Introducing the μORAC MK-I paralooper pedal

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WestOfBen
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Introducing the μORAC MK-I paralooper pedal

Post by WestOfBen » 22 Feb 2016, 10:13

Hi all, here's a story and a project.

For some time I had been thinking about ways to tame my Big Muff Pi (3rd gen Russian green) and TurboRAT pedals. In some contexts letting these things loose is fine, but there are other contexts in which these pedals have a tendency to be overpowering. Since I have been playing in a church band the last few years, this has been more important. It just ain't right to kick on the Big Muff and blast everyone away, as much as that sounds awesome!

Some time ago I experimented with the LS-2 option. This worked reasonably well. The downside was more complication on my board, with external patch leads and so on. At the time I couldn't see the benefit. What turned me away from this option also was the fact that mixing clean and dirty was tricky. Either the resulting mix was too clean and dirt diluted, or the right amount of dirt made having a clean signal inaudible or pointless.

So I ditched the idea and used a volume pedal to pull the gain back, especially for the Big Muff. This has worked fairly well with only one caveat, clarity and solid signal are lacking and finding that sweet spot not always easy. At this point you look around for paraloopers and Big Bottoms and either you can't afford it or can't find what you're after. I gave my old failed MXR M-80 to a mate to see if he could use the case to build what I sought from scratch. This didn't eventuate so I let it go.

In the meantime on my board was a Behringer PB100 Preamp Booster. For a cheap pedal this thing has really surprised. I've used it to match/boost instrument levels between my active Ripper and passive Rickenbacker. The best use of this pedal for me has been dropping the treble, slightly boosting the bass and level and using it as a "thunder" EQ. The curves on this thing are just about right for those moments you need a big low end with not a lot of mids and no treble, when someone is singing softly, or speaking and you're providing music. Church-goers will know what I am saying here. Or this effect is great just to add a dynamic, you're still playing and filling the low end but so much space is free for other instruments.

One day I looked at the PB100, looked at the LS-2 sitting on the shelf and wondered if the twain should meet... if the PB100 sat in the clean loop while Muff and RAT sat in the dirty loop, would that achieve the result I was after?

I have just seen what Rude_Mechanical is doing with his LS-2 "BB-2" mod. I thought of something similar and having now seen inside an LS-2 this is a really elegant solution. I'd already started my project so no turning back.

This is the start of the relationship. That switch and mess of wiring in the middle, that's a very special feature!

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Rickenbacker 4003JG, Epiphone Ripper, Marina P/J fretless, Tanglewood ABG, 1960s Rose Music Tempo SS semi-hollow bass, an acoustic guitar, GK 700RB-II, SWR Henry 8x8, some pedals
My band is called Ascribe!

WestOfBen
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Re: Introducing the μORAC MK-I paralooper pedal

Post by WestOfBen » 22 Feb 2016, 10:29

Did it work? Yes it did. This experiment started at somewhere around 11:30pm when I couldn't get back to sleep. The hasty wiring effort took about half an hour while I wrestled with the idea. The next hour and a half were spent with headphones on making wonderful wonderful big fuzzy and dirty tones.

The result is a tight low end underneath the dirty loop. I can turn up the tone on the Big Muff so it isn't too bottom heavy, and I can run the TurboRAT at a nice level of grind while still having low frequencies stay true. As many of you would know, all RAT variants lose bottom end. You can play with them all you like and if you try to get a decent bottom end you end up with not such a good tone. The TurboRAT is probably the worst, but does it sound so good...

Now, what's that switch in the middle? After the first 10 minutes of testing I wondered what would happen if I put the PB100 before the dirt pedals. End result was some sort of thick old school analog synthesizer type mess with the Big Muff and Turbo RAT both doing some very interesting things. Not usable for everything but there will be a something I can use that sound for. The switch is essentially a series/parallel function. Either the EQ runs alongside the dirt, or it feeds the dirt.

Where to from here? How do I package two pedals in one box? What kind of box do I use?

I looked at the mess of wires and thought it would be funny for people to be able to see inside. Transparent box it was going to be. I measured my board and by rearranging I found a spot that would suit. I looked at transparent boxes online and found nothing of the dimensions I needed. Got talking to a friend and he had a spare/damaged electrical box of some kind. It needed repairing but it was going to fit the bill.

