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Trouble is I need to know exactly what the bank switches are doing.

Actually, if you have to hold BOTH switches, then I really think that the stereo TRS might be the way to go, but then you need DPDT momentaries ... I think the Alpha ones are clickless (if the Alpha ones are what are in the Wampler pedals).

Both switches would have to have a common connection (sleeve and lug 1 on the switches). Then you just have the other connections attach to either the ring or the sleeve and lug 2 of the banking switches.

Remember that stereo TRS jacks exist, too, if you need to switch two connections.

If you have a legal question, you need to hire a lawyer. You shouldn't seek legal advice on a forum dedicated to doing it yourself because most of the people around here do it for themselves, not commercially, and therefore are unlikely to have advice about running a business or understanding business law in ... where was it you said you were from? On the off chance that someone here is a lawyer that deals in those sorts of things, chances are they aren't going to give you legal advice for your business for free on the internet.

Second, you're asking a general question about something that requires specifics. In general, circuits can't be copyrighted. Art of any sort can be, so layouts are copyrighted. Circuits can be pattented. Parts of circuits can be pattented. Trade dress is protected by law. No one could even venture an educated guess about how to answer your question without knowing exactly what you're working on.

I hope I don't sound like a jerk, but the above advice applies to everything where business and the law interact.

If you can't afford a lawyer to ask about the legalities of something you plan to do for a business, then do something you know is legal. Getting sued is not fun and a heck of a lot more expensive than a one-hour talk with a lawyer.

Finally, your second post indicates that you are making "circuit board changes." One way to stay safe is: Don't use someone else's work. Don't take someone's layout and make changes to it unless it's approved for commercial use. Don't use someone else's circuit without significant changes because that's just being a jerk (the world does NOT need another guy in his basement building tube screamers. Do something original). Don't use someone else's name, graphics, etc.

Also, welcome to the forum.

That looks so much more productive than my weekend ...

Mossy Sloth (I'm going with "it's thematic because sloths hang upside down") mainly. The Clipper Ship used the weird biasing (base to +9v instead of the collector or Vb) intentionally and the transistors go in the correct way. Then when I was working on the Mossy Sloth, it included part of the Clipper Ship, and at some point I decided to see how big I could make the collector resistors while using the same biasing network. I ended up flipping the transistors and completely forgot to make a note of it. I thought my Eagle library had something wrong with it.

I just did a bunch of testing, though, and it doesn't sound radically different to flip them around and rebias, but it does have a touch more gain (actual gain, not distortion ... the distortion levels aren't too different). I'll just make an alternate bill of materials ... it's really only four resistors that need to change to have them oriented right side up. I might box up another and do an A/B.

So I just realized that the slightly weird biasing I use on transistors in several circuits means that the transitors have to be in backwards ... and I've been putting them in backwards in a bunch of stuff! Oh dear.

Should the value of C6 affect the sound at all when switched to normal trem mode?

No, it shouldn't. It's not connected to anything in normal trem mode or the center mode.

It's possible you didn't notice some treble loss before you switched the cap.

Take a look at how the tremolo is accomplished: It's a big resistor in series with (essentially) the volume pot. It's like turning a volume control up and down. What happens when you normally do that? You get a little perceived treble loss. It's not a ton, but it's might be enough to notice when listening closely. (There's also a tiny bit of treble loss at R5 due to some "hidden" capacitance in FETs.)

When the depth is low, the resistance at the output is always less; as the depth increases, it will be more resistance on the "down" swing, so it might sound a touch less trebly. This happens in other optical tremolos like the Tremulus Lune, too. Actually, it happens with EVERY type of amplitude modulation to some extent, because treble is attenuated "faster" than bass frequencies. (This is why a lot of guitarists put treble bypasses on their guitar pots.)

But let's say that's not the part that's bothering you, or you also notice some treble loss (that bothers you) when the depth is at 0. Remember you can always ditch or reduce C2 to increase the treble. It'll also enhance the harmonic mode. But dirt will sound better with it in. One of those tradoff things ... :/

How come the mosfets need to be connected to a bias voltage or faux ground instead of actually ground?

They don't. It's six of one half dozen of the other as far as the sound is concerned for diode clipping, and I'm not aware of an electronic reason either. "Ground" is just a convention used for the description of a common connection. It could have been done in the original OCD for something as simple as making the layout or schematic easier

Diodes in the feedback loop like in the tubescreamer or Zen Drive are the different ones. The Zen Drive has them directly connected from the output (pin 1) to the inverting input (pin 2) -- that's a feedback loop and the diodes affect the gain of the op amp. The DOD and the OCD both just connect them from the output pin (pin 1) to something that acts like ground (Vb) and has no effect on the gain of the op amp.

Read The Technology of Tube Screamers on Geofex for an explanation of the feedback loop diodes.

in the OCD, they're referenced to the bias voltage, which acts as common (ground) for the op amp. It's common to use Vb for a faux ground. This is still hard clipping, just like in the DOD250, with Vb substituted for ground. The Zen Drive uses soft clipping like in a Tube Screamer. Diodes act a little strange in a feedback loop of an op amp, where they never fully conduct. It's complicated and I don't completely understand the mechanism. It's okay to just know that the two clipping methods sound a little different.

