I looked at this question a when the actives first came out. I also talked with Ian briefly about it in respect to triggering ADA's off the Transformer. Basically resolves down to three questions: the first two apply to the ADAs and DSP and the third to the current and voltage needed to drive the trigger:

  • how much power does the DSP and ADA1500 use in stand-by.
    The DSP consumes 9W and a ADA1500-5 20W ... or for the Actives: 58W is consumed in stand-by ... which is unacceptable to me. Here's the thread with: Andrews answer
  • Why not shut down the box completely. The current draw should be in the mW range.
    There are two answers to this which I don't buy completely as I think there are solutions (which I'll give a thought or two on at the end of this post)
    • The first answer is in Andrew's post ... Longevity ... the trigger shuts the digital amps off but not the power supply. This saves us 40W (as the amps are always switching even if there is no output. Each transition takes a bit of power. The 1500 Amps wattage is pretty high for a D-Amp ... this is, I believe, mainly do to its high rails (for all that headroom)). I think the Longevity part is about the in-rush current being hard on the transformer and caps.
    • The 2nd reason, I believe, is that they are concerned with the 12V trigger's current draw if a relay solution is used. I know when talking with Ian he mentioned something about that. The more triggers you have on a single line the more current gets drawn and the less likely the pre-pro will trigger anything,
  • Transformer triggering ADAs:
    Ian's answer on this was that the Transformers didn't have a 12V supply so they could not trigger a ADA. My thought on this is that a 12V trigger should trigger on anything above 3V. I know of other devices that do.


Ok, So any solution to this will add complexity and cost ... but I think it's worth it. So, there are a couple of issues. If you shut down the power supply then you'll need to get power from else where to boot it up again. The front panel button could flip a line voltage relay but what about the 12V trigger ... do you have a 2nd relay for that? Another solution is to have a stand-by power supply ...perhaps something from this family ucc28881. With a little research you might do better but this will get you below 1/2 watt. The longevity problem, I think (Mojo maybe a better person to talk about this), can be solved with a soft start solution ... here's a resource on that guide to soft start design

I do not think Ian and Andrew are trying cut corners here. They certainly didn't cut corners on the rest of these boxes. I personally think they didn't look far enough for solutions or perhaps they are not as sensitive to parasitic power as we are.