BYOC OD-2 refurb

While waiting for paint to dry I decided to refurbish the enclosure for my BYOC OD-2 (it's a modded TS circuit with a clean boost in the same case).

Here's why:
Attachment 34481

Step 1: unboxing. I had to cut the three wires from the power jack, but that's a simple fix
Attachment 34482

Step 2: heat gun, wire brush and a lot of elbow grease later:
Attachment 34483

Step 3: SCA filler primer left over from my TL-1TH kit:
Attachment 34484

That's as far as I got today. The plan is to respray with duplicolor red with a couple of white stripes, ala the classic Dodge Viper scheme. And the handwritten labels will be replaced with waterslide decals (ordered some sheets from Dr Decal and Mr Hyde today for the TL-1TH headstock).

Also, it currently has a JRC4558D but I might experiment with some other op amps to see what it sounds like. I have a Burr Brown OPA2134 and a couple of others.

Just thought of another mod to make. This pedal has a switch for toggling clipping between 1N4148 diodes, 3mm red LEDs, or no clipping. I might desolder the LEDs and add sockets so I can experiment with different LED colours. The higher forward voltage of other colours (like blue) might give me a bit more headroom to play with (since I tend to use lower gain settings).

Or it might just make no real difference at all ...

The op-amp should make almost no difference whatsoever. There are a couple that can affect the tone very slightly, but most will just drop in and do exactly the same thing. It's basically providing a clean boost to the signal which the gets clipped by diodes, so as long as the op amp is within its linear performance boundaries, then they should all perform in a very similar manner.

Brian Wampler tests out a whole load of op-amps in this video on a TS circuit, then changes the diodes.

http://youtu.be/PH2uj9bWfM4

I have watched that video a few times, most recently last week. I pretty much agree, and don't expect much difference but I still want to try and see what my own ears tell me. It's that video that gave me the idea to socket the clipping LEDs, since clipping diodes made a much more audible difference in it.

I will test a bunch of 20 4558Ds that I bought very cheap on eBay because I suspect they were too good to be true but haven't tried them in a circuit yet. I should test them in a known good circuit before I start building my next tagboard pedal (Barber Compact Direct Drive because I don't have all the parts for a Guv'nor yet). Hopefully they all sound exactly the same.

But mostly I just want my kit pedal to look a bit closer to my original vision which I abandoned out of laziness when the first paint attempt went awry :)

Got a second coat of filler-primer on today, and also started painting my home-brew 3 button footswitch (based on the Digitech FS3X circuit). No other progress due to spending most of the day hunting for Easter eggs and cleaning out the shed.

Pretty cool man, that is one giant PCB

Yeah, it is big. It's two mostly separate circuits, and has 4 16mm pots and 2 toggle switches mounted to the PCB on the other side. It's a snug fit into the 125B.

Got the red sprayed today. It's a Ford Hot Chili red that I got for $2 on clearance. Which gives me an idea for naming this reincarnation of the OD-2.
Attachment 34546

It's a stripey kind of day
Attachment 34600

I am making up some waterslide decals in a vintage feel racing font for both pedals, for the race car vibe I am attempting.

Cool! Looking good.

Thanks. The green one is for the barber.

Sent from my moto g(7) using Tapatalk

Decals (again).
Attachment 34606

Clear coat tomorrow, then a lengthy wait, some polishing and I can finally reassemble the pedal.

Rebuild finished:
Attachment 34641
Not 100% happy with the visible decal edges, but I only seem to notice them in photos. In normal lighting from a pedalboard distance they can't be seen.

Had some stuffing around last night trying to desolder the 3mm clipping LEDs (right-most position on the clip switch) and getting clean contacts. But I got it done and fitted sockets instead. Socket is currently empty but I can now experiment with different diode combinations (LED, schottky etc) to explore different clipping effects.

I was also happy that the pedal still works :)

Rough composite to show start and finish points:
Attachment 34642

Well that's a whole lot better!

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In normal lighting from a pedalboard distance they can't be seen.

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I use the "2 metre rule".
If you can't pick it from 2 metres... it's all good!

The 2 metre rule is an improvement over my old "blind man on a galloping horse in the dead of night" rule!
So there's hope for me yet! :o

With pedals, if they sound good, that's what matters most.

Quote:

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Originally Posted by McCreed

Well that's a whole lot better!

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Thanks! I am happy with how it turned out, but things still leap out at me. Like I wish I used a larger font on the footswitch labels. But it is nice to have finished one of my current pedal projects. Still have another 2 in progress, and two more in planning.

And not only does this pedal sound good (to my ears at least), I modded it to have socketed clipping diodes. I am looking forward to that experiment as well.

Nice job. I;ve never had much luck with painting enclosures but that looks great.

Quote:

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Originally Posted by Andy40

Nice job. I;ve never had much luck with painting enclosures but that looks great.

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Thanks Andy. One of the pedals I am planning is a stripboard build of a Red Llama, based on your recommendation. I am going to call it the Cranky Camel. I was going to go with Grumpy Gnu, but for some reason settled on Camel instead. I don't quite get the tone zone of the Red Llama yet though. Is it a fuzz? Overdrive? Distortion? A little bit of all three? But I like the fact that it's not another op amp based variation of a tube screamer.

Quote:

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Like I wish I used a larger font on the footswitch labels.

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It only gets worse as you older mate, believe me!

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Originally Posted by McCreed

It only gets worse as you older mate, believe me!

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I already wear multifocals, and need an illuminated desktop magnifier to do any electronics work, so I totally get it!

Mostly I think the larger font would have looked better. I already know all the controls by location.

I just spent a pleasant couple of hours experimenting with different clipping diodes at different gain levels. The results were more pronounced at max gain, which is to be expected - stronger signal = more clipping. My listening test mostly matches the measured diode forward voltages, with some exceptions which I don't understand (unless I didn't socket those diodes correctly).

I am too lazy to retype my notes here, so forgive the image:
Attachment 34663
According to the measured forward voltages, the yellow and green LEDs should have sounded much the same as red, but I couldn't get them to clip at all. I could neither hear clipping or see the LEDs light up.

I also tested asymmetrical clipping with a red LED and a 1N4001. I liked it the most. It had some of the openness of the red LEDs, but also some of the compressed fuzziness of the 4001s.

Interesting notes jug. What was your preference?

Quote:

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Originally Posted by Andy40

Interesting notes jug. What was your preference?

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At the drive levels I normally use, none of the LEDs clip much in this pedal, leading to that switch position sounding the same as the diode lift position (a common observation I have seen of this circuit). I had to push really hard to get colours other than red to clip noticeably at all (drive knob maxed, guitar vol maxed, bridge PU, hard attack on power chords). So in this circuit, red LEDs are the only useful option to me.

I really liked the sound of the 1N4001s, and my favourite was asymmetrical with 1 red LED and 1 1N4001. That's what I left in for now.

Note the pedal has a 3 way switch that selects between 1N4148 clipping, no clipping (diode lift) and the LED sockets.

I also have more experiments to do, since the pedal has a trimpot to dial in the max gain setting of the circuit. I have a lot of upward adjustment on this that I could try to drive the clipping diodes harder. I don't want to lose the sweet low-gain sound though.

Note, I have vintage style low output pickups. Mileage may vary with high output pickups, or by putting a boost in front of the pedal.

Those are my preferred pups too.