I have a DBX 200 program route selector which I am pretty much fed up with as it has dirty switches and I cleaned them once as best I can but it only helped some.
This explains what it does.
DBX 200 - Manual - Program Route Selector - HiFi Engine
What I want is to build a device that can replace it.
I need six stereo unbalanced inputs and six stereo unbalanced outputs.
I need it so that I can send any input to any output.
The connected devices are
Two USB sound cards
A reel to reel player/recorder.
An 8 track player/recorder
Two unused input/output positions which could be for future use.
The main inputs and outputs that connect to the tape out and tape in jacks of my preamp.
If I could get the switches cleaned good enough the existing device would work, but it is rather convoluted how the switching is done and each time I go to change a switch that isn't used much I have to fiddle around with the switches until I get them set in the right positions.
It's so convoluted how to do things with it that I cannot easily explain how to switch things for playback and record.
It is better than swapping cables around though.
Any ideas on how to build such a device to where only one input can go to one output while being able to feed any other input to an output.
An example is if I want to listen to my laptop while I'm recording a reel to reel tape to my desktop.
What I want is something straightforward and simple.
Flip a switch or turn a knob and an input goes to an output with some sort of protection so that multiple inputs cannot go to the same output.
This explains what it does.
DBX 200 - Manual - Program Route Selector - HiFi Engine
What I want is to build a device that can replace it.
I need six stereo unbalanced inputs and six stereo unbalanced outputs.
I need it so that I can send any input to any output.
The connected devices are
Two USB sound cards
A reel to reel player/recorder.
An 8 track player/recorder
Two unused input/output positions which could be for future use.
The main inputs and outputs that connect to the tape out and tape in jacks of my preamp.
If I could get the switches cleaned good enough the existing device would work, but it is rather convoluted how the switching is done and each time I go to change a switch that isn't used much I have to fiddle around with the switches until I get them set in the right positions.
It's so convoluted how to do things with it that I cannot easily explain how to switch things for playback and record.
It is better than swapping cables around though.
Any ideas on how to build such a device to where only one input can go to one output while being able to feed any other input to an output.
An example is if I want to listen to my laptop while I'm recording a reel to reel tape to my desktop.
What I want is something straightforward and simple.
Flip a switch or turn a knob and an input goes to an output with some sort of protection so that multiple inputs cannot go to the same output.
I like that, but it only allows one input to one output at a time.
I need something that can allow one output to go up to all six outputs if so desired.
Also should allow me to for instance send my reel to reel to my laptop to record it while recording my 8 track to my desktop while monitoring the audio from the desktop and switching between it and the laptop audio output.
Basically any input to any output at any time with protections so one output only goes to one input at a time.
I already know it's not going to be easy.
The simple way is to use six two pole six position rotary switches and be careful to not switch more than one input to one output unless there's a way with the switches to make it to when an output is selected, no other input can feed that output.
I need something that can allow one output to go up to all six outputs if so desired.
Also should allow me to for instance send my reel to reel to my laptop to record it while recording my 8 track to my desktop while monitoring the audio from the desktop and switching between it and the laptop audio output.
Basically any input to any output at any time with protections so one output only goes to one input at a time.
I already know it's not going to be easy.
The simple way is to use six two pole six position rotary switches and be careful to not switch more than one input to one output unless there's a way with the switches to make it to when an output is selected, no other input can feed that output.
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No, just one dual channel rotary switch, with six positions.
So you want to send any input to any output, AND any 'other' input to any 'other' output
(at the same time)?
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Perhaps you want one of these : AD8113 Datasheet and Product Info | Analog Devices
It has 4 more channels than you need though and the 100pin package would call for a custom PCB.
In a more DIY-friendly package is this one though its only 8*12 so you'll need more than one chip.
http://www.mouser.com/pdfdocs/zarlink_MT88120.PDF
It has 4 more channels than you need though and the 100pin package would call for a custom PCB.
In a more DIY-friendly package is this one though its only 8*12 so you'll need more than one chip.
http://www.mouser.com/pdfdocs/zarlink_MT88120.PDF
What you're asking for is know as a "Matrix" or "crosspoint" audio routing switcher. It's neither simple nor inexpensive to build. They are usually made with I/O counts in multiples of 8.
This example is viewed as an "inexpensive" unit:
Broadcast Devices GPM-300-8
Yes, it's a bit more than you asked for. A crosspoint/matrix switcher itself isn't too bad to make, but controlling it is a challenge. There are 64 crosspoints x2 for stereo. Every destination has 8 possible sources. The simplest type of control interface I can think of is a source selector, a destination selector and a take button to activate the selected crosspoint.
