Axiom Home Page Forums General Discussion What's New At Axiom LFR1100 Active

Just reread Andrews comments ...
think I understand

Front power switch is similar to trigger off (20W consumed in standby)
The rear power switch is completely off (0 Watts)
Is that correct?

Does the amp shut down and power up gracefully when using the rear switch?

Yes.

I've had no problem with turning the rear switch on. I've tried it with two 1000s and one 1500. There are no clicks, pops, farts or burps. On the 1500, when you turn it on, you will hear the pleasant sound of magnetostriction in the 30 pound toroid that graces the innards.

I have noticed when the rear switch is turned off on the 1500, and the front switch is still on, for about 753 msec, I hear a high frequency squeal in my VP160 as if someone quickly choked a squirrel. It surprises me every time, and every time I have to remind myself I don't house any humans or squirrels in my 160.

Being sensitive to phantom power (especially if it's over a watt, no less 58W) I'd like to propose that:

A) the DSP have a trigger which shut's it down completely ... and if there is any chance that there might be a transient on its output then the DSP also have a trigger out which shuts down the amp before the DSP (and turns it on after the DSP is settled).

B) the Amp shut off completely after say (10min). I can only guess that this is not being done because the power supply takes a while to come back up. For people who want instant on then maybe this option is switch selectable.

Thoughts?

What you're asking for is doable but it increases part count and complexity.

relay (preferably latching) or have a separate power module (TI makes a few single chip supplies which can efficiently supply what's needed at a few mW of cost)

Mojo,

You edited your post and left my answer hanging ...

in any case ... for the few parts it takes the product is greatly improved ... if you care about wasted energy ... not to mention paying for it (but I guess in the winter it's just adding needed heat) it's a no-brainer ...

Rich

Rich, I edited while you were posting your answer. It's actually not as simple as you proposed but yes, it can be done.

This begs the question - how many squirrels have you heard being choked?

Never seen one choking on a peanut? It must be Andrew's sense of humour designing a turn-off circuit that sounds like that.

https://youtu.be/xOcVuWMP9t8?t=15

I hope Ian is OK. Last I heard, he was bruising his corpus callosum trying to integrate the various driver curves for the active LFR1100 in the digital (DSP) domain. I hope he hasn't blown a brain lobe!