PASSIVE RELAY-BASED CONTROLL ROOM KITS BUILD/SUPPORT TREAD

[crisotop]

I've got a master recorder hooked up on output 7-8, with fixed input gain. In order to get unity gain from da to ad (so the metering is correct etc.) I can't attenuate my ad chain. My speakers have +/-6dB gain control, which means they are freaking loud and I have a usuable gain range of -60 to -45 on the crm.

Sorry I don't quite get your L-Pad recommendation, I always thought for balanced line-level connections a balanced H-Pad would be best?

Thanks
Christoph

 

[Igor]

OK, now I understand. Remove Rl, and use 6k total input resistance H-pad,
something like 2k-2k5-2k.

 

[plumsolly]

any suggestions for mounting the microphone for talkback? I suppose I'll just mount it in the rack portion? drill some small holes in a circular pattern, and mount the mic on the inside? (purusha's case came with no provision for mounting the mic) something that looks like this for the holes is what i was thinking:

Also, after much thought, I still don't understand how the tbc is supposed to integrate with the crm. I understand the power and talkback-on connections, but how does the audio integrate? The 9-pin connector is labeled TBK, but where is that supposed to go and how does it connect to the TBC? What is the purpose of having the talkback-on pins on the 9 pin connector? remote talkback switch? Sorry for all the questions - I stared at the schematics for many hours trying to make sense of it. Best, Ben

 

[Igor]

Mounting the talkback mic: I prefer cheap "Soundblaster" microphone mounted near the PC screen.
Yes, 9 pin connector used for external talkback combiner.
TB mic easy can be integrated through the option of talkback combiner PCB.
It powered from 12V relay's/digital supply, via onboard 12->+/-15V dc/dc converter.
Feed audio to TB combiner IN, connect phones amp to TB combiner out...done.
More info on this-here:
http://www.groupdiy.com/index.php?topic=31609.0
The box on photo looks very nice, but not as precision and clean as passive relay-based box. Just my mind.

 

[plumsolly]

Thanks Igor - now I see. your talking about a mic like this:

I bought this fellow here:
http://www.projectsunlimited.com/audioproducts/movieclips/products/audioDetailPrint.asp?CATEGORY=4&PARTNUMBER=AOM-6545L-R&GUID={2319C8F1-BB00-44B4-A9C0-3257E8B5FD72}
with the intention of mounting it in the rack case with the audio board.

The box on photo looks very nice, but not as precision and clean as passive relay-based box. Just my mind.

I agree - I looked at every option for an off-the-shelf monitor controller and decided it was worth investing in the CRM. Anything else in that price range would have been a compromise that I would have likely had to replace later.

I have a TBC board and am going to install it in the rack-mount case with the CRM audio board. The 1/4" jacks for the TBC are normalling jacks: can I wire the MTRL and MTRR outs on the crm to the normal audio inputs on the TBC? That way when nothing is plugged into the 1/4" input jacks it will normal to whatever source is selected by the CRM.

Thanks, Ben

 

[Igor]

Yes, MTRL and MTRR outs are same signal which goes to monitoring.
Good idea can be "normally-connect" MTR outs to TB combiner's jacks, on bottom side of pcb, and,
if separate mix for phones needed, connect outs 3-4 of soundcard to TB combiner from outside.

 

[plumsolly]

Exactly what I was thinking. Glad to know that it will work - Thanks, Ben

 

[Igor]

Yep. Let us know when it finnished, working, etc!

 

[plumsolly]

Hey Igor, got mine up and running. I will post pics in a few days. It is fantastic! I was wondering about a mute option. The only way I see to mute the output is by turning the volume all the way down - to "cut". Would it be possible to configure it so that you can toggle speakers on and off? So if I had speaker 1 on and hit the speaker 1 button again it would go off, without having to turn on speaker 2? Thanks for the great design! Best, Ben

 

[Igor]

You can use "dim" button as CUT. Press trim+dim, like ctrl+c, set offset -50, press trim, press dim, done.

 

[plumsolly]

Thanks Igor -  did that, and -50 is lowest it will let me set the dim to - wont go all the way to cut. If there is not a way to do it, that's ok - I'll figure out a work-around or I'll just turn the volume all the way down when I need to do I take - I track in the same room as the console, so I need no volume. Any further ideas would be appreciated. Pictures soon. Best, Ben

 

[Igor]

Sorry. I can't give any ellegant and simple solution here, without re-programming the controller chip.

 

[mks]

Just curious the (minimum) dimensions of the control surface is for this? I'm about to build a workstation and need to decide whether to build a 3U of 4U section for this. Looks like it wouldn't quite fit into a 3U.

Thanks to anyone that can answer this.
Take care,

Marc

 

[rob_gould]

Just curious the (minimum) dimensions of the control surface is for this? I'm about to build a workstation and need to decide whether to build a 3U of 4U section for this. Looks like it wouldn't quite fit into a 3U.

Thanks to anyone that can answer this.
Take care,

Marc

Hi Marc,

Depends on how creative you're willing to be

http://www.groupdiy.com/index.php?topic=35018.msg429095#msg429095

As you can see, this did require some breadboarding and quite a lot of extra wiring though...

 

[TheGuitarist]

Hey,

Just wondering if you could elaborate more on how to turn just one of the inputs into an output.

 

[mks]

That's a beauty Rob! Thanks. You just gave me a little shove over the edge there

Marc

 

[Igor]

If someone need .cdr file for measurements/etc, feel free to pm.

 

[TheGuitarist]

EDIT: Too expensive to buy.

Better question. What wattage do i need for this project

i'll be running the CRM, plasma displays and talkback meter.

Just a bit of a bump for my questions a couple of posts up as well. Just don't wanna screw anything up if i start cutting traces.

 

[Igor]

It was discussed on this thread some time ago how to convert the system into 2xIN/4xOUT.
Regarding the other changes... Sorry, the kit is complete, I don't want to ask my friend to rewrite program.
This kit is really excellent quality, and IMHO most clean audio-wise level control solution for less than $1.8k (for today).
BUT it has limited functionality in compare to CRM modules/mastering consoles I sell commercially.

To run plasma, talkback, and CRM.
In general: 12V/2A switching power supply for CRM/TB combiner, 2x(18...25)V 20-30VA toroidal trafo for plasma.

 

[TheGuitarist]

Ahh, so its too much work just to switch one of the inputs over (not really looking to switch all inputs and outputs as discussed)


And i'll need two transformers to run everything? Fair enough. Or could i do something similar to the talkback with just a 12-24 converter.