Building a pedal controller

[CodeMonk]

Dunno if that what you would call it, but perhaps the diagram below will help to illustrate the idea.


Changing the signal path bypassing each effect when I turn it "off" via the switch bank. Basically the effects would always be on, but using the stomp switches to bypass each effect when I turn it "off". I was thinking about using relays to accomplish this.

Thoughts, ideas? Stuff out there like this already that would work for regular stomp boxes (inexpensively I hope ?

Thanks

[GibsonGM]

Mucho complex, Monk...I'd personally go with a digital programmable patch unit like the new RP or something, rather than do that much mechanical switching!  For $200 you can buy something that will do what you want.    Alternatively, you could build 3-4 effects into a box, and route them via switches before each song.  Still too much work for me onstage, LOL...I just set 3 boxes how I like 'em, and stomp them on/off.  Generally what you're picturing is done with MIDI and 'computerized' circuitry, and would be a major undertaking...   

[Gus]

 search

http://www.diystompboxes.com/smfforum/index.php?topic=43104.0

[tmichutka]

Hey there,

  I'm working on the same thing.  I'm not sure what RP Gibson's referring to, but I hope I'm not doing this in vain.  Care to elaborate Gibson? 

  If you're ready to take this on, I'll give you all the info I've got.  Absolutely check out RG's articles at geofex.com regarding 2 different options to accomplish this.  One (http://www.geofex.com/article_folders/rmtswtch/rmtsw.htm) is essentially just a remote "true bypass loop switcher" where your effects are simply switched in and out in the same configuration (sounds like that's what you're after).  The other (http://www.geofex.com/Article_Folders/fxswitchr/fxswitchr.htm) is a much more complicated (for my feeble mind) remote switcher which can take any effect, put it anywhere in the signal chain, and can call up predefined banks of pedals.  I'm a noob so I'm going the simple route.  RG is a living deity by the way.  Just wanted to throw that out there.  Check out his article on Relays for audio signals (http://www.geofex.com/Article_Folders/relays/relays_for_switching_audio_signa.htm).

  Here's how mine is panning out.  The main unit (with the relays, 1/4" jacks, etc) is housed in a rack enclosure (http://www.fullcompass.com/product/287760.html).  The remote control (Stomp Switch Bank) is housed in a Hammond 1411ZU (http://www.mouser.com/Search/ProductDetail.aspx?qs=qVxIICNKHAGrGsQb3GIvrw%3d%3d).  They'll be connected by a DB25 M-M cable.  It's a slow build due to getting parts from different sources, planning the design, circuits, etc.  However it's not a complicated setup, per se, especially the circuitry.  If you need any help in regards to relay driving circuits, this sheet (http://www.jaycar.com.au/images_uploaded/relaydrv.pdf) has helped me quite a lot.  I bought some high quality Reed Relays (http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&ssPageName=STRK:MEWAX:IT&item=380003938623, these were a killer deal, they're about $10 cheaper each than at digikey) and I would certainly recommend doing the same so it lasts you.  As I mentioned before, I'm using DB25 cable/jacks to connect the units.  DB25 will certainly allow you to do much more than switching (ie, I'm passing 9VDC for my Crybaby and 12VAC for my Whammy pedal through the DB25), however you can use a number of other options such as CAT5, DE9, blah blah blah.  If you're using more than 6 loops it's important to choose the right 1/4" jacks due to space constraints.  Neutrik is a great option in this respect because they make numerous slim jacks and even stacked pairs that'll fit in a 1U enclosure (although those are PCB mount only), as well as many other options.

  All in all I expect to be spending around $150 - $200 for the whole shebang.  It breaks down like this: Relays - $50, Jacks - $30, Enclosures - $60, Misc Components - $20.  It's definitely saving you money over a Voodoo Labs GCX or anything comparable, but it's by no means the easy route, and it's not exactly cheap either.  Let me know if you make this and we can trade ideas and knowledge.

[GibsonGM]

Looks like you guys might be able to hash something out )
What I was talking about was something like a Digitech multieffects unit....wouldn't say you're doing this in vain at all, but the effort is going to significant! If I were that far into effects, I might consider just getting one of those. Of course, no DIY!   
Maybe you could re-house your pedal circuits in a rack box w/knobs on the front, and build the controller as a stand-alone unit connected to it?

