Big Muff Pi (Triangle Version) |
This is an NPN Triangle Big Muff Pi circuit that I started working on because Dragonfly was looking for verification help with his own layout. I was trying to make something that would fit in a 1590B. It may not be possible, with the three pots and all. 
I took the schematic from diystompboxes.com.
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scott said:
I WAS WONDERING ABOUT THE GREEN RINGER OR OTHER CIRCIUTS MY SON WANTS LEARN ELECTRONICS WOULD THE GREEN RINGER BE A GOOD CANDIDATE FOR BUILD?? DOES IT WORK AS IF BUILT AS SITE STATES?EMAIL ME I BE APPRECIATE,GOT TO GET HIM INTO SOMETHING HE LIKES ..POSITIVE TAKE CARE THNXX NICE SITE KEEP UP THE MAYHEM WORK LOOKS DRAINING..MR OCONNOR
Posted 21.08.2007 at 4:25 pm
gaussmarkov said:
i suggest that you make your first build a kit from generalguitargadets.com. the chances for success are highest and that’s important for building interest and confidence. my recommendation is the replica of the electroharmonix LPB2. this is a classic and relatively simple circuit.
good luck! gm
Posted 22.08.2007 at 11:17 am
dfx said:
do you have a pnp version of this fx? i got a couple of ac188 pnp germanium and would like to tinker with them.
thanks
Posted 16.09.2007 at 8:31 pm
gaussmarkov said:
hi dfx,
no, i don’t have a pnp version. but you can convert the npn version by reversing the polarity of the battery. if you had any polarized electrolytic capacitors, you would need to reverse their polarity as well. but there’s nothing in this circuit that requires an electrolytic.
all the best, gm
Posted 17.09.2007 at 5:05 pm
canbaz said:
Really nice work. I searched and studied on it really much and find that your schematic is the best, and most reliable.
I wonder, what are the differences between SYLOD988(The originals), 1N4148, 1N914 diodes. And you dont use a ceramic capacitor for C8. A reason? Is there any diffrence between
ceramic and film caps?
http://www.singlecoil.com/triangle/triangle.html
There is a PCB pattern here which i noticed some differences and the schematic at this site isnt true can you draw me the schematic of this pattern?
And i want a sound sample just to hear it before build, please.
Thanks really much. Well done.
Posted 23.11.2007 at 3:40 pm
canbaz said:
Also its better to use linear pots for tone control.100KB pot for tone, 100KA pots for volume and sustain. Dont miss it.
Posted 23.11.2007 at 3:48 pm
canbaz said:
Come on… I think the pattern isnt correct too. Can you please just look to the picture that shows inside the pedal which it writes “more detail”. And then tell me which schem is reliable. http://www.singlecoil.com/triangle/triangle.html
Posted 23.11.2007 at 3:56 pm
canbaz said:
Ok. After studying on it i undestood that your schematic is perrfect :). But still need answers about caps and diodes, asked above.
Thanks.
Posted 23.11.2007 at 5:40 pm
gaussmarkov said:
Hi canbaz,
I have not been online. I just found all of your messages. I am glad that you figured things out.
The 1N914 and 1N4148 diodes are virtually identical. Have a look at their datasheets and you will see this. The Fairchild datasheet for these two diodes is even the same datasheet.
I do not know how the 1N914/1N4148 compare with the diode that you mention.
Regarding C8, a ceramic capacitor would also be a good choice. I think capacitor selection depends a lot on personal taste and perception. So I do not give strong advice about the type to use.
All the best, gaussmarkov
Posted 23.11.2007 at 6:10 pm
Joe said:
I’m looking for a bigmuff schematic 3003 It’s an old pedal and i’m very new at this thanks
Posted 06.12.2007 at 12:02 am
gaussmarkov said:
Hi Joe,
I do not know about schematic 3003. I think tonepad.com has a file with several versions of the BMP schematic in it. That is a good starting place. And I bet there is someone out there who has a site with detailed comparisons of the various versions. I just don’t happen to know of one off-hand.
And this is a good question for Aron’s forum. You may not have joined that yet, so I recommend you check it out: diystompboxes.com.
Good luck, gm
Posted 06.12.2007 at 7:35 am
Chris said:
Hi there,
I was thinking of using this layout and substituting in the “Swollen Pickle” values as I heard that was essentially what Way Huge did. After comparing schematics between this and the Pickle, I noticed that the Pickle has a battery protection diode and what appears to be a filtering cap on the 9v. Are these items necessary for this build?
What are your thoughts?
Chris
Posted 06.12.2007 at 12:36 pm
gaussmarkov said:
Hey Chris,
My feeling, and I picked this up from MartyMart on the forum at diystompboxes.com, is that every build should have these features. So if they aren’t in the original design then I add them on a separate, small board or directly on the DC power supply jack.
