Boss Waza Tube Amp Expander
Move your mouse over image or click to enlarge
Boss Waza Tube Amp Expander Boss Waza Tube Amp Expander Front Panel Boss Waza Tube Amp Expander Rear Panel Boss Waza Tube Amp Expander Top Down View

Boss Waza Tube Amp Expander

by Boss
Love the sound of your valve amp's tone, but sometimes get frustrated at the lack of flexibility with its "sweet spots"? Well have no fear, ..

Read More

This item is currently OUT OF STOCK

Availability Available To Order


Love the sound of your valve amp's tone, but sometimes get frustrated at the lack of flexibility with its "sweet spots"? Well have no fear, the new BOSS Waza Tube Amp Expander is here to ease those worries (and much more!).


Version 2 Firmware Upgrade

For all new and existing owners of the Waza Tube Expander, BOSS have made a firmware upgrade available for free.

This upgrade provides the Tube Expander with powerful new DI enhancements, an increase in speaker impulse response support, and an increase of user IR slots from 4 to 32.

In addition to this, there's more microphone choices available for the built-in cab sims.

Simply head on over to the Waza Tube Amp Expander Downloads section at the official BOSS website, and follow the instructions there to take advantage of this awesome free upgrade.


A Valve Tone Lovers' Dream Come True

With the BOSS Waza Tube Amp Expander you get a unique and diverse range of professional-grade tone tools, that helps to increase your valve amp's versatility in both Live and Studio settings.

BOSS Waza Tube Amp Expander Highlights

  • First-of-its-kind tube amp command center, built with Waza expertise and the Tube Logic design approach
  • Advanced variable reactive load circuit with discrete analog components supports tube amps up to 150 watts
  • User-adjustable impedance tuning correctly matches the reactive load to your amp, retaining its natural tone, dynamic feel, and distortion characteristics
  • 10 recallable rig settings for storing favorite setups
  • Deep real-time performance control via GA-FC/FS-series footswitches and MIDI I/O
  • Built-in 100-watt Class AB power amplifier with discrete analog design and seamless volume control
  • Powerful DSP section with 32-bit AD/DA, 32-bit floating-point processing, and 96 kHz sampling rate
  • Customizable stereo effects with premium tone quality: compressor, delay, reverb, and four EQs
  • Seven mic'd cabinet emulations with five selectable mic types, plus four slots for loading user speaker IRs
  • External effects loop with selectable series/parallel operation and control jack for switching amp channels
  • Parallel speaker outputs for connecting up to two cabs for gigging
  • Balanced XLR line outputs (mono and L/R stereo) for connecting to FOH console, stage monitors, and recording devices
  • Headphones output for quiet practice with cranked-up amp tones
  • Dedicated editor software (Mac/Windows)
  • USB for direct audio recording and editor communication

So... what exactly is the BOSS Waza Tube Amp Expander?

Well, that's simple: it's a variable reactive load box, whilst at the same time being an active analog power stage, a mic'd cab simulator, an IR loader, and even a recording interface... all in one!

Oh, and it also comes complete with built-in BOSS effects, 10 fully customisable rig setups, and deep real-time control.

Essentially, with the help of Tube Logic technology, the BOSS Waza Tube Amp Expander allows you to achieve everything you've always wanted your valve amp to be able to do, and more.

A Happy Accident

During the development of the flagship Waza Amplifier Head, BOSS conceptualised the Waza Tube Amp Expander as a means of comprehensively testing and refining the amp's AC power voltage and output circuitry.

This custom-made load box was devised with capabilities far beyond those in any commercially available unit, and was such a success that it became the foundation for the Waza Tube Amp Expander.

Get That Cranked Amp Tone At Any Volume

As a vintage valve amp owner, I can confirm that some of the best tones it's capable of can only be achieved with the volume cranked high - unfortunately, my neighbours disagree.

Thanks to the Waza Tube Amp Expander's reactive load section though, you can now completely eliminate those unwanted artifacts that quiet playing usually introduces (changes in tonal character, dynamic response etc.). This powerful little box allows you to experience those same cranked-up sounds and playing feel, whilst controlling the volume to suit any situation!

With the help of th Resonance-Z and Presence-Z panel controls, you are able to optimise the impedance interaction with your amp's output transformer. Not only that, buy you can choose from 16 unique settings, and make your amp behave and respond as it if was connected to your favourite speaker cab!

Rig Control Options

Featuring the capability of storing up to ten different rig setups (each one including custom effects/EQ settings, cab/IR selects, effects loop on/off, MIDI program change, and amp control status) the Waza Tube Amp Expander is a dream command centre for both live and studio use.

Footswitch Compatible

With a single TRS cable attaching your GA-FC foot controller (available separately) to the Waza Tube Amp Expander, you can have instant access to the 10 stored rig setups. You also get real-time control of the delay, tap tempo, solo/EQ, effects loop on/off, and amp channel switching functions.

Add in a couple of expression pedals and you can even control output/effects levels too!