[drewl]

There's a couple guys out there (forget names) who build these exact set ups for famous and pro guys like the Edge etc.
Exactly like you want, the effects are in a rack by the amps and the multi switcher is out front.
I was thinking of maybe doing one with chips to do all the routing......I have everything I need at work.


http://www.guitarcenter.com/Carl-Martin-Octa-switch-Guitar-Effects-Switching-System-152013-i1386576.gc

http://www.musiciansfriend.com/product/Rivera-RM1-Guitar-Effects-Switching-System?sku=481685&src=3SOSWXXA

[drewl]

Here's the guys I was looking for....
check out their pix of stars gear.

http://www.customaudioelectronics.com/

[CodeMonk]

Mucho complex, Monk...I'd personally go with a digital programmable patch unit like the new RP or something, rather than do that much mechanical switching!  For $200 you can buy something that will do what you want.    Alternatively, you could build 3-4 effects into a box, and route them via switches before each song.  Still too much work for me onstage, LOL...I just set 3 boxes how I like 'em, and stomp them on/off.  Generally what you're picturing is done with MIDI and 'computerized' circuitry, and would be a major undertaking...   

Well, its actually simpler than it looks there, at least to me.
Basically I would have a relay mounted next to each effect (about $3 each from mouser). The stomp switches would trigger each relay either bypassing an effect of going into it.
I have thought about midi and those RP units as well as rack mounted units (like TC Electronics G-Major).
I like the sound of my effects as they are.
All the effects boxes themselves would be mounted in a cabinet (with a lexan cover so I could see all those cool lights ) and I just plug a few things in and go.

My relay idea is somewhat like this (over simplified here):

I plan one using a 12vdc relay and power supply, when a stomp switch is activated, it would send the voltage to the relay, activating the relay adding whatever effect into the chain (or taking it out by removing the current). Maybe a slightly larger PS (just enough to power LED's on the stomp bank).

That Carl Martin Unit does look VERY VERY appealing though. If only it could handle more than 8 effects .
I've got 10 on my pedal board right now, plus 2 more in a bag that I don't have room for (although those are a both a cheap flange (Johnson) and a cheap distortion (Dano FAB) pedal which I already have better ones on my board, Boss BF3 and an Ibanez TS808 (more OD really, but I like its sound better and I do have a metal distortion pedal anyway).

Anyway...good luck with your project tmichutka, keep use apprised and I will do the same. It may be a few weeks before I can begin I mine though.

And oh yeah, as I said before, the effects boxes will be mounted in a cabinet with some space above for a few rack mount units. I only have one right now, BBE Sonic Maximizer 362 I picked up at a pawn shop for $30 (I'm such a pawn shop whore

And I'm looking at these relays (the first one in particular):
http://www.mouser.com/Search/Refine.aspx?FS=TRUE&Ntt=*DPDT*+*Relays*+*12vdc*&Ne=688352+688335&N=254132+4294735256+4294643123+1323038&Ntx=mode%2bmatchall&Ns=P_SField&OriginalKeyword=DPDT+Relays+12vdc&Ntk=Mouser_Wildcards

[CodeMonk]

Sorry, a more accurate drawing of my relay system:

[tmichutka]

Yeah, I'll keep my individual effects too.  I've never been fond of any multi-fx units, although I like GibsonGM's idea of housing the effects PCBs in the rack unit.  Boss units would be tricky due to the buffered bypass and you'd still have to use relays for it, but I think it'd be pretty cool... kinda Gilmouresque!

CodeMonk, I see what you're getting at in your design but really, especially if you're doing this in a cabinet with rack rails, the only way to do it is put all the relays in a single enclosure (rackmount or otherwise).  If you try building individual relay boxes to go inbetween effects you'll quickly go well over $200, not to mention it's simply inefficient.  The only way I would recommend using individual relays for individual effects would be to install them in the same enclosure, but since you're effects don't appear to be DIY that's not an option (you can't fit a relay into a typical Boss, DOD, Ibanez enclosure... maybe an Electro-Harmonix but that's a moot point).

Here's why it's not an option; each relay requires a minimum of ground, on/off, input, output, send, and return.  It also requires a transient voltage supressing diode pulled across on/off and ground (unless you buy electromagnetically shielded relays).  Your design would require twice as many 1/4" jacks because you'll need to have an in and out in addition to a send and return on each box (40 total jacks with 10 effects).  The traditional way of building this project (RG's design) requires only one input and output, then individual sends and returns for each effect.  What this boils down to is that you're talking about building an individual relay box with power, jacks, and components for each of your 10 effects.  You're going to be running way more cable than you need to if you build individual relay boxes for each effect, requiring a buffer, and buying more cables.  The whole point of true bypass is to bypass the effect transparently, but the way you're talking about would bypass the effect over more than 10 feet of cable which is far from ideal.  The traditional way of building this project will bypass all effects or individual effects with an inch or less of either wire or PCB trace, which is comparable to a 3PDT switch.

