Big Muff Pi [Triangle] build report

[petemoore]

:shock:  :evil:
 Built on an 'L' shaped piece of perf, the circuit takes a right after the second transistor...lol, It was a bear getting this one going because I had to dig parts up and build resistor values for the 390k's and some other values. Pretty long build session, about 5 :shock:  hours...
  Took me a minute to look at the other two schematics and realize that Q2 probably wasn't [and wasn't] biasing because of a lack of bias resistor [the 100k to ground].
 Once I got all the problems figured out, all the voltages look good and the knobs work.
 It is smoother than I thought it would be.
 Lots of output, I haven't boxed it up or tried it out but on the little tube amp, if anything it seems like it could use more sizzle.

[MartyMart]

That's interesting, I made one last week and have a similar "feeling" about it - maybe you got some "L -shaped mojo" going on !!!
The use of 0.1 caps throughout is a bonus, as I hate all the low end in a
BM, everything seems to work "correctly" but I too think that it could get
a bit more "Nasty" and its a little bit "tame" now .... ?
Overall, a more useable sound though...... yes ??

Marty.

[petemoore]

It is great sounding as it sits, less Whiskery than my Biscuit [by about 3/4'']...if that relates...
 what really took the time is the battery clip...I should have set the DMM to voltage earlier, I was thumbuzz signal injecting too long, when I finally hooked up the DMM I got NO Voltage .... lol ...I din't look inside the clip, just ripped a new one on there.
 I'm thinkin' it's gonna be pretty cool the way the bass passes without becoming 'gangled' [the .1uf's seriesed with the BTB diodes], the first thing I noticed is the bass note definition, very 'well preserved'.
 I'm a fan of give and take, I spend a bunch of time on the circuit, then let the circuit have some time with me...figureing out 'how' it works and how it 'should/could' be used....sometimes this takes more than an hour of playing with' to find, [as in the case of my 'other' BMP], it took me a while...now I Really like that one...
 The Triangle needs a square [or rectangular] box. Then I can put it through the bigger amp, and dial it up...I'm excited because it does sound interesting, smooth...
 I think I should be having a linear pot for the tone control...I don't know if an audio adjusts to the same tones or not, or whether it's just a 'funny twist' ... fine tune CW side, coarse tune CCW side...

[jimbob]

Great job! I was working on my triangle aslt night but was having problems finding my correct values as well. A few times i had to connect a few resistors or caps in series or parellel to get close. I needed a 560pf  and had none so i used 2 102 greenie in series to get 500pf-which is what is actually called for for the stock version. Now its becoming very "EH" in the respect that im using what i got around but getting as close as possible. I bought a new /broken EH russian black big muff, bagged the board, making/perfing my own Triangle from Tonepad (thanks Tonepad) and using the case, 3pdt switch, and knobs ect... but on the case im going to label it- with something referring to the Triange Big Muff. I think ill personalize it a little- ive owned and sold three of those. Ill keeps this one and i thinking ill put the original in a diff enclosure. I say its a really under rated pedal (black russian version) Ive modded one before and thought it was better off left alone as i missed the original sound- but getting greedy for something better, so i modded it (2n5089's if i recall and germ diodes)

[MartyMart]

 I think I should be having a linear pot for the tone control...I don't know if an audio adjusts to the same tones or not, or whether it's just a 'funny twist' ... fine tune CW side, coarse tune CCW side...

Hmm, "Pot taper" should have its own forum  !!!!

I'm constantly exchanging lin for log and using "resistors" to try and taper things .....  :shock:
It depends so much on the circuit and I find that often when a "log" is
specified, that linear works better for me ..  :roll:

Ah well, keeps you guessing I suppose  

Marty.

[petemoore]

..And Ready To Go !!!
 I put a black diode and a 100uf across V+/V-, filter and Reverse Pole protection.
 I'm liking it because it IS different and has nice tone to it.
 Chords don't really sound louder than single notes, but they sound different, chords seem thick and not sizzly [slightly dull?], but the leads sound very smooth and sustainey !!
 LOW noise  floor on this one...always nice !

[jimbob]

I couldnt really tell what the pots were (kb or ka) AND some were upside down. Otherwise all were 100k

[petemoore]

I'm using:
 50k volume
 100k Tone
 250k gain
 Works fine.

[MartyMart]

I've got :

100k log volume
100k lin tone
100k lin gain

Seems good also

Marty.

[petemoore]

Too cool, through the MkII it's HUGE !!!
 One smoothe sustaining Fuzzer [OD?].
 No Doubt I'm Liking this One !!
 Works great with other pedals, likes my 'normal' settings, has almost no 'irritating byproducts', bass notes are thick, full, well defined...
                   
 [that's 10 smiles].
 Super Great I think is well enough left 'as is'.
 Knobs are working quite well, pretty even range, I must have got a 100k lin for the tone...
 As far as gain and volume pots go, that they don't follow the schematic is of no consequence to me. 50klog. is plenty of volume, and 250k probably stays at near full gain, has a even taper to it.

[jimbob]

I thought about having a switch between diodes 3 and 4 with germanium diodes and 1n1914's. not sure how that wires up though.

[petemoore]

When a Ge diode is placed in parallel with an Si, the Si will never see voltage high enough to meet it's threshold, because the Ge Diode clips at a lower threshold...so
 Wire the Si's solid, attach a Ge diode parallel and oriented as the Si, but only on one end, run the other end of the Ge through the SPST, and connect.

[jimbob]

sounds like a good idear

[petemoore]

Thank You Jimbob, it's reciprocal !!!
 I decided it was a good enough idea, to the point of sticking Ge Diodes right in the  sockets...tricky but easy too, I have a lead flattener'...the jaws of the needle nose pliers does that.
 This upped the grind considerably, I'm gonna try it some more this way
 I'll look up vocab better, but the black lines on the diodes are both at Bases of Q2 and Q3...other ends on collector, I figured this would not be assymetric since the stages are inverters....and a buncha other stuff like that, then had to see what it sounds like.