OK--Here are my impressions of the Basic Audio Squarewave+:
The Squarewave+ is John's take on the mid-to late-1970s Univox Square Wave fuzz, which had Balance (effect volume) and Wave Shape (tone) controls. As some of you know, Univox was a Unicord brand name, under which guitars amps and effects were all marketed, most famously for us effects junkies, the original UniVibe, and the Univox (Shin Ei) Super Fuzz. From 1975, Univox products were made in Japan--until the brand was phased out in 1978 and replaced by Westbury (the name of the Long Island town where Unicord had its headquarters, a few miles from where I grew up). Unicord was eventually purchased by Korg. The Square Wave was first produced in 1976, and discontinued in 1978, making it a pretty rare bird.
The original unit gets fairly mixed reviews today. It doesn't generate a square wave, but instead a crumbly fuzzstortion with a texture that won't appeal to the crowd that doesn't make friends with fuzz easily, but is of great interest to those latter-day fuzznauts searching for unique attack and decay characteristics to make their riffs stand out from the pack. As such, a clone was a worthy goal--to bring this circuit to an appreciative user base that likely couldn't justify the expense of a possibly unreliable vintage original.
If all John had done was produce a reliable, affordable clone I personally would have offered a hearty huzzah and placed my order; but John has gone well beyond that limited, though worthy, goal.
The first thing John did was ditch the rather uninspiring tone control, which to my ears merely afforded the user a choice between the stock crumbly-but-full-bodied fuzzstortion and (somewhat pointlessly) a slightly muddier version. It didn't, for instance, provide the level of tone shaping provided by the standard Big Muff tone control, which many DIYers chose to graft on when they made their own Square Wave clones.
In it's place, John has added a Gain control allowing the user to dial back the gain of the signal heading into the clipping portion of the circuit; a Clamp control which continuously varies the amount of diode clipping present in the signal, and a clipping selector, which allows for a choice between the stock germanium diode pair, a silicon diode pair, and a diode lift (no diode clipping). Obviously, the Clamp control doesn't effect the signal in the diode lift mode.
The sum total of these three very interactive controls is a variety of distortion textures ranging from a very slightly dirty boost, through smooth and/or fizzy/crumbly overdrive textures, to classic rock distortion, the original signature crumbling fuzzstortion, crushed kazoo-like tones, whooshing synthy decays, subtle uper-octave emphasis, and, when voltage starved, some very nice ring-mod-like tones.
The Germanium diodes, with maxed clipping and fuzz gain, will produce some of the more outrageous tones--this is where synthy and octave-up tones start to blend in with the base fuzzstortion. As you dial back the gain and/or the guitar's volume, the attack and decay characteristics increasingly stabilize and then begin to produce more overdrive-like sounds. On this clipping setting, however, the overdrive tones are definitely of the whooshy/fizzy variety and exhibit a quality reminiscent of a clean-blend--the fuzzyness seems to ride on top of the less distorted primary signal. With a Telecaster, many tones similar to a Harmonic Percolator were available in this mode. Turning the Clamp control clockwise reduces the amount of diode clipping--bring up the volume and bass content of the signal, and resulting in smoother, less fizzy and compressed, more integrated clipping characteristics. Another note--volume knob cleanup with the Gain control maxed is very smooth, without the shelving effects found on many vintage fuzz designs, and without the increase in treble sparkle that stems from varying load effects from the guitar. I found that this fuzz was exceptionally responsive to both volume and tone knob adjustments from the guitar. Note, however, that with the Gain control on the pedal rolled back, rolling back the guitar volume will also reduce the output level from the fuzz to a much greater extent than is the case with the Gain maxed.
In silicon diode mode, you get a comparable range of tones, although in all cases the signal is proportionally less crushed, compressed, or fizzy, with a more full-bodied tone. Based on my experimention with diode types in other circuits, I expected the silicon diodes to be much more middle-of-the-road, classic rock sounding than the germanium, and there is no doubt, you'll find it much easier to dial in the classic 70s fuzzstortion tones with the silicon diodes selected than with germanium. But, the Clamp control allows for much more overlap tonally than a selector switch alone would, and the most extreme clipping settings with the silicon diodes provided plenty of strangeways pump and bloom--in fact the closest I've heard to the tones from the Squarewave+ with silicon diodes selected and Gain and Clamp "maxed" is from a Rat clone with germanium diodes in a negative feedback path.
Lifting the diodes creates a volume boost, and both lessens the extreme degree of clipping compression and overload characteristics found with the diodes selected, and smooths out the inherent attack/decay characteristics of the circuit, bringing it somewhat closer in nature to a Silicon Fuzz Face, although still retaining it's own aggressive personality, and to my ears a tighter bass and less-scooped EQ pofile than the Si Fuzz Faces normally afford. This is the mode that allows for the most variance in lower gain clipping characteristics, with tones ranging from a nearly clean boost with Gain or guitar volume rolled back, through many classic overdrive, distortion and fuzz textures. This is also the mode you should go to if you want to take a break from the crumbling characteristic. I also found voltage starving the circuit to provide a greater level of adjustments to the overall feel of the pedal in this mode.
As always, YMMV, and do note that the fuzz is very responsive to the signal it is fed--both the lower and upper limits of the clipping range are different depending on whether you feed the box single coils or humbuckers, high level or low level signals. I personally loved it with everything I threw at it, but obviously humbuckers will result in a lot more saturation, and will more readily result in complete overload, with certain settings resulting in paradoxic effects such as the volume swelling as the note decays. For the greatest number of sweet-spots, I kept going back to my trusty Tele, but I also loved the tones with P90s, Filtertrons and other Mini-Humbuckers, and DeArmond Dynasonics. This is a bonus to me, because I find that many times the Dynasonics and Filtertrons have a somewhat coquettish response to my other fuzzes.
I'm not in a good position to do demos right now, but luckily, John has blessed us with demos which, imho, are very true to the sound from the actual pedal, and there have been other really good demos from users in the various Tour Boxes and otherwise.
John--please correct me if I've mis-stated anything. Special thanks to edkoppel, 'cuz you know why.
John--thank you for work and for sharing this hunk of fuzz. Next up--AF-50(ish)....