[Build] CAPI LC25-LC40, 500 Series Rotary Graphic EQ's, Official Support Thread

[3nity]

SO i just had a chance to pass some audio yesterday on my LC25 and im very proud to say that i works like a charm.
Is there no calibration needed i assume?

 

[jsteiger]

SO i just had a chance to pass some audio yesterday on my LC25 and im very proud to say that i works like a charm.
Is there no calibration needed i assume?

No sir, no cal needed for these  ;D

Congrats! Humans win!

 

[Fachjeremy]

Hello guys, i've just finished my new lc40, but when i put it in the lunchbox,  the resistor PR2 has burn... Someone have an idea? I can send pictures...

Best regards

Jeremy

 

[jsteiger]

All eight "PR's" are damping R's on the power rails. If one or more smoke look for issues below.

PR1 = +V for IC's A1-5 and then onto SW PCB so look for a short near R1 or D3.
PR2 = -V for IC's A1-5
PR3 = +V for DTO5
PR4 = -V for DTO5
PR5 = +V for A9
PR6 = -V for A9
PR7 = +V for A6-7
PR8 = -V for A6-7

 

[Fachjeremy]

All eight "PR's" are damping R's on the power rails. If one or more smoke look for issues below.

PR1 = +V for IC's A1-5 and then onto SW PCB so look for a short near R1 or D3.
PR2 = -V for IC's A1-5
PR3 = +V for DTO5
PR4 = -V for DTO5
PR5 = +V for A9
PR6 = -V for A9
PR7 = +V for A6-7
PR8 = -V for A6-7




For now, i've just PR2 who has smoke.  Have you an idea? I have placed the opamps on pcb socket, it is ok?
Have you some value  who can i Check? Can i put in the lunchbox for test, less PR2?

Sorry but i don't really understand your answer above.

 

[jsteiger]

If PR2 smoked you have a short or problem on the -V rail that supplies the IC opamps A1 thru A5. Or maybe one of them is installed backwards? Or you have shorted the pins for C2. If not that you have a solder bridge that touches one of the #4 pins on one of the A1 thru A5 opamps.

 

[Fachjeremy]

If PR2 smoked you have a short or problem on the -V rail that supplies the IC opamps A1 thru A5. Or maybe one of them is installed backwards? Or you have shorted the pins for C2. If not that you have a solder bridge that touches one of the #4 pins on one of the A1 thru A5 opamps.

Ok, thanks you, i will check all of this. I will keep you informed.

 

[Fachjeremy]

Just one thing again. The Jumper JP3-3 is in the good way?

 

[jsteiger]

JP3 is the DC link. It will connect other LC25 or LC40's Bypass controls. If you have 2 units side by side and the rack supports DC linking on pin #6, set both jumpers to "Y" for Yes. With both units in Active mode, flipping either one to Bypass with make both (or more) units also Bypass. This can be done with a rack full of 11 units if so desired.

 

[Wiz]

I have a LC25 that I finished.... I could have sworn I checked everything was working by running sweeps.... but maybe I missed one.

My 12.8Khz band doesn't boost or cut.

Everything else works...

I have been over the board.. I am pretty sure everything is where it should be.

Any thoughts... 

cheers

Wiz

Thanks Jeff...

turns out poor solder joint on the Gyrator.

all good now...

thanks again

Cheers

Wiz

 

[Fachjeremy]

Sound Great!!! Thanks a lot Jeff, now it's time to built a second... For stereo configuration.
https://www.youtube.com/watch?v=nTKqTsQJJgA

 

[jsteiger]

Sound Great!!! Thanks a lot Jeff, now it's time to built a second... For stereo configuration.
https://www.youtube.com/watch?v=nTKqTsQJJgA

Awesome Jeremy! Thanks for sharing!

 

[deadpoet]

Just a quick thumbs up for all things CAPI.

My first endeavor was a pair of VP28's, a pair of LC40's and 10x 2520 kit (with a pair of BT50's in the mail).

Building and testing went very well although the DOA's (just under 30minutes each) and 10 greyhills on the LC40 (about 4 hours in total for a single LC40) aren't *that* much fun to build  ;D


Good to know that you can install a DTO5 upside down and apply power for about 2 minutes (while wondering why it passes no audio  : ) WITHOUT it burning up or getting harmed in any way.


Thanks!
Herwig

 

[jsteiger]

Good to know that you can install a DTO5 upside down and apply power for about 2 minutes (while wondering why it passes no audio  : ) WITHOUT it burning up or getting harmed in any way.

Yikes! Glad no harm was done. 

 

[muffy1975]

Hi guys,

if anyone can be bothered,

can someone post a picture of the underside of their LC eq pcbs? Just want to connect the dots wit the mxr 108 eq which looks identical?

Michael

 

[mysticmerlin]

Hi, just built 2 LC25's. One is working fine but the second one is like 10db down and none of the left hand switches work, the right hand column switches seem to work fine. Any ideas welcome. Thanks

 

[jsteiger]

Hi, just built 2 LC25's. One is working fine but the second one is like 10db down and none of the left hand switches work, the right hand column switches seem to work fine. Any ideas welcome. Thanks

Possibly a bad solder joint on the headers or could be on one or more of the vertical R's on the switch PCB.

 

[mysticmerlin]

Thanks Jeff, I'll check that and get back.
Great gear by the way. The lc25 is just the ticket for shaping drums.

 

[mysticmerlin]

As usual you were right. I had a header that had a bad connection.  Working fine now. Sounds great.

 

[jsteiger]

As usual you were right. I had a header that had a bad connection.  Working fine now. Sounds great.

Excellent!!