I'd suggest carefully analyzing your true needs, and not the theoretical ones. Then you might hit the used market using the terms I've just given and find a professional device, probably capable of switching analog video as well. You can ignore the video part of course. But that's the industry these things were most used in.
I did build a large routing switcher many years ago using IC analog switches. Basically, each card was an 8x1 stereo module, 8 cards made up an 8x8. Kind of a beast really.
Doing a 6x6 doesn't help much as there are 8x1 multiplexers, even 8x8 matrix chips, but you won't find many 6-wide products.
I tried that a few times and it worked marginally at best.
The issue being the switches are those push on push off types that are pretty much sealed and the two rotary switches are pretty much sealed as well.
Would that for instance allow me to send my 8 track to my laptop for recording while I listen to my desktop which is recording a reel to reel tape and then switch to my laptop to monitor it?
Now if I knew how to program microcontrollers, those chips would be perfect as I could simply use two rows of 8 push buttons to determine what goes where.
Now it could be possible to daisy chain DPDT switches on each output so that when one switch is on for a specific output another switch if turned on will not send its audio to the output if it is before the already on switch, but will send its audio to the output if it is after the already on switch.
For six stereo inputs that would require 30 DPDT switches as I would not need to for instance send input one to output one as I would otherwise be creating a feedback loop.
I would build it in a metal case for shielding purposes possibly an ammo can as those are perfect for building circuits in.
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The DBX 200 is purely a mechanical switching system like the one I made.
The suggestions about using an IC chip to switch sources is actually a sort of downgrade, relying on the signal to pass through semiconductors.
If the DBX has sealed controls, I suggest using a Dremel, with a tiny needle-sized (1/16"-1MM) drill to make an access hole for the Deoxit to enter and properly wash those contacts.
The silver plated contacts do get tarnished over time, and need direct treatment.
I've had to do that on occasion, and it does work .
The suggestions about using an IC chip to switch sources is actually a sort of downgrade, relying on the signal to pass through semiconductors.
If the DBX has sealed controls, I suggest using a Dremel, with a tiny needle-sized (1/16"-1MM) drill to make an access hole for the Deoxit to enter and properly wash those contacts.
The silver plated contacts do get tarnished over time, and need direct treatment.
I've had to do that on occasion, and it does work .
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Be warned that flooding switches with contact cleaner may also create unwanted conduction paths, which becomes important e.g. when the same switch is responsible both for audio and an indicator lamp. If you are up to it, the Proper Way(R) still is taking the whole thing apart and cleaning contacts then. That implies you see a decent likelihood of getting things back together - working on switches of a certain complexity is not necessarily everyone's cup of tea.
For the input selection, two rotary 6PDT switches would be needed.
The problem is in preventing two different sources from being shorted together, by accidentally switching
the two different sources to the same output. You would need extra switch contacts to act as an interlock.
(Or, a 2k resistor in series with each source would help, with a level loss of 6dB if the same source is selected.)
For example, if rotary input selector #1 were set to source #3, then source #3 would have to be disabled
as a selection for rotary input selector #2 (and vice versa).
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This unit, has no lamps or electric power! - no indicator lamps.
It's only a mechanical switching unit.
As for "conduction", Deoxit is not conductive or harmful to any plastics.
I already stated a "proper way" to do the service.
The problem is making this situation overly complicated, when my suggested servicing mentioned is all that is needed, if the OP was satisfied with its operation before the messy switching happened.
Why complicate things ?
Some of the posts for answers get too much into a rabbit's hole.
Like taking a simple plane trip to NY from Philadelphia, via Russia.
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I was satisfied with the box as is, but it always had some switch problems.
Plus the switch functions are somewhat convoluted.
For instance with my laptop connected to sound processor 1, if I wanted to send my reel to reel connected to tape 1 to it I would have to do the following.
1. Monitor/line switch to tape
2. Monitor rotary switch switch to tape 1
3. Rec selector rotary switch to tape 1
4. Tape 3 line/copy switch to copy
5 Sound processor post/pre switch to post
6 Sound processor 1 byp/in switch to in
That's more complicated than it needs to be.
I want the ability to do that with the flip of a single switch and the process should now be this assuming the laptop is input/output 6 and the reel to reel is input/output 2.
1. Ensure no other inputs are going to output 6
2. Set input 2 to output 6.
That's much simpler.
The photo I posted showed one way I could do that only it takes 30 switches.
