balanced speaker switcher with remote

trying to figure out the best way to do this.

Need a speaker switcher that  has one set of balanced inputs that can switch between 3-4 sets of balanced outputs. But the kicker is to have it able to do switching be via cabled remote.

I don't really need volume control but having trims for each output would not be a bad idea.

So far I am thinking the trims will be on the main unit.


I have looked at the various commercially available options on the market and they are either  too expensive or have have way more then what is needed.

any suggestions?

Simplest would be to use a rotary switch but you have to skip through the channels.

For four seperate buttons and one at a time operation you can use latching push button switches.

Or knock the control circuit using a 40175. There should be a good example in one of my amp books. Unfortunately I am at home now so I can't upload images. I'll try to do it tomorrow.

However, buy this;

http://www.ebay.com/itm/Tascam-112-Studio-Cassette-Player-Recorder-For-Parts-of-Repair-/130724630913?pt=LH_DefaultDomain_0&hash=item1e6fcb9181

It will give you all the comoponents you need including the relays. There is an asic for logic control (Start, Stop, FF, RW and Rec) which would fit the bill nicely. You have five switch inputs and five on/off outputs.

Use the keypad for remote control.

Send me the knobs and the vu meters. I'll pay the shipping.

I don't mind manual switching on and off each speaker set, but remote is key. I was thinking of having control switches in the remote and having dc in the cable between...


for your 112's take a look at this.

http://www2.ppauctions.com/lot.php?l_id=15535&id=67&search=&cat=all&perPage=20&sort=2&thisPage=2

Cheers Pucho.

I'll bid for them. You pay the shipping and I'll send you all the electronics you need free.

However,  you can certainly put the latching switches in the remote box and use relasy on the receiving end. Simple.

there are a few lots with those 112's FYI.

I have a few in the shop that if I was allowed to, I would just send you those parts freebie. but sadly I am not.


You have given me some ideas though

Once again careful though has yielded a more convenient and sensible answer.  Who needs a remote after all?

Yeap. This happens all the time.

However, it also occured to me today that you could buy an IR remote controller/receiver, a Velleman kit or something and use it to control the relays. I used them on many jobs in the past.

hmmmmmmm 8) decisions decisions.

Approx. 20 years ago, the studio where I worked replaced our MCI 636 desk with an Otari Concept-One.  Both desks had only  "main" and "alternate" outputs for CR speakers.  I had installed a passive amp/speaker switcher in the MCI back in the 1980's, but decided to do something "better" for the new Otari desk.

At the time, I had been experimenting with the 4053 CMOS chip, using it as a triple SPDT analog switch with each switch element at the virtual ground and "wrapped" inside the feedback loop of an opamp to achieve ultra low distortion as well as excellent "off" signal suppression.

Last year, I drew up this doodle for someone, based on my recollection of the "switching cell" that I used in 1992:

http://brianroth.com/library/fetswitch.pdf

Of course, for balanced in to balanced out, you would need to add the appropriate circuitry as I did.

The active system I built consisted of two parts.  In the equipment/amp room was a 1RU box which handled the audio switching, which connected to card mounted inside the desk (via an unshielded multipair).

The card inside the desk used RS flip-flops built with quad NAND gates which served as latches to activate a given set of 4053's back in the amp room box.  I cooked up a clever (to me, at least!  lol) circuit for the RS latches so that if the user pressed a single speaker selection switch, then any previously selected speaker choice would be cleared.  But, if two or more selector switches were pressed at the same time, then all two/more sets of 4053's would all be turned on at the same time.

The original controller with the momentary buttons was installed in a blank panel to the right side of the Otari's master section.  You can see it towards the lower/right in this pic:

http://www.brianroth.com/projects/gv2010/day0/IMG_0082.JPG

In 2010, the studio retired the Otari desk and went with an Avid D-Command control surface, outboard mic preamps, etc.  So, I removed the control card from the desk and mounted into a new 1RU box with new momentaries, and mounted that into one of the rack spaces adjoining the D-Command:

http://www.brianroth.com/projects/gv2010/week%204/IMG_0067.JPG

You may ask "why six speaker choices?"  Well, three choices weren't enough, and the 4053's are in sets of threes, so I just went ahead and maxed it out at six.

Today, I would use the same control circuit, but use high quality DPDT relays such as the Panasonic TQ2 series, which Amek used in the 9098 desks.

Best,

Bri

thanks Brian

dumb q - could you use an infra-red remote?

I'm assuming that the application is for the producer to sit on the couch and switch speakers?

/R

Yes. I proposed it above.

That'll teach me for skim reading!
Sorry 'bout that.

/R

No harm done. I do that all the time.

For the application that I described earlier, an IR remote would not have been practical, since the audio switching unit itself was located in a different room with no line of sight to the control room.  Hence, the wired remote...

Best,

Bri

It can be simply done with logic at the switch head and relays switching balanced in the MR.  You already have trims on the power amps and monitors to balance the system so why over complicate.  Breadboarding or PCB designing unbalancing/balancing/trimming circuitry to support an unbalanced remote switch that is also a breadboarded circuit does not make sense to me personally when comparing the cost to a comm unit.  Those kind of projects always cost the client too much, or pay $5 an hour to make.  Usually it's best that we both curse a commercial supplier.

KISS with the Panasonic relays that Brian mentioned and a simple RS ff front end, or the two chip MUX-DEMUX monitor select circuit in the SSL 4K is an elegant front end.  You can get 6-ch switching from one pair.
Then it can be up-sold as a passive device.  win-win
Mike
PS: Props to Rochey for not hawking the EA 3 Button Controller, so I will mention it myself as the best way to start, IF you can get away with only three selections ; )

I've been working on the same circuit for our monitors.
Copy of a schematic i found on the forum, uses momentary switches, a CMOS 4001 and relays.
Its all on my home computer but i'll post it when i get home.
I've also made a single sided pcb layout. (un-tested..)

sodderboy said:

PS: Props to Rochey for not hawking the EA 3 Button Controller, so I will mention it myself as the best way to start, IF you can get away with only three selections ; )

Click to expand...

Thanks!

you could use a simple  cat 5 cable from the remote to the switcher.

I actually need to build one of these for myself.