Does Lava Rim 2 sound similar to 1977 muff fuzz

[paulrm]

I've just finished a Lava Rim 2 and I was wondering if it sounds like a 1977 plug-in EHX muff fuzz. I got it to try and reproduce the sound, I had a muff fuzz when I was a kid and wanted something similar in sound. The Lava Rim is very good, just wondering if I'm on the right lines here. Thanks.

[Harry]

Why not build the real thing?

[mth5044]

Wait, didn't you have one? Too long ago to remember what it sounds like?

[paulrm]

I was going to build one, but the PCB from general guitar gagets was for both. The circuit is almost identical except for the trim pots. I'll see if I can find an original on UTube. Trying to remember the sound of something I had 40 years ago is not easy. I did have a v4 IC based Big Muff as well, I do remember what that sounded like, it was very smooth, no crunch at all, I sold it though. I just built one of those, great pedal.

[Harry]

I've never built the Lava Rim, but looking at the schematic it should be quite similar. Biggest difference I see is the lava rim will have more gain from the 22uf bypass cap. The 220p cap will filter out a little highs and the .22uf output cap will allow out a little more lows. This might smooth out the distortion a bit. I would imagine that the Lava Rim's extra controls could be tweaked to be close enough to a Muff Fuzz sound, but it'd be up to you if you like the extra features or whether you want a 100% accurate Muff "replica".

[aron]

I remember the Muff Fuzz being kind of weak sounding. The Lava Rim seems like it has way more gain on tap in my samples. I would imagine that you can get very similar sounds with certain settings.

[brianq]

Both Lava Rim pedals are modified Fuzz Face types right? I've built #2 and it's got some great range! I really like the diode clipping on the output.Muff fuzz is basically the same in theory but way different sounding to my ears, another good pedal.

[Mark Hammer]

I picked up an EHX Nano Muff Overdrive on the weekend ($25 - I couldn't resist), primarily to mod.  And I suppose the Lava Rim 2 is a hot-rodded version of that circuit.  The Nano Muff arrives with Q2 gain preset with a 3k3 fixed resistor, rather than the 2k7 in the earliest issues.  Having long-since cannibalized my own first-issue Muff Fuzz (the type you plugged into the guitar) for parts, I can't compare whether the 2N5133s with a different emitter resistance sound the same as the contemporary 2N5088s.  I replaced the 3k3 with a 5k pot and 33uf cap, as shown in the Lava Rim, and installed an SWTC between the clipping diodes and volume pot, turning it into a 3-knobber with a much broader palette of sounds available.

The Muff, by itself, is a warm-sounding overdrive, and very quiet, thanks to the various 100pf caps and inductors EHX added to the basic circuit.  But for the price I paid, and the convenience provided by those sweet little 9mm green plastic-bodied pots with the small black knobs (epoxied to the inside of the 1590B box), it was an easy mod.  Photo essay coming.

[paulrm]

I used 2N5089 transistors for my Lava Rim but I'm going to try a mosfet. The Lava Rim has quite a bit of power compared to the Colorsound one knob fuzz that I made at the same time. The Colorsound needs a booster, I made a SHO to go with it.

[paulrm]

Well I used a J201 jfet and it sounds amazing, much more life. Having said that the last trimmer seems to have no effect on the sound? It's meant to adjust the clipping in diodes I think.

[aron]

I never put a J201 in there. Interesting.

[Mark Hammer]

The Univox Square Wave is also a Fuzz Face derivative with a JFET for Q2.

https://www.youtube.com/watch?feature=player_embedded&v=mYGjn7Q-F_E

jack Orman had a Fuzz Face derivative with a MosFet in the Q2 position, called the MosFace.  Both sound pretty good.

[brianq]

Yes, it's a BS170 mosfet. Also a great sounding fuzz! Another FF style build.