Big Muff Pi: Blender Mod + Momentary switch ?

[Glace_Noire]

I'm planning to mod my Big Muff Pi to use it in a more noisy way and to "destroy" my ambient loops at the end of the signal chain.

I've two mods in mind:

-A blender knob to mix dry/wet signal:
I've found this kit which has a buffer and the potentiometer
This kit has to be soldered as an effect looper inside the BMP, with some kind of send/return circuit.
http://pedalparts.co.uk/docs/Blender.pdf
This seems really easy to do, I'm just a little worried by the possible phase issue

Do you guys have already done this kind of blender mod on a BMP or any other fuzz pedal?

-A "momentary switch" that allows to momentarily "destroy" the sound by passing from clean to fuzz (Or blended sound thanks to the 1st mod)
I've in mind the left stompswitch of the Smallsound/Bigsound Fuck Overdrive

I have some questions about the type of momentary stompswitch I should use: 3PDT? 2PDT? 1PST?
I am not sure how to wire it too: should I just solder the momentary switch in parallel with the normal switch, in order to create an "or" logical function?

I've build some fuzz/od/boost kits but I'm still a beginner in electronic theory, so thanks for your help guys

[crochambeau]

I think all Big Muffs are polarity coherent, so I doubt you'd run into the phase issue that projects warns against. I'd suggest installing the kit electrically before cutting metal to be sure.

The momentary switch you speak of, this performs the function of the existing bypass switch, right? Use that as your guide.. I'd guess since you probably don't need LED support you can get away with a 2PDT on a true bypass or a 1PST (if in doubt, grab for both poles) if you're just talking to a FET.

[Glace_Noire]

Thanks for your help buddy!
I ordered the blender kit and some parts yesterday and so I expect the parts to arrive in the next few days.
Here it's a schematic of my mods. I will post some photos to document my project in this thread

[Glace_Noire]

I received today all the parts I needed from both pedalparts.co.uk for the blender kit and musikding.com for the knobs & switches.
I've already populated the blender PCB. (Daughterboard for the Big Muff PCB)

[Glace_Noire]

I finished the blender daughterboard wiring yesterday and the momentary switch today. I'll post the updated schematics
The electronic mods are done and tested, I've to re drill the faceplate and will paint it with grey hammerite.

[KaosCill8r]

That is coming up nice. I have built one of those blenders. I have it in a Mid-Fi demo tape fuzz clone at the moment. But I like that fuzz full on without the clean blend. So I'm thinking of hooking up the clean blend circuit to a Hogs Foot clone. Does anyone know if I'll have phasing issues with that circuit?

Sorry for hijacking your thread

[crochambeau]

Does anyone know if I'll have phasing issues with that circuit?

Sorry for hijacking your thread

The Hog's Foot is a single transistor with output on the collector, right? Yeah, polarity swap there. I was going to recommend just stringing two of them together, but it sounds like you like the sound of one full on.

Is the linked blender circuit the only show in town? You could bang out a simple circuit on proto or strip that will assign an inverted output to the effect and a non-inverted output to mix bringing everything back in phase (more or less), I've done it with a BPJ but not tried it with a FET, so my line of thinking may not be as transparent as theirs. Also, a single transistor offers less than unity gain when providing signal at both emitter & collector, so the full on Hog's Foot may not sound the same.



Ignore my drawn switch, just the points that tie to the switch are of interest. Referring to the previously linked Blender diagram on pedalparts, stick the SEND on the inverting output (sever it from the emitter), everything else down stream should be fine (you don't need a series run of DC blocking caps, select one cap large enough to support your low end). For the transistors I generally use (either BC547 or 2N3904) I find bias sits okay at R1 = ~500K & R2 = ~100K, if you're slapping a FET in there the listed 1M might be better.

OR you could build the pedal parts as stock and add this between send & effect as drawn, which will allow you the option of hollowing out your sound with the polarity switch.

[KaosCill8r]

No it's the Mid-Fi demo Tape Fuzz clone that I like with the full input signal. So the blender circuit was kind of just dead weight. I figured I could have that space in the enclosure to add some more functionality to the Demo Tape Fuzz.
I found that the Hogs Foot was just a little too muffled in stock firm so I though blending some clean signal with it would give a nice doomy bottom end tone. But giving the option of getting thick and muffled tone as I blend more signal into the Hogs Foot circuit. Would it work if I put a clean boost circuit after the Hogs foot? A bass booster on steroids.

[crochambeau]

Would it work if I put a clean boost circuit after the Hogs foot? A bass booster on steroids.

Yup, that'll bring it back around.

Sorry for continuing the derail! (hahaha)

Looking good! I've always wondered what my car would look like if I painted it in hammerite, I don't think I have the guts to try.

[KaosCill8r]

Thanks for the info dude. And I think Hammeriite looks good on everything. I painted an electric guitar and a bass with gunmetal Hammeriite and they both looked awesome when finished. A car would look great I think and way more durable than normal car paint. You could touch up any paint chips with a tooth pick and it would be virtually un noticeable. You have me thinking of painting my drum kit in Hammeriite now.
Sorry for continuing the continuing of the thread derail

[Glace_Noire]

Would it work if I put a clean boost circuit after the Hogs foot? A bass booster on steroids.

Yup, that'll bring it back around.

Sorry for continuing the derail! (hahaha)

Looking good! I've always wondered what my car would look like if I painted it in hammerite, I don't think I have the guts to try.

No prob with the thread derail!

Painting your car in hammerite would make it instantly 10x more badass, looking like a monolith. You surely earn some respect points in trafic jams haha
This paint is close to indestructible and is super easy to use even with a simple brush

[Glace_Noire]

Here it is!

[lordgalvar]

What kind of hammerite did you use? The multi-part can or spray paint? Or did you make your own? Just wondering because the paint looks nice!

I keep reading those debates of professional additive hammerite like things (I think it is siliconized) vs. hammerite spraycans vs. rustoleum vs. rustoleum hammerite equivelent. Kinda hard to get a straight answer about the paint because I think our VOC laws in the USA. Additol is something I found that gives the old hammerite finish...I don't know what you guys can get in France that we can't here.

Thanks man and great work!

[Glace_Noire]

Thanks for the kind words lordgalvar!
It's actually some standard hammerite can with what they called "dualtech technology" additive (they depict it like a "waxy additive)
I think that we have the same VOC laws here in France that you have in the USA so I think the hammerite formula is not different at all
Here it's photos of the actual can, it's in French but this is maybe quite similar to the US packaging



To get this finish I started with sanding, I laid one layer of white primer, then two hammerite layers (24h between each layers)

[lordgalvar]

Thanks for the info, bud. That stuff is kinda hard to get over here (have to special order it from one distributor). Thanks again.