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UAFX Del-Verb Ambience Companion Manual

This article contains complete operating instructions for the UAFX Del-Verb Ambience Companion effects pedal. 



A Letter From Bill Putnam, Jr.

Congratulations on your new UAFX pedal. We know that buying any new piece of gear requires an investment of time and money, and we aim to make your investment pay off!

At UA, we are dedicated to the idea of building “instant classics” — the type of music and audio gear that delivers album-worthy sounds to inspire you for decades.

UAFX pedals represent more than 20 years of research into vintage analog effects, coupled with next-generation digital engineering and rock-solid reliability.

Please let us know how we’re doing. Feel free to reach out to us via our website, and via our social media channels.

Thank you for your support, and enjoy your sonic exploration!


Bill Putnam Jr.



Del-Verb Quick Start


Download Del-Verb Quick Start Sheet




Get the Latest Firmware

Be sure to update your pedal’s firmware with UA Connect to get the latest features and functionality. To learn how to use UA Connect with your UAFX pedals, go here.




Del-Verb Overview

Pack your bags and embark on a delay and reverb fantasy. 

Built upon award-winning UAFX dual-engine processing and stunning sonic authenticity, Del-Verb Ambience Companion packs ready-to-wear emulations of classic reverb and delay effects, in a pedal designed for immediate inspiration.

  • Get three classic reverbs, from '60s tube amp spring, studio plate, and vintage digital hall
  • Explore vintage tape, analog bucket-brigade, and studio-grade digital delays
  • Sculpt three-dimensional soundscapes easily with simple controls and dual-stereo effect engines
  • Add tap tempo, download custom effect voicings, and more with the UAFX Control app

Dual Stereo Effect Engines for a Trip to Remember 

Del-Verb Ambience Companion's powerful engine runs separate stereo instances of each reverb and delay — letting you creatively combine effects with stunning three-dimensional stereo depth that is unmatched by any other stompbox.

Personalize your Pedal with a Mobile App

With the UAFX Control mobile app, you can add tap tempo and download custom voicings for each effect. 

Get UAFX Control

Del-Verb Features

  • The most authentic vintage reverb and delay effects ever captured in a single effects pedal
  • "Golden unit" spring reverb tank, pulled from a classic '60's American guitar amp 
  • Vintage German studio plate reverb sourced from The Plant (Sausalito, CA)
  • Bit-for-bit vintage '80s studio digital reverb algorithms 
  • Definitive emulation of iconic tape echo unit and legendary preamp 
  • Classic bucket-brigade analog delay effects with the color, texture, and tone of the original hardware
  • Pristine, studio-grade digital delays with dynamic and inspiring modulation textures
  • Add tap tempo, download custom effect voicings, and more with the UAFX Control app 
  • Silent switching, buffered bypass, analog dry through, optional spillover/trails, stereo/dual mono operation



Del-Verb Power

Note: Power supply sold separately.

UAFX pedals require an isolated 9 volt DC, center negative, 2.1 x 5.5 mm barrel connector (same as standard Boss connectors) power supply, which can provide 400 mA (milliamps) of current. Each UAFX pedal must be connected to a separate power supply, or connected to an isolated power connection from a multi-output power supply. Connect the power supply to the 9VDC connector on the pedal’s rear panel. 

When you first connect your UAFX pedal to a power supply, the footswitch LEDs cycle, showing that the pedal is starting up. The startup sequence takes about 15 seconds. There is no signal through the pedal during startup.

If power to your UAFX pedal is interrupted during operation, audio stops. 

Important Power Notes 

  • Each UAFX pedal requires 400 mA of current. Make sure your power supply can deliver at least 400 mA to the pedal for proper operation and performance.
  • An isolated supply provides power and grounding that is electrically separated, usually by means of a transformer for each connector. Some low-cost power supplies might have separate connectors, but might not provide true ground and power isolation, causing noise and ground loop hum. 
  • If your power supply has multiple outputs, make sure that each output provides true isolation, or that you connect your pedal to its own power supply.
  • It’s OK to connect a power supply that can deliver more than 400 mA. The pedal only draws the current it needs and will not be damaged if the supply is 9VDC.
  • If your power supply is not isolated, you might hear additional hum in the pedal signals. If the supply cannot provide 400 mA of current, the pedal might not operate properly, even if the LEDs and switches seem to be working. 
  • Daisy-chaining (running multiple pedals from one output of a power supply) is not supported.



