Orca Pedal - Design and Building

[Rob Strand]

've started to pay extra attention to the 2 patch cables that connect the wah to the patch bay. These were made up of good quality cable, and cheap pancake jacks. I believe that these jacks are causing an issue so have changed them to decent quality Neutrik jacks (see picture)

This has made a big difference.

I don't know why it didn't show up in your old configuration.   Nonetheless connector problems are a pain the butt.  When they kind of work it's hard to track down the problem.

[bettsaj]

They didn't show up as they weren't used on the previous configuration.... I changed them the other day when I had to rewire the rack and pedalboard to accommodate the different wiring routing in to the wah pedal. it was purely a space saving exercise and for convenience.

I'm not saying it's the sole reason for my issues, but it's certainly made a difference. Lesson learned........ You get what you pay for. My suspicions were raised when i pulled out one of the patch cables and found the plug part, both the tip and ground part loose and turning around in the body of the plug.

I still might place the Klon Buffer I have on the board.. just to see if that makes any improvement now I've changed the jack plugs.

Onwards and upwards... I have started to receive the parts for my ORCA pedal, so will etch the board etc as soon as i get a moment. I won't be able to get stuck into this pedal build for 2 weeks though as I'm off on holiday to Turkey next Tuesday so my attention is on preparing for that. However I have decided that the ORCA pedal will have a master volume control so you can adjust the effect output. This is needed as when you use it on the wah pedal that noise is soooooo loud. So on the pedal build it's a no brainer, a simple pot just before the output jack. I'm also going to incorporate an output buffer into the circuit on a separate board. Instead on having an external pot to alter the wah sweep i'll just have a trimmer inside the enclosure. The wah needs to be in the heel down position so a trimmer will only be required to "tune" the effect, set and forget.

The pedal is going to be based on a Clyde McCoy wah circuit, so I'm using a reproduction PC board for the build. Also, as the Pete Cornish ORCA has the ability to have 2 guitars plugged into it with an input selector i'm going to have the same thing on mine... This is going to be fun.

[Rob Strand]

I still might place the Klon Buffer I have on the board.. just to see if that makes any improvement now I've changed the jack plugs.

Onwards and upwards... I have started to receive the parts for my ORCA pedal, so will etch the board etc as soon as i get a moment. I won't be able to get stuck into this pedal build for 2 weeks though as I'm off on holiday to Turkey next Tuesday so my attention is on preparing for that. However I have decided that the ORCA pedal will have a master volume control so you can adjust the effect output. This is needed as when you use it on the wah pedal that noise is soooooo loud.

Good idea about adding the volume.  You could actually build a buffer at output of the ORCA pedal.   Buffer would be present in bypass mode or in effect mode.   If you start using fuzz-faces then that might cause a problem.   The separate buffer box is more flexible by far.

BTW,  some guitar cables have more capacitance than others.   It might be worth checking what yours are is usually spec'd as pf/foot or pf/m.     Small changes in the spec's are worth changing the cables for but if you cables are on the upper end of capacitance then it might be worth changing the cable.  It will only make a different for the long runs.

[bettsaj]

Rob, master volume before or after the buffer circuit

I'm literally going to wire it as follows:

A/B dual inputs with a stomp selector -> Clyde McCoy Wah Circuit (I'll wire it in reverse though circuit input to output, circuit output to input) -> master volume pot -> Klon buffer circuit ->  Output jack

The PCB's are prefabricated, with exception to the Wah PCB which I'll etch myself from an online resource. The PCB layout is below




Buffer circuit is this one https://shop.pedalparts.co.uk/Klon_Buffer/p847124_6346591.aspx



A/B is this small board https://shop.pedalparts.co.uk/A-B_Switcher_Box/p847124_13121620.aspx this is the page for the full build, but I'll just buy the PCB

[Rob Strand]

Rob, master volume before or after the buffer circuit

It makes more sense before the buffer.  That way the output impedance is always low.

(Also, you don't want the volume to affect bypass.)

[bettsaj]

I've also placed a buffer on the board after the wah, with the decent jacks now and a buffer I have sparkling highs and a nice strong guitar signal. Those pancake jacks were obviously choking the signal.

[bettsaj]

Good idea about adding the volume.  You could actually build a buffer at output of the ORCA pedal.   Buffer would be present in bypass mode or in effect mode.   If you start using fuzz-faces then that might cause a problem.   The separate buffer box is more flexible by far.

BTW,  some guitar cables have more capacitance than others.   It might be worth checking what yours are is usually spec'd as pf/foot or pf/m.     Small changes in the spec's are worth changing the cables for but if you cables are on the upper end of capacitance then it might be worth changing the cable.  It will only make a different for the long runs.

