Boss ME-25 Multieffects Review


The built-in Sound Library

A collection of patches, 6 categories, each with 10 variations that can be easily edited and stored, both for modern and classic styles. For this purpose the user can utilize a Boss software, completely free. The USB allows a fast and comfortable connection of the floorboard to the PC. Is available also a dedicated website, where users can listen and download new patches for the Sound Library and the Windows drivers.

A good device for the practising

A looper that can record up to 38 seconds and an AUX IN input to connect an external device, for instance a CD or a music player. The looper is compatible with the overdubbing, so other audio material can be added during the playback. This feature makes possible the construction of complex phrases too.

The Speaker Emulator

It cannot be absent in a modern device. It works with the COSM technology, it derives from the ME-70, and includes, for instance, ULTRA METAL, a powerful high-gain distortion, and the Super Stack, that is equipped with a dedicated button. We will see the comparison between the ME-25 and the ME-70 at the end of the review.

The Tuner

It lets you adjust the reference pitch (435 - 445Hz). During the tuning the floorboard is in bypass, so no effect is applied to the original sound. The volume can be controlled via the expression pedal.

Additional audio features

  • A/D conversion
  • 24-bit + AF method. The AF method (Adaptive Focus method) is a proprietary technology from Roland and Boss that improves the signal-to-noise ratio.

  • Nominal Input Level
  • Guitar input: -10dBu; AUX IN: -18dBu.

  • Nominal Output Level
  • -10dBu.

Setup and connections

Connections and Setup

Signal flow

The image below shows the signal flow, but this is a general order. It can change according to the selected patch or for a particular setting.

Signal flow


Seven modules, each with various options. We will put in brackets the available parameters.

COMP/FX (Compressor and other effects)

  • COMP (Sustain, Attack and Level)
  • It can generate more or less sustain.

  • T.WAH (Sensitivity, Tone, Peak)
  • It matches the intensity and the strength of the picking on the strings.

  • AC SIM (Low, High and Level)
  • An acoustic guitar simulator.

OD/DS (Drive, Tone and Level)

  • It adds more gain and can be used alone, for a clean with a good Punch, or together with a COSM amp for a distortion.

  • OD-1
  • Boss produced this pedal, for the first time, in the 1977. It produces the classic distortion of the '70s, mild, natural, much rich in nuances and with a great amount of gain.

  • The Ibanez TS808 Tube Screamer was introduced on the market in the 1979, but in Japan it was sold with another name: Maxon OD808. It provides a warm sound, much natural, perfect for Rock, Blues or Country, and was one of the favourite pedals of a guitar legend like Steve Ray Vaughan.

  • An Overdrive.

  • DIST
  • Much sustain and high frequencies.

  • A vintage stack.

  • An high gain amp.

  • It boosts mids.

  • CORE
  • It cuts mids.

  • FUZZ
  • Rather metallic.

PREAMP (Drive, Tone, Volume, Bass, Middle and Treble)

  • Much warm.

  • TWIN
  • The Fender '65 Twin Reverb, today, exists in a Reissue version that delivers 85 Watts. It features 10 tubes: Four 12AX7 for the pre-amp section, two 12AT7 and four 6L6 for the power amp. Speakers are two Jensen C-12k with ceramic magnets. Two channels, Normal and Vibrato, and two effects, reverb, obviously, and vibrato.

  • This patch is the emulation of the Fender Bassman. Designed in the '50s, for bassists, it became immediatly a legend among guitarists. It is perfect for Blues or classic Rock, particularly the 50-Watt version with four 10" speakers. Obviously it is all-tube. It was so famous in the '60s and '70s that many sector manufacturers copied its circuitry.

  • Another product famous for its Crunch: the Vox combo.

  • The Mesa/Boogie combo.

  • The Marshall sound of the '70s.

  • Again Marshall, but modern and high-gain.

  • 5150 DRIVE
  • The lead channel of a Peavey EVH5150.

  • R-FIER
  • The Mesa/Boogie Dual Rectifier.

  • The name explains everything.


For these effects the ME-25 provides four parameters: Rate (the speed), Depth, Resonance (the intensity), Level (the volume).

  • It reproduces the rotation of the speakers.

  • UNI-V
  • The Uni-Vibe. It was very famous in the '60s.

  • HARMONIST (Key, Harmony and Level)
  • It must be used playing only one note at a time. Fundamentally it duplicates the signal with an octave. The user can decide the pitch of the duplication.

  • It adds an octave lower. Two parameters, the volume of the direct sound and of the effect.

DELAY (Time, Feedback and Level)

  • 1-99 ms
  • 100-990 ms
  • 1000-6000 ms
  • TAP
  • When this patch is active, you can set the Delay time using the SOLO pedal. This feature is explained in the manual.


Certainly, the most poor section. Only one parameter, the volume, and only two options.

  • ROOM
  • HALL


This is a module of effects that can be used with the expression pedal.

  • WAH
  • +1 OCTAVE
  • -1 OCTAVE
  • When it is active the sound can be sustained with the pedal. For example, it can be used to hold a chord while playing a melody line. Interesting. It creates a very particular atmosphere.

vs ME-70

The main differences

The ME-25 is simple and direct, with some buttons that lets you choose the effect type and some variations. A simple preamp section, with three controls, lets you adjust the sound generation, and the quality/price ratio is really excellent.
The philosophy of the ME-70 is that everything must be directly accessible in real time. So it is much more complete and rich in controls on the front panel. It features a more advanced preamp section, with 6 controls, directly derived from the GT-10, and the compatibility with the EZ TONE function is an important added value, absent in the minor sister. Essentially, a more professional approach, but with a more important cost. The two images below explain everything.

ME-25 Front Panel ME-70 Front Panel

Final opinion

A device with all the necessary for the guitarist at an incredible price. The Sound Library provides a lot of ready-to-use effects, easily editable, and with the convenience of the software with which patches can be saved and organized. The USB connection is very useful and expands the flexibility of this Boss floorboard. The speaker emulator, thanks to the COSM technology, is rather valid. It works really well. A very good product.

Other reviews

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