Del-Verb Connections

To learn how to connect your UAFX pedals, go here.



Del-Verb Operation

You use the knobs and switches on Del-Verb to switch between the delay and reverb effects, and change the delay sound settings. Each of the six effects can optionally be assigned voicings (factory-configured effect settings) within the UAFX Control app.

Del-Verb features individual controls for the delay settings, and a single control for reverb level. If you optionally set a voicing for an effect with the app, that voicing is recalled every time you switch to the effect, along with the current knob settings. 

Note: Del-Verb’s delays play through the reverb, if reverb is enabled. 


By default, the left footswitch toggles the delay on/off, and the right footswitch toggles the reverb on/off. The behaviors of the left and right footswitches can be changed to suit your preferences using the UAFX Control app. 

Note: To learn how to use UAFX Control, go here.

The following footswitch modes can be selected in the UAFX Control app: 

Delay | Reverb*  The left footswitch toggles delay on/off. The right footswitch toggles reverb on/off. When toggled on, the footswitch’s LED stays lit.
Effects | Tap Tempo The left footswitch toggles both delay and reverb on/off. Tap the right footswitch two or more times to set the quarter note tempo.
*Default setting from factory and after restoring defaults

Delay | Reverb 

Delay: Press the left footswitch to toggle delay on/off. When enabled, the left footswitch LED stays lit. 

Reverb: Press the right footswitch to toggle reverb on/off. When enabled, the right footswitch LED stays lit.  

Effects | Tap Tempo

Bypass: Press the left footswitch to toggle delay AND reverb. When delay and reverb are on, the left footswitch LED stays lit. 

Tap Tempo: Tap (don’t hold) the right footswitch twice or more to set the quarter note tempo for the delay. The right footswitch LED blinks at the current tempo.

Effect Bypass Routing

Del-Verb effect bypass routing can be set for Trails Off or Trails On bypass using the UAFX Control app. Bypass routing determines how the pedal behaves when the effects are off. Note that Del-Verb outputs are always buffered.

Trails Off

When bypass routing is set for Trails Off and the effect is off, effects stop immediately when bypassed. By default, your UAFX pedal is set for Trails Off. 

Trails On

Trails On (spillover) bypass can be set in the UAFX Control app. When bypass routing is set for Trails On and the effect is switched off, delays and reverb tails play out naturally, rather than stopping suddenly.



Del-Verb Controls

Del-Verb’s knobs and switches control each delay effect similarly, but the effects vary, depending on the currently selected effect. See the individual delay and reverb effect details section for complete control descriptions.

Delay Time

Adjusts the delay time. Del-Verb’s delay time ranges, and whether delay time changes alter pitch, vary per effect. Note that quarter note tempo can also be tapped with the right footswitch, when tap tempo is enabled with UAFX Control.

When switching between effect types when very long delay times are set with the Delay knob or by tap tempo, delay times are automatically adjusted to compensate for the maximum available length.

Effect Delay time range Pitch altered by delay change?
Tape EP-III 80-700 ms Yes
Analog DMM 110-1068 ms Yes
Precision 120-1500 ms No*

*Pitch is altered with delay changes with certain voicings (labeled “glide”).


Adjusts the number of repeats. The Tape EP-III and Analog DMM will self-oscillate at higher feedback levels, and the Precision will repeat indefinitely at maximum feedback, but does not self-oscillate.

Self-Oscillation/Runaway Audio

When your sound is set to self-oscillate or repeat indefinitely with very high feedback, turning off the pedal does not stop the feedback. In Trails Off mode, it continues to run in the background and will return when you turn the pedal back on. In Trails On mode, it continues to play. 

To stop runaway audio, adjust Feedback lower. To quickly stop runaway audio, reduce Feedback to the minimum setting. 


Adjusts the level of delay that is mixed in with the dry signal. When you rotate this knob fully clockwise, the signal becomes 100% wet — you only hear the delayed signal and the dry signal is muted (kill dry).


Adjusts the delay character. Color has different functions depending on the active effect.

  • Tape EP-III – Adjusts the tape record level
  • Analog DMM – Adjusts the input gain to the delay
  • Precision – Adjusts the delay tone, darker to the left and brighter to the right, flat at noon


Mod adjusts delay modulation character and settings. The Mod control function varies depending on the active effect.

