The Dr. Scientist Tremolessence is a stereo analog tremolo pedal, built as a guitar effects pedal by the Canadian maker Dr. Scientist. It produces what Pedal of the Day's reviewer Mike B described as "a wide-sweeping, deep tremolo effect", and because the audio path is analog, he found it "warm and inviting, not too harsh like a lot of tremolo pedals can be"1. It sits among the more feature-rich entries in the tremolo pedal field, with two expression jacks and a Hold mode for swell-style playing.
Controls
The Tremolessence keeps its main panel to three knobs and a toggle, with trim-pots on the PCB for internal settings1.
| Control | What it does |
|---|---|
| Rate | Vary speed of tremolo effect, Hz to Hz1 |
| Depth | Vary intensity of tremolo effect1 |
| Volume | Op-amp based, range from less than unity to large boost1 |
| Hold toggle | Lets you engage the effect only while holding down the stomp switch1 |
| Hold knob | Vary the rise-time and fall-time of the tremolo effect when in Hold mode1 |
| PCB trim-pot: LED | Set the brightness of the on/off LED1 |
The Volume control is op-amp based and runs from less than unity up to a large boost, so it can also serve as a clean level lift when the tremolo is off, in the manner of a boost pedal1.
Expression and CV control
Two expression jacks set the Tremolessence apart from most tremolos. Each accepts either a TRS expression pedal, like those used with expression pedals generally, or a control voltage (CV) input from 0 to 9V1.
- Lower expression jack: controls the Rate knob, TRS input, 50k ohm, or CV input 0 to 9V1
- Upper expression jack: controls the Depth knob, TRS input, 25k ohm, or CV input 0 to 9V1
That means both speed and intensity can be ridden by foot or driven from a CV source such as a modular or control voltage system, which few tremolo pedals offer1.
Power and running in mono
The pedal runs on either 9VDC at 75mA or 18VDC at 150mA1.
At 18 volts the Tremolessence draws 150mA, twice its 9V draw of 75mA, so the power supply output needs to cover that current1.
Although it is a stereo pedal, it works in mono: mono in/mono out and mono in/stereo out are both supported, so a single-amp setup loses nothing by using it1.
What reviewers said
Pedal of the Day's Mike B, reviewing the pedal in August 2014, put it among the standouts of the type1:
"I've used many, many tremolo pedals over the years, and while most of them do a pretty good job, there are a few I've fo..."1
He also noted that the whole circuit is "housed in a nice, thin enclosure for maximum pedalboard real estate"1.
Videos
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Questions
Is the Dr. Scientist Tremolessence true bypass?
Yes. The Tremolessence uses true bypass, switched with a soft touch switch and relays. That means the pedal's circuit is taken completely out of the signal path when it is off, and the relay switching keeps the bypass quiet and reliable. The pedal also carries a limited lifetime warranty from Dr. Scientist.
Can the Tremolessence run at 18 volts?
Yes. The pedal accepts either 9VDC at 75mA or 18VDC at 150mA. Running it at 18 volts doubles the current draw, so make sure your power supply can supply 150mA on that output before you plug it in.
Does the Tremolessence work in mono?
Yes. Although it is a stereo pedal with stereo input and stereo output, it also runs mono in/mono out or mono in/stereo out. A player with a single guitar cable and a mono amp can use it exactly like any ordinary tremolo, and stereo rigs can run two amps or a stereo effect chain.
What does the Hold knob do on the Tremolessence?
The Hold knob sets the rise-time and fall-time of the tremolo effect when the pedal is in Hold mode. In that mode, the effect is engaged only while you hold down the stomp switch, so the knob shapes how quickly the tremolo swells in and fades out, which is useful for volume-swell style playing.
Can I control the Tremolessence rate with an expression pedal or CV?
Yes. The lower expression jack controls the Rate knob and accepts a TRS expression pedal with 50k ohm impedance, or a CV input from 0 to 9V. The upper jack does the same for the Depth knob, using a 25k ohm TRS expression pedal or CV from 0 to 9V.
Sources (2)
- Dr. Scientist Tremolessence Stereo Analog Tremolo, Pedal of the Day, 2014-08-13
- Dr. Scientist Tremolessence Stereo Analog Tremolo, Pedal of the Day, 2014-07-17
