[Build] CAPI CA-0252, Vintage 2520 Type Opamp, Official Support Thread

Help Support GroupDIY:

jsteiger

Well-known member
White Market Member
Joined
Apr 11, 2008
Messages
3,328
Location
Nashville TN
Hey folks!

Since the new CA-0252 (vintage 2520 type) discrete opamp kits are shipping, I figured its time to start the official support thread.

We have single kits as well as bulk sorted 10-packs available.

Full details and automated checkout can be had here:
https://capi-gear.com/catalog/index.php?cPath=233

The build guide is following my newish Pictorial Build Guide format. All BOMs, support docs and the build pictorial can be found here:
https://capi-gear.com/catalog/Build_CA-0252-DIY_Rev_A.php

Since this is the official support thread, please post all questions, components and/or build problems here. I will do my best to help you get things sorted. This is the place to handle issues, not with a direct email. Thanks for understanding.

And heres a pic of the beauty ;D
CA-0252-front-angle.jpg


Cheers, Jeff
 

FarisElek

Well-known member
Joined
Oct 26, 2019
Messages
375
It sounds gooood. I didn't think it would be much different than the gar2520. It is.
 

jsteiger

Well-known member
White Market Member
Joined
Apr 11, 2008
Messages
3,328
Location
Nashville TN
FarisElek said:
It sounds gooood. I didn't think it would be much different than the gar2520. It is.
In all of our extensive listening tests, to our ears they sound different than any other remake version. They sound closest and possible even a little better than the OG real deal.
 

critterkllr

Well-known member
Joined
Nov 5, 2010
Messages
311
Location
Dearborn, MI
jsteiger said:
In all of our extensive listening tests, to our ears they sound different than any other remake version. They sound closest and possible even a little better than the OG real deal.

Can you explain how they sound different from the others? I have red dots, gar2520s, and gar1730s, but haven’t heard OG opamps.
 

jsteiger

Well-known member
White Market Member
Joined
Apr 11, 2008
Messages
3,328
Location
Nashville TN
critterkllr said:
Can you explain how they sound different from the others? I have red dots, gar2520s, and gar1730s, but haven’t heard OG opamps.
I wanted to have a bunch of comparison clips by now but 2020 has different things in store for us! I would rather let some end users explain/describe as the amps find their way out into the world. Everyone seems to hear things differently especially when it comes to opamps.
 

critterkllr

Well-known member
Joined
Nov 5, 2010
Messages
311
Location
Dearborn, MI
Hey Jeff, not sure if this is the right place, but you really knocked it out of the park with these new opamps. They’re easily my favorite so far. Here’s my best description:

These CA-0252s are the most balanced opamps I’ve tried. I’m using a pair in one of my VP28s. It’s hard to describe this stuff,  but it’s like if the red dots were smoother, or if the Gar2520s were less pokey in the midrange.

My initial instincts are to use the CAPI CA-0252s for most things (including vocals), gar2520/1731 combo when I want to add more weight to something, red dots for acoustics, and gar1731s for synths and strings.
 

GrantB

Member
Joined
Jun 8, 2004
Messages
14
Location
Olympia USA
These were a real pleasure to build, the PCBs are great.  I was thinking the opamp didn't make much difference, but then I took out the gar1731s in my ML2s and tried AM10->CA-0252.  Now it sounds like the 70s.  You got me wanting to try all these combos.
 

iprovlek

Well-known member
Joined
Sep 6, 2010
Messages
717
Location
Zagreb,Croatia
Just wanna thank you Jeff for your new CA-0252 opamp....you nailed this opmap!!!

Before few months I had old API 2520 Huntington and made lot of takes with it, that I can match it with few opamps that I got!!!

Yesterday I finished CA-0252 and was astonished with this opamp, in compare with old Huntington,CA-0252 is almost the same in

sound....

I like the sound a lot, in my subjective opinion this opamp sound even better than old one....

Thanks  Jeff
 

jsteiger

Well-known member
White Market Member
Joined
Apr 11, 2008
Messages
3,328
Location
Nashville TN
iprovlek said:
Just wanna thank you Jeff for your new CA-0252 opamp....you nailed this opamp!!!

