Build Your Own Clone Message Board

I'm just about to build the muff clone but I'm going to substitute some of the components for Ram's Head specs using this info:

http://www.bmfeffects.com/byoc_large_beaver_mods.htm

What kind of capacitors should I use? The chart above calls for a 0.004uF capacitor but I'm having trouble finding one locally. Is there anything I can use as a substitute.

Also I picked up some resistors today but they look about twice as big as the stock ones. What should I be looking for?

I know these questions sound very ignorant but I'm just starting to get into DIY electronics. Any help is appreciated, thanks!

0.0039 caps will work for the 0.004 and 1/4 watt resistors are what you're looking for.

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Resistance is futile (if < 1ohm).

If you're really trying to nail that Ram's Head tone, I highly recommend grabbing a bunch of 2N5133 transistors from Small Bear and selecting 4 in the higher gain ranges (~300 hFE or above). I believe that was the most prevalent type found in the Ram's Head models.

I'd also recommend adding a couple of components to the BYOC board, labeled #2 (560pf cap across 390K resistor) and #5 (82K resistor to ground) on the pic below. I used an 82K resistor for Triangle V1 specs, but a 100K is appropriate for Ram's Head specs as shown on the schematic at:

http://pisotones.com/BigMuffPi/psst/BMP_versions.htm

Without that resistor, Q2 will not bias correctly (~1.25V as opposed to ~4.5V). I believe it's omission is an error, not limited to the BYOC board, but also omitted from a multitude of schematics that have been copied from an old EH schematic. I haven't seen or read about an original Big Muff that didn't have one there. Since the BYOC board follows the published Triangle V2 schematic faithfully, there's no spot for it or the 560pf cap, and they'll need to be top-mounted.



[EDIT] If you do decide to go with 2N5133s, this may help:

Thanks for the info Skiraly and thanks for that link Rog, it looks useful. One question: I was under the impression that the Ram's head had more gain than the Triangle Knob version, this being one of the sources of that info: http://www.stompboxes.co.uk/gpage1.html1.html The page you linked to seems to contradict that tho'. And to be honest this line from the page you linked would make me lean more towards building the Beaver stock: 'A little less gain than first Triangle. The tone circuit makes it sound with a pronounced mids scoop, so it makes it tricky to use in band context.'

What has your experience been Rog? Which do you reckon has more gain?

Also, any difference between carbon composition and carbon film resistors. I can get the carbon films for cheaper.

The Ram's Head version will indeed have less gain than the triangle. Think early Ernie Isley. In fact, Skreddy's version of this pedal is called "Ernie". I've seen that D*A*M page before, but don't quite understand the statement.

Still, all Big Muffs, whether Triangle, Ram Head, Russian, etc. (except the opamp version) share remarkably similar circuitry. All have two gain stages with clipping diodes in the feedback loops for massive amounts of fuzzy distortion. You can basically tweak the amount of distortion by carefully selecting the transistors and how they're biased. You can tweak the tonal response with some minor cap substitutions.

Assuming identical components otherwise, the ones I've built with 2N5133s have a softer sound to the fuzz. It's easier to recognize them as fuzz circuits. The ones with 5088s and especially the 5089s sound harder edged.

I do like the BYOC boards a lot, but on this particular board I always add the aforementioned resistor, as I believe it does belong there (even on the Triangle V2). Biasing that first clipping stage correctly does make the fuzz/distortion a little more aggressive.

There's no good reason to use carbon comps, unless you want more noise. Metal films will be the quietest and highest tolerance, but carbon films will work fine.

hey guys,

First post here, i wish that i would've signed up sooner....

I've been tweaking the BMP for a couple years now. Here's my findings for the best "agressive" BMP tones:

-Q1-Q3: Jumper the emmiters STRAIGHT to ground (aka the creammy dreamer mod)

-Colector resistors (Q1-Q3): Stock=10K Change to: 22K

-Base resistors (again: Q1-Q3) Stock= 10K Change to: 15K

-Change 390K to 470K

-Add diode clippers (1n914's) to the end of the circuit (after the Q4)

After you do those mods; you'll notice that the volume will increase x2, WAY more fuzz available, even more sustain, and note synsativity (Buzz words: Feel, touch synsative, etc.) will greatly increase.

this is my faveorite mod that i've come up with as far as turning it into a nasty fuzz-machine

Awesome, thanks a lot Rog. I'd prefer a little more gain so I've pretty much decided to make the pedal stock but I'd like to be as faithful to the Tri V2 as possible. Am I correct in saying that the V2 also uses an 82k resistor at position #5 in your picture and that that's the only change from the stock version? Also how exactly did you mount it? I'm not exactly sure what 'top-mount' means.

