My first Big Muff (Where have you been all my life?)

[Hiwatt25]

I just got done building a Big Muff Pi from MarkM's layout (verified) and I am in LOVE with this pedal.  It's noisy because the pots, battery and input/output jacks are just connected via alligator leads but I can't believe I waited this long to get/make one.  I'm a big fan of Spiritualized and Spacemen 3 so I was looking for something kind of over the top.  BTW the one thing I've learned about alligator test leads is that when you think you've bought too many, buy a dozen more.

Anyway, I've never owned a BMP before so I have a couple questions. 

• Should it gate or clip when you throw chords at it?  Mine does.  Not really hard, nothing goes totally away but I hear some and I like it.
• Should it be a little unpredictable? Sometimes it won't respond to the same note the same way.  Not total deviation but sometimes the attack or decay is a little different.
• I think I'm hearing/sensing compression.  Is that a common trait of this effect, because I love this too.

What I'm trying to figure out is, do I have a special BMP or are they all this cool?  It's almost as if you can play the BMP if you're kinda rough with it.   

[Seljer]

I've got a rather extensive clip of myself messing around with mine on http://seljer.dmusic.com/
built with the values from the russian one and BC547Bs for the transistors I believe

[Meanderthal]

 Congrads! Everyone should be exposed to the mighty BMP at least once... Been one o' my favorites since... Well, I think it was my second pedal...

As to your questions- the gating... no. Shouldn't do that. But, they're ALL different(no 2 are quite the same), so if ya like it... maybe that's part of the uniqueness of yours... or maybe one of the gain stages is misbiased...
The 'unpredictable' anamolies- yes. There will be weird unexpected things in there occasionally till ya get used to it...
Compression- hell yeah! That's why the drive knob is labled "sustain".

[nordine]

does it have 1uf caps all the way?
when too much bass feeds clipping stages and transistors, such artifacts appear everywhere

[Hiwatt25]

I think maybe, gating was too harsh a word, I've played with it more and I think what I described as gating is really just the compression kicking in and squashing some of the dynamics.  Gating would be a total lack of signal at all right?  Because it doesn't do that.  Again, this thing is a beaut.  This and my EA trem and I'm in space rock territory big time.

does it have 1uf caps all the way?
when too much bass feeds clipping stages and transistors, such artifacts appear everywhere

As for the caps, I used what was on Markm's layout.   My guess is you're asking about specific caps but I don't know which you are referring to cause I'm still a freshman.   

Thanks guys for the feedback.

[markm]

does it have 1uf caps all the way?
when too much bass feeds clipping stages and transistors, such artifacts appear everywhere

It's the Triangle version with .1uF caps.
See it here>>>http://aronnelson.com/gallery/album76/BigMuff_TRI_LAYOUT_001?full=1
Thanks for the KUDOS Hiwatt.....it sounds to me like it's behaving normally so, I think it'll be okay!
Again, thanks for your support and we'll miss ya here in the great northeast! 

[km-r]

anybody tried different trannies?
what would be the best one for this? bcxxx? 2n5088???
i dont have the cash to try them all.

[Meanderthal]

 2n5088 and 2n5089 are ok, but for extra mojo 2n5133 is good too. MPSA18 works well also. Those are the only ones I tried, the favorite being 2n5133. Really, you could use any high gain bjt tranny and be just fine. The differences in sound will be subtle, and I'd have been happy with any of them.

[oldrocker]

I tried 3904's and 5088's.  I stuck with the 5088's.  They sounded close to what my old BM sounded like although they both sounded good.  Ah yes the good ol Big Muff.  When I first started playing electric guitar I only had an LB1 booster which I used to turn up to much and blew the speaker out in my SS Univox 30 watt amp and had to get it replaced constantly.  This was 1974.  Then I heard a school band play and I asked the guitarist how he got that sound and he said "It's a Big Muff."  Well I just had to have one so I bugged my Mom into getting me one.  I eventually joined that band and the guitarist and I have jammed together ever since.  I played bass in the band after our bass player left the band but I started playing guitar again these days.  Of course we don't use the BM anymore but that could change.  It has a unique fat overdrive fuzz that would sound interesting in some songs.  We are into the classic rock sound and vintage pedals sounds are what sounds best.  We use all DIY stomps like : RAT, Hwy89, and 808 TS and we've been talking about the (Big Muff Pink Floydish).
And by the way the Big Muff on the bass sounds radical.
Check us out.
http://www.myspace.com/thedarrylplummerband

[AL]

I prefer lower gain transistors. It's an easy "mod" to throw in some sockets and start swapping transistors.

The best Muff I've heard is an old Ram's Head version a friend has. One seriously beat to death pedal but it sounds fantastic. I had it apart for some repairs. It had the old 2N5133's in it. The gain on these was hovering around 100. The 5088's have a much higher gain. Everybody's ear is different - and from what I've seen - everybody's Big Muff is different.  Try the sockets if you can.

AL

[col]

I've built a few with BC184C and BC549C transistors. The one I use all the time has BC184Cs in it. It is based on the foxy lady/triangle circuit. I saw a picture of an original in Guitar mag and all the caps were ceramic.
I really like the op-amp version too (blasphemy), especially with a compressor for extra-long sustain.

[oldrocker]

I've wanting to try an opamp version BM for a long time.  I hear a lot of good things from people who have built one.  Looking at the schematic it uses a 741 and a 4558 which looks like an unusal design.  So I may have to breadboard one up this weekend and give it a shot.

[Hiwatt25]

Wow, this thread has taken kind of a cool turn.  I always socket my transistors (a tip I picked up while following the Gus Smalley build tutorial BTW).   I fear that I'll burn them up when soldering them so I guess the added bonus is that it makes it a breeze to try different transistors .

Is it possible to mix different transistors or does the bias scheme count on them all being of the same type?  If it won't ruin anything I'd be willing to try that.  Heck even if I fry a couple trannys it'd still be worth it.  The weirder the better for me.

Thanks for all the great input. 

[AL]

I didn't had any problems swapping different transistors. The BC??? I ended up with were about 150hfe and the ones I removed were around 500hfe. At one time I think I had 3 different transistors in my BMP.

AL

[Meanderthal]

 Yep, you can mix em all up. It'll still work.

I wanna repeat though- the difference is subtle. Playin' around with the tonestack makes much more obvious differences.