BOSS OC-2 synth mod with sound clips

[avvie]

Bummer. Switched it and got the exact same effect... it just changed knobs.

But I did discover one thing: the excessive sounding was coming from having the bass turned up on my tone controls.... I turned the preamp down and rolled back the bottom and it stopped squealing.

[gastric]

Cleaned up POST #1 to compress all my notes from the various posts into a [theoretically] more concise and more organized read.

The "synth mod" OC-2 sounds totally awesome into an Oxfuzz Germanium. Better than any of the other fuzzes I've tried it through. Super massive sounding, yet clear and authoritative.

[gastric]

Anyone else successfully implement this mod yet?

Without being able to increase the volume output from the "synth mod" on OCT1 I'm still on the fence as to how usable it really is. It's easy enough to roll back your instrument volume to clean up the gating of the signal. But I don't have a desire to stick a LS-2 or booster after it to bring the signal up to match that of the normal OCT1 tone.

I do think the synth mod is totally usable for OCT2 though. Sounds great blended into OCT1 a little for a different flavor. In comparison the stock OCT2 is pretty much worthless on bass.

[jbednarski]

Originally Posted by gastric

And..... I whipped up a clip demonstrating all of the raw tones you can pull directly from the board. Again, check my page, scroll to the bottom. At this point I probably should create a dedicated BOSS OC-2 page.

Of particular interest is how awesome OCT2 sounds without the envelope or filter section applied. Note I'm really making a barely educated guess as to the points on the board where to pull the signal. The envelope point doesn't sound like I thought it would. I thought it'd be more like the raw octave tone but with some VCA applied, instead it sounds vastly different. But you do get more volume out of OCT1 from the envelope point on the board.

I'll send you mine if you'll wire it up with a switch for all these different tones. Just tell me how much you'd charge. I'm all dyslexic with an iron.

[sillyfabe]

I did the mod and I'm not sure what I did but when the synth mod is activated the Oct-1 become -2 and -2 becomes -1. I actually like it better this way as the -2 sounds amazing! Also changed the LED for a green one. Run the synth -1 into a wooly mammoth and it's the best gated fuzz sound ever!

[Explorer]

I"m mildly curious how it sounds if you just bypass the filter section, but retain the envelope follower for closing the signal's volume. I'm assuming you all want a hard gate, though....

[gastric]

Originally Posted by Explorer

I"m mildly curious how it sounds if you just bypass the filter section, but retain the envelope follower for closing the signal's volume. I'm assuming you all want a hard gate, though....

Got that all covered on my sound clips page. I pulled the signal after the oscilator, envelope section, then after the filter (factory sound) so you can hear each.

You can easily get a better gate simply by rolling your instrument volume down. It doesn't drop the "synth mod" volume, but lets the oscilator gate better. In fact, better than the factory OC-2 sound in my opinion.

Do any electronics people have the ability to:

* Provide a small gate circuit we can tie into the existing circuit signal and power path?
* Provide a small amplifier circuit we can do the same with to boost the "synth mod" output?

[Explorer]

Thanks for that, Gastric! It's interesting that the envelope follower appears to push that output to almost sound like a ring mod on the oscillator. That clip makes me think I want to look into this piece of gear, as I almost never just run a raw waveform with no envelope, instead running things like my Mothership through a Groove Regulator in order to get some articulation on a line, instead of it just being constant buzz.

[Skrogh]

Well it is not that strange, since that is what is happening. What you call the envelope follower, is just a phase-inverter (ring modulation with a square wave) controlled by the "oscillator". The phase of the signal is invertet every second cycle, creating a note one octave below, and a 5th above + some harsh overtones.
But dang, I have to do this mod at some time; sounds wicked. Though I think I will add a pot for filter control.

[gastric]

Originally Posted by Skrogh

...I have to do this mod at some time; sounds wicked. Though I think I will add a pot for filter control.

You do that. Then provide instructions for the rest of us along with some sound clips.

[Skrogh]

I just have to find a lin 1M dual gang pot; Then the filter range will be 100Hz to way over 20kHz.
Just replace the two 330k resistors in the first filter, with the pot.

[used squid]

i just modded my taiwanese oc-2 works great. dpdt switch to return to factory settings whole shebang. mine also swapped control between the oct 1 and oct 2 controls i figured i just swapped them putting everything back in the box.

if we could gate out the noise created by nonmusical notes, mutes, finger noise etc it would be super bad but im sure that;ll come in time.

[gastric]

Originally Posted by used squid

if we could gate out the noise created by nonmusical notes, mutes, finger noise etc it would be super bad but im sure that;ll come in time.

Roll your instrument volume back 1/2 way or so. You should find it doesn't reduce the "synth mod" output volume, but removes most of the pre/post note glitching.

If you guys are getting swapped OCT1/2 then I'm guessing the instructions are wrong, just move the wires from the board to the other side of the switch. Or run the wiring from the switch to your OCT1/2 POTs to the other POT.

