# Dissecting Distortion Pt. 3

### In last month’s column, we looked at images of sound waves with and without distortion. I’d like to examine those photos again for some more analysis. In Figures 1

In last month’s column, we looked at images of sound waves with and without distortion. I’d like to examine those photos again for some more analysis.

In Figures 1 and 2 we can see that the waveforms have about the same amplitude (vertical height when viewed on an oscilloscope). Amplitude corresponds to the size of the signal in volts or electrical strength, thus the bigger the waveform the louder the signal. This is a general rule and there are always exceptions – test equipment can be set to see things in many different ways. However, for this discussion, remember that a bigger wave represents a louder signal.

In Figure 1 we have a nice, round sine wave. This represents a clean signal with no distortion. Figure 2 shows a square wave and believe me, it is nasty sounding. In the lab, we “look” at audio gear with a square wave running through it. A square wave, although not pleasing to the ears, can visually represent how a particular piece of gear is performing; in this case, the squarer the wave is, the better the gear is passing the signal without altering it. For applications requiring pristine audio, the wave should be very sharp and uniform. Introduce EQ, filtering, overdrive or distortion and the wave begins to take on non-linear shapes.

A particular piece of gear or its components all have a limit on how much signal, voltage and amperage that they can handle accurately. After a certain point, distortion begins to occur. If we were to add to the signal level in Figure 1, there would come a point that the gear could no longer handle the increase and the sine wave would begin to flatten and take on the appearance of the square wave in Figure 2. In this case we would be overdriving the limits of the particular piece of equipment or the component’s ability to cleanly pass the signal, thus the term “overdrive.” Overdrive is the easiest way to cause distortion.

Looking at Figures 3 and 4 we can see how a pedal affects the signal. Milder distortion is shown in Figure 3 and total annihilation of the signal is shown in Figure 4. In Figure 4 we see total compression of the waveform; the amplitude is diminished as compared to the wave in Figure 1. Although the wave is smashed down, it is very rich in harmonic frequency content and can sound as loud as the sine wave in Figure 1. Figure 4’s wave shows the same fundamental frequency as in Figure 1, except with about a zillion harmonic derivatives induced by the pedal’s circuitry. While amplitude is relative to loudness, so is the complexity and harmonic content of a signal.

Distortion and overdrive pedals basically derive their sounds by two types of processing. The first and easiest way is to increase the gain (amplitude) of the signal. The second way is to change the shape of the original signal by adding, subtracting, filtering, etc. We can use transistor gain staging, diode clipping, harmonic regeneration/feedback, opto circuit manipulation and many other exotic circuit derivatives to cause distortion. However, it should be noted that both methods come with a price; overdrive or distortion obtained by a function of gain usually has a corresponding increase in noise, while circuit manipulation of a signal is often described as “tone sucking” and alters the original sound of the signal.

Great examples of this are FET transistorbased pedals (the typical “Tube Screamer” type of pedal). FETs are an easy and inexpensive way to obtain gain, but they get noisy as the gain increases. They also produce a loss of low-end frequency response, mid frequency peaking and harshness in the upper frequencies. The gain increase and mid boost is killer for pushing a 100-watt amp into orbit for a solo, but the loss of low-end response and increased noise is not acceptable for bass players. Note: Many Tube Screamer-type pedals have IC chips as their major component (in particular the beloved 4558), but the chips are based on FET technology.

And always remember the basic premise of overdrive and distortion: when you are practicing by yourself soak it up to the top, but cut it way back when you get with the band.

Come see us at the Orlando, Nashville, Spartanburg, Dallas, and Summer NAMM shows where the boys and I can give you an earful. We enjoy teaching, ‘cause rock n’ roll ain’t noise pollution (most of the time)!

Sarge out.

Gary "Sarge" Gistinger
President, Creation Audio Labs, Inc.
creationaudiolabs.com

## Catalinbread Releases the Fuzzrite Germanium

A faithful recreation of the Germanium Mosrite Fuzzrite with a modern twist.

From the years of 1966 to 1968, Mosrite produced two distinct fuzz circuits---one outfitted with silicon transistors, the other with germanium parts. Of the two, the germanium version is by far the most rare, with original designer and Mosrite employee Ed Sanner estimating that around 250 ever made it out the door. In that final year of production, Mosrite shifted exclusively to silicon parts, making germanium components a thing of the past. However, by 1968 the public was hungry for fuzz, having heard it on a handful of recordings, most notably "In-A-Gadda-Da-Vida" by Iron Butterfly and "Incense and Peppermints" by Strawberry Alarm Clock. These two buzzy, sinewy fuzz tones were part of a wave of psychedelic rock gaining traction in the mainstream, and both were recorded prior to the introduction of the silicon Fuzzrite.

Other purported users of this early Fuzzrite circuit include Ron Asheton of the Stooges, Norman Greenbaum on "Spirit in the Sky", Henry Vestine of Canned Heat, and many others. Catalinbread have a germanium version at their disposal, and we've used it as a benchmark to create an extremely faithful version with a modern twist. Just like the original, the Catalinbread Fuzzrite Germanium includes two NOS PNP germanium semiconductors with a polarity inverter IC so it plays nice with all forms of power. Unlike the original, Catalinbread added a toggle switch to shift into modern mode, significantly beefing up the low-end content to suit more contemporary rigs.

### Playing The Fuzzrite Circuit For The First Time!! | Feat. Catalinbread Fuzzrite Germanium

The Fuzzrite Germanium is out now and available for \$179.99 at participating retailers and catalinbread.com.