Thanks to everyone who's replied, there's a lot of interesting info here!

Obviously, I haven't seen every triangle-era pedal, so I can't say definitively that all of them had that particular resistor from the base of Q2 to ground, but everyone I've talked to/corresponded with has seen one there. That, and the fact that Q2 just won't bias right without one there leads me to believe its omission from the original schematic was in error. I add it in all cases, V2 or not. For a V2 clone, I add an 82K, and that's the only change I make.

Click on that picture I posted above and you'll see a resistor in the top right corner of the board that isn't mounted in the usual way - there are no holes on the board for it. Instead, one leg of the 82K resistor is wrapped around the topmost leg of the 2.7K resistor on the right side of the board (which goes to ground), and the other leg (follow the shrink wrap) is tied to the topmost leg of the 8.2K resistor (which goes to the base of Q2). In the pic, you can see little balls of solder there where the 82K's legs are soldered to the existing components. I shrink-wrapped the longer leg as it goes around the .1uF cap just to make sure it wouldn't short on anything.

Here's a pic before the caps go in. You can see the top-mounted resistor better...



For triangle V1 specs, or any other discrete Big Muff variant besides the 2nd version, there's also an extra cap to top mount. This is the #2 reference on the picture in my first post. One leg of the cap is tied to each leg of the 390K resistor (or whatever value is appropriate for your build), so it "bridges" that component. Leave this cap out for a V2 build.

I've been doing a lot of research into the the various versions of vintage muffs. I've yet to find one that matches any schematic exactly anywhere for any version exactly 100% until the green russian. Those have been pretty consistant.

I've been buying and barrowing all the vintage muffs I can get my hands on. What I've been doing since there's so much confusion over which versions have what values simply because EHX was not consistant in their production runs, is cataloging all of my findings and I will be publishing the "average" component values for each version.

My sample population isn't large enough to declare anything definitively yet, but I'll tell you this so far. All of the rams heads I have seen had NPN BC239C in them.

Maybe when I get more time I'll put out an open call to vintage muff owners. I'll pay for shipping and give out byoc gift certificates as incentive. Seems like a worthwhile crusade.

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*patience is a virtue*

Please do not PM me. email is prefered. keith@buildyourownclone.com

Definitely had my hands on a couple with 2N5133s, and one that had, strangely enough, 2N5087 PNP trannies. So yeah, they definitely used whatever they had.

While I hate the mojo thing with a passion and now have GeekMacDaddy to blame for a large investment in NOS Russian germanium transistors, I did purchase about 100 2N5133 trannies awhile back and did try them in a Muff build. I will say that there was a pleasant but slight difference between them and 2N50xx's. The drawback is that the 2N5133's can be very noisy. I say socket and experiment with trannies. What I like and hear will not be the same as what you like and hear.

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Resistance is futile (if < 1ohm).

I've seen this too. I've read that some of the first Triangle era Muff's were PNP and used FS36999 PNP transistors. I can't seem to find any FS36999 and in fact that may be a EH designator for some other PNP tranny EH relabeled <shrug>

I'm building a PNP version with a layout I designed based on this layout and using 2N5087's.

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I... have become... uncomfortably numb...

That's the one I used for mine
http://board.buildyourownclone.com/viewtopic.php?t=4750
It sounds great!

The FS36999 was most definitely an in house relabel. I'm sure the "FS36999" consisted of batches of all different makes and models considering EH's problems with parts sourcing in the early days. And I would be very suprised if we don't see a real EH reissue of the triangle muff with the mystical "FS36999" that will probably be 2N5087 relabels. The best thing about an EH Triangle muff reissue would be that Mike Matthews himself would officially put to rest the debate over what the correct specs are....unless he intentionally used inconsitant values again just to screw with everybody.

_________________
*patience is a virtue*

Please do not PM me. email is prefered. keith@buildyourownclone.com