[gastric]

For those of you that have done this mod try this out:

OCT1=Max
OCT2=10:30 O'clock
DIRECT=1 O'clock

Send the OC-2 into some medium gain overdrive, I'm using my EHX English Muff'n tube overdrive. Start with your instrument volume way down. You should hear just the OCT1+2 signal with it well gated and tight. Slowly roll your instrument volume up. You should note the OCT1+2 output remains constant and only the direct signal increases it's respective volume. Oviously at max volume, at least on my gear, the OCT1+2 tones get a little noisy/glitchy on the decay if you don't play super clean and tight.

Nothing super exciting. But gives you an easy way to change the overall tone live without diddling your effect box.

[gastric]

OK, so I now have three OC-2 in my possession and am ready to go full bore mad scientist on these things. Here's my current thoughts:

* Input volume cut on/off - acts like rolling your instrument volume 1/2 way to help cause the raw oscillator sound to gate well, would likely be worthless when running the factory signal path.
* Envelope (ringmod) circuit on/off - takes that section of the circuit out of the signal path.
* Filter on/off - takes that section of the circuit out of the signal path.
* Variable filter cutoff - adjusts filter cutoff and sound
* Switch between latching footswitch on/off toggle and momentary. Might be fun to bop from bypass to the octave momentarily for extra noise making fun.

And have those controls available individually for each OCT1 and OCT2, with the exception of the latching/momentary option.

Anyone have some clear, specific ideas on how to provide all of that with the least amount of physical toggles/knobs added to the pedal? It'll be a challenge or impossible to jam all of that into the factory enclosure. Might require rehousing.

[Skrogh]

If you can live with some trade-offs, I can think of a way to do this with 3 switches and 2 pots.
There is a type of switches called on-z-on switches; they are good because they have three positions.

The filters will be controlled as following:
One pot for each of the filters - to control cutoff of the sallen-key filter.
One switch to switch off the two RC filter in front of the two sallen-keys; for both OCT1 and OCT2.
switching the RC filter off and rolling the knobs all the way up removes the filter.

The other two switches will control the waveform and behavior of OCT1 and OCT2.
Switch one (OCT1): Ring ON/Ring OFF/Ring OFF+Volume cut
Switch two (OCT2): Ring ON/Ring OFF/Ring OFF+momentary

Does that make any sense?

[gastric]

I was thinking three switches, pot for cutoff.

* Input cut on/off
* env/ringmod on/off
* filter on/off
* Cutoff pot

Though trying to jam 6 switches and 2 pots into the factory enclosure is likely impossible. And doesn't account for momentary bypass, if that's even possible.

[Skrogh]

Jamming 6 switches and two pots in there is impossible, that's why I thought of the three-position switches.
I don't see a reason to turn the volume down, when the envelope follower is active, since that would just lower the output volume too.

The input volume can't be adjusted separately for the two octaves, so no reason to have a switch for both octaves there. (Pitch is only detected for one octave, then divided for the second)

I think the momentary switch is possible, as I have seen broken BOSS pedals, that were broken in the way that they were momentary. Will have to look into that tomorrow.

By the way, try sticking a booster in front of the OC-2 to overdrive it, then shut the filter off, solo OCT1 - sounds very smooth and synthy.

I think I'll be ordering some switches and pots soon-ish and install as much as I can fit in that small box.

(Dang I need an envelope filter to go with this!)

[gastric]

Originally Posted by Skrogh

I don't see a reason to turn the volume down, when the envelope follower is active, since that would just lower the output volume too.

Note I'm talking about input volume to the overall circuit. Likely only useful when not using the env/ringmod, though I haven't personally tried routing through just the octave+filter wtihout that part of the circuit yet. But soloing just the octave without the env/ringmod nor filter benefits from a lower input volume to help gate the output.

Originally Posted by Skrogh

The input volume can't be adjusted separately for the two octaves, so no reason to have a switch for both octaves there. (Pitch is only detected for one octave, then divided for the second)

I haven't actually studied the circuit to see how that would work. But that's slightly disappointing as I pictured using OCT2 with just the octave soloed so it's more usable, but with OCT1 factory. Would probably sound excellent.

Originally Posted by Skrogh

By the way, try sticking a booster in front of the OC-2 to overdrive it, then shut the filter off, solo OCT1 - sounds very smooth and synthy.

I've overdriven the factory sound, but haven't tried with the octave sound soloed. I'm imagining it just being a runaway, non-stop tone between notes.

Originally Posted by Skrogh

I think I'll be ordering some switches and pots soon-ish and install as much as I can fit in that small box.

I'm going to let you run with the mods and pave the way at this point. You apparently have much more electronics experience than I do.

I'd personally be willing to try rehousing in a slightly larger enclosure if it meant maximum mods. Or, reduce all of the mods to just a control for the cutoff, and a toggle to bypass the ringmod circuit as you could then just jack the cutoff really high which should theoretically be the same as having the filter off anyway. So the cutoff maxed would effectively "bypass" the filter.

I can just remember to roll my instrument volume back when bypassing the ringmod section of the circuit.

[gastric]

For the Japenese boards I've decided it's too much of a PITA to try to jam switches into the chassis. So I'll leave OCT1 factory and just hard wire the "synth mod" signal for OCT2. Blends well, sounds good soloed, or just roll it's volume all the way down for your normal 'ole OCT1 tone that you originally fell in love with. Got one in the FS forum if you want it. I'll have another shortly.