mma
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Dank:
You have it pretty much right. The MiniDSP is a two channel, 4 output digital crossover, and the preamp outputs go into it, and the four outputs drive (2) woofers (bass horns) and (2) tweeter horns.
I am using Vellman K4700 'speaker protectors' that provide two functions: one is delayed turn-on via relays (I have two of these units, for a total of 4 relays). The relays sit between the amplifier and the drivers. The second function is to prevent DC from reaching the drivers. I do not use this function, but rather, am only intending on using the relay contacts themselves.
The reason I have gone this direction is that the power up of this system is at present, too complicated for my wife to deal with on a regular basis (and truth be told, annoying to me, too, to have to follow each and every time). The problem surrounds the MiniDSP powering up and then powering off, and the transients that come through to the amps. Good sized pops on all four drivers. Sometimes good enough to dislodge pictures from my walls.
My concern is that, in the arrangement I have conceived, all four amplifier channels (2 on the SE84 and 2 monoblock Mosfets ) are coming on with no load for approximately 6 seconds, after which the relays close and the loads are applied to the amplifier outputs. This gives ample time for the MiniDSP to boot and become stable. And, the SE84 does not really produce output for many seconds after that (owing to tube warmup).
I just don't want to damage the amps when they start under no load, even if it is only 6 seconds.
I may use the relays to switch SCR relays to apply the AC to the amps- this will used the K4700's to now sequence the power on/off instead of connecting the loads. However, I still would like the MiniDSP to be the last guy off in the chain, delayed by as much as 15 seconds (to give the SE84 time to leak down).
I have also considered gin-ing up a microcontroller sequencer that does this (delayed power on for the amps, delayed turn off for the minidsp). That would solve the whole matter, but would take a bit more time to conjure.
Thoughts?
-M
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