My =ultimate= multi-fx pedalboard...W.I.P

[sfr]

Multi FX units are great.   

My unit wasn't constructed the way it was mainly about getting everything I was using at shows into an easier to handle and set up rig in the shortest amount of time possible (i.e., when I started putting things together, I really needed them *yesterday*) while still being very easily modable, as I was was far from having arrived at "my sound".  (I was still at the point where my rig changed every gig (usually as I built some new toy).   But I was tired of making a mad scramble to set up - it took me longer than the drummer.   The current unit has evolved over time to become what it is now, which is far from ideal, but works.  It's utilitarian.  I'm still tweaking things, figuring out what I actually want and need in a live situation.  At some point in the future, I would love to rebox the thing into a nicer looking unit, a slightly different setup.  But I'm playing shows now, and I need this now.  I put the whole thing off a lot longer than was ideal because I kept planning and changing things and working on inconsequential parts and eventually I just had to get to work and build something because doing nothing wasn't changing my situation.   

But things I noticed building mine:

Foot size - I had to center my footswitches at least 2.75" apart, if I remember correctly.  Sometimes it's still not big enough.  Footswitches above other footswitches had to be raised for me to not hit them. 

Board size - you can cram a lot of boosters, distortions, and other things in small spaces, but flangers, delays, and tremolos with way too many LFOs start taking up room inside.  So don't forget to take this into account, and plan on having an adequate depth (and the apropriate standoffs!) to squeeze pots and switches and such in the "layer" between the board and the enclosure if need be. 

Knobs - a tiny board (like the Trem Lune) with 5 knobs still needs space big enough for five knobs.  That's why I like what you've drawn (and the Cornish style projects) more than what I have - you've sort of moved away from the "box per effect" paridigm that I've still carried over into mine from when these where individual boxes.   But your method seems to make it more difficult to identify at a glance what belongs to what.   

As far as being able to select which type of pedal is being activated by a footswitch - this is a great idea in some instances, but just because you aren't using both boosters at the same time, does that mean you wouldn't want to easily be able to use one or the other, during a single song?  This is something that bit me in the rear in some iterations of my multi-fx projects - I have used rotary and toggles to select between different similar pedals, only to find that I really wish I could have gotten that other one at the crescendo of some song, instead of the one I was using at the begining. 

If you're working with what appears like it will be a rather large box, I'd see about integrating any volume/wah/expression pedals you plan on using right into this thing as well.   I know I hate having those couple of "external" things to still drag around.  Same thing with the tuner - I'd stick it right in the box as well. 

Ultimately, I think the way to really do this (And something I plan on implementing some point in the future) is to implement external switching - whether or not you move the effects themselves off the floor, having the effects switched via relays (for the true-bypass hardcore) or CMOS switching, or Boss-style or whatever will make life easier.  That makes them switched with a high-low logic signal, and you can do it from anywhere, and easily, and in a variety of ways.    Even if you don't program some fancy micro controller thing, even just switches to route what effects bypass control gets tied to what footswitch means you can cut down on the switches on the floor, and change multiple effects (contiguous or not!) with a single switch. 

Heck, many of my songs, while they may be performed differently every night, follow the same progression of effects that are on through the song each time - I'm obsessed with the idea of remote switching and programming to arrive at a three switch system - one switch to select a song, one switch to advance to the next preset for that song, and one to go back a preset if I mess up.  Hide all the effects in an box next to the amp, and just make everyone wonder.  (Although I'd still need to open the box up to tweak knobs between songs, I guess.)

[fikri]

You might need to take alook at RG. Keen's FX switcher project then, it is simple yet effective.

[Auke Haarsma]

@Mark. That's a cool idea. Way too cool. Darn...you just added another "must have" to my already too big project Continueing down that road: What about a stereopath from start to end, and giving each fx the following option:
-Out of the chain
-Stereo A
-Stereo B
-Stereo A+B

This should be possible with a fourway switch, maybe a small slider above each section.

