http://www.smallbearelec.com/servlet/Categories?category=Knobs

Thanks for that. It’s sort of what I thought I saw in the one picture I could find, but I didn’t want to leap to conclusions. Turns out, the conclusions were right. Chalk up another victory for intuition.

The NKT275 units are preferred germanium units for Fuzz Faces these days. I have no idea what sort of supply is remaining out there, but I’m pretty confident no company as big as EHX would launch a product based on it unless there was some sort of supplier big enough to justify the launch.

The distinguishing feature of the traditional transistor-based Big Muff is that it uses double-clipping. That is, it boosts and clips, then it boosts and clips all over again. The degree of boost used in each stage, and the manner which bandwidth is trimmed or enabled here and there, as well as the width of the scoop in the tone circuit, plays a role in the tonal quality found from issue to issue, not to mention within issues (according to Magic Mike himself in a business mag interview). That is not to say that other designs can’t sound fuzzier, but the sustaining quality of the traditional silicon BMP stems from the design telling the signal “Hold on a sec, I’m not done with you yet”.

The G4BM, in its use of NKT275s, and non-reliance (at least from the gutshot) on diodes for clipping, would appear to be another Fuzz Face derivative. It is nigh impossible to estimate the number of designs derived from the basic Fuzz Face structure utilizing feedback from Q2 to Q1. Over the past 50 years, they just keep coming and coming. And for good reason: it is a very rich test bed for yielding different distortion qualities via small adjustments to bias, feedback, etc. The early Muff Fuzz itself was a FF derivative (albeit with a fixed gain), and the Double Muff might be described as a distant relative of the G4BM by packing in two cascadable Fuzz Face-like circuits.

I have every confidence that EHX has gathered up a sufficient supply of NKT275 trannies to launch a viable product. That said, the supply IS limited. Assuming it hasn’t gone digital by then, I expect to see Big Muff PIs being made in some form a decade from now. The same can probably not be said for the G4BM.

First off, let’s tidy up the terminology: there ARE no “germanium chips”.

Second, consider that, if anyone could or would do it, Mike Matthews and EHX would arrange for production of a limited run of germanium transistors, or at the very least buy up the world’s NOS supply (or close to it) of a given germanium transistor, the way he did with the Matsushita MN3005 for the Memory Man in the 90’s.

That said, there is a LOT of unit to unit variation in germanium trannies, so you’d need to have a large supply of them in order to pick out the usable ones and have a dependable product. Small boutique houses can afford to use varying components, but a major manufacturer risks damage to their brand if they can’t turn out a consistent product that sounds exactly the same at every Guitar Center. Admittedly, this is but one pedal in a VERY large stable of excellent products, but even so, unit-to-unit variation within a pedal can breed some hard feelings and, in tandem with forums, can release a tidal wave of “bad press”.

All of which leads me to ponder that a) there isn’t a whole lot about the pedal that *depends* on germanium, and b) there is no grand plan to have as many of these in the world as there are Big Muff Pi’s. The one confirmed gutshot I’ve been able to find shows that it is mostly a surface-mount board, with what appear to be two pairs of germanium transistors mounted to the board, and a dual op-amp I each channel.

To the best of my knowledge, Visual Sound did not “recommission” the Panasonic/Matsushita chips. There are currently two manufacturers of several of the chips (MN3205, MN3207, MN3102): Beiling and Coolaudio, the latter providing chips to Behringer.

You can use a plain old stompswitch to connect an amp to this speaker or that. The problem is that a) you may get pops/thuds, which are not appreciated in a gigging context, and b) it’s not especially good for the amp to go from no load to proper load, instantly, while on. Bear in mind the stompswitch in that pedal is a break-before-make type.

Yes. In fact, it is normal for the vast majority of envelope-swept filters, and is due to what many call “envelope ripple”.

The envelope-follower in the pedal attempts to “average out” the properties of the incoming signal, and produce a DC voltage proportional to the amplitude as it changes. The tracking of that amplitude is based on making some tough decisions, though.

Imagine you were driving a car with a digital speedometer display. How often should it update the speed? You certainly want to know that you’re under the speed that the officer with the radar gun, down the road, is looking for, so the display needs to keep current. But you don’t want your display to keep flashing 53-54-53-54-52-55-54-55-53. There needs to be some rate-of-updating that hits the sweet spot and provides the information you need, no more, or less, frequently than you need it.

Same thing with envelope-followers. One can average out over a longer period, or a shorter period. Averaging out over a longer period gets you a smoother decay, but it also gets you a much longer decay. Averaging out over a shorter period gets you a faster response, and quicker decay. But unfortunately the decay phase of a plucked string has a lot more burps and farts to it than is readily apparent, by ear alone. So, a quicker response is accompanied by greater susceptibility to envelope ripple in the sweep of the filter.

To some extent, using photocells to control the filter helps a lot, since they are juuuusssttt sluggish enough in their response that they don’t sense and respond to every little wiggle in the envelope. The Dr. Q and Bass Balls both use transistors as their control element, rather than photocells, and I’m sure you’ll hear more of the burbling in them than in the Mini Q-tron, simply because every bit of ripple in the envelope is responded to by the transistors.

The speed of the sweep in your Mini-Q is dictated by R21 (33k), R22 (1M), and C21 (47nf). In principle, changing C21 for a 100nf-220nf value would average out over a longer period, and reduce some of the burbling, but would decay slower. That may or may not suit your playing style. Alternatively, reducing R22 makes the decay happen faster; ideally, it ends before the wobbliness in the envelope shows up.

A non-electronic strategy is to force a quick decay in the envelope with the butt of your picking hand. If you can get the string, and sweep, to decay within 700-1000msec after picking, then you tend to avoid the rippliest parts of the string’s vibrations. Again, that may not suit everyone’s style.

I hope this clarifies some things for you. Any designer will tell you that coming up with an “all-purpose” envelope follower that tracks well, keeps ripple low, and has a low parts-count, is no small task.