Cart 0

MYSTERY BRAIN BS-301 ™ tape echo


MYSTERY BRAIN ECHO BS-301 ™ vintage japanese preamp & digi tape echo.

MYSTERYBRAIN  now in Killer Magenta  (shipping end of July)

This classic 301 analog Japanese preamp & ambient Tape Echo simulator circuit is a unique circuit design thar started out as a single preamp pedal ( Dynobrain & Atomic Brain ) in 2008 and was morphed into a full Tape echo simulator in early 2017. 

We designed its spacial echo side around a PT2399 chip with an analog delay circuit that loves to be pushed into saturation. Some folks call this Setzer-in-box or the all in one #rockabilly pedal, you make the call. Its all here powered by a 9v power supply(not incl) that only used 85mA max.

A re-301 input preamp (based on vintage roland) plus an echoplex pre* w analog photocell vibrato actually in the tape echo repeats w an adjustable EP preamp* on the front of the echo circuit, plus a preamp gain booster.    Even added an FX loop insert for your favorite overdrive (like the Nocturne DC Fluid Drive) or vintage reverb (Nocturne El Pescadoro)

the MYSTERY BRAIN ECHO 301v. 4 a vintage Japanese preamp & digi tape echo.

All the great sounds of the ATOMIC BRAIN preamp a replication based on the original Roland 301 Echo Chamber (see description of preamp in the BS-301 section for more info)

<If you are not in the USA, please click international shipping in the check out cart, if you accidently choose US Stateside shipping you will have to then pay the additional charge in order for me to ship. I am a single person operation and I want your purchase to get to you so...At this time we are using as they are reliable and trackable for international shipping unlike overseas >


I've replicated the sounds and response of the famous japanese 301 space echo and for a limited time, you can choose the optional boutique NOS 70s analog 7 pin linear op-amp or the more modern 8 dip Opamp chip. (Honestly there is hardly a difference between this op amp chip and the 8 pin chip variety. B#SS / R#land stopped using the first TA7136 and moved to the 741 8 pin chip when production stopped on the TA chip and nothing was missed.)   I use as standard, the quieter and higher audio grade Burr Brown OPA chip (a modern 8 dip opamp chip).

Its my preference, super reliable, beautifully responsive and easily replaced anywhere in the world if needed (I socket all my chips on the circuit board) but if you want the fun of having the NOS 70s Linear Toshiba opamp chip, its avail as an option charge below*.  

(the TA chip is basically a non existent chip w pocket-fulls avail on the planet, I have a super limited stash of my own and only willing to let some out of the fold at this time, and rare means its cost a bit more. Again you arent missing much w this chip. The Burr Brown is wonderful and the *NOS Toshiba version is just a tad cooler and slightly vintage noisier)

I'm all about fixing the things that needed fixing in the original 301 preamp, so you will find top audio grade low tolerance metal film resistors & metallized poly film tone caps, Neutrik in/out jacks.  Not to worry though, all the vintage feel, touch dynamics and response of the original 301 are here. Once you stomp it on, you will never turn it off.

"Every guitar I own sounds like more of itself, a more better pedal is what this is and I never turn if off" - to quote Brain preamp owners.

 Note : Version 4 has a new feature. We've added a TRS fx insert jack that is a send/return effects loop that allows you to place your favorite pedals BETWEEN the Mystery Brain's Preamp circuit and the Echo circuit.   btw.. An affordable and quality patch cable for this feature is the:

EBS Right-angle 1/4" TRS to Dual Right-angle 1/4" TS

higher quality, heavy duty patch cable for this feature is the:

a quality right angled version of the TRS stereo to dual 1/4" cable here at

This will let you keep the Mystery Brain at the end of the pedal board but allow you insert any or all of your other pedals between the MB's atomic brain preamp and the echo circuit.. yes its brilliant. 


pedal dimensions (5 5/8" x 4 5/8" x 1 9/16")

link to manual (thanks Henry)




*thanks to Joe Carducci of Gretsch for filming and producing this video, as well as Tim Harman of Tru-Arc bridges for being the interviewer and guitar demo riffer. His Gretsch Jet sounds so good through the Mystery Brain and my Moonshine '39 1x12 combo) ..also props to Timmy on the Gretsch Bass, and Dave Miller for letting me use his D-cut falcon, I want one!)






hear the Mystery Brain via 60 Cycle Hum reviewing Rival Guitars, click below>

note: graphics logo done by the master of low brow Art & Album covers all over the globe, Vince Ray @


link to manual (thanks Henry)

or video manual on youtube:


internal settings on the Mystery Brain revealed:

thanks TeleTalks for this review!!


Long Winded description:  go get a mug of tea or coffee. (or watch the 12 min video below..thats debatabley shorter hah! )

100% analog vintage tone, texture and dynamic replication of the 70's Japanese RE-301 Space echo PREAMP w a boost mode, AND a digi Tape echo sim using analog photocell modulation for chorus or vibrato in the slapback. Tape Echo uses a low res digi chip for its repeats but the entirety of its circuit is analog including the opamp preamp section and boost section of photocell modulation. yep!

I've added a DB cut/clean switch if you want less saturated attack going into the front of the delay circuit(inside box*). This lo res digi tape emulator has been tweaked to let the brawn and mids attack of the Brain preamp hit it hard and saturate to the point of slightly overdriving the slapback and giving more smear to the response. Slight but its there so sweetly, an unusual quality not found in most basic digital delay pedals.

In addition there is a defeatable (toggles on and off) analog modulation circuit that affects the wet signal of the echo repeats and interacts with the emulators Mix, Repeat, and Time functions. This allows subtle shimmer, dimensional chorus all the way to fast trem pulse and off kilter vibrato at slower deeper rates (additional trimmer inside for wet/dry ratio on modulation Vs.4). To be straight up, this cool analog photocell modulation was added just to make the Brain Preamp sound like my actual 301 Tape echo, I built this pedal around.

