Alt monitor switcher

[sintech]

From the schematic, the black line should point to positive volts.

I'm assuming ground is at the other end of the relay coil

[Matt Sartori]

it would be good to have a run of let's say 100 PCBs made...

sintech? 

Mattia.

[Artur D'Assumpção]

By the way,

Most of you should already know this but in the 4000 service manual there's a schematic for the original switcher that was manufactured by SSL.

Cheers,

Artur

[marcmozart]

Which page of the service manual - can you scan and post please?

I just finished mine using Mattia's schematic above. Not sure if I have followed it 100%, but it works great. I have a tiny little click on one side of the speakers but not enough to worry about.
Couldn't get the capacitor to work in the schematic, the relay would either not switch or not prevent the audible click when switching.

Anyway, job done and happy!

By the way,

Most of you should already know this but in the 4000 service manual there's a schematic for the original switcher that was manufactured by SSL.

Cheers,

Artur

[Artur D'Assumpção]

Section 5-6, pdf page 108

Hope it helps!

[marcmozart]

Thanks! This is what I've done, just used 4 relays and added a diode across the relay contacts.

[sintech]

Marc, thinking about the last time I did one of these, seem to remember putting the caps over the Audio contact, not the power.

[marcmozart]

Marc, thinking about the last time I did one of these, seem to remember putting the caps over the Audio contact, not the power.

That makes sense, since when switching within the console there are also caps after the switching.

[Matt Sartori]

took mine off, bad memory...

M.

[jimlfixit]

The SSL diagram shows the 2 Alternative Monitor switch wires usually on DL 59.

This DL is for the remote Producers Panel and earlier 4 and 6K consoles didn't have this fitted unless the 3u 621 Producers Panel was ordered from SSL. In most circumstances, look for 2 DL pins (not 3 as is the case for the audio circuits) normally around circuits 25 - 32 on one of the centre section DL's (31, 32 or 33).

When you have found 2 pins on a DL within a circuit, unscrew and drop the DL down and look at the label which could be Z02 for the Alt switch or Z01 for the Red Light switching. Both of these should end up in the 104 way MRAC connector, M1 at the 651. Of course you can bleep through directly from the switch to the DL pins to identify the Alt switching wires.

I think the Alt switch may have, either a 12 or 24 volt T5.5 lamp inside but am not sure (check it out). Whatever the case, I also think that the bulb is powered by the external switcher box power supply rather than the console but I may be wrong.

Hope this helps from Jim Lassen (www.profcon.co.uk). Also on FACEBOOK

[marcmozart]

I think the Alt switch may have, either a 12 or 24 volt T5.5 lamp inside but am not sure (check it out). Whatever the case, I also think that the bulb is powered by the external switcher box power supply rather than the console but I may be wrong.
(www.profcon.co.uk). Also on FACEBOOK

On my 1992 G, the ALT bulb is powered even when no external switcher connected. Found the Pins on DL59 (and my console has a 621 Producers Panel). Wondering about the red light switch. Couldn't get it to close. Maybe it's connected to the Logic being in Record?

[jimlfixit]

Hi Marc
If the Alt switch lamp is powered regardless of any external switching taking place, it would probably mean that the Alt switch is a 2 pole version with the SSL supplying power to the lamp on one pole and just the 2 external contacts on the other pole.

To have these Alt contacts on DL59 would seem unusual as, to use them, a user would need another DL (which is expensive) just to use 2 pins for this function. Again, look at DL's 31, 32 and 33 which should have the 2 pins on there in most cases.

Red light switching: This was designed so that, when the console is in record mode, an external relay could light up a sign by the recording area live rooms to warn people NOT to enter in case they interfere with the recording process. I think that this is automatically activated when the console is in record mode so, you should just need 2 wires from these Z01 contacts wired out to an external relay to power some illuminated signs in the right places.

[michaeldtech]

Regarding the click you should swap things around L-R and ALT-MAIN to determine if it is the switcher or the amp.  Usually a click or pop is shield/grounding related.  Did you short the +/- in MUTE positions or use a load resistor?  Changing to load resistors helped with light pops in my experience.  It helped compensate for differences in amp inputs.
Mike

[neumann25]

Can you guys point me to what kind of relays to look for? Perhaps a mouser.com Link?

I think I have a spare to sell if you just want to buy it made.