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BOSS OC-2 synth mod with sound clips

#22
Kwesi said:
You think so? Sounds pretty phat to me. I'm tempted to grab an OC-2 now but I don't have any space on my board, lol.
Click to expand...


On laptop/iphone speakers I didn't hear much difference but on my sony mdr-xb500 "extra bass" headphones I heard a significant difference. It could just be the hardware I’m using exacerbating the difference but if audio fatness was measurable in celebrities I would estimate the oc-2 synth mod to be rosie odonnell vs and standard oc-2 + fuzz likened to kathy kinney (mimi from drew carey show).

Irregardless (yes this is a word) I still like the sound and I will be modding one sometime in the future. Figured it was an observation that maybe should be discussed.
 
#24
I know I know. I was just looking at this the other day. I still stand by my claim because I like saying it, typing it, looking at the word- also it appears in enough reference books for it to count in my unofficial book.
 
#25
I'll try to get some clips of the two of them pushing some filters so you can hear the resulting difference. The two different outputs definitely react differently to different effects downstream. The "synth mod" sounds way better through the Zoom, in my opinion. Turns the Zoom from a mediocre gated synth fuzz to an excellent one, it never sounds that solid pushed by the normal OC-2 signal.

You can hear the EHX Muff'n fatten up the low end of the "synth mod" signal. But the "synth mod" doesn't push filters as well, I think too much of the signal is in the upper range VS the heavily focused low push of the normal OC-2. At least that's my theory. But I certainly am just guessing. I'll let the clips do the talking.
 
#26
Gastric thanks for getting this started. I bought some switches and will be trying this mod later today. Had also been thinking of using a pot instead of a switch as Kevteop suggested, possible 250k. May give it a go before soldering everything up. Will keep you posted on any results
 
#27
Dazonbass said:
Gastric thanks for getting this started. I bought some switches and will be trying this mod later today. Had also been thinking of using a pot instead of a switch as Kevteop suggested, possible 250k. May give it a go before soldering everything up. Will keep you posted on any results
Click to expand...

Yes, I've learned the hard way to test everything with the little alligator clips before committing to the soldering. :)

If it were easier to get the weirdo BOSS footswitches out of the chassis I'd simple pull the entire thing out of the chassis which would've made working on it much easier. But my local electronics guy usually only has 1-2 of the BOSS footswitches around, if any at all.
 
#28
Gut shots of my Japanese BOSS OC-2.

boss_oc2_japanese_pcb_01.jpg


boss_oc2_japanese_pcb_02.jpg


Red dot is where I ran WIRE #1 from, soldered to top of cut/severed right lug of OCT1 pot. Again, this is for Japanese PCB specifically.

boss_oc2_japanese_pcb_02_wire1.jpg


boss_oc2_japanese_pcb_03.jpg
 
#33
Thanks, Dazonbass, you're right... I just didn't fool with the knobs enough. I now have OCT 2 full on, Direct Level at 3 o'clock, OCT 1 at 7 o'clock. It's following pitch much better at this setting, and almost sounds just like that Muse guy when I play "Uprising" ;)

Be sure to post what happens when you alter it, and how to do so.
 
#34
You can hear in my clips I'm typically soloing OCT1 only and it's clearly tracking my pitch, and it stops output when my playing stops. Then again I didn't do the full mod exactly as the YouTube video directs. I just ran a single wire drawn in as the thick black line on my drawing for OCT1.... or so I think that's what I did. Haha.

If you leave the filter section enabled for OCT1 then it's going to simply sound like a normal OC-2 I think. Just removing the envelope section shouldn't alter the output much I wouldn't think. I never thought the stock OC-2 has much of a wide range of output volume in response to playing envelope anyway.
 
#35
Added another clip comparing the two OC-2 into the KORG G5 and BEF PRO. I did my best to unity the OC-2 > Fuzz output to the perceived output of the "synth mod" OC-2 just to even the field for comparison. But keep in mind if your fuzz output is louder than the "synth mod" output that drastically changes how the filters would respond to each since most are envelope (volume) based.

Again, scroll to the bottom: Various bass and guitar effects sound clips - cgraham.com

I think the difference is fairly small, but noticeable in many cases. I think leveraging a change to the stock filter section to raise the cutoff and just hack of the very, very high tones would likely bring these two tones much closer together. Again, totally sacrifice OCT2, have a switch that routes the 4013 into the signal path the 4027 usually takes so you can toggle OCT1 between the factory path and whatever mods you do to what would normally be the OCT2 path. You could even leave the OCT2 knob and maybe split the signal down BOTH paths for blending them.

Oh the possibilities!
 
#37
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.
 
#38
gastric said:
Then again I didn't do the full mod exactly as the YouTube video directs. I just ran a single wire drawn in as the thick black line on my drawing for OCT1.... or so I think that's what I did. Haha.
Click to expand...

Okay, so I'm not gifted in this dept... do I understand you correctly:

You ran the lead from the resistor to the OCT 1 potentiometer circuit, and did NOT run the second lead from resistor to OCT 2. I'm assuming you still cut the tracer and wired it only as a single pole, double throw?
 
#39
I literally took a wire from the resistor R48 to the OCT1 pot right leg. Red wire pictured. I opted to cut the leg as opposed to scrape PCB traces. Not sure if you can do that on a Taiwan pedal.

The black wire is the raw OCT2 waveform run directly to the OCT2 pot right leg, also cut.

I have not used ANY switches as I don't currently have any. So just hard wired which negates the ability to use the factory filtered signal for me at this time. Unless I move the wire again.

I always test/experiment with alligator clips to make sure it works correctly before committing to soldering. Could really use some smaller clips for working on tight projects like this.

boss_oc2_japanese_pcb_04.jpg



If someone can come up with a small gate schematic we can sacrifice the 9V battery compartment to install the PCB, then run wires down into the chassis exactly like the 9V clip is done. No idea where I'll be installing switches on the Japanese pedal, probably way down by the input/output jacks if I want them externally accessible. If they'll even fit there.
 
#40
gastric said:
I literally took a wire from the resistor R48 to the OCT1 pot right leg.
Click to expand...

AHA! As I'm drawing this out, I'm seeing that the YT video has wires 1 and 2 wired backwards from what you're describing! Outside of that, what you've done is the same but without the addition of the switch.

I'm going to alter this and see what happens...
 

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