All the other fun stuff it creates is a bonus palette of effect and space.  If that isnt something you need on all the time, just turn it off and get a smidge more delay time.   Rates from about 15ms - 600ms tape delay times. Bathtub funk, honky tonk to vintage Gallup and Scotty tape slap, to full blown Brain Seltzer Orchestral Neo-Billy all the way to 70's/80's vintage DMM'ish Edge vibe and Space Rock.

An added joy unique to this box is that the Abby Mode on the Atomic Brain section, really takes on an almost light overdrive boost when the Tape echo emulator is engaged and the Bass Cut is all the way to the right at 5 oclock. Like the vintage bassman rig that clips in the upper mids but stays fat and woody in the lows.. I swear this thing carries that ghost but I want to be careful not to go down a path of hyperbole, this wont turn you into Brain Seltzer, there's more involved haha.  This Mystery Brain BS-301 is solid 18 yr journey of chasing that particular guitarists tone and texture, more so his unique pick attack and dynamic control. Born out of love for my upbringing in vintage roots rock (gospel, surf, Honky Tonk, neo-rockabilly) and STP, what? Yep, its been developed on stage in front of weekly live audiences, honed and refined for many yrs as a pedal builder. I've had many a space echo, and this one has been torn down many times. Most recently the motor needed servicing. More reason to just have a pedal version of this old beast!

*notes about trim pot functions inside the pedal:

inside the pedal is a micro sized metal trim pot that controls the boost/cut of the secondary echoplex preamp that sits after the Space echo preamp/atomic brain. This input preamp is at the front of the echo circuit and I have it set a hair above neutral. so if the Brain preamp is on then you will hear a slight raise in output when it hits the front of the echo circuit. Then.. the vibrato circuit ALSO has its own preamp but that is only experienced on the echo slap back. If you turn up the preamp trimmer on the echo circuit, your repeats get dirty and noisier. Turn it back the other way and its level decreases a bit and cleans ups. NOTE: it unlike the big blue trimpot inside, isnt meant to be continually turned and if over turned, will snap off. Reading glasses and an eyeglass,jewelers screwdriver works a charm... like I mentioned the blue trimpot is more sturdy and it controls the wet.dry boost of the vibrato circuit. I have it all set up so that when the atomic preamp is on, it pushes on the front of the echo circuit and causes a tiny bit of saturation to the echo chip creating a more realistic vintage tape vibe. Putting on the vibrato switch, even if set to a subtle warble then enable one more gain stage completing the emulation of an old tape machine. Now.. one could go, hey I thought this was a pure re-301 tape echo emulation box. It is, but I've given it more option and versatility BECAUSE mr. Brian Setzer records in the studio not only w his space echo but w his fulltone tube echo and vintage echoplex. He's been quoted as also laying echoplex over the entirety of his finished tracks so on his albums, you are hearing a mix of RE-301 and echoplex to a degree. Thats what the Mystery Brain BS-301 gives you, and is so appropriately named.

< A response from a significant customer base on comparison features between the 1970's Roland RE-301 Space Echo (discontinued by Roland and used only for educational purposes of discussion) and the Nocturne Mystery Brain BS-301:

There are a number of things going on w an RE-301 space echo that we have to first sort through first.

1. the space echo is a line level multi effects(built for insert into a PA systems effects buss, or for keyboards ie. low Z) unit w 3 channels w their own individual preamps and dB pads.

2. It has a switchable stereo analog chorus effects circuit.

3. it has a solid state spring tank circuit.

4. it has a mechanical tape echo circuit

5. it has a treble and bass EQ recovery boost section that only functions on the wet level of the effects, does not work on the dry guitar signal.

6. In order for a high Z(high impedance) signal like a guitar, bass guitar,etc there must be some form of impedance corrector in line between the space echo and the instrument. Otherwise it sounds dark/muddy.

7. we remove the remote stomp switch jacks! we eliminate 2 of the xtra channels, we eliminate the reverb and the analog chorus.

..........but instead we give it

A. single preamp channel that has a proper impedance correction and we

B. add both a bass cut (full to lean low mids) and

C. a presence cut switch, for a wide variety of guitars and pedal board signal option.

D. We place an analog photo cell LFO (vibrato chorus) to the wet only slap back for both chorusing/vibe effect/tape warble sim.

E. and we give the really well built hybrid analog digi tape echo an extra preamp in its front end from an echo plex w a mini trim pot for you to add or cut* (explain later). and finally

F. we bring back a form of recovery boost switch/stomp called Abby mode.

G. and replace remote switching jacks w hard wire stomp switches that are true bypass.

 *A smart word on Op-Amps:

"The ironic part is how consistent op amps sound, and even different types can typically sound very similar. Why? They all do basically the same thing, especially at 9VDC.
...99% of the reason that the "operational amplifier" was created was because it is consistent and linear. Distortion or clipping was not ever a part of its design, ever. It was actually designed to provide a large amplitude gain and have the "positive and negative" portions of the audio signal "match" in amplitude. "
" -author unknown


 a good word:

 "I have both and originally bought the mystery brain as a backup for the re 301. As I’ve really learn to use the mystery brain I almost never use the re 301 anymore. Tonally they are about as close to identical as can be once I dialed it in. The echo has some differences but one thing about the re 301 is that my echo changes depending on what brand of tape I use. Overall I couldn’t be happier with the mystery brain, in fact I have debated selling my re 301 but I still use it in the studio for other applications aside from guitar." - Michael Mitropoulos

1 yr warranty on all parts and labor, shipping not included. All sales are final.

Share this Product

More from this collection