Volt 1 Hardware Manual


This article contains complete instructions for Volt 1 hardware controls and connections.

Note: To learn how to set up Volt with audio software and how to redeem your bundled software, please see UA Connect with Volt Interfaces.




Article Contents



Getting Started

To begin with setup, follow the steps below. The UA Connect software guides you through the process step-by-step.

  1. Download and install UA Connect from www.uaudio.com/volt/start 
  2. Launch the UA Connect application
  3. Follow the instructions within the app

To learn how to set up Volt with recording software and how to redeem your bundled software, please see UA Connect with Volt Interfaces.



Introduction & Overview

A Letter from Bill Putnam, Jr.

Thank you for choosing Volt as part of your music making experience. We know that any new piece of gear requires an investment of time and money — and our goal is to make your investment pay off.

Universal Audio’s family of audio interfaces represent the best examples of what UA has stood for over its long history; from its original founding in the 1950s by my father, to our current vision of delivering the best of both analog and digital audio technologies.

Volt’s best-in-class audio quality serves as its foundation, but this is just the beginning. Volt is also the perfect "on-the-go" audio interface and features an exclusive analog Vintage Mic Preamp circuit, inspired by our legendary UA 610 mic preamp. Plus, some Volt models feature the analog 76 Compressor inspired by our iconic 1176 limiter heard on thousands of classic records. Volt also includes MIDI for connection to a wide range of devices, and direct monitoring capability for latency-free recording.

At UA, we're dedicated to the idea that technology should serve the creative process — not be a barrier. These are the very ideals my father embodied as he invented audio equipment. We believe Volt will earn its way into your creative workflow by providing stunning fidelity and rock-solid reliability for years to come.

Please feel free to reach out to us via our website www.uaudio.com, and via our social media channels. We look forward to hearing from you, and thank you once again for choosing Universal Audio.

Bill Putnam, Jr.


Record Like a Pro, Anywhere.

We created Volt 1 for singers, guitarists, and content creators who want to easily record audio with legendary studio sound. Plug right into your Mac, PC, iPad, or iPhone and Volt just shows up — ready to capture your inspiration with professional sound, courtesy of Universal Audio.

Record Yourself with Best-in-Class Audio Quality

From the team that brought you the game‑changing Apollo interface, Volt 1 delivers superior studio sound quality, with more character and tone than any USB interface in its class. 

Capture a Legendary Vocal with Vintage Mic Preamp Mode

Few sounds can compare to a vintage Universal Audio 610 tube preamp, as used to record everyone from Ray Charles to Van Halen. Volt 1 gives you the rich, full sound of this iconic UA preamp, thanks to its built-in tube emulation circuitry, a UA exclusive.

Get a 30-day Free Trial to UAD Spark

Start creating music with the best gear ever made using UAD Spark, an ever‑expanding library of world‑class plug‑ins and instruments for a low monthly price. UAD Spark plug‑ins run natively on Mac and will give your recordings the professional analog tones heard on your favorite albums.

Try UAD Spark

Stay Inspired with a Curated Suite of Audio Software 

Some audio interfaces give you a smattering of random audio apps. Not Volt. Instead, we put together a bundle of serious music production tools, virtual instruments, and plug‑ins from the industry's best.

Easy In, Easy Out

Volt 1 gives you simple 1-in/2-out audio connections. Just plug in a mic or instrument to the front panel. Then connect your speakers or headphones to monitor your audio with no latency. With Volt, you’ll be creating like a pro, fast.

iPad & iPhone Ready

Traveling light? Plug Volt 1 into your iPad or iPhone, and you can easily create beats and samples, record your band’s rehearsals, and edit songs anywhere (requires external Volt power supply and an Apple Lightning to USB Camera Adapter, except iPads with USB-C).

Capture Inspiration for Years to Come

Featuring rugged all-metal construction and sleek, vintage-inspired industrial design, Volt 1 elevates your production space with impeccable style, built to last decades.