At the front of the chain a buffer+splitter. At the end a mixer/blender, and/or footcontrolled blend? This could even allow me to blend clean with distorted etc...sounds too cool to not try to implement.

@sfr. Thanks for sharing your 'real life' experience! Very insightfull. The knobs will be put 'away' from the fx, but will still be ordered by putting names and lines around the control panel (the winered bar around the knobs). Your ideas combined with the above make me lean towards 2 switches for each section. Boost, OD, Dist, Fuzz, Mod, Delay/trem.. This allows for enough options to get that extra cresondo (I hear you there!).

@fikri. Thanks for the tip. I've been checking it out, relais based switching looks cool indeed. However, I fear the pcb's will get to big (I need like 10+ switches) and it's quite expensive to build. 'Traditional' switching is cheaper.

It's getting more and more solid in my head. But what about sound quality? Will all those switches, input buffer, mixer/blender etc not degrade the sound too much? Because, of course looks and tweakability count, but sound quality is what is more important in the end.

[Mark Hammer]

It's getting more and more solid in my head. But what about sound quality? Will all those switches, input buffer, mixer/blender etc not degrade the sound too much? Because, of course looks and tweakability count, but sound quality is what is more important in the end.

Short answer = Nah.  The switches won't degrade sound quality, and any splitters and mixers will not detract either.  The only real sonic impact they might have is if you haven't planned out your board carefully, and the wiring is going all over the place.  There, you run a risk of oscillation of other audio nasties.

One spiffy idea I got from Craig Anderton years ago was that of "stations".  A 2-pole, 6-position switch can be used to select (with TB) which of 5 circuits (or none) is inserted into a given position in the chain.  This can serve as functionally equivalent to a patch panel where this thing is routed here, and that thing there, except its cleaner and there are no external wires.  Ultimately perhaps not as flexible as a true patch panel, but damn close.  You can also make one of the stations an external loop, or make one of the positions selected for any station an external loop.

[sfr]

@fikri. Thanks for the tip. I've been checking it out, relais based switching looks cool indeed. However, I fear the pcb's will get to big (I need like 10+ switches) and it's quite expensive to build. 'Traditional' switching is cheaper.

I started looking at the CD4053 based switching over Geofex before I started building my unit.  I never got it working (it is a functional circuit, the problems where my fault - probably around my PCB design for the unit) but I started ordering parts.  I was looking at combining it with the "pancake" switches (also at Geofex)  When you start looking at the bits needed in quantities of maybe 25 or more, switching like that becomes cheaper than mechanical switches - if you use a conventional actuator for a tactile switch, it seemed like it broke even.  Of course, the additional time involved in crafting extra circuit boards, making switch actuators (if you go the "pancake" route) and mounting things in a less than "normal" way is of value, but strictly from the $ spent aspect, I managed to get the costs down significantly. 

Of course, I got hung up, and as I said, needed the unit ASAP, so left that by the wayside, since most of my DIY pedals where already in enclosures, and I had mechanical switches to re-use when boxing them up. 

Which reminds me, I have 25-30 CD4053 chips and a new PCB layout I never finished . . .

As far as the size of switching PCBs,  it's often easier to stick a "thin" PCB (use axial rather than radial caps, etc.) somewhere along the walls of an enclosure, than mount a big ol' 3PDT right in the middle of things.  The genius of the "pancake" switches at Geofex are that the entirety of the switch is now on the *outside* of the enclosure.  If you want a more part of the switch, even an actuator and a tactile switch can take up considerably less room than a mechanical switch, if the room you need is "depth" and not horizontal space.  Removing large items that go into the enclosure depth-wise like that can allow you "stack" multiple boards in the same space with careful planning.

[Auke Haarsma]

It could be cheaper (but not that much), but I already have a dozen or so dpdt's so I rather use them.

