PASSIVE RELAY-BASED CONTROLL ROOM KITS BUILD/SUPPORT TREAD

[Igor]

Hm... check resistor's values.

For people who asked me how to change SUB to SPK3, i.e

Changing the SUB to Speaker 3 (i.e. instead of having spk1 or spk 2 and sub over it, one of 3 speakers: spk1/spk2/spk3)

http://s251.photobucket.com/albums/gg291/diy33609/CRM/CRM%20sub%20to%20spk%203%20mod/

cut = magenta

connect = white

Please ignore wrongly cutted and connected back trace here:
http://i251.photobucket.com/albums/gg291/diy33609/CRM/CRM%20sub%20to%20spk%203%20mod/P1060837.jpg

All tested and rechecked twice.

 

[KasperNyhus]

Hi Igor

Got the CRM kit, and its looking really good! ;D

I know only very little about power supplys, so I have to ask why you use a switching type PSU in this CRM? Because of noise? Could a "normal" trafo based voltageregulated supply work?

I have tried to search the forum for an answer.

Thanks, Kasper

 

[Igor]

This thing is absolutely indifferent to power supply noise up to say 20 millivolts.
The power supply goes to relays coils and control ONLY.
So, use 12V 2A "digital" power supply and enjoy. Seriously, one of my friends running
same kit connected to +12V of hard disk connector of his PC. (Not recommended, just for example).

Use balanced equipment and ground properly. Dat's it.

I got 10 of A6833 (discontinued chip, relay driver) from local supplier. About 6-7 PCB's are still in stock. In case of whatever....mail etc

 

[KasperNyhus]

Ah I see. That makes a lot more sense. 

I'll ask my local electronics dealer guy. Yesterday I asked one of the other guy at the store, but he only found 200W+ expensive computer psu's...

In case of faliure of finding a PSU that works, do you have one spare? If Im lucky it will get through the customs...

 

[KasperNyhus]

PSU fixed.

Just a little question to ask now. I got some small yellow capacitors from Igor's kit marked "104" but the pcb print says "224" - is this ok? I looked at the pictures and the capacitors I got appear smaller than those Igor has used.

Thanks,

 

[zayance]

PSU fixed.

Just a little question to ask now. I got some small yellow capacitors from Igor's kit marked "104" but the pcb print says "224" - is this ok? I looked at the pictures and the capacitors I got appear smaller than those Igor has used.

Thanks,

If it's for PS bypass caps, 104 (0.1uF) will do, 224 means 0.2uF

 

[tomcat]

Ah I see. That makes a lot more sense. 

I'll ask my local electronics dealer guy. Yesterday I asked one of the other guy at the store, but he only found 200W+ expensive computer psu's...

In case of faliure of finding a PSU that works, do you have one spare? If Im lucky it will get through the customs...

Look harder, they are all over. Reichelt (bad for Denmark), RS & Newark / Farnell. Should be able for you to get them in Denmark as well

 

[KasperNyhus]

Thanks guys!

Well for the PSU I found a 12v trafo originally bought for a DIY pultec which i switched because it was noisy when used as step-up... So i can easily make +-12v. A little bit more work but no waiting on shipment...

 

[timmygrimm]

Got my CRM kits!

Should I worry about matching resistors?

Igor, PMed you about .cdr files. Do you have files for the back panel of the rack as well? Need to have proper dims for connector spacing. If anyone else has 'em please send my way.

Ordered this psu as per earlier post:

http://www.mouser.com/Search/ProductDetail.aspx?R=S-25-12virtualkey63430000virtualkey709-S25-12

Hope it is good!

Thanks for this!

Tim

 

[Igor]

Resistors within 2% are fine, with max error +/-0.1db.
For .cdr files: please mail me (igor_jazz at yahoo), will send.
As well, http://ij-audio.com/downloads/CRM_DESIGN_COREL.zip

 

[timmygrimm]

Has anyone else tried to open these files? I can open the controller file, but the rear panel file will not open with my version of Corel. If anyone can post an .eps , .ai, etc I will be your best friend.

Tim

 

[Igor]

Corel 13

 

[arcOne]

I can't seem to be able to find the relays for this anywhere. Is there an alternative to the MH4-12H or am I just looking in the wrong places?

 

[Igor]

http://il.farnell.com/te-connectivity-axicom/v23105a5003a201/relay-pcb-dpdt-12vdc/dp/1608360
http://il.farnell.com/te-connectivity/mt2-c93402/relay-pcb-dpco-12vdc/dp/9913653
http://www.ebay.com/itm/1PCS-RY12W-K-TAKAMISAWA-12V-DPDT-Miniature-Relay-/220926306163?pt=LH_DefaultDomain_0&hash=item33703be773
etc etc

 

[arcOne]

Thank you for the quick response.

So will any 12v DPDT relay with the DIP 16 footprint will work?

 

[Igor]

Yep. Coil resistance should be higher than say 500R; use 50000 cycles and more rated relays for reliability;

Now, that's important.

Some guys told about clicks. The system should be balanced; it should have less possible DC offsets; that's all.

For the rest... do something performing better audio - wise, I want to see it!

 

[Leonardo_007]

maybe a stupid question but how would you connect the CRM to the existing mixing console? via the monitor out plugs?

 

[Igor]

maybe a stupid question but how would you connect the CRM to the existing mixing console? via the monitor out plugs?

Nope. You don't need the weirdness of console's monitor section soundpath and 2 volume controls.

For every console and purpose it will be different, however, possible to do it next way.

Say, INP1 of CRM connected to main A/D output; INP2 of CRM connected to main(master LR) console output;
master also slplitted to converter's input. If you need SOLO (AFL, PFL etc) monitoring, need to find on
console's monitor section card the point before relay (FET switch) where SOLO comes to, add pair of THAT1646,
maybe, will need a buffer before THAT1646, dep. on situ, and patch it to say INP3 of CRM.

You have in this case INP4 left for another 2TRK.

Nowadays, we used to SOLO/AFL/PFL from ProTools (or another workstation), as well as send to headphones... but, for AUX/groups monitoring,
if you have large console and sending to headphones, or use group processing from here, having console's SOLO point at CRM input can be useful.

In case somebody going to use my CRM with existing console and need SOLO/AFL etc hookup, just write here,
will need schemo of your console mon section.

 

[Leonardo_007]

issue has been resolved.

 

[Moby]

Hi guys, I'm using this great unit for a long time in my studio but i never find some spare time to picture and post here. So, here we are










Click on thumb for large pic's  8)