REC-40D · MP3 Audio Recording

REC-40D Mini Voice Recorder with 40-Day Audio Storage

The REC-40D records mono MP3 audio through a Knowles microphone and saves it to a removable microSD card. Measuring 22 × 18 × 8 mm, it starts recording as soon as power is applied. A 32 GB card holds up to 40 days of audio, depending on recording settings. This is storage capacity, not battery life.

Removable 32 GB microSD card included in the original package.
Knowles microphone with pickup up to 12–15 m (39–49 ft) under favorable acoustic conditions.
Mono MP3 recording.
5–24 V DC external power input.
Automatic recording when power is applied.

Product code: REC-40D

Currently out of stock. For a new installation, the PICO2 Wi-Fi audio transmitter is the replacement option, with local recording and remote access through an app.

Technical consultation and support.
+39 080 302 6530

REC-40D Features

Extended audio storage

A 32 GB microSD card stores up to 40 days of audio, depending on settings. Recording for an extended period requires a suitable power source throughout the session.

Removable storage

Retrieve the card to transfer recordings without removing the recorder from its mounting location, provided the card slot remains accessible.

Automatic startup

Recording begins when the module receives power. The standard version accepts a 5–24 V DC supply.

Full Description

Compact recording module for extended sessions

The REC-40D combines a Knowles microphone, recording electronics and a microSD slot in a 22 × 18 × 8 mm module. External power supports long recording sessions without relying on an internal battery.

Audio is saved as mono MP3 files. A 32 GB card provides up to 40 days of storage, with actual capacity depending on audio settings. Recordings can be played on Windows, macOS, Linux or Android using a standard MP3 player and a compatible card reader.

Microphone and removable memory

The Knowles microphone can pick up sound from up to 12–15 meters (39–49 feet) away under favorable acoustic conditions. Speech intelligibility depends on background noise, distance and microphone placement.

Removing the microSD card provides access to the recordings while leaving the module installed. Recording must be stopped before replacing the card; removable storage does not mean uninterrupted recording during a card change.

Power options

The standard version operates on 5–24 V DC. Custom lithium-battery configurations were also offered. Runtime with an external battery depends on battery capacity and the module’s current draw.

REC-40D is out of stock: PICO2 replacement option

The REC-40D is currently out of stock. PICO2 is the alternative for new audio recording installations. This page retains the REC-40D specifications for existing owners and anyone evaluating a replacement.

The PICO2 Wi-Fi audio transmitter records to microSD even without an Internet connection. When connected to a 2.4 GHz Wi-Fi network with Internet access, it also supports live listening and remote file downloads through an Android or iOS app.

PICO2 supports continuous or voice-activated recording (VOX), saves WAV files and accepts microSD cards up to 128 GB. It adds remote audio functions rather than duplicating the REC-40D hardware.

Replacing an existing installation

PICO2 measures 45 × 25 × 6 mm without its battery and requires 5 V DC. Optional interfaces are available for 12 V sources and 220 V AC power. An installation wired for the REC-40D’s 5–24 V input needs its power supply and available space checked before replacement.

View PICO2 specifications →

REC-40D Technical Specifications

Audio and Storage
Model	REC-40D
Availability	Out of stock
Replacement option	PICO2
Microphone	Knowles
Pickup distance	Up to 12–15 m (39–49 ft) under favorable acoustic conditions
Audio channels	Mono
Recording format	MP3
Storage	Removable microSD, up to 32 GB; card included in the original package
Audio capacity	Up to 40 days, depending on settings; not a battery-runtime rating
Recording startup	Automatic when power is applied
File playback	Windows, macOS, Linux and Android with MP3 playback software and access to the microSD card

Dimensions and Power
Length	22 mm
Width	18 mm
Thickness	8 mm
Standard power input	5–24 V DC
Custom power options	Lithium-battery configurations were offered for the original model
Battery runtime	Depends on the external battery and current draw; no fixed runtime specified
Current draw at 8 kHz	5.4–7.6 mA
Current draw at 16 kHz	7.3–8.8 mA
Current draw at 24 kHz	9.6–11.2 mA
Current draw at 44 kHz	16.0–16.8 mA

Current-draw values correspond to the sample rates listed in the original specifications. The test supply voltage is not specified.

Applications

Long-duration room recording

External power and removable storage support extended sessions in fixed installations. Retrieve the MP3 files for playback and archiving.

Vehicle installations

The 5–24 V DC input supports integration with a suitable DC power source. Recording starts automatically when the module receives power.

Compact installations

The small module fits installations with limited space. Keeping the card slot accessible makes it easier to retrieve recordings without removing the recorder.

Frequently Asked Questions

Is the REC-40D available?

The REC-40D is currently out of stock. PICO2 is the replacement option, offering local recording, live listening and remote file downloads through an app.

Does the 40-day rating refer to battery life?

No. It refers to the maximum audio storage capacity of a 32 GB microSD card, depending on settings. The REC-40D requires external power; runtime on a battery depends on the battery used.

Can PICO2 replace the REC-40D?

Yes, for room audio recording. PICO2 adds Wi-Fi access and app control, but its dimensions and power requirements differ. Existing installations need a space and power-supply check before replacement.

Can PICO2 record without Wi-Fi?

Yes. It records locally to microSD without Internet access. Live listening and remote downloads require a connection.

Can I connect PICO2 to the existing REC-40D power supply?

Not without checking it first. The REC-40D accepts 5–24 V DC, while PICO2 requires 5 V DC and uses optional interfaces for other power sources. The existing supply must be checked before connection.

Do REC-40D recordings require special software?

No. The MP3 files work with standard audio players. A compatible card reader is needed to access the microSD card.