I've been workingo n the CE-2 Tonepad Corrrral chorus, really nice! It's tested on the breadboard and selected to be included. I also drew up a more conceptual diagram of how my multi-fx should look. It helps me get things straight in my head. I like the blender/mixer idea! Here it is:

[Mark Hammer]

Looks like your planning is going well.  My recommendation for inclusion of a splitter/mixer has a number of origins in what have traditionally been post-production sounds.

• Sometimes you want clean signal mixed in with processed, and this lets you adjust proportions.
• Sometimes you want to process delay differently than straight.  For instance, perhaps you want a specially EQ-d delay or reverb signal in tandem with a wooly-sounding primary signal.
• Sometimes you want to combine multiple sources/types of modulation, and you need to be able to adjust which sources/types dominate.  For instance, imagine you have a phaser and flanger going in parallel at two different speeds.  Which one do you want to be highlighted, and which one forms the bedrock?
• A splitter-mixer allows you to have momentary punch-in/punch-out of delay.  Say you have a delay pedal in your 2nd path, and the delay-only output feeds your mixer.  If you have switch control over what goes to the input of the delay then you have the ability to keep playing and hear the tail of what is still recirculating in the delay line without adding new content (Line 6 calls this "trails" but there are probably other pedals that do it too).  Alternatively, if you have switch control over the output of the delay line, you can keep playing and instantly "release" what has been building up in the delay line into the mixer.

You are quite right in wanting to be able to keep the two signal paths amenable to either a mono mix OR remaining separate for stereo out.  Both of these are viable and valid.  Just one word of warning, though.  You cannot always guarantee that the phase-coherence is maintained across all pedals.  Some present inverted outputs.  For that reason it is wise to have phase-inversion capability on one of the two mixer inputs.  That also can serve as an interesting tonal tool as well, even when the two paths are in phase with each other.

[fikri]

Which reminds me, I have 25-30 CD4053 chips and a new PCB layout I never finished . . .

It is pretty easy actually, but i was too lazy to make my own PCB...

Pong : great planning, i hope your wiring will be as neat as your drawing ! keep up the good work

[Cliff Schecht]

Ignore these guys blabbing on about keeping it simple, I've got a pedalboard of 14 (sometimes up to 18!) effects and it's the one thing I know will work when I bring it over someones house or something. Worst comes to worst I have backup plans but I've never had this thing let me down, at least not yet... I finally like the order and placement of all of my effects, now I just need to finalize a few more PCB's and fix up a few effects (mainly my clean boost and TS808 in one). 1.5A regulated power supply inside the box as well as any other special power supplies and a power strip. I want to get it into some sort of flight case type deal soon but I don't really care right now.

[blanik]

Ignore these guys blabbing on about keeping it simple, I've got a pedalboard of 14 (sometimes up to 18!) effects and it's the one thing I know will work when I bring it over someones house or something. Worst comes to worst I have backup plans but I've never had this thing let me down, at least not yet... I finally like the order and placement of all of my effects, now I just need to finalize a few more PCB's and fix up a few effects (mainly my clean boost and TS808 in one). 1.5A regulated power supply inside the box as well as any other special power supplies and a power strip. I want to get it into some sort of flight case type deal soon but I don't really care right now.

metal master, jews driver, anal... (can't make out the other word)!!!
you're into some creative renaming...!    lolll

[enigmur]

I believe it's Anal Probe 

[Cliff Schecht]

I believe it's Anal Probe 

Yup . Like I said in another thread my roommate went crazy with the label maker and a few of the things actually stuck. I still like the Jewah (pronounced jew-wah) myself .

[Auke Haarsma]

I think they key is to have as much fx and flexibility as one can, without making to project too complex.

I've been on a short holiday the last couple of days, without fx, internet, phone. Just my Guild acoustic and friends great time! Getting back I really have to read this thread carefully again, just to get my idea clear in my head again

Yesterday I bought 150 pins and 150 "thingies-where-the-pins-fit-in". These pins will be pcb-mounted and the other thingies will be put at the end of the wires. This makes my wiring neat (I hope!) and allows for disconnecting and changing fx orders, since the wires are solidly connected, but not soldered.