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Rickenbacker 4003JG, Epiphone Ripper, Marina P/J fretless, Tanglewood ABG, 1960s Rose Music Tempo SS semi-hollow bass, an acoustic guitar, GK 700RB-II, SWR Henry 8x8, some pedals
My band is called Ascribe!

WestOfBen
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Re: Introducing the μORAC MK-I paralooper pedal

Post by WestOfBen » 22 Feb 2016, 10:37

What's that small circuit board in between the two pedals? We'll get to that later. A keen eye will reveal the answer to electronics buffs.

Picked up a sheet of 4mm acrylic/Perspex for about $30 and set about re-learning how to work with this stuff. I remembered plastics in high-school and enjoyed working with it. I have basic tools and a willingness to learn and make mistakes.

First things first, to make a bottom plate. Recessed bolt heads underneath required countersinking and two risers inside. At this point I didn't have the right adhesive for Perspex, but these seem to have held ok.

What you're about to see is not the highest quality workmanship. Honestly I have done the best I can while balancing skill and patience (who doesn't want to finish a project yesterday?!?).

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Rickenbacker 4003JG, Epiphone Ripper, Marina P/J fretless, Tanglewood ABG, 1960s Rose Music Tempo SS semi-hollow bass, an acoustic guitar, GK 700RB-II, SWR Henry 8x8, some pedals
My band is called Ascribe!

WestOfBen
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Re: Introducing the μORAC MK-I paralooper pedal

Post by WestOfBen » 22 Feb 2016, 10:47

The next question always comes - what am I going to call this thing?

It is transparent. It will have vertical supports for the circuit boards. I can maybe colour the vertical supports with Sharpie Neon markers (coloured Perspex is too expensive to buy in sheets just for a couple of pieces) and I would like for it to have some flashy lights.

Memory bank retrieved the name ORAC. You can go research that one. Some of you might already have the answer. But this is a smaller version, so it is "micro". "μ" is the Greek letter for micro. μORAC it is and this is the first version, MK-I.

Plenty of planning on paper went into this before making the first cut. That said, you can only measure as well as you can. The walls of the box are angled with a difference of 0.5-1mm from top to bottom. Nothing is truly square.

Jump forward a week or two and this is the direction we are going in. The clear piece in the middle is the bridge support between the two boards.

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Rickenbacker 4003JG, Epiphone Ripper, Marina P/J fretless, Tanglewood ABG, 1960s Rose Music Tempo SS semi-hollow bass, an acoustic guitar, GK 700RB-II, SWR Henry 8x8, some pedals
My band is called Ascribe!

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Rude_Mechanical
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Re: Introducing the μORAC MK-I paralooper pedal

Post by Rude_Mechanical » 22 Feb 2016, 10:50

Where's the like button when you need it? :)
"Turn everything to 11, dump instruments in front of the amp and manipulate pedals for 5 minutes" - me.

WestOfBen
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Re: Introducing the μORAC MK-I paralooper pedal

Post by WestOfBen » 22 Feb 2016, 10:54

This photo reveals something about that mystery circuit board. Some flashy lights were always the plan, but what if the flashy lights could mean something? Given this pedal is about achieving a good solid sound, if not professional, then I would want to monitor the output level when I kick it in the guts.

Enter a $14 Jaycar Electronics sound level meter! Conveniently nestled in the V of the bridge support.

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The next part of this journey was to drill more holes in the case, check and double-check the support pieces and refine, hacksaw, file, sand and polish using a TV shopping Twist-a-Saw dremel like tool with a small buffing wheel.

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Rickenbacker 4003JG, Epiphone Ripper, Marina P/J fretless, Tanglewood ABG, 1960s Rose Music Tempo SS semi-hollow bass, an acoustic guitar, GK 700RB-II, SWR Henry 8x8, some pedals
My band is called Ascribe!

WestOfBen
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Re: Introducing the μORAC MK-I paralooper pedal

Post by WestOfBen » 22 Feb 2016, 10:59

Thanks Rude_Mech!

More updates to come. I'll leave a gap because that was just after Christmas and around that time I was searching for adhesive. Eventually found some Scigrip stuff that works a treat. Took three weeks to find it though.
Rickenbacker 4003JG, Epiphone Ripper, Marina P/J fretless, Tanglewood ABG, 1960s Rose Music Tempo SS semi-hollow bass, an acoustic guitar, GK 700RB-II, SWR Henry 8x8, some pedals
My band is called Ascribe!

basshack
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Re: Introducing the μORAC MK-I paralooper pedal

Post by basshack » 22 Feb 2016, 11:20

Need more than just a "like" button. That's awesome even to a non-pedal guy.
... dial in some "J" to angry it up!

