The Free The Tone Ambi Space AS-1R is a stereo digital reverb pedal from Japanese maker Free The Tone, the result of what the company describes as a long development period combining its analog and digital technology1. It offers six reverb algorithms, keeps your dry analog guitar tone unadulterated while the digital reverb signal is blended in on the way to the outputs, and is programmable and MIDI controllable2.
MusicRadar's review calls it "a superb studio-quality reverb" with "a really detailed and natural-sounding character" not far off the quality of rackmount studio reverb units2. Delicious Audio describes it as producing "the high quality, natural and musical sounding reverberation realized in this compact device"3.
What it does
The AS-1R processes reverb digitally, using a 32-bit dual core chip and a 32-bit high precision DSP3. The dry path is the important design point for players who care about tone: MusicRadar notes the pedal preserves "the dry analogue guitar tone unadulterated", with the reverb signal blended in by the Mix knob on its way to the outputs2. Your straight guitar signal never goes through the converters.
Free The Tone's original algorithm combines various elements to produce complex reverberation3. Six reverb modes are provided: spring, plate, room, hall, cave, and serene4. Two of them, CAVE and SERENE, are the company's own newly developed sounds, where early reflections and late reverberation are added in multiple steps to realize a complex harmonic structure comprising enhanced frequency components3. Delicious Audio's verdict on those modes:
"all of which creates an almost magical, transparent and spatial sounding reverb like you've never heard before"
The pedal is not guitar-only. Delicious Audio notes it "can of course be used for electric guitars and basses, as well as for acoustic guitars and vocals, it is equally at home" in recording and mixing3.
The controls
The control panel holds PRE DELAY, DECAY, TONE, MIX and MODE knobs, an INST (-10dB) / LINE (+4dB) level selector, and a KILL DRY switch8.
| Control | What it does |
|---|---|
| MODE | Selects the reverb algorithm: spring, plate, room, hall, cave or serene48 |
| PRE DELAY | Sets the delay before the reverb begins; MusicRadar found it "certainly adds a much needed realism and depth", and notes it produces a ducking-style effect in Spring mode2 |
| DECAY | Sets how long the reverb tail lasts; MusicRadar found it "adds interesting and reactive dynamics"2 |
| TONE | A low- or high-cut that brightens or darkens the effect, which MusicRadar found works "without being too harsh"2 |
| MIX | Blends the reverb signal with the dry signal; fully clockwise is a 50/50 mix, and it can also be set to 100% dry27 |
| INST/LINE switch | Matches the input level to the device feeding the pedal87 |
| KILL DRY | Back-panel switch for 100 percent wet output28 |
The Kill Dry switch deserves a note for anyone running an effects loop or recording setup:
The Kill Dry switch on the back panel enables 100 percent wet output, which MusicRadar notes gives "extra options for effects loops, recording/mixing" where you want only the reverb signal2.
Power, MIDI and connections
The AS-1R runs on 9V DC with negative center polarity and a current draw of 280 mA57.
Pedal of the Day specifies a supply of 280 mA or more with negative center polarity7. That draw rules out battery power and means a low-current daisy-chain output may not be adequate.
Connections are stereo in and stereo out: stereo inputs switchable between instrument and line level, plus a pair of stereo outputs, which MusicRadar found gives the pedal practical use for stage and studio2. The maker's specifications list input impedance of 1MΩ or higher on the INST input and 300kΩ or higher on LINE, with maximum input levels of +3dBu (INST) and +11dBu (LINE), and an output load impedance of 10kΩ or higher18.
MIDI is a big part of the pedal's design. MIDI in enables remote bypass switching, choice of reverb mode and algorithm type, parameter adjustment and preset selection2. Up to four settings can be memorized as presets, and those four presets can be recalled by MIDI program-change numbers4.
Versions: the AS-1R and AS-1R-CS
The AS-1R also exists as a Custom Shop version, the AMBI SPACE AS-1R-CS, which Free The Tone lists as a digital reverb with the same core identity: a variant of the AS-1R, the reverb unit the company created by combining its analog and digital technology1. The CS shares the same control set (PRE DELAY, DECAY, TONE, MIX, MODE, the INST/LINE switch and KILL DRY), the same stereo L/R input and output with the L input usable as mono, the same maximum input levels of +3dBu (INST) and +11dBu (LINE), and MIDI IN via a DIN 5-pin connector1.
What reviewers said
MusicRadar's overall verdict was short: "A superb studio-quality reverb."2 Pedal of the Day, reviewing it in January 2017, wrote of "huge waves of sound, lush reverb filled with joy and emotion and some of the warmer digital tones we've heard in a reverb", concluding that it "sets a pretty high standard for other manufacturers to follow and improve upon"7.
"With huge waves of sound, lush reverb filled with joy and emotion and some of the warmer digital tones we've heard in a reverb"
Guitar Pedal X included the AS-1R in its 2021 roundup of stereo reverb workstation pedals, listing its six algorithms and $380 price alongside its 9V DC, 280 mA power requirement5.
Videos
Andertons Music Co
FreeTheToneMovie
Mike Hermans
Questions
Can the Ambi Space AS-1R run in mono?
Yes. The pedal has stereo L/R inputs and outputs, and the L input and output are usable as mono connections. You can feed it a single mono input and take a single mono output, or run it in full stereo with two inputs and two outputs for a wider reverb image.
How many presets does the Ambi Space hold?
Up to four settings can be memorized as presets, and those four presets can be recalled by MIDI program-change numbers. The pedal is programmable and MIDI controllable, so you can switch between stored reverb sounds remotely rather than bending down to turn knobs on stage.
Does the AS-1R work with line-level gear and vocals?
Yes. A small switch on the pedal selects between Instrument and Line input levels, so it accepts guitar-level signals or line-level signals from mixers and recorders. Delicious Audio notes it can be used for electric and bass guitars, acoustic guitars and vocals, and is equally at home in recording and mixing.
What does the Kill Dry switch on the Ambi Space do?
The Kill Dry switch, on the back panel, enables 100 percent wet output, removing the dry signal entirely. That gives extra options for use in effects loops and for recording or mixing setups where you want only the reverb signal, blended elsewhere rather than inside the pedal.
What polarity power supply does the Free The Tone AS-1R need?
It runs on 9V DC with negative center polarity and a current draw of 280 mA, so it needs a supply rated at 280 mA or more. That draw rules out a battery and means a small daisy-chain output may not be enough; a dedicated 9V output is the safe choice.
What are the CAVE and SERENE modes on the Ambi Space?
CAVE and SERENE are Free The Tone's newly developed, original reverb sounds. In these modes, early reflections and late reverberation are added in multiple steps to build a complex harmonic structure with enhanced frequency components, which Delicious Audio describes as a transparent, spatial sounding reverb.
Sources (8)
- AMBI SPACE AS-1R-CS｜CUSTOM SHOP カスタムショップ｜Free The Tone, Free The Tone
- Free The Tone AS-1R Ambi Space review, MusicRadar, 2017-07-18
- Free The Tone Ambi Space AS-1R Stereo Digital Reverb, Delicious Audio, 2021-10-13
- Free The Tone Announces the Ambi Space Digital Reverb, Premier Guitar, 2016-09-26
- Guitar Pedal X, Guitar Pedal X, 2021-08-16
- AMBI SPACE / AS-1R｜Products 商品紹介｜Free The Tone, Free The Tone
- Free The Tone Ambi Space AS-1R Reverb, Pedal of the Day, 2017-01-23
- AMBI SPACE / AS-1R｜Products 商品紹介｜Free The Tone, Free The Tone