  • Tape EP-III – Changes the tape type. NOS tape left, worn tape right
  • Analog DMM – Changes the modulation type and depth. Vibrato left, chorus right, off at noon
  • Precision – Modulation type, speed and amount. Flanger left, chorus right, off at noon


Adjusts the level of reverb that is mixed in with the dry signal. When you rotate this knob fully clockwise, the signal becomes fully 100% wet — you only hear the reverb signal and the dry signal is muted (kill dry). Fully counter-clockwise, there is no reverb signal. 

Delay Effect

Select the delay effect with this switch. 

Reverb Effect

Select the reverb effect with this switch.

Left Footswitch

Press to toggle the effects (Effects + Tap Tempo mode) or to toggle the Delay effect (Delay + Reverb mode).

Left Footswitch LED

The left footswitch LED stays lit when both effects are active (Effects + Tap Tempo mode) or when the Delay effect is active (Delay + Reverb mode). 

Right Footswitch

When in Delay + Reverb mode (default), the right footswitch toggles reverb on/off. When in Effects + Tap Tempo mode, the right footswitch taps tempo.

Right Footswitch LED

When in Delay + Reverb mode (default), the right footswitch LED stays lit when the reverb is active. When in Effects + Tap Tempo mode, the right footswitch LED flashes at the current tempo.



Del-Verb Effect Details

Del-Verb includes three delays and three reverbs from our UAFX library. The specific functions of the knobs for each delay effect wary, depending on the capabilities and features of the delay effect. 

This section contains the specific control details for each delay effect, along with a controls map diagram for quick reference. You can download the control map diagrams, along with a blank recall sheet for noting your own settings, via the link below.

Download Del-Verb Control Maps & Recall Sheet



Del-Verb Delays

Whether it's the warm repeats of a '70s Maestro EP-III tape echo, the thick color of an Electro-Harmonix Memory Man, or UA's modern-sounding Precision Delay, Del-Verb's suitcase is packed with the definitive effects found in UA's mothership — Starlight Echo Station — for easy access to killer sounds in a flash.* 

Note: You can select and assign alternate Tape EP-III, Analog DMM, and Precision delay voicings using the UAFX Control app.

The following delay effects are available on Del-Verb.

Effect Description
TAPE EP-III A glorious system of motors and tape, vintage early-'70s tape echo units are beyond legend — and Del-Verb’sTape EP-III is, soup-to-nuts, the most complete circuit emulation of the classic hardware. From its wow/flutter randomness to the sound of the tape splice, every eccentric trait of the hardware is here. Plus, you can tweak your repeats with New or Worn tape, for tons of color and texture. 
ANALOG DMM Syrupy repeats, thick modulation, and mind-bending sci-fi effects are calling cards of this vintage American bucket-brigade delay. Del-Verb captures the best characteristics of multiple handpicked units from the late-'70s/early-’80s, modeling the entire circuit — right down to the unpredictable clock rate dumping — giving you startling "whoosh" effects, astonishing vibrato and chorus textures, and all the hazy zaniness of the original.
PRECISION Featuring pristine, mirror-image repeats with dynamic, shimmering modulation effects, the Precision effect is a goldmine of modern delays. Easily craft with touch-sensitive, studio-grade flange and chorusing textures and pepper your creations with ping-ponging repeats, adding movement and interest to your parts. 

*All trademarks are property of their respective owners and used only to represent the effects modeled as part of Del-Verb Reverb Companion.

Tape EP-III Control Details

Control Description Additional Info
Delay Time Delay time range is 80-700 ms. Delay pitch varies as delay time is changed.
Feedback Amount of delay repeats Past about 3 o’clock, delay repeats begin to self-oscillate. As you increase the feedback knob, tape hiss from the multiple repeats increases, as on the actual unit. At high settings, the delay’s self-oscillation can create interesting textures or washes of sound. At extreme settings, the self-oscillation creates distortion and noise.
Mix Level of delay signal mixed with dry signal. When fully clockwise, the dry signal is muted (delay is 100% wet).
Color Record level, adjusts gain of tape recording. Leave at noon to match hardware gain, increase beyond noon to add overdrive and saturation.
Mod Adjusts the tape age and machine. On the left half of the knob, the tape machine is a new old stock “closet classic” machine with new old stock tape and a snappy compander compression circuit on the record head. On the right half of the knob, the machine is a mid ‘70s unit, less well-maintained, with very worn tape and plenty of warbling, chorus-like repeats.


