Auto-Wah RingMod and Fuzz/MOS face channel switcher-Help Please

[Dirty Horse]

Hey there everyone.

I'm currently doing a project at university designing (to a certain extent) and making effects pedals.

The 2 pedals i'm currently making are a Fuzz Face/MOS Face pedal in which the user is able to switch between the 2 circuits (like a channel switcher) and i was going to make an auto-wah based on the http://www.diystompboxes.com/pedals/HE_Auto-wah.PDF model but to mix it up i fancied putting in a ring mod on the end with a wet/dry mix and mod frequency controls as well as those already present on the HE autowah.

I have a couple of questions regarding the make up of both units, but it's probably best to explain what i have already come up with before asking so bare with me:

The fuzz/mos is essentially 2 separate circuits, each with it's own power supply. the switching process comprises of a DPDT switch and a 3PDT switch wired as follows
DPDT:
a1  0  0  a2      where [a1] is connected to the jack input and [a2] is connected to the circuit output selector on the 3PDT
  1  0  0  2      [1] is connected to the circuit input selector on the 3PDT and [2] to the jack output
b1  0  0  b2     [b1] is connected to ground and [b2]to the jack input

the 3PDT is set up as:
       a2
a1 0  0  0 a3
  1 0  0  0 3
b1 0  0  0 b3
       b2 
where [3PDT a1] is connected to circuit 1 in, [3PDT 1] is connected to [DPDT 1]. [3PDT a3] is connected to circuit1 output and [3PDT 3] is connected to [DPDT a2]
[3PDT b1] is on the second circuit input and [3PDT b3] is on circuit 2's output.

i'm reserving [3PDT a2, b2 and 2] for channel indicator LEDs.

Sorry if the explanation is a bit dodgy.
My questions are: With the proposed switching, will i actually need 2 power supplies or will 1 do for both fuzz circuits?
Is this switching method good, bad or ugly?
and if bad or ugly, how can i make it better.

Regarding the auto-ring-wah, i'm probably going to chain the ringmod after the autowah output. i've not thought about this one as much and was wondering whether it's likely to cause a massive problem just to plonk it on the end. i do want to avoid having 2 foot switches on this pedal and 2 power supplies. any comments will be helpful.

Thanks for your time, sorry if it was a brain sore.

-Will

[Dirty Horse]

i know there's someone to help me

probably pretty easy questions too.

[Cliff Schecht]

Schematic or it never happened!

But seriously, I can't (or my brain can't) make out what you are talking about. Give us a diagram, a schematic or something because it's obvious nobody wants to figure out your text explanation . I don't get the point of what you're trying to do..

[Ben N]

First off, slow down. Try making one thing at a time. Are you new at this? If so, welcome.

Second: What Cliff said.

Third: What do you mean by "power supply"? Do you mean batteries? Do you mean jacks for wall warts? Do you mean filtering/polarity protection? Do you mean a voltage divider to create a reference voltage?

Fourth: There are many different variations of the Fuzz Face. Which you are making will have something to do with the answer, especially if you are planning one built around PNP transistors, like the original germanium FF. That would definitely necessitate separate power supplies, and separate grounding schemes, as well.

Lastly: I honestly did not follow your question about the auto-wah/ring mod thingie, but the general rule of thumb around here is to ask about a single project per thread. Post questions about separate projects and circuits separately.

When your query is clear and specific you are much more likely to get a response (or many of them) to your satisfaction. People here are actually quite eager to help.

(BTW, I'm not trying to be obtuse by not giving you a straight answer. You haven't given enough information, so I am trying to help you put it out there. Plus, I don't honestly know that much about it. )

[Dirty Horse]

thank you both for the responses 

First off, slow down. Try making one thing at a time. Are you new at this? If so, welcome.

I've made projects before, nothing amazingly complex, but i am new to the board so thank you for the welcome.

What do you mean by "power supply"? Do you mean batteries? Do you mean jacks for wall warts? Do you mean filtering/polarity protection? Do you mean a voltage divider to create a reference voltage?

i meant batteries/jacks for the wall. As it turns out, i asked a friend and they helped me out in that area. and the switching method is fine as well.

I am making an NPN fuzz face and an NPN/MOSFET fuzz face. they'll be mounted on the same board and configured so the user can switch easily between them while playing. rhythm/lead style.

this is sorted now, it's the ring-wah i'm needing ideas on now.

what would be the easiest way to do this?

thanks again

-Will
edit: and i wasn't taking you as being obtuse. i utterly realise the need to ask the right question and cut out the gumph.

[Ben N]

OK, again, still somewhat unclear: do you want to run the utowah and ringmod together? Do you want to be able to switch between them? Do you have specific circuits in mind? I don't really know anything about combining an autowah with a ringmod, but my gut tells me that it might be better to have the ringmod (which generates tones by taking the sum and difference of the input and a carrier tone) first, followed by the filter. Just take the envelope signal off the input to the whole kit and caboodle, before the ringmod, where the dynmics are intact. Usually the best course is to experiment. Breadboard them, and try it. One thing you may want to check out is using the envelope detector from the autowah to control the ringmod. IIRC, Craig Anderton suggests that in IPFM (my copy of which has disappeared, sadly, so I can't confirm this).

[Dirty Horse]

i basically wanted to have the auto-wah and a way to blend the ring mod signal with it. i was thinking of putting the ring mod after the auto wah and using a wet/dry blend to add the effect to the auto wah signal, but i think putting it first may be better.

either way both circuits will be put on breadboard first as this will give the flexibility to play around with effect order.

i was looking at the HE autowah on this site (link is in my first post on this topic) and the musicfromouterspace ring mod http://www.musicfromouterspace.com/analogsynth/RingModulator/RingModulator.html

the only problems being i have no idea what i need to use for the carrier and i don't necessarily need both modes (at least not on a foot switch).

and thanks for helping me refine my questons. i am really sorry about my long-windedness. the problem is i know what i mean but don't necessarily know conventional terms etc...

[Ben N]

That RM schematic, like a lot of the ones available on the web, is mainly intended for analog synthesizer use, so there is always  presumed to be a VCO (voltage cointrolled oscillator) around to provide the carrier signal. Look here for a RM intended for guitar, including its own freq-adjustable oscillator, the circuitry around IC4. I suppose you could probably borrow that for your AD633 based ring mod. You would probably also have to preamp the guitar signal to provide a strong enough signal for the AD633 input, but the input stage of the HE autowah might do just fine for this, just tap in between pin 1 of IC1 and R4. You could use a simple opamp mixer, like the one at GGG, to combine your autowah and RM signals. You will probably have to do some tweaking to get everything to work together, which is why it is long past time for me to get out of the way and let someone else offer you some GOOD advice. That, or get started on your breadboard.

[Dirty Horse]

thanks for your advice. i'll have another poke around with it for a bit and try and get a simulation running tomorrow. it's late here now.

Thanks again ben enn