The cable I'm using is as follows:


Brand - Van Damme
Cable Conductor - Bare silver plated UPOFC wire; Stranding - 3 x 0.20mm + Bare UPOFC wire; Stranding - 4 x 0.20mm
Cable Resistance - Conductor Ohm/Km 47
Cable Capacitance - Core to shield pF/m <90
Cable Screening   - Screen 1; 0.40mm conductive thermoplastic. Screen 2 ; 80 x 0.10mm close lapped OFC wire
Overall Diameter - 6mm
Cable Jacket - Flexible PVC/Neoprene composite

[Kevin Mitchell]

Aww I'm late to the party. A few years back I wanted to build one of these and used an octavia transformer for a quick n' simple unbuffered wah. It was pretty cool but the sweep was backwards compared to the original.

Why would you want it further down your pedal board line? I understand it would convenient to not have to worry about where it is but still.

Super cool with delay;

-KM

[Rob Strand]

I've also placed a buffer on the board after the wah, with the decent jacks now and a buffer I have sparkling highs and a nice strong guitar signal. Those pancake jacks were obviously choking the signal.

Cool.  Not sure what those pancake jacks were doing.

The cable I'm using is as follows:
Brand - Van Damme
Cable Capacitance - Core to shield pF/m <90

That cable is definitely in the good region for a 20ft run.  Some "good" cables are double that and crap generic cables can be 4 times that.  I have a table that shows a Van Damme "low capacitance" cable at 55pF/m.  There two ways to spin this, the 55pF/m will allow longer run of cable for the same total capacitance as the 90pF/m.    If you run the 55pF/m over 20ft then you will get a little more highs but some people might argue it's a little bright, so that becomes a preference thing. 

Aww I'm late to the party.
Super cool with delay;

Extremely cool sound.    Don't worry, for some reason I didn't know that either and I've listened to Pink Floyd for a *long* time.   I just assumed that sound came from a synth or one of the many gizmos they used in the studio.

[PRR]

>>     Cable Capacitance - Core to shield pF/m <90
> ....crap generic cables can be 4 times that. 

Seems unlikely. Example? 360pFd/m or 120pFd/ft?

It suggests a really fat center and really-really thin insulation. Since center-metal is expensive, insulation is cheap, that's bad design.

[Rob Strand]

Seems unlikely. Example? 360pFd/m or 120pFd/ft?

It suggests a really fat center and really-really thin insulation. Since center-metal is expensive, insulation is cheap, that's bad design

Yes it's a crazy high value.   For those cases I'm only quoting specs.  In isolation you might even suspect that a per meter value was quoted as per foot.  However, I have measured quite high values in the past.  The only reason I even checked is I couldn't believe that a 5m cable took out the highs on my bass.

EDIT:
Looks like other guys have seen some crazy values as well, post #3 by Blake Hawkins
https://steelguitarforum.com/Forum11/HTML/001992.html

[bettsaj]

Why would you want it further down your pedal board line? I understand it would convenient to not have to worry about where it is but still.

The reason is, I wanted it after my drives.

[Kevin Mitchell]

The reason is, I wanted it after my drives.

Kinda thought of the orca effect as a one trick pony but I guess I'm curious to know how that would sound 

-KM

[bettsaj]

I'm thinking of creating a schematic in Eagle, and designing a PCB layout for this...... There isn't a resource at all out there and I think it might appeal to a small amount of Floyd fans, and maybe the odd person who's curious.

I'll integrate the 3 schematics into one schematic (Wah, input selector, buffer and master volume), so people don't have to fudge a box with 3 separate boards like I am.

[bettsaj]

UPDATE:

Just back from my holiday (2 weeks in Turkey... 43°!!!) And have just ordered the inductor for the build. I've gone with a standard 500Mh inductior, but a cheaper one. As I'm not really using it for it's wah tone per se, it'll do for this.

I'm now thinking of adding a switch to turn the Orca effect on and off, so when it's off you can vary the tone of the wah effect manually, or maybe introduce the ability of plugging in an expression pedal to vary the wah.

How complicated would it be to include a socket to have an expression pedal??

[Rob Strand]

How complicated would it be to include a socket to have an expression pedal??

If you want the expression pedal to function like a wah pedal the easiest way to do it would be to use a stereo socket which switches both contacts.  When the plug is out it connects the internal pot.  When the plug is in it connects the external pot.    You only need two switched contacts as the ground doesn't need to be switched.  It's possible you might get noise problems.

This type of thing, but there's many other types which will work,

[bettsaj]

Update:

At long last, the inductor has arrived. it was ordered a via seller in Greece, and appears to be just what I'm after. I could have sourced a more expensive inductor that was more period correct, but as I'm only using it in an Orca pedal build, i didn't see the point.

https://www.ebay.co.uk/itm/500mH-Wah-wax-coil-inductor-Halo-McCoy-handmade-nos-copper-magnet-wire-madein-GR/202708655447?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2057872.m2749.l2649

Now I can start building this thing...... Photos to follow, and likely also some questions

[Kevin Mitchell]

Found this today buried in one of my work desks;


So one could "Orca mod" their old school wah pedals. But I'd rather put it in a box as Cornish did.

-KM