Mac Mini (intel) With 3 Belcanto Dacs Usb Attached, How do I send the same stream to these 3 amps? Options

[David75]

I have an intel mac mini
I have 3 Belcanto USB dacs.
I can play each of them separately, they work extremely well.

I have a problem though.
I would like to be able to play the same tune to all 3 of these amps at the same time.
IE: If I play a song in iTunes, all 3 amps receive the same stream via USB
Each amp has is attach to one of the four usb outputs on the mac mini.

I tried the aggregate device idea, under midi app control.
The thing is that this aggregate device is composed of 3 separate stereo systems. It's correct.
However, I can't assign the same stream to each system, thus the same 2 channels to each
set of speakers.
So I can play only one amp at a time and need to go to the conf to change the amp I want to
play.

Does anyone know how I can change the settings so that the itunes stereo stream is duplicated one the 3 usb amps at the same time?

I don't want to have a device beetween the mac and the amps for several reasons:
1st: I'm certain it's just a code line and the mac is higly capable of this, however no one ever thought about it and cared to enable this.
2nd: I don't want a third party piece of hardware to mess with my system.

Thanks for any idea of input on this

Bye