## Walrus Audio Slötvå Review

### Presets extend the flexibility of an already expansive and easy-to-use reverb.

Intuitive. Great range in all controls. Well-built.

Some digital artifacts at long decay times.

\$229

Walrus Audio Slötvå
walrusaudio.com

4
4.5
4.5
4.5

Walrus Audio is a prolific builder, but, as the five reverb pedals in their lineup suggest, they have a real affinity for manipulating time and space. The beauty of the Slötvå reverb (which is derived from the company’s very similar Spin FV-1 chip-based Slö reverb) is how satisfying and simple it makes dramatic shifts between time/space textures.

Slötvå’s big departure from the Slö model is the addition of three presets, enabling quick switches between vastly different reverbs. But Slötvå’s interface is also pretty easily mastered and manipulated on the fly without using presets. And that operational flexibility makes Slötvå just as capable of delivering surprises as predictable, repeatable results.

Slötvå’s three algorithms all range to super-long decay times, especially when you hit and hold the sustain button. “Dark” adds a minus-one-octave signal, rise adds an almost reverse-like swell effect, and dream adds a latch function that effectively “freezes” the reverb signal. In all three modes, the octave content can reveal chorale-style overtones and discernibly digital artifacts at long decay times. Some players love and utilize these sounds to great effect. So, try before you buy if you don’t know where you stand. If you’re untroubled by a little shimmer at expansive settings, however, Slötvå is a fun, intuitive, and performance-practical way to source a genuinely expansive range of unobtrusive to ambient reverb sounds in a compact, easy-to-wrangle unit.

## A Sunburst Solidbody, Straight from Sears

### With such a flashy flame top, the Silvertone 1445 was built to catch the eyes of department store shoppers.

I don’t know what’s going on lately, but I’m breaking down all over and my shoulder is the latest to crumble. When I was a kid I would practice guitar in my bedroom near a radiator with an ungrounded amp plug and I’d get a zap right through my guitar and into my hands. Well, my shoulder pain is like that now, only without the cool story of rock ’n’ roll survival. I simply woke up one day like this. After a few weeks of discomfort, I figured I’d try out a new pillow, since mine are flattened like a wafer. I ventured out to the mall and, much to my sadness, saw the local Sears store shuttered, with weeds growing up from the sidewalks and concrete barriers blocking the large glass doors. I know I don’t get out much, but, man, was I sad to see the Sears store I’d known since childhood closed-up like that. My wife was laughing at me because apparently it had been closed for some time. But since I seem to exist on a separate timeline than most folks, it was all news to me.

The 1445 combines an elegant sunburst top with surfy accoutrements and makes a few noticeable nods toward both Fender Jaguar and Mosrite styles.

In the parking lot, I stretched my shoulder and gave some thought to Sears and department stores in general. Back in the day, I would see stacks of new vinyl records in the store, alongside the classic, huge hi-fi stereo systems. I feel like I grew up during a great time, where I had one foot in a bygone era and the other foot pointed towards gigantic technological breakthroughs like computers. But I also feel kind of bummed about missing out on the whole electric guitar/department store connection. My good buddy Mike Dugan recalls those times, and while most kids were charging towards the toy section, he was checking out the electric guitars and amps. Can you imagine?

“I feel kind of bummed about missing out on the whole electric guitar/department store connection.”

For those of you who also missed the Sears guitars, here’s a quick primer: They were almost all branded Silvertone and, in the late ’50s and early to mid ’60s, were manufactured by either Danelectro, Harmony, or Kay. By the tail end of the ’60s, a lot of Silvertone guitars were Japanese imports that were priced and aimed at beginners. I’ve always felt that the Silvertone guitars were a bit on the conservative side of the spectrum, and there weren’t many crazy designs or finishes.

The headstock on this 1445 , with binding and its sloped shape, is an elegant touch for a beginner’s guitar.

This Silvertone 1445 model hails from around 1969. It’s a cool 3-pickup model that features an offset shape with some exaggerated lines. Built at the Kawai factory, the guitar has an ebony fretboard and some standard Kawai appointments, like the in-house vibrato, electronics, and pickups. There is an on/off mini switch and volume knob for each pickup as well as a single tone knob. Around this time, Kawai was starting to cut corners in subtle ways, one of which included underwinding the pickups, which, in most cases, resulted in a thinner sound. Luckily, the series wiring in these guitars can produce quite the powerful sound. The finish is a nice-but-kinda-blah sunburst with some flamed wood. The flame veneer was a new thing for the Japanese guitar makers at the time, and I think there was some elegance attached—especially for a guitar targeted toward beginning players.

Strapping on one of these late-’60s 1445s is a familiar-feeling experience, offering up a cross between a Fender Jaguar and a Mosrite vibe. Often, Kawai electrics of this era were neck-heavy and the headstock would take a dive on you when slung around your shoulder. But the 1445 features a thicker body with a thin laminated neck. Kawai had basically perfected that laminate-neck-making technique, mostly to prevent warping, and these guitars usually hold up very well, even though the necks on are quite slender and narrow.

The Silvertone triple-pickup 1445 cost \$78.95 in the 1969 Sears winter catalog and only lasted for a few years. I’ve seen all sorts of variations on this model, like bound bodies and necks, different colored pickguards, and different knobs. I suspect a lot of you out there started on a Silvertone. One has to marvel at the sizable influence Sears stores had on generations of folks. I’m really going to miss that local Sears and the feeling of nostalgia it evoked. Not quite like the electric zaps flowing into my shoulder right now, but still powerful!