Fablab

Re: API 553 PCB
« Reply #20 on: December 22, 2014, 01:46:57 PM »
Hi Kevin, thank you for the photos.
Unfortunately the PCB of your module is the original API that has some little differences in the traces from the Datatronix PCB posted by Gary


gar381

Re: API 553 PCB
« Reply #21 on: December 22, 2014, 08:34:43 PM »
Looks like there is a slight difference in the original and datatronix layouts .
When I get mine out of the rack I'll get some tight shots of this area.

GARY
RETIRED.....  from 51yrs in Show Biz

gar2520, gar1731,garAM10,gar918 DOAs at  http://capi-gear.com/catalog/index.php?cPath=71_72
NEW Sphere section  http://gar381interests.com/gar381interests.html

Re: API 553 PCB
« Reply #22 on: December 23, 2014, 07:13:22 AM »
Great Gary, some photos of your Datatronix module may help a lot

gar381

Re: API 553 PCB
« Reply #23 on: December 23, 2014, 09:25:10 PM »
Here is one of my Datatronix Modules with the DOA removed
so you can see the traces thru the PCB.

The markings for R13 and R14Make no sense to Jeff's Skitz.
These 2 Rs are un-need anyway so I just ignored them
 
 Looking at what I did to make these guys work... note the 2 Jumpers.
This puts the PCB in sync with Jeff's Skitz (except R13 & R14)

Hope this helps! :)
RETIRED.....  from 51yrs in Show Biz

gar2520, gar1731,garAM10,gar918 DOAs at  http://capi-gear.com/catalog/index.php?cPath=71_72
NEW Sphere section  http://gar381interests.com/gar381interests.html

Fablab

Re: API 553 PCB
« Reply #24 on: December 24, 2014, 01:05:27 AM »
This help a lot Gary !! :)

As I need to have a balanced input and unbalanced output, do you think it is possible to use this eq without the output transformer with a 10k:10k transformer for balancing the input?

Merry Christmas to all!
Fab
« Last Edit: December 24, 2014, 04:21:46 AM by Fablab »

gar381

Re: API 553 PCB
« Reply #25 on: December 24, 2014, 07:36:17 PM »
This help a lot Gary !! :)

As I need to have a balanced input and unbalanced output, do you think it is possible to use this eq without the output transformer with a 10k:10k transformer for balancing the input?

Merry Christmas to all!
Fab

You can use your input trafo  and keep the output trafo but run it unbalanced.

GARY
RETIRED.....  from 51yrs in Show Biz

gar2520, gar1731,garAM10,gar918 DOAs at  http://capi-gear.com/catalog/index.php?cPath=71_72
NEW Sphere section  http://gar381interests.com/gar381interests.html

Re: API 553 PCB
« Reply #26 on: December 25, 2014, 01:53:07 AM »
Hi Gary,
is it possible to use a 1:1 output transformer instead the original 1:3 one?

Walrus

Re: API 553 PCB
« Reply #27 on: December 25, 2014, 07:21:16 AM »
Just wire it so you only use one winding.
Kevin.

Re: API 553 PCB
« Reply #28 on: December 25, 2014, 12:31:55 PM »
Kevin, my question is if I can put on these module a 1:1 transformer intead of the original one that is 1:3
and what happens using a different ratio  :)
Happy Christmas

gar381

Re: API 553 PCB
« Reply #29 on: December 25, 2014, 08:17:43 PM »
1:1 vs 1:3.. 

With 1:1 You lose just a bit south of 10db of gain vs 1:3

It will work But stock 553s use 1:3 on the output.

GARY
RETIRED.....  from 51yrs in Show Biz

gar2520, gar1731,garAM10,gar918 DOAs at  http://capi-gear.com/catalog/index.php?cPath=71_72
NEW Sphere section  http://gar381interests.com/gar381interests.html


Fablab

Re: API 553 PCB
« Reply #30 on: December 26, 2014, 06:30:31 AM »
Gary,  when you say to run the output trafo unbalanced you intend joining the negative of transformer with the ground?

gar381

Re: API 553 PCB
« Reply #31 on: December 26, 2014, 04:03:16 PM »
Don't unbalance on the module pcb.  Unbalance it in your external cabling from your 500 series rack.

GARY
RETIRED.....  from 51yrs in Show Biz

gar2520, gar1731,garAM10,gar918 DOAs at  http://capi-gear.com/catalog/index.php?cPath=71_72
NEW Sphere section  http://gar381interests.com/gar381interests.html

Re: API 553 PCB
« Reply #32 on: December 27, 2014, 01:59:08 AM »
Great Project!
anyone knows where I can find some 2520 PCBs in Europe?

gar381

Re: API 553 PCB
« Reply #33 on: December 28, 2014, 12:50:56 AM »
RETIRED.....  from 51yrs in Show Biz

gar2520, gar1731,garAM10,gar918 DOAs at  http://capi-gear.com/catalog/index.php?cPath=71_72
NEW Sphere section  http://gar381interests.com/gar381interests.html

Re: API 553 PCB
« Reply #34 on: December 28, 2014, 03:40:54 AM »
Thank you Gary
Do you know if there is a 2520 type opamp that can be used without transformer?
I am considering to use a couple of these modules in a portable channel strip
« Last Edit: December 28, 2014, 04:07:28 AM by Strawtles »

gar381

Re: API 553 PCB
« Reply #35 on: December 28, 2014, 02:19:50 PM »
You don't need a transformer for any of them.  Just use at least a  470uf/16v cap on the output of each DOA but  do
use a trafo to get that IRON MOJO  :)  Transformers are your friend !!

GARY
RETIRED.....  from 51yrs in Show Biz

gar2520, gar1731,garAM10,gar918 DOAs at  http://capi-gear.com/catalog/index.php?cPath=71_72
NEW Sphere section  http://gar381interests.com/gar381interests.html

Re: API 553 PCB
« Reply #36 on: December 29, 2014, 05:16:34 AM »
 :)

Re: API 553 PCB
« Reply #37 on: January 01, 2015, 01:47:10 PM »
Gary, do you know if there is a 2520 type opamp that works with  +28/-28 Volt?
Happy new year to all!

Re: API 553 PCB
« Reply #38 on: May 28, 2020, 06:52:09 AM »
Does anyone know what the dimensions of the board are?  Looks like it may be different than the standard 500 series spec dimensions I can find?  Thanks!