Re: calrec PQ1549 help thread
« Reply #420 on: August 16, 2018, 11:26:25 AM »
Hello, I#m almost done with the pcb's of the gyraf calrec EQ. just one question, the 22uF electrolytic Cap on the one board is not on the pcb layout from the gyraf site. wich orientation is it ??? can somebody help me please, thankx !!!


Re: calrec PQ1549 help thread
« Reply #421 on: August 16, 2018, 11:27:19 AM »
heres the pcb from gyraf

musika

Re: calrec PQ1549 help thread
« Reply #422 on: August 25, 2018, 10:11:21 AM »
This is how I oriented mine... after looking at the schematic, the drawings are hard to read for that particular 22uf cap.  So I am not 100 percent sure either.  Maybe someone can verify.
« Last Edit: August 26, 2018, 08:42:30 AM by musika »

erquere

Re: calrec PQ1549 help thread
« Reply #423 on: July 27, 2020, 08:53:13 PM »
Hi ! Im' almost done with the building of the calreq stero EQ, but there's a part I don't manage to find : caps for the ALPS Spun buttons, 6mm diameter, does anyone have found an alternative ?

Best regards
Used to be a journalist but I prefer build comps and eqs

audiophreak

Re: calrec PQ1549 help thread
« Reply #424 on: July 27, 2020, 09:28:49 PM »
Hi ,
      I may have a set , and can give you some alternatives , not home at the moment but will check in the next couple days and let you know , very least can get you some part numbers.

Cheers
" Music washes away from the soul, the dust of everyday life "   ... in loving memory of my Father.

peterc


Re: calrec PQ1549 help thread
« Reply #426 on: September 06, 2020, 02:11:21 AM »
Hi all, long time listener, first time caller!

I’ve gone through the entire thread and appreciate all the advice that everyone has provided.  I thought I would be in the clear when I fired my eq on but alas, it sounding funny.

I’m powering the EQ with a 15v power supply, the positive rail on all ICs hits around 15.5 v and the negative rail hits -14.7, nothing problematic.

When I run signal through, it’s completely distorted, almost in a hilarious way - honestly, it sounds cool but I’ve got my fair share of dirty outboard signal destroyers. 

The distortion almost sounds bit reduced and if the signal going in is lowered, only the transients are passing through the output. 

I’ve gone back over the board and corrected any bridges that I noticed, etc but there’s no improvement to the signal.  Is there any area on the board that I should concentrate on?  I have the feeling that there might be a resistor that’s letting too much signal through somewhere on the PCB and it’s clipping the signal somewhere.

I’m finishing the second set of PCBs this week and am hoping the other one works so that I can compare the 2.  I’m eager to get the first up and running though.  Any advice is greatly appreciated!

gyraf

Re: calrec PQ1549 help thread
« Reply #427 on: September 07, 2020, 05:24:47 AM »
http://gyraf.dk/gy_pd/calreq/calr_eq.gif

Look at the outputs of the opamps in turn - the signal goes through the input opamp, then 6A(out=pin1), 8A(out=pin1) 10A(out=pin1) and 12A(out=pin1)

When you know where you loose signal integrity, you have a place to start your search for err.

/Jakob E.
..note to self: don't let Harman run your company..

Re: calrec PQ1549 help thread
« Reply #428 on: September 07, 2020, 08:47:47 AM »
http://gyraf.dk/gy_pd/calreq/calr_eq.gif

Look at the outputs of the opamps in turn - the signal goes through the input opamp, then 6A(out=pin1), 8A(out=pin1) 10A(out=pin1) and 12A(out=pin1)

When you know where you loose signal integrity, you have a place to start your search for err.

/Jakob E.

Thanks Jacob, I followed your advice last night and was able to identify where the signal goes bad.  Turns out one of my op amps was bad, replaced it and now everything is working as it should!

 

Related Topics

  Subject / Started by Replies Last post
1 Replies
2809 Views
Last post July 12, 2012, 10:29:52 AM
by gyraf
6 Replies
2670 Views
Last post August 30, 2014, 01:53:13 PM
by G-Sun
3 Replies
824 Views
Last post December 04, 2018, 02:31:32 PM
by darnell
2 Replies
582 Views
Last post March 06, 2019, 04:55:00 PM
by moamps