Analog DMM Control Details

Control Description Additional Info
Delay Time Delay time range is 110-1068 ms. Delay pitch varies as delay time is changed.
Feedback Amount of delay repeats. Past about 3 o’clock, delay repeats begin to self-oscillate.
Mix Level of delay signal mixed with dry signal. When fully clockwise, the dry signal is muted (delay is 100% wet).
Color Input gain; adds gain to delay repeats. Leave at noon to match hardware gain, increase beyond noon to add overdrive and harmonics.
Mod Modulation type and depth; modulation is off at noon. Speed is fixed to match the original hardware. The left half of the knob controls Vibrato amount, and the right half of the knob controls the Chorus amount. Set the knob at noon to disable modulation. 


Precision Control Details

Control Description Additional Info
Delay Time Delay time is 120-1500 ms. Delay pitch does not vary as the delay time is changed, except with specific “glide” voicings.
Feedback Amount of delay repeats. Fully clockwise, delay repeats repeat indefinitely. However, they do not self-oscillate.
Mix Level of the delay signal mixed with the dry signal. When fully clockwise, the dry signal is muted (delay is 100% wet).
Color Delay tone (flat at noon). To the left, cuts treble. To the right, adds treble. At noon, tone is flat.
Mod Modulation rate, depth, feedback, and mix. Combines control of multiple parameters to provide light to heavy modulation. The left half of the knob controls flanger modulation and the right half controls chorus modulation. Set the knob at noon to disable modulation. 



Del-Verb Reverbs

From the tube-driven springs of an American mid-'60s combo to the haunting sound of a German plate reverb and the lushness of an '80s digital studio classic, Del-Verb gives you the same reverb algorithms found in Golden Reverberator, the TEC Award winner for Best Effects Pedal in 2022.

Note: You can select and assign alternate voicings to the Spring 65, Plate 140, and Hall 224 reverbs using the UAFX Control app.

The following Reverb effects are available on Del-Verb. 

Effect Description

The tube-driven spring reverb from classic '60s American guitar amps is a heavenly sound like no other. But no two spring reverb tanks sound alike. So we auditioned over two dozen tanks, ultimately handpicking and modeling three tanks from a trio of vintage amps. Unlike other spring reverb emulations, UA's "whole amp" approach faithfully captures the reverb circuit's unique tube clipping character. The end result is all the drip, clang, whistles, and overtones of real tube-driven spring reverb.
Tip: With the UAFX Control app, you can load voicings on Del-Verb that use each of the three reverb tanks we modeled.

PLATE 140 The dense, haunting sound of late-1950s studio plate reverb is integral to more than 60 years of classic recorded guitar tones. Del-Verb’s uniquely voiced plate — sourced from The Plant recording studio in Sausalito, California — frames your tones in hazy ambience as warm as the midday sun. 
HALL 224 Introduced in the late 1970s, digital studio reverb allowed progressive guitarists to venture further into atmospheric exploration — fueling the platinum pop and alt-rock guitar tones of the 80s, 90s, and beyond. Del-Verb’s Hall 224 effect gives you the exact, bit-for-bit algorithm of a studio staple, with all of its lush, grainy tails and mesmerizing modulation textures.



Del-Verb Specifications

All specifications are subject to change without notice.

Power requirements

(power supply sold separately)

Isolated 9VDC, center-negative, 400mA minimum 

2 x ¼” unbalanced TS

(input 2 for stereo connections)


2 x ¼” unbalanced TS

(output 2 for stereo connections)

Bypass modes

(switchable within UAFX Control app)

Buffered bypass with or without trails
Input impedance

500 Kilohms (Mono In)

1 Megohms (Stereo In)

Output impedance 500 Ohms
Maximum input level 12.2 dBu
Maximum output level 12.1 dBu
Frequency response 20 Hz to 20 kHz, ±1 dB
USB Type-C For registration and firmware updates via computer

Wireless technology

Transmitted Frequency Range

Maximum Output Power

Bluetooth v5

2.400 GHz – 2.4835 GHz

+4.35 dBm


(with knobs and protrusions)

Height: 2.56 inches, 6.5 cm

Width: 3.62 inches, 9.2 cm

Depth: 5.55 inches, 14.1 cm

Weight (unboxed)

1.24 lbs

0.567 kg




Del-Verb Safety

safety-symbol-exclaim.png Caution: To help maintain the safety of your product, the chosen power supply must be a certified power supply complying with Limited Power Source (LPS) requirements with the following characteristics and electrical ratings: Isolated 9VDC, center-negative, 400 mA minimum, 2.1x5.5 mm barrel connector. Additional details at

safety-symbol-book-info.png Before using this unit, be sure to carefully read the applicable items of these operating instructions and the safety suggestions. Afterwards, keep them handy for future reference. Take special care to follow the warnings indicated on the unit, as well as in the operating instructions.