I like the sound a lot, in my subjective opinion this opamp sound even better than old one....
Thanks for the kind words! At the end of our R&D we kinda felt the same! Its a very tall mountain to climb as far as sonics go.  :)
 

31cc7

Active member
Joined
Aug 25, 2019
Messages
43
Location
London, UK
I got 3 10-packs for my mixer recently. I am thinking what would be the best strategy to build them.

In the past when I built 20 gar2520 I've been assembling each step for each PCB, so that when I did the last step I had all 20 completed.

I am thinking about doing the same again, but in one of the books I read says it may be more efficient to build something completely one by one.

Which strategy worked best for you?

I am sorry if this is a bit off-topic.
 

JohnRoberts

Well-known member
Staff member
Moderator
Joined
Nov 30, 2006
Messages
20,198
Location
Hickory, MS
31cc7 said:
I got 3 10-packs for my mixer recently. I am thinking what would be the best strategy to build them.

In the past when I built 20 gar2520 I've been assembling each step for each PCB, so that when I did the last step I had all 20 completed.

I am thinking about doing the same again, but in one of the books I read says it may be more efficient to build something completely one by one.

Which strategy worked best for you?

I am sorry if this is a bit off-topic.
I might be tempted to build up one completely first to confirm that all the parts needed are there, and it works.

Then I would generally do one component at a time in all the boards that saves the effort of looking up where every part goes, every time.

JR
 

a.beck

New member
Joined
Oct 24, 2019
Messages
1
I've recently received one of these and I'm keen to get into building it, but is there a full .pdf of the assembly instructions available somewhere?

Ideally I'd like to download and print a single document and just refer to that while I work. I seem to recall doing this with the previous kits I've made. Am I remembering correctly?

Thanks!
 

jsteiger

Well-known member
White Market Member
Joined
Apr 11, 2008
Messages
3,328
Location
Nashville TN
a.beck said:
I've recently received one of these and I'm keen to get into building it, but is there a full .pdf of the assembly instructions available somewhere?

Ideally I'd like to download and print a single document and just refer to that while I work. I seem to recall doing this with the previous kits I've made. Am I remembering correctly?

Thanks!
Here are the build docs and build guide. https://capi-gear.com/catalog/Build_CA-0252-DIY_Rev_A.php
 

31cc7

Active member
Joined
Aug 25, 2019
Messages
43
Location
London, UK
JohnRoberts said:
I might be tempted to build up one completely first to confirm that all the parts needed are there, and it works.

Then I would generally do one component at a time in all the boards that saves the effort of looking up where every part goes, every time.

JR

I have gone with building all 20 at once. The fact that I had 10 on each board made it much easier. It took me a couple of evenings.
One thing I found important was to clean the boards afterwards as I had a couple of shorts which got removed after cleaning.
I put them in my summing mixer and I am extremely happy with them :)
 

jsteiger

Well-known member
White Market Member
Joined
Apr 11, 2008
Messages
3,328
Location
Nashville TN
31cc7 said:
I have gone with building all 20 at once. The fact that I had 10 on each board made it much easier. It took me a couple of evenings.
One thing I found important was to clean the boards afterwards as I had a couple of shorts which got removed after cleaning.
I put them in my summing mixer and I am extremely happy with them :)
Awesome! Great to hear you like 'em!
 
Joined
Jan 20, 2021
Messages
2
Hi; first post - semi-noob.

Built 6 of the wonderful and amazing ca-0252.

Have a problem with one of them. I'm getting crazy hum, some distortion, and a large amount of DC offset.
This is while testing it in the Fader position of a working VP-28 preamp.

Any idea where I went wrong? All the opamps were cleaned with flux cleaner and checked for bridges and cold joints under magnification. Thanks!
 
Joined
Jan 20, 2021
Messages
2
Hi - don't mean to bump but is it possible that I fried Q1? I know it was reversed on one of these and I had to turn it around.

Have a problem with one of them. I'm getting crazy hum, some distortion, and a large amount of DC offset.
This is while testing it in the Fader position of a working VP-28 preamp.
 

echoplex

Well-known member
Joined
Jun 29, 2011
Messages
169
Location
Germany
FarisElek said:
It sounds gooood. I didn't think it would be much different than the gar2520. It is.

Can you describe a little in detail how it differs from the gar2520?
 
Top