calrec PQ1549 help thread

[Deepdark]

Hi there.

May I know who sells the board now?  Thanks folks

 

[jasonallenh]

Hi there.

May I know who sells the board now?  Thanks folks

PCB grinder was selling them, but ran out. I believe in a previous conversation, Gustav said he could get a new batch at a 10 board minimum.

=jh=

 

[Deepdark]

Allright. If Gustav hadn't have time to release that one once again, I could always check by my side to print a couple of pcb's, if there is enought people interested in it

 

[ateshk]

Hi,
I am building a stereo Calrec EQ. I finished both channels and I wired one to test. It sounds very low in volume and distorted. I have been looking for errors, I fixed a few solder joints and switched ICs but nothing changed.  Did anyone had any similar experience? or any suggestions for troubleshooting/fixing this?

 

[gyraf]

ateshk,

Please read through this thread - you're not the first one to have some problems.

Jakob E.

 

[jasonallenh]

Hi,
I am building a stereo Calrec EQ. I finished both channels and I wired one to test. It sounds very low in volume and distorted. I have been looking for errors, I fixed a few solder joints and switched ICs but nothing changed.  Did anyone had any similar experience? or any suggestions for troubleshooting/fixing this?

Go back and find my posts in this thread- I gave some specific solutions to common problems.

 

[ncoak]

hey folks...4 years later and i'm out to fix the frequency distribution issue with my calrec, i'm at a bit of a loss.  on each band, the range is correct, but the frequencies are bunched towards the end position of the pot (in the high mids, for example, 5k is just a hair away from 7k). i thought maybe i had used linear pots by accident, but i bought some replacements, spent all day fiddling with them and arrived right back where i started.

anyone have any insight as to something else i'm overlooking that might be the cause of this? everything else works great, just can't dial in the correct frequencies. i'm using C100k dual pots as specified.

thanks in advance for any tips!

 

[jasonallenh]

This sounds like you don't have rev log pots... Can you find the part number you used?

 

[kante1603]

This sounds like you don't have rev log pots... Can you find the part number you used?

That is what I thought too.


Best,


Udo.

 

[ncoak]

and i as well! the replacement pots are alpha C100k....the "C" denotes rev log, correct?

got them here:
http://www.ebay.com/itm/6x-ALPHA-C100K-Dual-Stereo-Potentiometer-Log-Taper-pots-/170532518779?ssPageName=ADME:L:OC:US:3160

 

[kante1603]

and i as well! the replacement pots are alpha C100k....the "C" denotes rev log, correct?

got them here:
http://www.ebay.com/itm/6x-ALPHA-C100K-Dual-Stereo-Potentiometer-Log-Taper-pots-/170532518779?ssPageName=ADME:L:OC:US:3160

Hi,me again.


Taper codes are quite different by manufacturers,and it´s even important if it´s an old or newer code.
There´s a lot of info to find in the internet,here´s one (scroll down please):


http://www.resistorguide.com/potentiometer-taper/


You say the frequency are bunched towards the end position.May I ask what happens when you turn ccw,do they spread wider the more you turn to ccw?
If so then yes,you have a log. pot instead of rev.log.
I had something similar a while ago on a different project.


Good luck,


Udo.

 

[ncoak]

right, the frequencies spread wider the further ccw it is turned - i knew this was likely indicative of the wrong type of pot, but read somewhere that C denoted revlog...that link clears it up, thanks very much. thought i was losing it!

will report back.

 

[kante1603]

right, the frequencies spread wider the further ccw it is turned - i knew this was likely indicative of the wrong type of pot, but read somewhere that C denoted revlog...that link clears it up, thanks very much. thought i was losing it!

will report back.

"C" often even indicated a center dentent position,just for info.
Not in your case of course.


Have fun,


Udo.

 

[PeteC]

Hi just finishing up my 2 channel calrecs and due to test them this weekend.
One question

I haven't come across just a 2 pin balanced input like the one input Jacob's board before.
I am used to making 3 pin connections to xlrs on my inputs and outputs.

I am assuming I just need to ground the earth connection somewhere convenient on the board or chassis, and use the "hot" and "cold" xlr connections for the "+" and "-"  on the pcb.

Is this correct ?

cheers
Pete

 

[G-Sun]

Yes, generally pin1 to chassis
(but I'm no expert)

 

[PeteC]

All good - works a treat -
One channel up and running - now need to start on the second channel.

Studer 169 after that...

Cheers
Pete

 

[PeteC]

Ah,
actually getting a bit of farty blocking distortion on some ( bass heavy settings )
But i think its just me driving the inputs too hard from the DAW send.

Pete

 

[PandaTornado]

I have read quickly through this thread (sorry for being lazy) but could not see if anyone else had stumbled upon the same problem I have. Mine is almost done, everything has been checked and should run fine, however, as you can see from the attached photos, I am afraid that the solder joints on the upper channel will be able to get in contact with the lid of the case (risk for shorting the circuit).

Has anyone else had this problem? and more important, what was your solution? I will put some insulating tape on the solder joints of the pot close to the frontpanel as they propose the greatest risk, but it seems a little heavy to put it all over the circuit boards.

Does anyone know of any material that can be put on top of the boards, which is not harmed/altered/affected by the current running through the circuit and which works as an insulator? I have thought about using some antistatic plastic, but I do not know how it behaves then getting "powered".

Thanks in advance for your help.

 

[PeteC]

Hi

I had the same issue on my recent 1073 build and used 1.5mm rubber sheet cut to size for the entire board just held in place by pressure between the board and the case and it works perfectly.  Lots available in cut sizes on ebay.

cheers and good luck with it
Pete

 

[PandaTornado]

Hi Pete,

thats a great idea, I'll go straight to ebay to see what's there. Thanks for the advise