Finally replacing the old “Radiotechnika S-90″ speakers with newer (and smaller) ones. Decided to go directly to the top and bought Genelec 8040:s for the job.
Of course this meant upgrading the AV-receiver with one that has preamp outputs and support for the newer HD audio codecs. Decided to go for the Sony STR-DA2400, a good value amp with the features I need but nothing extra. However there is no control output to switch the power off from the active speakers when the amp is in standby. However as I have done some HW hacking earlier I didn’t let that bother me too much.
Basically the first alternative would be to use current sensing switch on the AMP powerline, but that’s somewhat unreliable.
The other way of course is to take the information from the amp somehow. As the amp has a Sony proprietary DMPORT connector which can supply power for eg. charging iPod that can easily be used for the job.
The DMPORT connector is a small with tiny-weeny contacts so DIY one would not be possible, so ordered a iPod adapter and slashed the cable near the DMPORT connector revealing the wires. Having checked the other end attached wires to the screen and (thin) red wire (the thicker red is shielded audio) to get 5v output. This 5v output is then used to drive a relay (thru optical isolation) to control the speaker power.
I’ll post some pictures later on the finished device.
