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ToadWorks PipeLine Tremolo Pedal Review

The ToadWorks PipeLine channels harmonic vibrato from early Fender Brownface amps.

Download Example 1
Smooth Tremolo
Download Example 2
Fast Harmonic Vibrato-Stereo
Download Example 3
Slow Harmonic Vibrato-Stereo
Clips recorded with Anderson Cobra Special-S and Clark Beaufort and Allen Old Flame (for stereo). No other effects.
Holding this compact light green box in my hand, I have to ask the age-old question: “What makes this little tremolo box different from all other little tremolo boxes?” Scanning the top panel from left to right and top to bottom, the answer appears immediately. The first control encountered is a mini-toggle Mode switch that toggles between Tremolo and Harmonic Vibrato. I don’t recall ever seeing another pedal with this term. So, you may ask, wha’sup with harmonic vibrato?

Back to the Future
To answer that question, we need to take the time machine back about half a century to sleepy (at the time) Southern California. The folks at Fender have been cranking out amps for several years now and are sitting pretty atop the pro market. There are other small companies such as Standel, Carvin, Valco and Danelectro vying for market share and special niches. One of these companies is the Magna Amplifier Co. They have a brilliant engineer who has developed not a tremolo but a true vibrato which is making waves (pun intended) in the marketplace. They have an artist in their stable named Lonnie Mack who is topping the charts with superb guitar instrumentals and a distinctive sound never heard before, and Robert Ward has brought that sound to the Blues airwaves. They have definitely attracted the attention of Leo Fender.

Magnatone amps are heavy, expensive, and volume challenged, but they are selling; they also have a patent application pending for their vibrato system (later granted). Fender engineers try to meet the challenge with a tremolo system they call “Harmonic Vibrato.” Yes, it is a tremolo system misnamed by Fender as a vibrato, but it is broadly welcomed along with the new “Brownface” front panel controls, white/brown Tolex covering, and new circuitry. By general consensus, it sounds great, but does require a lot of new circuitry and expense. Is it worth it?

History shows the harmonic vibrato going away along with the Magnatone amp at the advent of outboard effects pedals. Interestingly, no commercial stompbox has ever really duplicated the Magnatone sound, though many have tried.

Wobbly Tone 101
To understand this better, let’s explore the difference between tremolo, vibrato, and harmonic vibrato. Tremolo is amplitude modulation—louder and softer, as in taking your pinkie and pulsing the volume control on your guitar. Vibrato is frequency modulation, as in wiggling the whammy bar (known correctly as a vibrato bar), changing the frequency of the sounded tone. “Harmonic Vibrato” is purely an electronic construct in which the preamp signal is split into high and low frequency bands, run through a phase inverter, which puts the two bands out of phase, an oscillator to add the pulse, and then usually recombines them into one signal.

However, one of the other major distinguishing features of the Pipeline is that after phase inversion the high-frequency band and low-frequency band may be split into a “stereo” output, i.e., each band has a separate out which may be routed to separate amps. Each amp will enable separate control of the two bands. Great design for the true tremolo lover.

Down the Pipeline
The other controls and features are pretty standard for an analog tremolo. Continuing left to right on the top row is the Waveform control. This varies the undulating wave from sinusoidal (smooth) to sawtooth (choppy) and all forms in between. The next control is Speed, which varies the frequency of undulation or, more correctly, the period of the wave. Counterclockwise is slow, clockwise fast. Next is the Intensity control, which varies the mix of the effected with the non-effected signal (wet/dry mix). Counterclockwise is dry, clockwise is wet.

In the center, you’ll find a bright white LED status light and on/off switch. The switch takes the pedal in and out of true bypass mode, and there’s the expected pop when the switch is pressed. On the sides of the unit are the input jack and expression pedal jack (more on that later) on the right side; and the two (mono/stereo) outs on the left side. The front of the unit has the 2.1mm barrel jack for a 9V regulated power supply.

Removing the back panel allows access to the mini-pot control of the LF cutoff frequency. Also found is the battery connection for the 9V power source. I would recommend always having a battery installed, even if you always use an external power source. The Pipeline is a well-built and compact unit with a nicely painted cast metal case.

Riding the Waves
In use, the signal-to-noise ratio is good for a tremolo unit—they all make noise. The sound itself is full and focused, pleasant to the ear. My preferences may be a bit biased, since my first real amp was a Brownface/white Tolex Twin that I bought in November 1960. Flipping the Harmonic Vibrato switch on the Pipeline brought back a flood of memories from the 12 years I played that amp; from Duane Eddy and Link Wray instrumentals played at local sock hops to psychedelic six-nighters in Minneapolis bars. So, yes, I like it very much, though there are some areas I can see room for improvement.

First off, I found the speed control difficult to use. When starting at minimum speed and traveling to maximum speed nothing much happens until about 3 o’clock. In the next two clock hours, it accelerates from two beats per second to a “helicopter flutter,” making it somewhat difficult to obtain the desired speed. This can be fixed by plugging in an expression pedal, but then the speed is slowest when the “pedal is to the metal” and fastest when the pedal is up position—the opposite of what I consider intuitive.

Also, the status indicator light does not pulse in time with the tremolo setting, so when starting a song you must adjust on the fly or make some noise before the downbeat. Neither is a good option if the guitar plays the intro. A blinking light could get you very close to the desired speed before hitting that first note.

The Final Mojo
I love the sound of the Harmonic Vibrato, so for me the speed control issues are of minor importance. The availability of stereo output is also a nice feature, though I don’t think it has wide application. I could see using it in the studio or in a jazz trio setting… but then, of course, you would be hauling two amps around. The unit is sturdy, compact, and quiet—valuable assets when mounted to a pedalboard.
Buy if...
you want to recreate the coveted brownface harmonic vibrato tones, or just a good tremolo unit.
Skip if...
you don’t use tremolo or are happy with the effects you have in your amp or multi-effects unit.

Street $250 - ToadWorks -