The Nocturne Brain JR BARNYARD is an octal tube style preamp pedal, built to emulate the preamp circuit of the Gibson EH-150 and EH-185 amps of the late 1930s and 40s1. It is an analog, class A discrete transistor (BJT) preamp that uses a mix of imported Soviet germanium and Fairchild silicon diodes at its core1. The maker describes the basic sound as a punchy, honky, almost reedy or flutey late 30s and 40s swing tone, or cranked up, a full on wooly 50s Chicago rhythm and blues sound1.
Delicious Audio, which featured the V2 version in July 2021, describes the pedal as Nocturne's take on the vintage 1930s to 40s octal tube amp circuit found in early Gibson and Dickerson amps, and notes the builder behind the company is a self-described "ol' American rockabilly boy true to old school heritage"2.
A pre-war hot preamp in a pedal
The JR Barnyard is a preamp pedal rather than an overdrive or distortion: it shapes the front end of your tone the way the preamp section of a pre-war amp would. The maker calls it a "Pre-War Hot Preamp," a 1930s to 40s octal tube amp character pedal1. Delicious Audio describes the V2 as a FET based preamp using a hand selected, spec'd NOS Motorola transistor2, while the maker's current page specifies the circuit as transistor (BJT, not FET) based1; the two sources disagree on the transistor type, and the maker's page is the newer statement.
The component list is part of the appeal for vintage-minded builders: Soviet germanium and Fairchild silicon diodes, NOS Mial caps, NOS Cornell Dubilier and Mullard or Wima film caps, Switchcraft jacks, and hand wired leads1.
The pedal is not limited to guitar. Delicious Audio notes it works on guitars and basses, and also on electrified mandolins, ukuleles, banjos, or any other instrument with a pickup2.
The controls and switches
The current standard model is a single stomp version with a blend control between the normal and mic channels, in a smaller compact size than the original1. The layout is simple:
| Control | What it does |
|---|---|
| Left knob | Volume1 |
| Right knob | Blend between two channels: all the way left is the clean/normal channel, all the way right is the hot/mic channel; at about 11 o'clock the hot channel begins to blend into the clean channel1 |
| Left switch | Presence cut1 |
| Right switch | Bass or guitar mode1 |
| Body depth switch | Deep or flat1 |
| Bright switch | Voiced for a variety of guitars, mandos, ukes, banjos and dreadnoughts1 |
The blend control is the heart of the design. The original handwired version used a second stomp switch on the left to blend in the hotter mic channel of the EH-185, which the builder added so he could dial in more texture21. Version 2 replaced that second footswitch with the blend knob between the normal and a virtual, hotter mic channel, letting you dial in extra texture to taste2.
Handwired and standard versions
The standard model is the single stomp version with the blend control and smaller compact size. The handwired original version is available as an upgrade option1.
The handwired version uses PCB through hole components; the standard version uses mini component SMD circuitboards1.
The maker's page notes the standard model ships in a Cola color1. The earlier V2 version, covered by Delicious Audio in 2021, is documented separately on the Nocturne JR Barnyard Pre-War Hot Preamp V2 page.
Power, warranty and ordering
The pedal is powered by a standard Boss style 9V DC adaptor, with no power supply adapter included; the maker requires an audio quality 9V DC supply only1. Players on 230V mains in the EU or UK are directed to the Boss PSU230 9V DC power supply1.
These are built per order and there are no returns. The warranty covers 1 year on all parts and labor, with shipping not included, and no power supply is included1.
Videos
Tommy Harkenrider
R.J. Ronquillo
The Nocturne Brain
Questions
Is the Nocturne Brain JR Barnyard true bypass?
Yes. The Nocturne Brain product page states the pedal is true bypass, so with the effect switched off your signal passes through without buffering or coloring. Delicious Audio's writeup of the V2 version confirms the same.
Does the Nocturne Brain JR Barnyard come with a power supply?
No. It runs on a standard Boss style 9V DC adaptor, but no power supply is included, and the maker specifies an audio quality 9V DC supply only. Players on 230V mains in the EU or UK are pointed toward the Boss PSU230 supply.
What Gibson preamp is the Barnyard based on?
It is more or less designed to emulate the preamp circuit of the Gibson EH-150 and EH-185, the 1930s and 40s octal tube amps. Delicious Audio also traces the circuit to early Dickerson amps, the company that taught Gibson how to build those amps.
Can the Nocturne Brain JR Barnyard be used with bass?
Yes. The right toggle switch selects bass or guitar mode, and Delicious Audio notes the pedal works on guitars and basses as well as electrified mandolins, ukuleles, banjos and any other instrument with a pickup.
What is the difference between the handwired and standard versions?
The standard model is the single stomp version with a blend control between the normal and mic channels in a smaller compact enclosure, built on mini component SMD circuitboards. The handwired original version is available as an upgrade and uses PCB through hole components.
Sources (2)
- JR BARNYARD® EH-150 /185 octal tube style Preamp, The Nocturne Brain
- Nocturne JR Barnyard Pre-War Hot Preamp V2, Delicious Audio, 2021-07-22
