The Master Effects Monorail is a bass preamp pedal adapted from the Traynor Monoblock II bass amplifier. It puts the tone shaping of that amp in a pedal format, with a 5-band active gyrator EQ and Gain and Level controls, so a bass player can dial in their tone from a pedalboard. It sits in Master Effects' line of bass preamps alongside the Super Eight Hundred Plus, the Super Two Hundred, and the Thespian Valve Preamp.1
The controls and 5-band EQ
The Monorail carries five controls: Level, Bass, Middle, Treble and Gain. Level sets the output volume, Gain drives the preamp section, and the three tone controls shape the low, mid and high ranges.1
The heart of the pedal is its 5-band active gyrator EQ. A gyrator EQ uses active circuitry to simulate the inductors found in older graphic equalizers, which is a common approach in amp-style preamp pedals. The Monorail's five bands have center frequencies at 40, 100, 250, 1000, and 2500Hz, which Master Effects describes as a way "to fine tune and dial in your tone".1
| Control | What it does |
|---|---|
| Level | Sets the overall output level |
| Bass | Adjusts the low frequencies |
| Middle | Adjusts the midrange |
| Treble | Adjusts the high frequencies |
| Gain | Sets the amount of drive |
The Monorail's controls are Level, Bass, Middle, Treble and Gain, giving a bass player the basic preamp shape of the Traynor Monoblock II bass amplifier it is adapted from in pedal form.1
The maker does not publish center frequencies for the EQ bands, so the Bass, Middle and Treble controls are best read as a conventional three-band preamp EQ rather than a fixed graphic set: Bass shapes the low end, Middle the body and midrange of the note, and Treble the attack and upper definition, with Level setting overall output and Gain setting how much drive the preamp produces.1
Power, price and ordering
The pedal uses a standard boss-style 9V/100mA power supply, the same center-negative 9V format used by most pedalboard supplies. Because it draws 100mA, it needs a supply output rated for at least that current.1
The Monorail is built to order. Master Effects states that orders typically ship within 2 to 4 weeks.1
The price is $259US plus shipping, as of the maker's product page dated 26 October 2026. Shipping within Canada and the US is $20US, and shipping to the UK, Western Europe, Australia, and Japan is approximately $60US. Customers outside Canada are responsible for any customs, import or VAT charges their country levies on the pedal.1
Build and warranty
Each Monorail uses a professionally assembled PCB and is assembled by hand in Calgary, Alberta, Canada. Master Effects describes the end result as "high quality pedals that sound amazing, are consistent from pedal-to-pedal". Each pedal comes with a 1 year warranty on parts and labor, which excludes damage from an improper power supply or misuse.1
Videos
Master Effects Pedals
Questions
What amplifier is the Master Effects Monorail based on?
The Monorail is Master Effects' adaptation of the Traynor Monoblock II bass amplifier. The pedal takes the preamp circuit of that amp and puts it in a pedal format, so a player can get the Monoblock II's tone shaping from a pedalboard rather than from the original amplifier.
What frequencies does the Monorail EQ cover?
The Monorail has a 5-band active gyrator EQ with center frequencies at 40, 100, 250, 1000, and 2500Hz. That range runs from deep sub-bass content at 40Hz up through the midrange and into the upper presence range at 2500Hz, letting a player fine tune and dial in their tone.
What power does the Master Effects Monorail need?
The pedal uses a standard boss-style 9V/100mA power supply. A supply capable of delivering 100mA at 9V is needed, so a low-current daisy-chain output may not be enough on its own.
Where is the Master Effects Monorail made?
Each Monorail uses a professionally assembled PCB and is assembled by hand in Calgary, Alberta, Canada.
How long does a Master Effects Monorail take to ship?
Master Effects states that orders typically ship within 2 to 4 weeks. Shipping within Canada and the US is $20US, and shipping to the UK, Western Europe, Australia, and Japan is approximately $60US.
Sources (1)
- Monorail, Master Effects