I'm not trying to come across as rude or mean or anything, nor am I trying to shoot down your idea.  I just don't want you to start building this and then find out once it's too late what I've told you.  The idea you're talking about would be better suited for just a few effects, not a monster pedalboard like ours

Check out the links I referred you to, particularly the articles on RG's designs.  I'd definitely recommend the first one, which was the simpler of the two.  The end result is exactly the same as what you suggested, it'll just be more streamlined and efficient.  By the way, this project can definitely be done cheaper than $100, it's just costing me more because I'm building it with nice enclosures and components so it lasts a lifetime (or at least a few gigs).

[Gus]

A few things

You need to read and think and test the circuit so you don't have popping caused by the relay.  The old ampage had posts about relay switching IIRC.

You should use a protection diode on the relay(s)

When I built a relay switcher for a friend I installed a clean buffer before all of the relays and had to design a circuit so the relays did not cause a pop

If the unit is going to be on the road make sure the wires to connectors are stain relived

As a test,  build a one relay switch and use a high gain effect to check for popping.

Check geofex

[tmichutka]

Hey Gus,

  Thanks for the info.  As far as my project is concerned I should be okay with popping because I'm using an electromagnetically shielded reed relay which also includes a protection diode, but I'm definitely going to test this rigorously before actually building the whole thing. 

  You mentioned strain relief for the wires connecting to the jacks.  Am I right in guessing that essentially involves leaving a little extra slack on them?  I'd definitely like to build this to last so I'm trying to take any and all precautions, etc.

  I haven't installed a buffer before the relays, would you recommend that even if the signal isn't travelling particularly far?  I guess if I have 3 or 4 effects routed we're talking an extra 8 feet of cable, huh?  What type of buffer did you use, JFET?

  This is going to sound like such a rudimentary question, I hope I've got this right but... For the on/off signal, can I use an SPDT switch with the pole connected to a resistor and transistor in series traveling directly to the on/off lug of the relay?  Then have one throw connected to 12VDC+, and the other throw connected to either ground or nothing at all?  Will that correctly open and close the relay?

  Any other recommendations/tips on this would be greatly appreciated.  I'm right in the midst of moving from design to build and as you can tell I'm "learning" as I go.

Thanks!

[mattpocket]

That octaswitch is exactly what I've been looking for! Thanks!

[Gus]

I built it with a 24VDC supply and used an FET input opamp as a fixed noninverting gain of 2 with a input R of 470K or 1meg IIRC. 

There are different shells for DB connectors, sometimes you can slip a piece of tubing over the cable (and clamp it with the shell to the cable) that extends out an inch or so the cable can't be bent as much at the clamp area.  Look at a wall wart power supply there is often a strain relief at the body over the power output cable.

[CodeMonk]

I drew this up this morning. Its a basic PCB design for the relay. Its a tad sloppy, made a last second change on the right side there


And I too have been thinking about popping. Will look into that further of course.

And as far as strain relief, good idea there. I saw these connectors that you push together, then they screw together to lock. Think like the old BNC type connectors but larger.

And I'm looking at DPDT relays, where with no juice, its in one "on" state, and another "on" state when power is applied. So that my stomp switch send power or not depending on its state. Or something like that (I still need more caffeine).

[CodeMonk]

Somewhere in here are the connectors I was taking about.
http://catalog.tycoelectronics.com/catalog/bin/TE.Connect?C=10574&M=FEAT&P=2345,73827&U=&BML=10576,17560,17685,17686&LG=1

Can't seem to find them by the part number that was listed on the package at the store though.
Part numbers listed were:
746-7 : 28 conductors
744-5 : 37 conductors

These look much better than the standard D type connector, although quite a bit more expensive.
At the store they had the kits complete with everything you need, except the pins   (and cable of course).
$27 for the 28 conductor, and $32 for the 37 conductor.

While I was there, I picked up a relay. Wish me luck

[CodeMonk]

Relay board drawing, corrected.
Sorry, was thinking in terms of a switch.


And GUS, do you still have the designs you spoke of about the clean buffer as well as the protection diode and the circuit so it doesn't pop. And where would the diode go? Recommended diode?

EDIT: Nevermind about the diode. Found some info on that.

I tested it last night, Used just an old flanger and it popped, not badly but with a high gain effect and a cranked amp, it would definitely be noticeable.
And I was only testing with a little 10 watt amp. But with my AC30 cranked up it would really be noticeable

Thanks a ton GUS for all your help thus far.

BTW, this is the relay I used (R40−11D2−12,  It was the only 12VDC one the store had in stock) :
http://www.nteinc.com/relay_web/pdf/R40.pdf


Again, thanks so much for your help.