Speaking of Effects...

The BOSS Waza Tube Amp Expander comes complete with a built-in effects engine and external effects loop, bringing a wealth of sonic enhancements to your tube amp.

Featuring options for Compressor, Delay, EQ and Reverb, with bags of customisable settings, all powered by an onbaord DSP with class-leading 32-bit AD/DA, 32-bit floating-point processing, and 96 kHz sampling rate, further shaping your perfect sound couldn't be more convenient.

In addition to this, the external Effects Loop offers selectable Series or Parallel operation, with support for both line-level devices and standard stompboxes.

So Many Output Feeds...

So you've dialled in the perfect settings on your amp, set the Boss Waza Tube Amp Expander up correctly, and are now looking to see what your output options are.

Well, worry not, because this fantastic device allows you to feed your audio through to stage cabs, mixers, recording devices, and headphones simultaneously!

Thanks to the integrated 100-watt Class AB analogue power stage and parallel speaker outputs, you can drive up to two speaker cabs.

In addition to this, balanced mono and stereo line outputs feature tone shaping properties in the shape of mic'd cab simulation and user IR's. These send ready-to-mix direct signals to the main PA mixer, stage monitors, and recording devices, allowing your analog audio sound exactly as you want it to.

There's also a USB output, giving you another direct feed for tracking your preferred DAW software, and even a dedicated headphones output for silent practice time.

Customisation Options

Despite being ready to rock right out of the box, the BOSS Waza Tube Amp Expander offers you even more creative potential once you connect a computing device to the USB socket and open up the dedicated editor software.

This editor allows you to alter effects and EQ's in minute details, as well as select from seven different mic'd cabs for the direct outputs (including the option to choose between five different mic types and adjustable placements).

Add to this even more tweaks for MIDI, system parameters, and even a loudness contour for those big, full tones at whisper-levels, and you'll be wondering where the BOSS Waza Tube Amp Expander has been all of your life.

Available to Order Now

If you'd like to query the availability of this item, be sure to contact our Online Sales Team or your Local PMT Store directly!

Alternatively, place your order Online today and choose from our range of Home Delivery options!

BOSS Waza Tube Amp Expander Technical Specs

From Tube Amp Input

  • Maximum Input Power: 150 W
  • Input Impedance: 4/8/16 ohms (selectable)
  • Safety Load (power off): 16 ohms

To Speaker Output

  • Rated Power Output: 100 W (8 ohms)
  • Load Impedance: 4-16 ohms

Nominal Output Level

  • Line Out L/R: +4 dBu
  • Line Out Mono (FOH): +4 dBu

FX LOOP Nominal Output Level

  • -10/+4 dBu (selectable)

Maximum Output Level

  • Line Out L/R: +20 dBu
  • Line Out Mono (FOH): +20 dBu
  • FX Loop Send: +6 dBu (-10) /+20 dBu (+4)

Input Impedance

  • Fx Loop Return: 1 M ohmOutput Impedance
  • Line Out L/R: 600 ohms
  • Line Out MONO (FOH): 600 ohms
  • FX Loop Send: 1 k ohm


  • Power switch
  • Speaker Out knob
  • Line Out knob
  • Phones knob
  • Resonance-Z knob
  • Presence-Z knob
  • Rig knob
  • Reverb knob
  • FX Loop button
  • Effects button
  • Solo/EQ button
  • Amp Ctl button
  • Speaker Impedance switch
  • Input Level switch
  • L/R Gnd Lift switch
  • MONO (FOH) Gnd Lift switch
  • Loop switch
  • Level switch
  • Send Gnd Lift switch
  • Return Gnd Lift switch
  • AMP CTL switch


  • Power
  • Write
  • FX Loop
  • Effects
  • Solo/Eq
  • Amp Ctl
  • Input Sig/Peak


  • From Tube Amp jack: 1/4-inch phone type
  • Speaker Out jacks (OUT A, OUT B): 1/4-inch phone type
  • Line Out L/R connectors: XLR type
  • Line Out MONO (FOH) connector: XLR type
  • Phones jack: Stereo 1/4-inch phone type
  • Send jack: 1/4-inch phone type
  • Return jack: 1/4-inch phone type
  • FX Loop jack: 1/4-inch phone type
  • GA-FC jack: 1/4-inch TRS phone type
  • Amp Ctl jack: 1/4-inch phone type
  • USB Computer port: USB B type
  • MIDI (IN, THRU/OUT) connectors
  • AC IN jack
  • Power Consumption: 100 W


  • Owner's manual
  • Power cord
  • Rack mount angle x 2 (for EIA-2U)
  • GA-FC sticker


  • Width: 380 mm 
  • Depth: 296 mm 
  • Height: 110 mm 
  • Weight: 6.8 kg


Weight (kg)4.0000

Customer Reviews

This product doesn't have any reviews yet, why not write one?

Write Your Own Review

Only registered users can write reviews. Please, log in or register