E-Lektron A28-DSP Live Mixer User Manual

1. Introduction

This manual provides detailed instructions for the E-Lektron A28-DSP Live Mixer. It covers setup, operation, maintenance, and troubleshooting to ensure optimal performance and longevity of your device. Please read this manual thoroughly before using the mixer.

2. Safety Instructions

• Power Supply: Use only the provided USB-C power adapter. Ensure the voltage matches the device requirements.
• Water and Moisture: Do not expose the mixer to water, rain, or high humidity. Avoid placing liquid-filled objects on the device.
• Ventilation: Ensure adequate ventilation around the mixer. Do not block ventilation openings.
• Heat Sources: Keep the mixer away from heat sources such as radiators, heat registers, stoves, or other heat-producing appliances.
• Cleaning: Disconnect the power before cleaning. Use a dry, soft cloth. Do not use liquid cleaners or aerosol cleaners.
• Servicing: Do not attempt to service this product yourself. Refer all servicing to qualified service personnel.
• Placement: Place the mixer on a stable, level surface to prevent accidental falls.
• Phantom Power: When using condenser microphones, ensure phantom power (+48V) is activated only when necessary and after connecting the microphone.

3. Product Overview

The E-Lektron A28-DSP is a compact audio mixer designed for various applications including recording, live streaming, and music playback. It features multiple input channels, a built-in DSP effects processor, Bluetooth connectivity, and a USB interface for PC/Mac.

Key Features:

• 2 Microphone/Instrument channels with switchable +48V phantom power.
• Combined XLR/Jack inputs for versatile connectivity.
• Mono/Stereo line channel for additional instruments.
• Stereo LIVE channel with 3.5mm TRS jack.
• Stereo MP3 player channel with recording function, switchable as a USB interface.
• Stereo Bluetooth channel for wireless audio streaming.
• 99-channel 24-bit DSP effects processor with adjustable parameters.
• Balanced studio-quality analog inputs and outputs.
• USB 24-bit audio interface compatible with Windows (XP and above) and Mac OS.
• XLR main outputs for active speakers or amplifiers.
• Headphone output.

Front Panel Layout:

Below is an image illustrating the front panel controls and connections of the E-Lektron A28-DSP mixer.

Figure 3.1: Front view of the E-Lektron A28-DSP Live Mixer, displaying the microphone/line inputs, various channel controls, the DSP effects section, and the main output controls.

Rear Panel Layout:

The rear panel contains the power input and main power switch.

Figure 3.2: Rear view of the E-Lektron A28-DSP Live Mixer, highlighting the EXT. DC IN (5V/1A) USB-C port and the POWER ON/OFF switch.

4. Setup

4.1 Power Connection

1. Connect the provided USB-C power adapter to the 'EXT. DC IN (5V/1A)' port on the rear panel of the mixer.
2. Plug the power adapter into a suitable power outlet.
3. Turn on the mixer using the 'POWER' switch on the rear panel. The power indicator light will illuminate.

4.2 Connecting Microphones and Instruments

• Channels 1 & 2 (MIC/LINE): Use XLR or 1/4" TRS/TS cables to connect microphones or instruments to the combined input jacks.
• Phantom Power: For condenser microphones, activate the +48V phantom power switch located near the MIC/LINE inputs. Ensure microphones are connected before activating.
• Mono/Stereo Line Channel: Connect additional instruments via 1/4" jack.
• Stereo LIVE Channel: Connect external audio sources (e.g., smartphone, tablet) using a 3.5mm TRS jack.

4.3 Connecting to Output Devices

• Main Output (MAIN L/R): Connect active speakers, power amplifiers, or PA systems using XLR cables to the 'MAIN L' and 'MAIN R' outputs.
• Headphones (PHONES): Connect headphones to the 1/4" TRS headphone jack for monitoring.

