Alt Speaker button

[Franz]

Hi guys! Do you have any idea where to buy or how to build a relay box to switch between two speakers (or 4) with the Alt button?

[jimlfixit]

There is a basic circuit on here somewhere which Chris Simon posted in April 2020 but it doesn't show the power wiring for the relay. Needs a box, a DC power supply and probably some extra 10N caps.

Hope this helps from Jim Lassen.

[Dave Dicson]

It's not that hard to build with DPDT Dip relays. I have 1 in 1 of are studios is just 1 in with 2 outputs X 2 for left and right. It has all XLR's. It is power with just a 12 volt wall adapter.
I have another 1 which is twice the size in another room, which it has it's own internal power supply. This 1 switches 4 speakers depending the combination of the switches on the SSL console.
In another room, there is just a 4 position passive "serial" switch with DB 9 connectors to XLR's. It switches 4 speakers.

[Franz]

I've never made one and it would be nice to have a step-by-step guide to build it! Thanks for the answers!

[jimlfixit]

Hi, I found the basic circuit on this website but forgot to save it but will try again!
SSL never provided a relay switcher box for this but I built a few in the late 1980's but can't find the details. These days, there are more examples to switch between up to 3 sets of speakers with volume controls from one set of stereo outputs but they are not cheap.

Anyway, a temporary fix could be using the SLS output (Studio Loud Speakers) which is on the patchbay and comes out of DL33.
To use this you need to turn DOWN the mini LS first and THEN turn up the SLS volume which has a separate volume on the 651.

SLS is probably not used much these days as it was a function fitted on SSL's decades ago when musicians could listen to the recording whilst still in the studio live area and not going into the Control Room.
I am a drummer and also a studio wiring person so I know both sides of the glass in a studio (much more on that later).
Try the SLS function out for now and hope this helps.
Regards from Jim Lassen based in Maidenhead, UK

[horizonsound]

There is a schematic in the freely available service manual.

Section 5, Page 6.

Anthony.