Got gear but little talent!

WestOfBen
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Re: Introducing the μORAC MK-I paralooper pedal

Post by WestOfBen » 22 Feb 2016, 11:31

One more update. Vertical supports in approximate positions while deciding what colours to use and where.

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And all supports "glued" in place. This adhesive is interesting stuff. Single tube, dries clear if you're sticking Perspex to itself. It turns slightly milky with the case, probably due to different plastic composition. THis is not a glue as such, but a bonding agent so it eats the plastic while filling. A couple of messy bits where I made some mistakes. Overall some rough edges are fine.

By the way, both pedals use momentary or JFET switches. A couple of heavy duty momentary switches seem to do just fine.

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Rickenbacker 4003JG, Epiphone Ripper, Marina P/J fretless, Tanglewood ABG, 1960s Rose Music Tempo SS semi-hollow bass, an acoustic guitar, GK 700RB-II, SWR Henry 8x8, some pedals
My band is called Ascribe!

WestOfBen
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Re: Introducing the μORAC MK-I paralooper pedal

Post by WestOfBen » 23 Feb 2016, 00:42

With both boards roughly in position I marked the additional holes to be drilled. Learning from first tests on Perspex, it is absolutely important to start with a reasonably small pilot hole, say 3-4mm and work your way up. I had picked up a bench vice, some new files and a great set of drill bits for $9, which in a later magazine were valued at $49... bonus!

Some of the holes were larger than 10mm. Drilling these for the case and the Perspex were tense moments each time, it is very easy to shatter this stuff. Medium speed with my also not very expensive GM cordless drill I have had for well over 5 years now. The tedious part was filing them out round enough. In the first pic below, the three holes for PB100 control knobs were at least 12mm, since the knobs are recessed. The two momentary switches were similar. The rest weren't so bad.

This next step included some mistakes, second and third attempts. Finally I arrived at something close to what I imagined. To start with I wanted individual LED "bars" in some kind of ascending waveform kind of form. I did not succeed in mounting/soldering/bending all the LEDs very evenly. There's probably up to ~1mm difference across the lot. Getting the faces of the bars to the same level was proving near-impossible because I was relying on the bar sitting at the collet/lip of the base of each LED. Therefore each bar was a different depth. See first pic below.

"SCRAP THAT!" were words not unlike what I used after realising I wasted an hour or two on that idea. Seriously, it was going to look terrible. It looked like it was going to work and then it didn't, it got worse. A new "single bar" idea seemed great until I showed I was useless at drilling 10 x 3,4,5mm holes in anything resembling a straight line. I also cut the bar too short so it didn't bridge the gap between the middle bridge support and the bottom of the case. Scrapped and started again, this time with more patience. I'd like a pedestal drill. We have one at work I could have used, but I didn't have the patience to go to work or wait until Monday, then I would have to learn that drill anyway.

The next few pictures after that show the single bar idea actually completed. I did want to file a V notch between each segment, but again tests showed I couldn't achieve perfectly parallel lines. Maybe this is where a mitre box would help. Instead I marked out the lines and scored with a scalpel on a metal ruler edge. Some marker colouring, attach to a base and line it up and test. I think that will do for now. The holes also recess deep enough to hide the uneven LED placement.

Pictures show unlit and lit on two angles. You can see some rough unfinished parts. The bottom support for that circuit board is attached to the base plate. The hole in the pink vertical support is for a A/B500K pot which allows the sensitivity of the light bar to be adjusted.

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Rickenbacker 4003JG, Epiphone Ripper, Marina P/J fretless, Tanglewood ABG, 1960s Rose Music Tempo SS semi-hollow bass, an acoustic guitar, GK 700RB-II, SWR Henry 8x8, some pedals
My band is called Ascribe!

WestOfBen
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Re: Introducing the μORAC MK-I paralooper pedal

Post by WestOfBen » 23 Feb 2016, 01:21

Those last steps gave a real sense of achievement, but the next few I can almost smell it. Truth is I have been smelling Perspex for weeks now, but this is a different smell... victory is so near!

What we have going on here is one of the final fitments for wiring. Looking at the underside, the top two outputs are for pedal-out and dirty-send. I've nicked the channel (A) return jack for the dirty-send, since the EQ return will be wired direct to the series/parallel switch.

