RCA switcher = rocket science?

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Guys this thing seems simple enough but I can’t get the thing to work how Id like.
I’m trying to get input 3 and 1 to play at the same time but no luck. I spent like an hour flipping every switch and moving the monitors from monitor out to tape out. Anyone know exactly the way this works? I just can’t seem to wrap my head around the matrix of it. 😅
I can get it to work either or but I feel like it should be able to blend two channels??
There’s 3 options for every switch.
Thank you!
 

bouldersoundguy

Well-known member
It's not a mixer. It's designed to select one source at a time. That said, I would expect it to sum inputs unless it has some kind of feature to prevent two sources from being connected to the output at once.

Two questions. Does it work as a source switcher? Is it an active device, requiring power to operate?
 

rob aylestone

Well-known member
I had one like that, they're just passive and switch - and the switches just connect ins to outs, but using a common bus, so pretty much one thing at a time. Some were switches with 'over-centre' springs so when they click, they switch and the design would prevent two at the same time, but other designs were make-before-break and those didn't click and you could set them to a half-way house where there was the possibility of two being connected at the same time. If you open it up and post the insides, we'd be better able to tell, but as you cannot make it work after fiddling, I suspect what you want is just impossible.
 

RFR

Well-known member
Judging by the oxidation on the Allen screws, it’s been in a very high humidity environment.

I take it apart and i a deep clean of the switches. It won’t change how they function but it will work better.

What exactly are you intending to use it for?
 
this is passive and you can get two at once but I think it’s not intentional by the designer because one of the outputs turns out to be really quiet and usually through one speaker.

I think I’ll just live with it cuz it’s a convenient little passive box but it can’t do everything.. that’s fine!

i thought maybe the dubbing feature would allow two channels.
 
The purpose I was going for while at fidgeting around with the switches was to play back audio from my computer while simultaneously running the mix out of my 688(midistudio), so I could hear the keyboard input from the 688 as well as the track I was playing back.

I ended up using my computer speakers which are not nearly as good but not the worst speakers in the world either.
 
Judging by the oxidation on the Allen screws, it’s been in a very high humidity environment.

I take it apart and i a deep clean of the switches. It won’t change how they function but it will work better.

What exactly are you intending to use it for?
I should definitely give the insides a clean. When I bought it was very dirty. when I go inside I’ll post photos of the electronic guts too!
 
No spare inputs on the 688? That would let you hear both and be technically much nicer?
the 488 I just upgraded from had a 2TR in input but the 688 does not. If I got a 1/8 audio to stereo xlr or 1/4 that would work. I use more 1/4 ins than xlr in my configuration so 1/8 to stereo xlr would work but that seems a bit much 😅 but yea I’ll keep this setup for now til I get around to buying or making one of those cables.
 

sweetbeats

Reel deep thoughts...
Dude…the 688 has umpteen more inputs than the 488. I have one of each in the studio right now. You seriously are struggling to find two available inputs on the 688?
 

rob aylestone

Well-known member
It does seem a sensible use of a couple of channels if you have them spare. For what it is worth, in 1974 I took two Sony spare phon-phono stereo cables from a cassette recorder and made a combiner with some strip block connector, and PVC insulation tape. Just the screens and centres doubled up - twisted together, because back then I could not solder. I then fed my two cassette decks into one input. A simple parallel connection. A year or two later when electronics became my thing, I meant to add the isolating resistors that were visible in every little mixer design - as in the signal came in, went through a resistor, then to the pot, then out from the pot wiper. I looked at my parallel, no component combiner/splitter, and figured it worked perfectly well, so why bother. The cassette decks were not even bothered by the occasional dead short from my bodged up cabling, just no sound. I suppose now if I needed one, I should do the job properly, but that simple combiner/splitter worked so well!

If you don't mind savaging your switch box, you have all the parts to make it work as you want, if you can solder.
 
Dude…the 688 has umpteen more inputs than the 488. I have one of each in the studio right now. You seriously are struggling to find two available inputs on the 688?
Well the thing is I’m using it in junction with the midiizer and tsr-8 so that’s 7 tracks right there in the dual bus.(minus 1 for smpte) and stereo ins add up quick.
Basically I definitely have enough ins but I’d have to figure out if I want them as xlr or 1/4”, plus i didn’t have either of those cables on deck when I was fiddling with this box.

The box is useful because I have a lot of different ins and outs going on between the computer, the 688, and the 32-2. Just thought it would be easier and I like the vibe of this thing.
I just want to understand the matrix all the options hurt my brain lol
 
It does seem a sensible use of a couple of channels if you have them spare. For what it is worth, in 1974 I took two Sony spare phon-phono stereo cables from a cassette recorder and made a combiner with some strip block connector, and PVC insulation tape. Just the screens and centres doubled up - twisted together, because back then I could not solder. I then fed my two cassette decks into one input. A simple parallel connection. A year or two later when electronics became my thing, I meant to add the isolating resistors that were visible in every little mixer design - as in the signal came in, went through a resistor, then to the pot, then out from the pot wiper. I looked at my parallel, no component combiner/splitter, and figured it worked perfectly well, so why bother. The cassette decks were not even bothered by the occasional dead short from my bodged up cabling, just no sound. I suppose now if I needed one, I should do the job properly, but that simple combiner/splitter worked so well!

If you don't mind savaging your switch box, you have all the parts to make it work as you want, if you can solder.
Your right if I open this up I’m sure there’s some way I can mod it to achieve the desired result!
 
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