[Icom] 756Pro and Behringer MX602A

[George, W5YR]

Steve Garwood wrote:
> 
> Hello 756Pro users.....
> 
> I'm looking for comments on the hookup of the MX602A with the 756Pro
> series....  I had heard that some use one of the rear panel connectors...
> Wondering how the PTT and cabling is addressed to make it look good....
> Thanks!

Following is the writeup I usually send out when requests come in for
information about my MX602A application. A necessary first step in using
this information is to go to the Behringer website and download the spec
sheets for the 602 in order to get the block diagram. Their address is

		http://www.Behringer.de

I use a footswitch for SSB operation and QSK-Full Breakin for CW. The
cables are a problem, but I use all black and coil up the excess and secure
with tie wraps. They hide well behind the other equipment on the operating
desk!

--------------------------------------------------------------------------------------------

You need to start by getting very familiar with the functional block
diagram of the 602 in the manual or specs. Once you are onto the
terminology they
use in the pro audio world, then life gets easier.

My present setup uses the 602 as the complete audio control and interface
system for the computer soundcard (in and out), a Kachina 505DSP radio
(transmit audio in and receive audio out) and an Icom PRO (transmit audio
in and receive audio out). Both radios have the audio connections at the
rear-panel connectors to access signals as near to the digital data streams
as possible. The 602 drives a stereo amp and speaker system from the Tape
Out connectors.

I have found that the best way to describe all this is to just list how I
use each connector on the 602; follow along with the block diagram in the
manual:

MIC 1                   XLR from Heil GoldLine

LINE IN 1               Unused

MIC 2                   Unused  

LINE IN 2               Unbal. from Heil ProSet HC-5 mic

LINE IN 3/4  LEFT       Receive audio from PRO from ACC1 output.

LINE IN 3/4  RIGHT      Unused

LINE IN 5/6  LEFT       Receive audio from Kachina 505DSP ACC1 output

LINE IN 5/6  RIGHT      Unused

STEREO AUX RETURN LEFT  Left channel output from soundcard

STEREO AUX RETURN RIGHT Right channel output from soundcard

AUX SEND                Soundcard MIC input

PHONES                  Heil ProSet headphones

CTRL ROOM OUTPUT LEFT   Unused

CTRL ROOM OUTPUT RIGHT  Input to dual-trace scope for monitoring audio
waveforms

MAIN OUT LEFT           Transmit audio input to Kachina ACC1 transmit audio
input

MAIN OUT RIGHT          Transmit audio input to PRO ACC1 transmit audio
input

TAPE OUT L              Left stereo input to amp

TAPE OUT R              Right stereo input to amp

TAPE IN L               Unused

TAPE IN R               Unused

I use the AUX controls for each input channel to control the level of
signal sent to the soundcard MIC input. The AUX RETURN sets the level of
stereo output from the soundcard to the radios. The MAIN MIX sets the level
going to the transmit audio inputs of the radios. The PAN or BAL controls
for each channel control how much signal from that channel goes to the Left
and Right outputs, respectively.

You can adapt this setup, which is fairly extensive, to your own needs. I
hesitate to go much further since you need to get acquainted with the 602
and work through the diagram to see what I am doing with my connections. It
may take some trial and error to get all the bugs out, but once you have
it set up, it is a joy to be able to control everything so easily from one
location.

I strongly urge you to use the rear-panel connections and to avoid using
any of the analog internal audio circuitry in the PRO. The receive audio is 
*good* using the internal circuitry but it is *great* when taken out
through the 602,
equalized to suit your ears and speakers/headset and played back through
real speakers.

One more thing: the 602 makes an excellent computer/radio interface for the
digital modes. And it seems to be RFI-proof as well. An outstanding piece
of gear for under $70!

Finally, the cables: Radio Shack. They have everything that you need. I use
the 6 ft cables but that may not work for you. You can tell from the
connectors on the 602 and your other equipment what you need on each end of
each cable. Just coil up the excess cable to contain it and to add a touch
of r-f proofing.

BTW, Bob Heil saw a picture of my 602 and remarked that I was the first guy
he had ever seen who could use all the connectors on a 602!   <:}

72/73/oo, George W5YR - the Yellow Rose of Texas         
Fairview, TX 30 mi NE of Dallas in Collin county EM13qe   
Amateur Radio W5YR, in the 56th year and it just keeps getting better!
QRP-L 1373 NETXQRP 6 SOC 262 COG 8 FPQRP 404 TEN-X 11771
Icom IC-756PRO #02121  Kachina #91900556  IC-765 #02437

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