On the matter of that switch. It is a DPDT ON-ON. LS-2 channel (A) send goes direct to the PB100. The PB100 output goes to one side of the switch and also jumps across to (A) return, as described above. The other side of the switch is fed by (B) send. So the switch simply feeds (A) or (B) to the dirty-send (external). But (A) always receives the straight PB100 signal.

Mathematically or alphabetically I like to keep letters in their order but maybe that doesn't work. These are the labels I was thinking of using for the switch. Any thoughts?

X/Q - Dirt is parallel or "over" the EQ (Q/X doesn't quite look right, or does it?)
Q+X - EQ is added to the dirt, or EQ is before dirt

Where possible I have kept I/O jacks mounted to their boards. I could have gone the whole hog and compacted this thing further, but at this stage it is beyond my capabilities... and patience. I think it has been a bonus to be able to use old guitar lead jacks internally. It didn't take too long to connect the dots.

In theory it should only take a few hours. The LS-2 has a power outlet also. I have suitable jacks to make a daisy chain also to power up the LED light bar. Also the light bar input source will be the pedal output, meaning it will still light up if the LS-2 is off. One important thing needs to happen - grounding for the LS-2. This thing is very sensitive and all of the jacks need their grounds connected, which makes sense because the original Boss enclosure is metal. If I don't do this it will squeal.

On the underside I plan to cut some thin 1-2mm clear plastic sheet to protect the boards. Under that I was thinking of using some guitar pickup type medium-density foam, cut to thickness, to support the underside. I can't think of any other way. The LS-2 sits approx. 3-4mm off the bottom, while the PB100 is maybe 18mm off the deck.

That last picture is a rough idea of how it looks from the top down. Not a very good picture really. Many components are all over the shop. It does show how bare one side is though. Another circuit of some sort might need to fill that void one day. For now you can see what's inside a Boss LS-2, sort of...

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Rickenbacker 4003JG, Epiphone Ripper, Marina P/J fretless, Tanglewood ABG, 1960s Rose Music Tempo SS semi-hollow bass, an acoustic guitar, GK 700RB-II, SWR Henry 8x8, some pedals
My band is called Ascribe!

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slowlearner
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Re: Introducing the μORAC MK-I paralooper pedal

Post by slowlearner » 23 Feb 2016, 07:04

We need a VID! :)
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Macbass
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Re: Introducing the μORAC MK-I paralooper pedal

Post by Macbass » 24 Feb 2016, 07:06

And the main question from anyone who actually remembers "Blake's 7": does it actually SOUND like Orac?

(I know it's not meant to but one can only hope.)
1982 Moonstone Eclipse, Aguilar Tonehammer Pre, Peavey power amp, Markbass CL106, Various pedals...

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jamiesdad
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Re: Introducing the μORAC MK-I paralooper pedal

Post by jamiesdad » 24 Feb 2016, 07:18

awesome ... needs a video
Tokai / Fender / Ibanez / Fairfield / Cave / MXR / Boss / GK / Schroeder

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WestOfBen
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Re: Introducing the μORAC MK-I paralooper pedal

Post by WestOfBen » 24 Feb 2016, 10:04

Thanks for your thoughts guys!

Video will be done as soon as it's finished, which shouldn't be far away. I only need to find a couple of hours to finish the wiring and a few other things. My next session at church is Sunday week. I hope to have it finished by then.

As far as sounding like ORAC, that depends on what other pedals cause this thing to do. Once this is finished, my board will be as below.

Digitech Bass Whammy Reissue -> Korg Pitchblack tuner -> EB 25K vol -> MXR Bass Octave Deluxe -> Crossfire Tremolo -> MXR Bass Chorus Deluxe -> μORAC -> Dunlop 105Q wah -> Boss RV-3 delay/reverb -> MXR M-80 Bass DI+

μORAC:
(EQ/clean) Behringer PB100 preamp/booster
(FX/dirty) ProCo TurboRAT -> EH/Sovtek Big Muff Pi (3rd gen green Russian)

What symbols might I use/draw for series and parallel?
Rickenbacker 4003JG, Epiphone Ripper, Marina P/J fretless, Tanglewood ABG, 1960s Rose Music Tempo SS semi-hollow bass, an acoustic guitar, GK 700RB-II, SWR Henry 8x8, some pedals
My band is called Ascribe!

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