[BTW, the OCD is kind of a bad example of implementing MOSFET clippers. MOSFETs conduct in both directions, one way being the generic body diode (acts like a silicon diode) and one being something special created by going gate+drain-->source. You could omit the 1N34A and the 2N7000 it's attached to and have just leave the remaining MOSFET by itself and have the same clipping structure. The Zen Drive has them both done correctly, where the extra diodes ensure that the MOSFETs only . Even more interestingly, had the MOSFETs both been implemented correctly in the OCD, the distortion would sound very similar to the Zen Drive because MOSFETs do not go into hard clipping until a fairly high voltage threshold is crossed (above 3 volts) but they start clipping around 1.2V.]

I didn't think of looking up the sch on the amp...good idea jimilee. what would i use these in place of? any ideas?

Measure them. Compare with a few other diodes you have around.

They look cool.

Can't help with the second half of the request, but try a tube screamer. It restores the mids scooped out by the muff, and can bring the treble back up and cut some mud from the bottom. If you run it after the muff, you'll get the muffy sustain but more of the TS's EQ. If you do it the other way around, you'll get more of the muff in the final sound but it'll have a little more clarity. A lot of people also run a treble booster in front of a muff for a similar effect.

However, you could also just use an EQ on either side. There were several albums and tours where an EQ (or just as often a Treble and Bass Booster*) was part of the chain according to Gilmourish.

*This is a treble booster with an input cap blend; you could easily build it on Brian's Rangemaster PCB.

It's The Avatar's afterlife!

Last question: switch down is harmonic mode, correct? Is it normal to lose low frequencies at higher depth settings in this mode? Will modifying C6 help preserve them at all?

On your build, yes, down is harmonic mode (if you're not sure, it's the mode where the gate of Q3 is fully grounded).

The pedal in general boosts the upper midrange and treble frequencies to counteract some cancellations created by the harmonic mode and some general treble loss at R5 in full-range mode. If you used a 1uF (older value) for C7, then definitely swap it out for the 4.7uF in the current BOM. Morgan over on BYOC preferred a 22uF, but I actually had some issues getting that to work (this is going to sound weird, but the pedal had less output when I tried that and I had to crank the volume, even though that makes no sense to me ... it could have been some internal resistance in the electro I used, so maybe a tantalum is the better call for larger values).

The other thing that can happen is that if Q3 is a REALLY high output JFET, it could simply overwhelm the signal. But since yours is biased a little cold, I don't think that's what's going on here, so I'd consider a swap at C7 first.

However, I will suggest playing with it in a mix before desoldering if you can; what sounds like too much sparkle or too much bass loss now might sound a little better with context. I know that can sound like a cop-out or adspeak, but I actually remove C2 in mine to get it a little brighter and create a stronger harmonic effect, and that's going through a bright amp with a single coil guitar.

Finally... for a guy who doesn't actually sell anything, you've got the best customer service in the biz, Jon 

Aww, thanks. I'm just trying to give back to the community. I've learned so much from this. Plus your pedals (specifically the Pixar series) were one of the things that inspired me to start building and do the cute handpainted stuff.

One more thing: the squealing only happens with the guitar volume rolled up. If I turn it down, it doesn't squeal.

Does it not squeal regardless of how high the volume is set if you roll off your volume a hair?

That is REALLY weird. Until you said that, I was going to assume it was LFO bleed and suggest a larger limiting resistor to IC1, but that's sounding almost like positive feedback ... [EDIT: HOLY CRAP I WAS RIGHT!]

Try audio probing at the output to Q1. Is the squeal present there?

I'll try to think of some more things to help, but I need to know the exact point in the circuit that the squeal is happening. I'd rather you didn't have to put a floating resistor in there to the input wire, but that possibility exists.

On the LFO side, you can try a chip with some more gain if you socketted it. Like a 4558 (the original chip for this LFO) or maybe even something rail to rail like a LM358 if you have one (in fact, that might have enough gain to clip the LFO wave). Also, is your waveform control working properly? The square wave setting is the one that should do a real "on-off" sound. And the phasing will be most evident on a more sine wave setting. Just trying to cover all the bases to make sure nothing else is wrong in the LFO. Also, R15 and R18 are the final arbiters of how much effect the LFO output has on the LEDs (they are the power rail references), so maaaaybe fiddling with them (especially R18) just a hair will improve things, but we're getting into desoldering land.

at max rate, it sits at a steady 4.0 and doesn't swing at all. In fact, all of the pins seem to be behaving this way.

I'd chalk this up to your multimeter not reading it fast enough. It's always best to read LFOs with the rate at minimum. But we've established that it's working, we just want it to work a little harder now.

If you get through all this stuff and are still dissatisfied with the total depth, try temporarily jumpering the rate LED (just do it with an alligator clip). If that "fixes" it, I can tell you how to kind of hack the board to move the indicator LED. I'd really rather you didn't have to do that, though, obviously.

In my etools legacy program, I can't find all black. weird.

Classic jimi!