abechap024]

I've got 530 main boards out the wazzoo... (Personally I wouldn't give you a button for them!)

The only thing you typically need to replace to get a 530 working is the sliders... are drop-in replacement slide potentiometers not available? -I've never sought one out...

Yes, I think the original sliders are all but non existent. I believe these new boards fit a readily available replacement slider. Though I dont know for sure. I just soaked mine in deoxit and they work fine now.

 

[gar381]

http://www.ebay.com/itm/JJE-2520J-DISCRETE-OPAMP-SOCKETS-API2520-REPLACEMENT-UPGRADE-2520-FORMAT-/231151336089?ssPageName=ADME:B:SS:US:1123

The solder joints look pretty suspect as well........

The answer is YES..

JJE2520 on left gar2520 on right

Same circuit and part values.  Artwork moved around quite a bit.
It's a sloppy clone of a modern version of a Huntington.

GARY

 

[Walrus]

I would have said Studio Systems Division clone.

 

[JohnRoberts]

a clone of a clone of a.........  ;D

JR

 

[mitsos]

a clone of a clone of a.........  ;D

JR

I think it's a 4th generation clone ;D

Here is an older BC2520 PCB, single sided, made and sold by member Bauman back in 06-07 (?).  I think he was the one who first used Peter Purpose's schematic but with BC and BD transistors. Peter P did the first clone of the old 2520s using hard to find transistors.

 

[gar381]

I think it's a 4th generation clone ;D

Here is an older BC2520 PCB, single sided, made and sold by member Bauman back in 06-07 (?).  I think he was the one who first used Peter Purpose's schematic but with BC and BD transistors. Peter P did the first clone of the old 2520s using hard to find transistors.

mitsos has his history right to the best of my memory. 

Around '08 or '09 I contacted pete about doing an updated version to offer as inexpensive complete kits for our members.
In order to fine tune this guy the way I wanted , I decided to do a 2 sided version.  I cleaned up the transistor footprints,
added separate footprints for C2-R10, added decoupling cap footprints and fixed the NFB problem that
was causing the instability problems of the earlier versions.  I also fine tuned a few part values then did
lots and lots of listening.  This is how the 2520BC-Q2 PCB also known as the gar2520 DOA came into being.

GARY

 

[mitsos]

added decoupling cap footprints and fixed the NFB problem that was causing the instability problems of the earlier versions. 

a-ha.... yes the secret life (and death) of those old opamps.. I have a few half-built old version BC2520s  which I never finished because of the burnups.  If you can shed some light on how to fix them, I'd love to pull these out of the drawer..

cheers!