24ch API SUMMING MIXER DR-2402

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Haha, for some reason I thought that master volume was 25k that's why I was confused!  :-[

Thanks
Neil
 
Hey guys. I have few parts DR2402, and thinking this put together. Did i good thinking(pic's)?
 

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Rob Flinn said:
use the Bournes pots because they are really good quality.    Split a rubber grommet in half & put it on the shaft behind the knob so it creates a bit of friction between the knob & the panel.

Well so I tried this, and imo it didn`t work very well. Quite hard to get the same feel on all the pots.

Now that CAPI is almost empty of these:
http://capi-gear.com/catalog/product_info.php?cPath=50_131&products_id=227

anybody knows where I can get these from? Both Mouser and Digi-key has a 500 minimum order, as they are non-stocked. Or maybe I should go for the OMEG`s, as buckethead did.

I want that smoooth feeling when turning pots. The Bourns in the BOM are way too light to turn, and I want this mixer to shine  8)
 
fragletrollet said:
Rob Flinn said:
use the Bournes pots because they are really good quality.    Split a rubber grommet in half & put it on the shaft behind the knob so it creates a bit of friction between the knob & the panel.

Well so I tried this, and imo it didn`t work very well. Quite hard to get the same feel on all the pots.

Now that CAPI is almost empty of these:
http://capi-gear.com/catalog/product_info.php?cPath=50_131&products_id=227

anybody knows where I can get these from? Both Mouser and Digi-key has a 500 minimum order, as they are non-stocked. Or maybe I should go for the OMEG`s, as buckethead did.

I want that smoooth feeling when turning pots. The Bourns in the BOM are way too light to turn, and I want this mixer to shine  8)

I would email Jeff at CAPI and ask him if he will be getting anymore soon. He only had 28 of the 10k center dent pots a few weeks ago and now he has 93 of them. You never know!

 
Ok, so I finally finished all my opamps (Phew) and I am at the point where I need to get the potentiometers mounted on to my case. Here is a really embarrasing question :-[

I bought the potentiometers from the BOM but the volume are smaller than the inner plate holes. The pan pots fit fine on the inner panel but I can't figure out how to mount the volume pot. How did you all mount the Potentiometers and what did you use? If you have pictures that would be great!

Thanks
 

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Connect them directly to the panel and not to the sub-panel?

I couldn`t fit my meters inside the bracket, so I had to make a bigger hole. Then I realized my pan-pots don`t fit the small panpot holes (not long enough to mount on the helping panel) so I`m either dithching the panel (means I have to glue all the switches to the panel, or use outer washers) or do some serious cutting of the "help panel".
 
Another question:

Routing from ACA/BO and out, here`s how I understand it:

Outputs from ACA goes to the master volume stepped switch. How do they connect? The ELMA switch has an input, output and ground. Each ACA has a balanced output, so +/- and G. I`m guessing G to G  8)  but what about the rest?

Here`s how I imagine I should hook up the rest:

From master switch to l/r booster inputs. Main output from BOOSTER to insert switch relay card input. Send outputs from relay card to one of the "free flying" xlr outputs.
Back from "free flying" XLR inputs to the "Return input" on the relay card. The final Output are the XLR`s soldered to the Relay board.

Secondary outputs from Booster circuit is split in two, one stereo set goes to the alternative outputs (last set of male xlr`s) and one stereo set is sent to the VU Buffer.

Mute switch is connected to the Mute terminals on the 2ACA/BO.


Got everything right?
 
lukas said:
Look on my post, there is schematic ACA(i think is correct), and mute switch.

Yeah, it`s the same from CAPI

http://www.capi-gear.com/catalog/images/gallery/PCBs/2-ACA-Bo/CAPI-2-ACA-Bo-Rev-B.1-schematic.pdf

According to the doc, the insert board should be inserted between the ACA and Booster stages. But since the insert board has the main outs on it (and the DR2402 manual states that the insert board is fed by the Booster), I figured this should be the last stage after the booster outputs. Im also confused by the rotary switch`s "in, out and G(round)" terminals, and what to do when I have a balanced signal coming into this thing. Tie - to ground in the cable, then to the input of the switch? Output to Booster inp? Ground on switch to...?

The mute control is also not totally clear to me. Afaik, the signal is un-muted when  Q2 (?) recieves -16V into one of the Mute inputs (and the other one is ground?). So  -16V to the (top of the) Mute switch on the frontpanel, "wiper" (middle lug) to the signal input on the Mute input of Booster stage, lowest lug to the ground input on the Mute input of the booster stage?  ???

Also, if one wanted some inherent gain in the channels, I guess one might be able to do so by changing some of the feedback resistors? In the 2ACA/BO it would be either R13/R10 or R7/R2? Could it be done on an individual channel basis? I know there aren`t any schem for the DR-2402 (yet?) but I`m guessing it would be easy spotted for the trained eye? Or are the opamps in the DR2402 just used for circuit buffering and have no "gain" in them? Even with my limited knowledge this seems wrong...?
 
Im just saying something for you to try but iirc wouldn't a switch in that scenario be used like a rheostat?
+ or - in and Ground out then?
Just an idea.
 
Checked with my multimeter (often helps, this...  ::) ) and the resistance varies between the Input and Output (10k resistance when the fader is down, 0r when the fader is up). Resistance is constant between Input and Ground (10k), and resistance varies between Out and Ground (opposite to how Input does).

So + from ACA output to INPUT on the switch (- shorted to ground on ACA, or at the end of the cable?) ?
Output and Ground on elma to Booster circuit? Then what`s the difference to running ground out from aca to elma?
 
I Just thinking the Capi redrawn ACA from  API console, and ist everything allright(however they works).  On my way this will be something like from  "TheBox" schem. (but maybe different topology).
 

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I did wire it like in the attached graphic (quick and dirty paint job) ;)
Works like a charm!
 

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