4.4 USB Connection to PC/Mac

• Connect the mixer to your computer using a USB cable.
• The mixer will be recognized as an audio interface (sound card) by your operating system (Windows XP or later, Mac OS).
• No special drivers are typically required.

5. Operating Instructions

5.1 Channel Controls (CH1, CH2)

• GAIN: Adjusts the input sensitivity for the connected microphone or instrument. Set to an appropriate level to avoid clipping (distortion).
• HIGH/LOW EQ: Two-band equalizer for adjusting treble (HIGH) and bass (LOW) frequencies of the input signal.
• FX: Controls the send level of the channel's signal to the internal DSP effects processor.
• VOL: Adjusts the overall volume level of the channel in the main mix.
• LOW CUT: Activates a high-pass filter to remove unwanted low-frequency rumble.

5.2 Stereo MP3 Player / USB Interface

• MP3 Playback: Insert a USB drive with MP3 files into the USB port. Use the transport controls (Play/Pause, Next, Previous) to navigate and play tracks.
• Recording: The mixer can record audio directly to a USB drive. Press the 'REC' button to start/stop recording. Note: Recording quality is 128 kbps MP3 at 44.1 kHz.
• USB Interface Mode: When connected to a computer, this channel can function as a sound card for streaming audio to or from the PC. Select the mixer as your audio input/output device in your computer's sound settings.

5.3 Bluetooth Connectivity

1. Activate the Bluetooth function on the mixer (refer to the display for 'BT' mode).
2. On your mobile device (smartphone, tablet), enable Bluetooth and search for available devices.
3. Select 'E-Lektron A28-DSP' from the list to pair.
4. Once paired, you can stream audio wirelessly from your device to the mixer.

5.4 DSP Effects Processor

• The mixer features a 99-channel 24-bit DSP effects processor.
• Selecting Effects: Use the 'MODE' knob to scroll through the available effects (e.g., Hall, Chorus, Flanger, Tremolo, Echo, Reverb). The selected effect number will be shown on the display. Press the knob to confirm selection.
• Adjusting Parameters: Each effect has two adjustable parameters (PARAT1, PARAT2). Use the corresponding knobs to fine-tune the effect characteristics.
• Applying Effects: Use the 'FX' knob on individual channels to send their signal to the DSP processor. The 'DSP EFX' volume knob controls the overall level of the effects in the main mix.

6. Maintenance

• Cleaning: Regularly wipe the mixer's surface with a soft, dry, lint-free cloth. Avoid abrasive cleaners or solvents.
• Storage: When not in use for extended periods, store the mixer in a cool, dry place, away from direct sunlight and extreme temperatures.
• Cable Management: Ensure cables are not tangled or stressed to prevent damage to connectors and ports.

7. Troubleshooting

7.1 No Sound Output

• Check if the mixer is powered on and the power indicator is lit.
• Verify all volume knobs (channel, main, headphone) are turned up.
• Ensure cables are securely connected to inputs and outputs.
• Test with different cables and output devices (speakers, headphones).
• If using phantom power, ensure it is activated for condenser microphones.

7.2 Bluetooth Not Connecting

• Ensure Bluetooth is enabled on both the mixer and your mobile device.
• Make sure the mixer is in Bluetooth pairing mode.
• Move your mobile device closer to the mixer.
• Try unpairing and re-pairing the devices.
• Check if other devices are already connected to the mixer's Bluetooth.

7.3 Poor Recording Quality via USB

• The mixer records to USB at 128 kbps MP3. This is a standard compression level.
• Ensure input gain levels are set correctly to avoid clipping or low signal.
• For higher quality recording, consider using the mixer as an audio interface with a computer and dedicated recording software, which may offer more format options.

8. Specifications

9. Warranty and Support

E-Lektron products are designed for reliability and performance. For warranty information, please refer to the documentation included with your purchase or contact your retailer. For technical support or service inquiries, please visit the official E-Lektron website or contact their customer service department.