ZMACS with power station and solid state preamp

Stage & Studio ZMACS
,
1

Hi all,

I’m using a ZMACS and a PS-2A and would like to integrate a solid-state amp into the system, but I want to be 100% sure I’m not doing anything unsafe.

From the manuals:

ZMACS: not intended for solid-state amps with BTL / ungrounded outputs
PS-2A: not intended for solid-state amps with current feedback and ungrounded outputs

My solid-state amp is a Boss Katana and my house is currently ungrounded (this will be fixed, but for now I need to consider both cases).

Please confirm if this understanding is correct:

  • Katana → ZMACS (power amp in/out) is safe in a properly grounded location
  • Katana → ZMACS (power amp in/out) is not safe in an ungrounded location
  • Katana preamp only → ZMACS (FX Send → Amp In) is safe in an ungrounded location

If so, question about ungrounded operation - would either of the following be safe?

Option 1

  • Katana FX Send → ZMACS Amp In
  • PS-2A in the ZMACS attenuator loop, used as the power amp

Option 2

  • Katana FX Send → PS-2A Line In
  • PS-2A connected to ZMACS via the attenuator loop

My goal:

  • use PS-2A as a power amp for a solid-state preamp (and as a attenuator for tube amps)
  • drive two cabinets
  • avoid re-patching cables (tube amps already use PS-2A in the attenuator loop)

Even if only some of the above goals can be achieved safely, that would still be great.

Thanks in advance for any guidance!
Cheers
Bart

2

Hi Bart and welcome to the forum!

It gets a little technical but “BTL / ungrounded outputs” refers to voltages on the two wires that connect to the speaker. One wire is usually grounded and the voltage on the other wire carries the power. However, BTL is a method of connecting power amps to speakers where both wires carry power: when one is pulling, the other is pushing. In this way they are not referenced to ground, so kind of ungrounded.

This is why these are actually both unsafe! i.e. it is not referring to your house’s wiring but more to the internals of the solid-state amp’s power stage.

Yes, your only option is to go out of the Katana preamp and into the ZMACS that way.