The Nocturne Atomic Brain full size is a preamp pedal from The Nocturne Brain, built as a replica of the vintage Japanese preamp circuit from the Roland RE-301 Tape Delay, the machine known as the Space Echo. The maker describes it as "the wider box version for the big booted folk": the same circuit as the compact Atomic Brain 301 in a larger enclosure, aimed at players who want more room underfoot1.
Where the original RE-301 preamp was a fixed-gain stage inside a tape echo, the Atomic Brain turns it into a controllable pedal. The maker describes the result as a very reactive, tube-like dynamic enhancement where notes bloom and chords ring out while the guitar tone stays up front and pure2. It is aimed at guitar, pedal steel, keys and bass3.
A Space Echo preamp circuit as a pedal
The circuit is the preamp stage of the Roland RE-301, which the maker notes was actually much quieter, with greater headroom, than its predecessor the RE-201, a machine that used random non-spec carbon film resistors and transistors1. That headroom is what makes the circuit work as a pedal preamp: it pushes an amp without the noise floor of the earlier echo's parts.
The Atomic Brain is not a straight copy. The maker has improved the input impedance, extended the gain range and added a Bass Cut that the original RE-301 did not have1. The opamp is also updated: a modern single opamp in 8-pin DIP format gives less noise, wider bandwidth and less distortion at higher saturation points than the original Toshiba linear opamp, and a NOS metal can chip is available as an upgrade1.
The maker describes the overall character as a "vintage-modern" contour, with the bass control able to help a thinner signal open up with a fatter dynamic bloom1.
The controls and modes
The full size Atomic Brain runs in two modes, NORMAL and ABBY, with a global gain control, a Bass Cut and a right toggle switch1.
| Control or switch | What it does |
|---|---|
| Global gain | Sets the preamp level; with all toggles up and ABBY engaged, turning it just above unity gain makes thin guitars fuller with the amp2 |
| Bass Cut | Keeps a cranked small amp's speaker from farting out; at 7 o'clock the tone sweep gives a leaner, tighter modern flavor, at 4 to 5 o'clock the vintage full low mids of the original character1 |
| ABBY switch | Opens the preamp gain range wide for a solo boost mode, making everything about 35% more dynamic than NORMAL; the more the normal channel gain is turned up, the more boost ABBY gives1 |
| Right toggle (up) | Replaces the Billy Brain voicing, bringing a bigger, more vintage blonde Fender Showman / Bassman attack1 |
| Right toggle (impedance) | Shifts the input impedance; in the up mode it feels louder but actually increases sensitivity to pick dynamics, benefiting master volume amps, piezo pickups and electric basses wanting more growl2 |
The ABBY mode is worth understanding, because it works differently from a conventional boost. The maker is explicit that it does not use cascading gain or doubled diode clipping like other drive boxes; it simply opens the preamp's gain range wide1. With both footswitches engaged, the input impedance is very responsive, which the maker says suits master volume amp players looking for plenty of "rawk"1.
History: from the RE-301 to the Dyno Brain
The Atomic Brain sits at the end of a line of Nocturne preamps built on the Space Echo circuit. The full size version is described by the maker as "all the great sound of the DYNOBRAIN w/ an ABBY mode that opens up the preamp for solo'ing"1: it takes the Dyno Brain's voicing and adds the ABBY boost, while the right toggle in the up position replaces the Billy Brain with a bigger, more vintage blonde Fender Showman / Bassman attack1.
The compact Atomic Brain 301 carries the same lineage in a smaller box with a single stomp switch2, and a repro "old school handwired" version of that pedal is available to order2. The Atomic Brain name is a registered trademark, U.S. Trademark SN 87678190, with logo artwork by Vince Ray2.
The pedal is built per order rather than stocked: the maker states there are no returns, with an average turnaround of 3 weeks, delivered via USPS Priority insured, or DHL insured internationally2.
Questions
Is the Nocturne Atomic Brain true bypass?
Yes. The full size Atomic Brain uses Switchcraft jacks with hardwire true bypass, so with the pedal off your signal passes without the circuit in the path. The compact Atomic Brain 301 is also described by the maker as true bypass.
What does the ABBY switch do?
ABBY opens the preamp's gain range wide for a solo boost mode, which the maker describes as making everything about 35% more dynamic than the NORMAL mode level. It does not use cascading gain or doubled diode clipping like many drive boxes. The more the normal channel gain is turned up, the more boost ABBY gives.
What is the Atomic Brain's circuit based on?
It is a replica of the vintage Japanese preamp from the Roland RE-301 Tape Delay, the machine known as the Space Echo. The maker has improved the input impedance, extended the gain range and added a Bass Cut that the original RE-301 did not have.
What is the difference between the Atomic Brain and the Dyno Brain?
The full size Atomic Brain carries the sound of the Dyno Brain with an added ABBY mode that opens up the preamp for soloing. It also replaces the Billy Brain voicing when the right toggle is in the up position, bringing a bigger, more vintage blonde Fender Showman and Bassman attack.
Is the Nocturne Atomic Brain analog?
Yes. The full size Atomic Brain is an analog preamp, hand wired with a socketed opamp. The maker moved to a modern single opamp in 8-pin DIP format for less noise and wider bandwidth than the original Toshiba linear opamp, with a NOS metal can chip available as an upgrade.
Sources (3)
- Atomic Brain™ full size hand wired version for the large footed, The Nocturne Brain
- ATOMIC BRAIN® 301 Analog preamp, The Nocturne Brain (thenocturnebrain.com)
- MYSTERY BRAIN BS-301 ™ Circuit Rider ltd. tape echo by The NOCTURNE Br, The Nocturne Brain (thenocturnebrain.com)
