calrec PQ1549 help thread

GroupDIY Audio Forum

Help Support GroupDIY Audio Forum:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.
Hi All  ,
        Here is a  2u face plate graphic in Illustrator I've done for this project , waiting for some shelve / Q symbols from braeden here - http://www.groupdiy.com/index.php?topic=51403.msg654531#msg654531

  or I may just try my hand at it  ;D    just posting to get some feedback / suggestions , I will post the Illustrator file once I've  verified it works and all  measurements and clearances are correct.

  its has pieces of a graphics from benlindell and Scale-O-matic
 
 

Attachments

  • Calrec PQ.jpg
    Calrec PQ.jpg
    693.8 KB · Views: 179
Audiophreak, are you intending on doing a front panel from this artwork, I need a panel myself and wonder if you would do an additional one?
Cheers
Michael
 
Hi Junction,
                I dont produce the panels myself,  I'm doing this artwork graphic but I send the Illustrator file to Chae a Prodigy Engineering here - http://www.groupdiy.com/index.php?topic=43688.0 - along with my Par metal case front panel for Laser engraving , and I Drill the holes myself.
    When I finish this graphic I'll post it and the Illustrator file here for all.
 
Hi everybody :
this is my first post and this is my first project .my Calreq EQ dos not work and I need your help.
I am completely novice in electronics and if I ask some simple questions, it is because of that and thank you to all of you.
also my English is not good and I am sorry about that, I am trying to improve it.

ok, at first I should said that the problem is when I push the bypass button to activating EQ , I dont have any sound and I only have some kind of noise like woooooooo!!!!!
I dont know I should start finding mistakes from where !!!I checked all part of PCB and I found 3 extra shorts connections and I fixed them but it is steel has the WOWWW sound instead of music.

please tell me, what can I do for finding problems ??any voltage measurement ??where?? testing resistors, Caps and ICs ???is it possible to say voltage of every pin of ICs and I check it to know that witch part has problem??

I made power supply board with 7918 and 7818 and in my output of power supply, I have 17.5 DC voltage .has it any problem or it is ok??
 
Should work from +/-10V and up to +/-18V.

Try tracing signal through the circuit - look at the schematic - and find the place(s) where you loose your signal. Then check for component integrity, traces and soldering around that area.

Jakob E.
 
gyraf said:
Should work from +/-10V and up to +/-18V.

Try tracing signal through the circuit - look at the schematic - and find the place(s) where you loose your signal. Then check for component integrity, traces and soldering around that area.

Jakob E.

Thank you jakob for your answer,I found something in circuit that I cant understand it from schematic.in my circuit ,these three area are connected too each other when I test it with multimeter(Red,green,Blue) therefor ( 0 and B-) will be connect to each other.it should be like this or there is a problem here??I checked soldering very carefully around here and  22u cap and 100K resistor, both of them are OK .....
07979203070969634222.jpg
 
Hi All,
    This is the latest revision of my 2U dual Calrec EQ front panel , I'm sending this out soon for laser engraving, all questions, comments welcome , "Q" and shelving graphics I had to make in Illustrator and buttons are Alfa 10.3mm dia.  , cut/boost and freq. graduations are for 3/4 inch  ( .750 ) dia. knobs.
 
 

Attachments

  • Calrec PQ.pdf
    121 KB · Views: 81
Looks very good indeed.

1 - you may want an indicator lamp or led to monitor on/off status

2 - the fonts you're using has some VERY thin/spikey edges (serif's) - which can cause problems in cnc-engraving, less so in laser-engraving.

Let us see a pic if/when it's done!

Jakob E.
 
Thanks so much Jakob !!

  I'm pretty sure I've spent more time on the front panel layout and graphics than stuffing the PCBs , PSU and  doing the metal work on the case  :eek:

    The power switch I plan on using is Illuminated , but can add one to another file and post that too.
  Good point on the Font style , I haven't had a front panel CNC'd yet, will keep that in mind, also I will be posting the actual Illustrator files , so fonts could be changed fairly easily. 

Thanks again, and Thank You for this and all of the wonderful projects and knowledge you've shared.
 
gyraf said:
You can see it from the layout: red and blue are (and should be) connected. Green should NOT be connected to these..

Thank you again.I found that and fixed it but steel have no sound and only WOWWWW....

is it possible to tell me how can I check the IC voltage to understand that they received right voltage or not??now all pins socket are about 17 volt(PSU is 18 Volt) ...is it correct or something is wrong??or if you have a better way please tell me,I dont know how should I check the component in circuit and I should start from where??
 
You need plus AND minus 12 to 18V for this circuit, referring to ground/0V.

Look up the IC data sheet to see where it wants its supply power.

Then measure all ic's to verify that the right pins have the right voltages (taking much care not to short power pins to anything else!)

Jakob E.
 
Hey all,


I'm a newcomer to the DIY addiction, but fell for it heavily - I just ordered Gustav's PCBs and a whole bag of components for the 1549 - looking forward to solder-smoke filled evenings!

I have a question for Jakob though: since most of the stuff I plan to eq is unbalanced (synths and such), would it make sense to bridge the unbalancing/balancing in/outputs and connect plugs there directly, or is that wrong thinking on my part? I have seen the separate short thread on that, but wonder if there's a way to keep both options permanently.

Thanks!
 
Hellooooo ,
                    would someone confirm that with the push-button switches on the PCB that the switch in the OFF / up / or non-pushed position that the Q is wide and the ON / down / or pushed in position the Q is narrow.
   
sudden panic as I sent out the panel to be laser engraved  :p

Thanks  :)
 
Hi Jakob. :)
I found the problem of my circuit and now I have sound :D.one of the main reasons was soldering oil!!!
thank you for your helps very much.but there is a problem yet,when EQ is on I have a noise that i can only  hear it  in very high gain but it is a noise and it is not common,some noise like when you touch some parts of circuit  or supply board and when I do this, this noise  increases( noise is like zzzzzzzz sound)

EQ is not in the box yet I want to solve all the problems and after that put it in the box.please tell me what the main reasons for these kind of noise are??the quality of component(OP Amps, caps and pots) can be effective?(for example in PSU or EQ bands).?thank you again.
 
if you have buzz noise, that will be hum.

This is common when it's not mounted in a metal enclosure.

For testing, throw everything inside a grounded (connected to 0V) metal box and recheck.

If there is still hum, it must come from your power supply (assuming that it's not in your input signal). Then clean up powersupply.

Jakob E.
 
Hello everyone,

I built the psu gyraf put up here.
http://gyraf.dk/gy_pd/calreq/minipsu.pdf
thanks gyraf.

I'm not sure if I have the correct component in the 1A Bridge position.
Pic attached. 
The text on it is DB102 V718

Also, do you think I should heat sink the 78/7915's?
Would it matter if they are attached to the same sink?
 

Attachments

  • IMG_0794.JPG
    IMG_0794.JPG
    506.6 KB · Views: 69
Back
Top