Key Features

  • Desktop 1-in/2-out USB audio interface with class-leading 24-bit/192 kHz audio conversion for Mac, PC, iPad, and iPhone
  • Vintage Mic Preamp mode lets you record voice or guitar with the rich, full sound of a classic UA tube preamp 
  • Essential suite of audio and music software including Ableton, Melodyne, UJAM’s Virtual Drummer, Marshall, Ampeg, and more
  • Studio-quality headphone amplifier for loud, clear monitoring
  • USB bus powered to reduce cable clutter
  • 48V phantom power for condenser microphones
  • Direct Monitoring for latency-free recording
  • Stylish, rugged construction built to withstand years of use
  • 1-in/1-out MIDI connections
  • USB-C to USB-A cable included

System Requirements

Please visit this article for Volt system requirements.



Volt 1 Hardware Descriptions

All hardware controls, connections, and indicators are explained in this section. 

Front Panel


(1) XLR/TRS combo input 

Connect your microphone, instrument, or line level source here. The combo input connector accepts XLR and ¼” (6.35 mm) plugs. 

A microphone is typically connected with an XLR connector, and an instrument or line level signal is connected with a ¼” (6.35 mm) TS or TRS plug. 

Preamp gain and impedance automatically adjusts for line or mic signals, based on whether the plug is XLR or ¼”, along with the state of the INST button. 

Press the INST button to toggle the impedance and gain of the line input to accommodate a Hi-Z instrument, such as an electric guitar or bass. 

Tip: The Vintage Preamp can be used on mic, line, and instrument inputs.

Balanced and unbalanced connections

  • The line inputs on Volt are balanced when connected with TRS connectors to balanced equipment. 
  • Use TRS (balanced) audio cables for the best results with balanced audio sources. Balanced equipment uses three conductor wiring (via TRS or XLR connectors) to reduce interference and electrical noise, and to provide better audio quality over longer cable runs. Use TS (unbalanced) cables for instruments that are not balanced, such as an electric guitar or bass, or an unbalanced synth or sound module. TS connections may also be suitable for shorter input cables, where electrical interference noise may not be an issue.

(2) Gain Knobs

These knobs adjust the preamp gain for the microphones, instruments, or line level devices attached to the associated inputs. For optimum gain, rotate the gain knob to adjust the input signal level while monitoring the source that is connected, so the input meters (3) show signal but do not light red.

(3) Input Meters

The Input Meters show the signal level of the input, which is controlled by the Gain knob. The red input LED lights when the input signal is near 0 dB. 

Tip: Clipping occurs when the signal is overloaded. When clipping occurs, the top of the waveform is squared off, creating distortion that may be unpleasant. Clipping has creative uses, but is usually avoided. To prevent clipping, adjust the gain so only green and yellow meters light, and the red LED doesn't light.

(4) Vintage Button

Press this button to toggle the Vintage Preamp. The Vintage Preamp can be used on mic, line, and instrument inputs. 

The Vintage Preamp adds a carefully crafted analog tube preamp emulation, inspired by Universal Audio’s all-tube 610 console preamplifier, to the sound. When the button is lit orange, the circuit is active. 

(5) Instrument Button (INST)

Press this button to toggle the impedance and gain of the line input to accommodate a Hi-Z instrument, such as an electric guitar or bass. This button is lit green when the Hi-Z input is enabled.

Tip: Generally speaking, the INST button should be off when connecting a line-level source such as a keyboard or sound module, unless you need more gain. 

(6) 48V Phantom Power Button

Press this button to toggle 48V phantom power at the XLR microphone input. The LED blinks red while phantom power is activating or powering off. The LED is lit solid red when phantom power is active.

Phantom power is required by most condenser microphones, but is usually not required with dynamic microphones or ribbon microphones (phantom power can damage some ribbon microphones). 

Note: Disable phantom power before you connect or disconnect the microphone.

(7) Monitor Knob

Rotate this knob to adjust the volume of speakers connected to the Monitor outputs. The output signal level meters indicate the output levels. 

(8) Headphone Output

Connect stereo headphones to this output. Headphones are connected with a ¼” (6.35 mm) TRS plug. If your headphones have a ⅛” (3.5 mm) plug, use a TRS ⅛” to ¼” adapter.

(9) Headphone Volume Knob

Adjust the headphone volume with this knob. The headphone volume control is independent from the Monitor volume control. 

Note: The monitor output and headphone signals are the same. 

(10) Direct Monitoring Button

Press this button to enable or disable direct monitoring. Direct monitoring is on when the button is lit blue, and off when the button is unlit. 

Important: Direct monitoring applies to the input signals only. You always hear audio from your computer or audio software regardless of this setting.

