Programmable switcher.

[dist]

Hi

I want to build an 6 loop 6 program looper. That is 6 footswitches to select between 6 programs of 6 loops.

So the first thing i do is to search Geo of course and find this article http://www.geofex.com/article_folders/fxswitchr/fxswitchr.htm

It SOUNDS pretty easy. but there are oufcourse questions and something i don't understand.

1.The fotswitch Logic part (img 9) i sort of understand the function and building of. But is there a specific diode used on the D inputs!

2 Than only one signal goes to only one relay driver right? (Img8) And than to the switches that decides if that program turns on that relay?

3. Is there a specific diode used here?

4. Will the relaydrivers drive 6 relays simultaneously, or do i need another relay to let power trough to the fxloop relays?

5.The diode across the relay coil?

[dist]

Is the princip realy this easy?

[R.G.]

1.The fotswitch Logic part (img 9) i sort of understand the function and building of. But is there a specific diode used on the D inputs!

All of the diodes can be 1N4148.

2 Than only one signal goes to only one relay driver right? (Img8) And than to the switches that decides if that program turns on that relay?

The footswitch logic makes sure that only one output is active at any one time. All the others are off. The one active footswitch signal goes to one relay driver and out of that relay driver to the DIP switches that select which relay(s) get turned on.

3. Is there a specific diode used here?

All of the diodes can be 1N4148.

4. Will the relaydrivers drive 6 relays simultaneously, or do i need another relay to let power trough to the fxloop relays?

The MOSFET relay drivers can drive six relays simultaneously.

5.The diode across the relay coil?

All the diodes can be 1N4148.

I encourage you to NOT go order all the parts for this and try to build it all at one time. Instead, build a small piece of it. For example, order the logic and diodes for the footswitching logic and get that part to work with only LEDs attached to it. When it properly switches LEDs, then build ONE relay driver and ONE relay. Get that to work reliably before ordering all of the relays and jacks.

It's actually quite a simple thing, but there is a lot of repetition and there are many ways to get it to not work. Work slowly, one part at a time.

[frankclarke]

Some thoughts here: http://www.guitar-pedals-effects.com/.SwitchWitch.ProgrammableRelayLoopSwitch.html

[dist]

Quote from: dist on Today at 01:49:14 PM
4. Will the relaydrivers drive 6 relays simultaneously, or do i need another relay to let power trough to the fxloop relays?
The MOSFET relay drivers can drive six relays simultaneously.

Is that Max six relays og atleast six relays.
What vould i do if i wanted to drive more relays.?

I encourage you to NOT go order all the parts for this and try to build it all at one time. Instead, build a small piece of it. For example, order the logic and diodes for the footswitching logic and get that part to work with only LEDs attached to it. When it properly switches LEDs, then build ONE relay driver and ONE relay. Get that to work reliably before ordering all of the relays and jacks.

I've already got most of the parts. Relays switches resistors diodes and caps. I think i even got some BS170 laying around. I only nead to order the chips.

And i am draving PCB for one part at the time. I always bouild and test first builds one step at the time.

[guitarman89]

Some thoughts here: http://www.guitar-pedals-effects.com/.SwitchWitch.ProgrammableRelayLoopSwitch.html

amazing!!
It's just the project i'm looking for!!!!!! Great!

A simple question
for 12-loops should i follow the 6loops' schematic? (adapted for pic16f877)

[R.G.]

Is that Max six relays og atleast six relays. What vould i do if i wanted to drive more relays.?

The BS170 can drive up to 500ma. It depends on your relays. I recommend the NEC EA2-12V relay. That is a relay that's intended for low level signals and has a coil resistance of about 1K, so it takes 12ma to drive one. 500ma/12ma = 41.7, so one BS170 could drive over 40 of these relays. Some relays need as much as 100ma or even more per relay. There is no substitute for knowing the details.

[dist]

Thank you very much for the help. I will start on this project as soon as i get my hum free aby to stop humming 

So much to do, so Little time.

I'm simply amazed of the knowledge of some of the people om this forum.

[frankclarke]

A simple question
for 12-loops should i follow the 6loops' schematic? (adapted for pic16f877)

The project would be a fixer-upper, the schematic shown is for a 6-relay circuit. The 40-pin chip just has more ports and more potential relays. Copy and paste. The hardware isn`t too difficult, the software is moderately difficult. I still have the programmer board, I don`t know what happened to the compiler. Build it with just the LEDs first. The LEDs worked fine, I must have shorted a relay driver at some point .

[dist]

I just came to think about something.

Is it possible to connect another 4049 to the circuit to get 12 programs, and maybe another to get 18 a.s.o.?

[Rodgre]

Not to stray too far from the subject, but I was lucky enough to pick up one of those BC Rich boxes way back when. It is a cool device, and I always wondered why there weren't more boxes like that, and why the BC Rich model never caught on. Strangely enough, though, I've yet to find the right place to use the BC Rich switcher in my rig. I think the best thing I've done with it in the last ten years was to conduct a blind test of every Tube Screamer variant that we had in the studio. You'd be surprised at how much a Soundtank TS-5 can still sound great next to a real vintage TS-808.

I recall the old Boss SCC-700 effects system, before digital multi-effects were available, and always wanted one.



Of course in this day and age, that seems so cumbersome when you can have a multi-effects unit the size of a cup of coffee for less than the price of one Boss pedal. (Not that I'd ever be caught dead in public without at least a dozen super-cool analog pedals on my pedalboards! )



Does anyone know how that Boss system worked? This was early-80's technology, so it probably involved lots of discrete logic circuitry and could be done much more efficiently with modern components.

Back in the day, when I was in Electronics class in high school, I fantasized about building such a system, but using simple DIP switches to pre-program the effects I wanted for a particular patch, controlled by a single footswitch. I suppose I could have done it much easier with relays. It never left my notebook.

I've also thought about MIDI control of a relay-based switcher, inspired by both the Bradshaw system as well as the lesser-known Scholz MIDI Octopus. With enough ability to create your own PIC-based devices, it seems that it wouldn't be too impossible for one to build something like that. Unfortunately, I'm probably just talking out of my a**, since I'm so green when it comes to digital circuit design that just because effects loop switching seems like a simple task, doesn't mean that it is.



Roger

[Dean Hazelwanter]

Back in the day, when I was in Electronics class in high school, I fantasized about building such a system, but using simple DIP switches to pre-program the effects I wanted for a particular patch, controlled by a single footswitch.

Sort of like this? http://www.diystompboxes.com/smfforum/index.php?topic=39449.0

I've also thought about MIDI control of a relay-based switcher, inspired by both the Bradshaw system as well as the lesser-known Scholz MIDI Octopus. With enough ability to create your own PIC-based devices, it seems that it wouldn't be too impossible for one to build something like that.

Not MIDI, but sort of like this? http://www.diystompboxes.com/smfforum/index.php?topic=56264.0

[dist]

Would it be problematic to connect the programming switches to select loop pr program instad of program pr loop as in fig 9

If I'm not misstaken as written in the article there is a series of switches for each loop that decides witch program is going to turn that loop on.
I Would like to make this box so i select witch loop a program turn on.

maybe something like this.



That way it would be easy to have a toggle to select two ore tree different versions of that program.

[R.G.]

You can do it either way, but no matter which way you do it, you must isolate the relay drives from one another so that they don't couple back through the relay connections.

The logic of the programmable switcher at GEO is that the footswitch turns on a program. The DIP switch selects which relays are in a program. I believe this is what you're wanting.