I have some problems figuring out how I'll do the Channel A, Channel B, Chanel A+B or Off per effect switch. 4 position switches aren't available everywhere.

[Auke Haarsma]

update: after 'experimenting' with 3P4T rotary switches, I figured I need 4P3T rotary's to do my channel switching... only downside: I can't put a fx on both channels. It's either A, B or Bypassed. Ah well, the next little bit will probably make up for that.

I've been putting down the input-splitter, which will turn the mono-guitar input into two channels, and the output mixer, which will then be able to blend the two paths together. These schematics are based on the ROG Splitter/Blender. Well, I split the splitter/blender into two sections: Input splitter is pretty much as ROG has it:


(pin 8 has +9v ofcourse)

The output mixer is a little different though:



The ROG splitter/blender is designed to blend the two channels back to mono. I've there for added this:
-a switch which selects between stereo or mono output
-a switch which selects between 'onboard' pot for blend control or external Expression pedal for blend control. I've opted for a footswitches here, since this allows for some nice options of blending. A 'preset' with the potmeter, and complete control over the blend (thus being able to 'select' a channel -100% A is in fact like muting B, etc.). Does remind me of my digitech GNX4, with the 'warp' feature for amp-models ... however... I'm on the analog road now

Do the schematics and ideas look ok to you? I do really appreciate any comment or criticism!

[Auke Haarsma]

"Where the heck have you been?" you may ask...
"I guess he dropped his too-big-too-ambitious-project...." some1 else may say...

Well NO! Since my new job I've been on the road a lot (including spending three weeks in Ohio, usa...). The little sparetime I had I did use to finish a pedal for some1 else and for a two day recording session with my band.

But the project is still going well. The majority of PCB's have been made, pretty much all parts have been delivered, ideas still coming in my head on how to put all things together. Some pics:


Parts...parts...parts


Some of the pcb's, drilled and ready to be soldered.


and some previous projects...half canabalized...


I'm still not sure how to wire all fx together. I know I'll be using a 4p3T rotary swith to select channel a or channel b. But I'm not sure how I can use an external (mono) fx-loop with two channels.

[Auke Haarsma]

progress report.... images say more than words, so the image first:



Above you see most pcb's populated (expcept offboard wiring). The next step includes:
-powersupply (I had one based on MAX1044's, but those are too weak. Now I'm using a laptop powerspupply with extra filtering)
-SHO, TS808 (parts are already on the pic...pcb not yet )
-Channelselection-pcb (Chan A, Chan B, off)
-FX-activation switch-pcb (Mil2 bypass)
-Splitter and Mixer part.

When those things are finished I can start testing and debugging (the above fx have been tested on the breadboard, but not yet on the pcb).

For the Channel selection I will use 4p3T rotary switches. This leaves me with one position ('off') which isn't too usefull (I can swith each fx on/off with a footswitch). It's just that I don't have a good idea what to do with that extra rotary position. I considered mixing chan A+B, but that's too complicated. I thought of using it as a selection to send fx to the fx-loop, but that's also too complicated. Any idea's are welcome... for now I just leave that position empty, so the effect is either on channel A or on channel B.

[Auke Haarsma]

I have a question about shielding.

I plan on shielding the wooden enclosure (as per Basic Audio's website). Now, if I put the pcb's next to eachother, would they interfer with eachother? Would I need to shield the seperate fx from eachother? Or can I just put them all next to eachother in the shielded wooden enclosure without any probs?

[Auke Haarsma]

update:

last night I finished designing the PCBs in eagle. The powersupply, the splitter, the blender, the SHO. All have been put down in Eagle. I hope to etch them this weekend. With some luck I can start testing the fx also.

[tranceracer]

Etches look great!  Keep us posted on the progress!

-tR

[Thepilot]

those etches look really cool- what clad pcb do you use?

i'm excited to see how this beast turns out.