Paul
Posted 06.12.2007 at 2:33 pm
Chris said:
Wow, I had never thought about using the DC jack. Great idea!
Posted 06.12.2007 at 2:42 pm
gaussmarkov: diy fx » Nordic’s Big Muff Pi Triangle Revision said:
[…] sent us a revision of the gaussmarkov.net Big Muff Pi Triangle layout. He added his own artistic touches and created something that differs from most of our layouts in […]
Posted 31.05.2008 at 2:06 pm
Thaxt said:
Hi,
I’m the (very happy) owner of a 1970-71, triangle-era BMP. The trannies are the SPT 87-103 originals, as are the GY819 diodes. All caps are ceramics. (class III?)
I spent a good deal of time recently (re) scoping out all the componentage, & have built a 2N5088- based close approximation of its (yep-remarkable) sound.
While some resistor specs are off a bit, & there are components that make it bassier, (mods commonly found on GGG site, etc & others),I think that it’s notable sound derives mainly (tho not enitrely) from those SPT trannies & GY diodes. No one seems to be able to locate the SPTs, & EH is not talking, so I can;t tell their saturation characteristics…there is a whomping 8+ volts on Q3, (the better to really drive that tonestack, I guess). Q1 reads out around 4.3 V, Q2 about 4 V, & Q4 reads around 6.8 V + @ the output.
The tonestack features a low-cap of .012uf, & the common .004 for a hi-cap.
The characteristic sonic mojo here is a tough educated guess…I’ve A/Bed it w my mods, & I can see why this thing is so prized.
Would I put actual mods oton the original board ?
Lol - I had to hem & haw about just putting in the true bypass switch (silly,but…) & a 9V adapter plug on the soft aluminum side!
Posted 17.06.2008 at 2:36 pm
Thaxt said:
Does anyone know if those GY819 diodes might be Shottkys? Or just some silicon variation? EH was likely picking from lg, EZ ily found, grab bag lots of parts, I’d say. Whoever was making these & the trannies, they’re long gone.
The IN914s come pretty close to replicating the exact characteristic, Triangle BMP sound envelope ,but, there is a great compressive impact (?) that I think does not come entirely from the 500pf (ceramic) feedback loop caps.
Posted 17.06.2008 at 2:44 pm
Thaxt said:
The secret of this pedal is getting that (wide-parameter) tone control into just the right sweet spot for whatever you’re doing.
While chords & double stops are mindblowing w this (original) thing - smoothly ascending double stops can sound almost like flanger regeneration a bit - any good tweaking & modding can get you into that zone effectively.
I can’t wait to get a hold of a 14 pin, 3904 transistor array chip, so I can Pickle-ize the Triangle (interpret unexpected metaphor any way u like)
Posted 17.06.2008 at 2:52 pm
gaussmarkov said:
Thaxt,
Thanks for all the sharing.
8V on Q3’s collector is presumably producing quite a bit of asymmetrical clipping at that stage. Did you bias your 2N5088 approximation the same? What resistor values did you use?
Cheers, gaussmarkov
Posted 17.06.2008 at 8:16 pm
Thaxt said:
Yes - tho, the voltages on my mod are puny compared to BMP originalis.
Q3 has a 33K resistor on its collector, 120K on the base to gnd, & 150 ohms from emitter to gnd.
I did find the (or a) secret to getting IN914 diodes close to the original GY819 ones: just double them in both feedback loops, for a grand total of 8 1N914s - this will give much more impact, sustain, & overtones reminiscent of the 1970 BMP.
If you triple them (3 on ea side of the to feedback loop on Q2 & Q3, you’ll get one heck of a sustaining superbuzz - albeit with noise + buzz when & if you turn the sustain control up.
The large 220 + uf cap from V+ to gnd mod didn’t help w this, but, the 3X IN914 diode-in-ea-direction tweak is an awesome mod for some players (or bands’) purposes, & I suggest people just try it out. Maybe some NR in your recordings can tame that extra buzz (not too bad) out.
The again, some bands would dig that liveness, & hypersensitivity!
Posted 05.07.2008 at 6:04 pm
Thaxt said:
As general guide to tweaks, modders should try misbiasing this pedal all over the place - just small resistive changes can yield amazing results.
I guess the same holds for the deliberate misbiasing of any trannies on just about any classic pedal that uses them. Small increments @ a time, subbing pots into circuits,& truning them a bit @ a time, playing your axe thru the breadboaded circuit, can be really productive.
I sliced a small RS project box in half, mounted a 1/4″ phono jack into a hole drilled each, & mounted these on either side of my breadboad layout,one side going in, one out. Hence, I can just route my axe into the circuit, make changes, & just play to check out what each sounds like as I’m modding.
I’ve ended up using 6-position rotary switches - or extra pots - to make certain misbias-resultant uniquenesses onboard into some mods.
Posted 05.07.2008 at 6:15 pm