How would that work in being able to send any input to one or all outputs or send multiple inputs to multiple outputs?
Correction that would take 36 switches as I have to account for the main input/output coming from and going to my preamp.
To keep the labeling simple I would label it all with numbers and make up a chart detailing what each is and mount it to the wall using some command strips.
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If you had six rotary switches, one for each output, each switch with six positions to select from the six inputs; how close would that come to your needs?
With this any output can select any input but can only select just one input; any number of outputs can select the same input.
Clearly the box you currently have is more sophisticated than this, so what else does it do that you need? For example, you could add another ‘monitor’ output with its own rotary switch but this one selects from the six outputs. The monitor can only select one output, which in turn can only select one input, so no shorting of inputs.
Geoff
With this any output can select any input but can only select just one input; any number of outputs can select the same input.
Clearly the box you currently have is more sophisticated than this, so what else does it do that you need? For example, you could add another ‘monitor’ output with its own rotary switch but this one selects from the six outputs. The monitor can only select one output, which in turn can only select one input, so no shorting of inputs.
Geoff
Six switches like you suggest would work perfectly.
I would want to do 8 though if the box I choose has the room.
I will have one input/output for connecting to my preamp's tape loop and the other one would be so that I have an even number of channels.
So that would require two pole switches with 8 positions.
I'm thinking perhaps to keep it simple I may use 1/4" stereo jacks and some 1/4" stereo to RCA stereo cables.
With a metal box I won't have to worry about using shielded wire and if I use non-isolated jacks I won't have to worry about running grounds.
The box I currently have doesn't really do anything special that the box I want to build won't do. In fact the box I am building will do more than the original box and will do it better.
So with the switches you suggested, this.
Becomes this with the laptop on in/out 1 and the reel to reel on in/out 5
1. Set out 1 switch to input 5
Now that is much simpler isn't it.
Here's how the switch for OUT 1 would be wired up.
OUT 2 would be wired the same only IN 2 would be NC.
So on and so forth.
I can then send any input to any output or multiple outputs except the output that is part of an in/out channel.
I would want to do 8 though if the box I choose has the room.
I will have one input/output for connecting to my preamp's tape loop and the other one would be so that I have an even number of channels.
So that would require two pole switches with 8 positions.
I'm thinking perhaps to keep it simple I may use 1/4" stereo jacks and some 1/4" stereo to RCA stereo cables.
With a metal box I won't have to worry about using shielded wire and if I use non-isolated jacks I won't have to worry about running grounds.
The box I currently have doesn't really do anything special that the box I want to build won't do. In fact the box I am building will do more than the original box and will do it better.
So with the switches you suggested, this.
Becomes this with the laptop on in/out 1 and the reel to reel on in/out 5
1. Set out 1 switch to input 5
Now that is much simpler isn't it.
Here's how the switch for OUT 1 would be wired up.
OUT 2 would be wired the same only IN 2 would be NC.
So on and so forth.
I can then send any input to any output or multiple outputs except the output that is part of an in/out channel.
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The important thing with such a switch is never to short two of the input channels together by routing them to the same output.
However its fine to connect two outputs to the same input. Thus you use rotary switches only on the _outputs_ selecting the source for that output. Thus size 2x6 rotary switches are needed. Which are readily available (this is why the original unit is 6 channel, not 8!).
However you want quality heavily gold-plated leaf switches to make a reliable unit, not cheapo silver-palladium switches - signal levels aren't enough to stop oxidation of switch contacts, hence the requirement for gold for a long trouble-free life (and thick gold to resist wear and tear)
Another way is to bring out 6 short jack leads from the front panel and have 6 sockets, patch-bay style. Cheap and cheerful and an intuitive interface too!
However its fine to connect two outputs to the same input. Thus you use rotary switches only on the _outputs_ selecting the source for that output. Thus size 2x6 rotary switches are needed. Which are readily available (this is why the original unit is 6 channel, not 8!).
However you want quality heavily gold-plated leaf switches to make a reliable unit, not cheapo silver-palladium switches - signal levels aren't enough to stop oxidation of switch contacts, hence the requirement for gold for a long trouble-free life (and thick gold to resist wear and tear)
Another way is to bring out 6 short jack leads from the front panel and have 6 sockets, patch-bay style. Cheap and cheerful and an intuitive interface too!
Personally I would be nervous of connecting all the grounds of all your connected devices together by clamping the ends of their I/O cables to a metal box. Also, I think I would use twisted pairs for each audio path.
Geoff
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