Alesis HD24/D&R Dayner Ground Loop

[cymatics]

I have a D&R Dayner that I have been running with 3 ADAT XT20s for the last few years. In order to get the ADATs connected to the console free of ground loops, I had to telescope the ground at the channel inputs. The wiring schems was as follows:

ADAT OUT ---> Dayner IN

TIP---------------------RING
RING----------------SLEEVE
GROUND---------x

I was using the Elco +4 outputs of the ADAT. The Channel inputs on the Dayner are unbalanced +4 & -10 on the same TRS connector (-10 on the tip & +4 on the ring)

I recently purchased an Alesis HD24 that I have been totally unable to connect to the Dayner with out creating a ground loop. At this point, I'm just about out of ideas for trouble shooting. I have disconnected every single connection from the console except one output from the HD24. I have attempted every conceivable method of custom cable assembly to connect the HD24 to the console to no avail. I have confirmed that both devices are plugged into an outlet that is referenced to the same ground.

I have a cheap (low quality) isolation transformer that successfully broke the loop. However, 24 channels of high quality isolation transformers is out of my budget right now.

The only other success I have had in breaking the loop is plugging the power cable of the HD24 into a grounded-to-ungrounded outlet adapter. While this successfully broke the loop, I am wary of implementing it as a long term solution.

Is there anything else I can do other than lifting the earth ground of the HD24?

If there is any other info I can provide that may be helpful in solving this problem, please let me know.

- jon

[Jim Williams]

If you have the XR with balanced outputs try floating the shields at the input of the HD and float the shields at the return to the D+R. Since the signal is balanced in and out of the XR, shields need to be connected only at one end, usually to send ends. By floating shields at the destination, ground currents are broken from causing a loop.
If you have the 48 k machine, try floating the shield at the D+R inputs, but connect the plug as if it were balanced. It's a impedance matched output so the small resistance on the low signal side should prevent looping.

Jim Williams
Audio Upgrades

[JCV]

Sorry to reply to this thread such a long time after it was posted, but I happen to own a Dayner as well, for a bit more than a year now, and have always had this ground loop problems.
I use mine with Aurora Lynx converters.
Has Jim Williams' advice solved the problem ?
I've just changed the connections into the Dayner and into the converters and it doesn't change anything. The only thing that helped was disconnecting the shield on the master send of the desk, but I didn't find anything working with the Tape Ret...
On the Dayner, the +4 and -10 inputs are summed if you send signal to both...

Jean-charles

[JCV]

And when you say "I have a cheap (low quality) isolation transformer that successfully broke the loop.", do you mean you used a passive device with a transformer to unbalance the signal before hitting the Dayner TapeRet ?
thanks

[JCV]

Ah. I connected the dayner Tape Returns as you did your connections and it worked perfectly in removing the ground loop !
thanks