  • Read the instructions.
  • Keep these instructions.
  • Heed all warnings.
  • Follow all instructions.
  • Do not use this apparatus near water.
  • Clean only with dry cloth.
  • Do not block any ventilation openings. Install in accordance with the manufacturer’s instructions.
  • Do not install near any heat source such as radiators, heat registers, stoves, or other apparatus (including amplifiers) that produce heat.
  • Do not defeat the safety purpose of the polarized or grounding-type plug. A polarized plug has two blades with one wider than the other. • Protect the power cord from being walked on or pinched particularly at plugs, convenience receptacles, and the point where they exit from the apparatus.
  • Only use with attachments/accessories specified by the manufacturer.
  • Refer all servicing to qualified service personnel. Servicing is required when the apparatus has been damaged in any way, such as power-supply cord or plug is damaged, liquid has been spilled or objects have fallen into the apparatus, the apparatus has been exposed to rain or moisture, does not operate normally, or has been dropped.
  • This equipment does not contain a fuse or any other user-replaceable parts.
  • A compliance marking label is provided on bottom of the unit.

United States Class B Manual Statement

NOTE: This equipment has been tested and found to comply with the limits for a Class B digital device pursuant to Part 15 of the FCC Rules. These limits are designed to provide reasonable protection against harmful interference in a residential installation. This equipment generates, uses, and can radiate radio frequency energy and, if not installed and used in accordance with the instructions, may cause harmful interference to radio communications. However, there is no guarantee that interference will not occur in a particular installation. If this equipment does cause harmful interference to radio or television reception, which can be determined by turning the equipment off and on, the user is encouraged to try and correct the interference by one or more of the following measures:

  • Reorient or relocate the receiving antenna.
  • Increase the separation between the equipment and the receiver.
  • Connect the equipment into an outlet on a circuit different from that to which the receiver is connected.
  • Consult the dealer or an experienced radio/TV technician for help.

Japanese Class B Manual Statement

この装置は、クラスB機器です。この装置は、住宅環境で使用することを目的としています が、この装置がラジオやテレビジョン受信機に近接して使用されると、受信障害を引き起こ すことがあります。取扱説明書に従って正しい取り扱いをして下さい。VCCI-B

(This is Class B equipment. Although this equipment is intended for use in residential environments, it could cause poor reception if used near a radio television receiver. Please follow all instructions in the instruction manual.)

License exempt. This device complies with Industry Canada license-exempt RSS standard(s). Operation is subject to the following two conditions: (1) this device may not cause interference, and (2) this device must accept any interference, including interference that may cause undesired operation of the device.

Le présent appareil est conforme aux CNR d'Industrie Canada applicables aux appareils radio exempts de licence. L'exploitation est autorisée aux deux conditions suivantes : (1) l'appareil ne doit pas produire de brouillage, et (2) l'utilisateur de l'appareil doit accepter tout brouillage radioélectrique subi, même si le brouillage est susceptible d'en compromettre le fonctionnement.

Taiwan NCC Warning Statement

本公司產品取得NCC 低功率射頻器材審驗證明依據「低功率射頻器材技術規範」之新警語如下:「取得審 明之低功率射頻器材,非經 核准,公司、商號或使用者均不得擅自變更頻率、加大功率或變更原設計之特 及功能。低功率射頻器材之使用不得影響飛航安全及干擾 合法通信;經發現有干擾現象時,應立即停用,並 善至無干擾時方得繼續使用。

The company's products have obtained the NCC low-power radio frequency equipment verification certificate according to the new warnings of "Low-power radio frequency equipment technical specifications" as follows: "The low-power radio frequency equipment that has obtained the verification certificate shall not be changed by the company, firm or user without approval. Frequency, increase power, or change the features and functions of the original design. The use of low-power radio frequency equipment shall not affect flight safety and interfere with legal communications; continue to use.


Used electrical and electronic equipment should not be mixed with general household waste. Please dispose in accordance with local regulations.

  • IEC 62368-1
  • FCC ID: 2AXKQ2029
  • IC ID: 26610-2029
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