ZMACS V1 and Boss TAE Core

Stage & Studio ZMACS
1

The TAE Core works fine when I put it in the switched attenuator loop. When I hook a rack processor up to the TAE Core effects loop, there is a high pitched whistling. I tried the ground lifts on both the TAE Core and the ZMACS, and there was no change.

Any ideas?

2

@mcdyas, welcome to the community!

This is a ground loop issue, as you suspected too and the problem is coming from the additional path to ground caused by the FX loops (and/or the TAE Core).

If you unplug the FX does the problem go away?

If so, you need to take a look at how the unit is powered, can you plug everything into the same extension cord?

If that does not make a difference, you need to use an audio isolation transformer in the FX loop to break the loop.

Do you have any pedal in front of the amp or just FX processor?

3

Yes, if I take the rack unit out of the Core FX loop, the problem goes away. If I only use a single effects pedal in the loop, there is no problem. All the gear is being powered by a CypberPower CP1500PFCRM2U PFC Sinewave UPS; so I guess that is the same as the same extension cord. There is also a ticking sound when the volume on the Core is not turned up; when turned up it starts the whistling.

4

Replying to myself-

I had my pedalboard feeding the ZMACS, and when I went from guitar direct to ZMACS the issue resolved. I tried it that way with the Core in the switched loop of the ZMACS and also with a full WAZA TAE unit in the switched loop; both with the rack effects unit in their respective effects loops. It worked fine with both as long as I did not have my pedalboard feeding the ZMACS. I guess I have some ground loop issue between the pedalboard and the ZMACS.

Thanks.

5

Sounds like you had pedals in front of the amps and in the FX loop. We have seen that using separate power supplies for the front and FX loop effects can clear this issue up also.

FYI On the back panel of the ZMACS there is an instrument-level and isolated LINK output. The isolation can be useful but probably not in your case, it is intended to be use to link together multiple switches.