Direct monitoring notes

  • When enabled, direct monitoring slightly reduces the volume from your audio software so you can clearly hear your input signals.
  • When direct monitoring is on, disable the software monitoring feature in your audio software to prevent signal doubling, which can make your input sound thin or “phasey.”
  • When direct monitoring is off, you may notice your inputs have latency (a slight delay) before they are heard, as a result of buffering and signal processing by the audio software. 

What is direct monitoring?

Use direct monitoring on Volt to hear your input signals with no delay in your headphones and monitor speakers.

With direct monitoring, you hear the input signals directly from the Volt hardware with no delay or latency, bypassing your audio software’s buffers

When you monitor input signals through your audio software, those signals pass through the software before you hear them from the Volt monitor and headphone outputs. These signals use the software buffer, which causes latency — an amount of delay that increases as the buffer size is increased. 

Use direct monitoring when you are recording sources that you don’t need to monitor through your software. For example, use direct monitoring for vocals or instruments that don’t require you to listen to effects or plug-ins in your software.

(11) Host Indicator

The host indicator is lit blue when Volt is recognized by the computer or device. 


Rear Panel


The rear panel is used to make audio output connections, the USB connection to the computer, and MIDI connections.

(12) Monitor Outputs

Connect your stereo speaker system to the monitor outputs. Connect the left speaker to Monitor 1/L and the right speaker to Monitor 2/R. You can use TS (tip-sleeve) or TRS (tip-ring-sleeve) ¼” (6.35mm) cables. 

Balanced and unbalanced connections

  • The outputs on Volt are balanced when connected with TRS connectors to balanced equipment. 
  • Use TRS (balanced) audio cables for the best results with a balanced stereo speaker system. Balanced equipment uses three conductor wiring to reduce interference and electrical noise, and to provide better audio quality over longer cable runs. TS connections may be suitable for shorter output cables, where electrical interference noise may not be an issue.

Note: The monitor outputs are not powered. You will need to connect the cables to either powered speakers or an amp with speakers.

(13) MIDI I/O

You can connect a MIDI device to Volt with standard 5-pin MIDI DIN cables. Connect the MIDI OUT of your device to the MIDI IN on Volt, and the MIDI IN of the device to the MIDI OUT on Volt. 

You may not need to make both connections. For example, a MIDI controller might only be connected to the MIDI IN on Volt, and a MIDI sound module might only be connected to the MIDI OUT from Volt. 

(14) USB-C

Connect Volt to a USB 2.0 (or higher) port on your computer with a USB-C to USB-A cable (included), or with another cable. 

For example, you can connect with a USB-C to USB-C cable if your computer has a USB-C port. For iOS or iPad devices, connect the interface with a USB-C cable (iPads with USB-C) or with the Apple Lightning to USB Camera Adapter (other iPadOS and iOS devices).

Note: Volt is bus powered when connected to ports that meet USB 2.0 specifications. However, some USB ports, such as those on low-quality hubs, don’t meet USB specs and cannot supply adequate bus power. If Volt doesn’t power on, connect Volt to external 5VDC power to compensate for the underpowered USB port.

(15) 5VDC Power

Volt is bus powered when connected to a USB port that supplies adequate power. You can use the 5VDC connector to connect to power when required (for example, if you want to reduce power drain on an iPad or laptop, or if the USB port or hub is not able to provide enough power). 

Tip: You can power Volt by connecting the included USB-A to barrel connector power cable to a USB power adapter, then connecting the barrel plug to this power inlet on Volt.  

(16) Power switch

Apply power to Volt with this switch.

(17) Kensington security slot

Use with Kensington-compatible security devices to secure Volt hardware.






No power

  • Make sure Volt is connected to a port that meets USB 2.0 specifications.
  • If bus power is insufficient, connect Volt to external 5VDC power to compensate for the underpowered USB port.
  • Make sure the power switch is in the ON position.

Host indicator doesn’t light

  • Power Volt off and back on.
  • Try a different USB port or USB hub.
  • Try a different USB cable.

Crackling audio, dropouts, glitches

Increase the buffer size setting in the software on your computer. When recording, you can use direct monitoring to record without latency at higher buffer sizes.

(PC) ASIO driver not available in DAW

Install the Volt hardware driver with the UA Connect app.



Volt 1 Specifications

For Volt 1 specifications, please visit this article.



Articles in this section