UGREEN 90748 CM596 Bluetooth 5.3 AUX Receiver, 15H
UGREEN 90748 CM596 Bluetooth 5.3 AUX Receiver, 15H
Overview

Key features
Role
a rechargeable receiver that adds Bluetooth music and hands-free calling to a car stereo, powered speaker or home audio system with a 3.5mm AUX input.
Audio path
A phone, tablet or computer is the Bluetooth source. SKU 90748 receives that programme audio and sends it from its 3.5mm plug or supplied cable into an AUX input. It cannot transmit television or seat-screen audio to Bluetooth headphones.
Codec boundary
Power design
Up to 15 hours of music/calls and about 200 hours standby are shown in media, measured under UGREEN conditions. Volume, calls, age, temperature and signal strength affect results. USB-C charging; about 2 hours is the listed full-charge time. This is a battery-powered receiver, not a permanently bus-powered USB audio interface.
Audio direction and connector roles
A phone, tablet or computer is the Bluetooth source. SKU 90748 receives that programme audio and sends it from its 3.5mm plug or supplied cable into an AUX input. It cannot transmit television or seat-screen audio to Bluetooth headphones.
Connector rule: a source/output must feed a destination/input. USB power, USB host data, analogue AUX and Bluetooth radio roles are separate even when one enclosure handles several of them.
Start safely: set the correct mode, select the target input and lower every volume control before testing.

Sound, codecs, calls and latency
Codecs
Latency
No millisecond latency figure or gaming mode is verified. Bluetooth delay varies with the source, codec, application and radio conditions.
Microphone and calls
A built-in microphone supports hands-free calls. media describes DSP processing that reduces environmental noise for clearer speech; it does not make the cabin silent and is not listening ANC.
Real-world fidelity
Source file, negotiated codec, radio conditions, analogue cable, amplifier and speakers/headphones all affect the result. A newer Bluetooth number is not automatically higher sound quality.

Use scenarios
Scenario 1
Adding wireless music and calls to an older car AUX system.
Scenario 2
Streaming from a phone to a powered speaker with a 3.5mm input.
Scenario 3
Portable home-stereo reception without leaving USB power connected.
Scenario 4
Shared-car use with two paired phones and one active programme.
Scenario 5
Navigation prompts and podcasts while controls are set before driving.

Setup and usability guidance
- Step 1: Charge the receiver before first use.
- Step 2: Connect its 3.5mm output to the target AUX input and select that input on the stereo.
- Step 3: Power on SKU 90748 and open the source Bluetooth menu.
- Step 4: Select the UGREEN/CM596 receiver entry and test at low volume.
- Step 5: For a second source, pause the first device, then pair the second according to the manual.
Usability rule: establish one clean path first. Add a second source, listener, output or peripheral only after the first works reliably.
Controls
The multifunction and side controls handle power, pairing, supported playback, volume/track functions and calls. Use the CM596 manual for press timing.
Second-device behaviour
Two Bluetooth source devices can remain connected. Only one programme should play at a time; pause the first source before starting the second.
Recovery
If reconnection fails, disconnect the second source, forget the receiver on both hosts, power-cycle the unit and pair one host again at close range. Use only the CM596 reset timing in the supplied manual.

Compatible devices and systems
Class: Bluetooth-audio phones, tablets and computers as sources; car stereos, powered speakers, amplifiers and home audio equipment with a 3.5mm AUX input as destinations.
- Match the operating-system/audio profile and connector role, not only the Bluetooth logo.
- Confirm whether you need programme audio, microphone return, peripheral data or file transfer; these use different profiles.
- For AUX/RCA products, confirm the destination is a line-level input and already has its own amplifier.
- For PC adapters, verify driver requirements and disable a competing built-in Bluetooth radio.
- For two-way products, confirm that the chosen TX or RX mode matches the wired device.

What this product does
- Receives Bluetooth audio from a compatible source.
- Outputs analogue audio to the stated 3.5mm and/or RCA line input.
- Supports only the call, control and source-count behaviour documented for this revision.
- Reconnects to a saved compatible source when powered and available.
- Modernises existing audio equipment without replacing its amplifier or speakers.
What this product does not do
- receiver only; no Bluetooth-headphone transmission, aptX, LDAC, optical/RCA output, USB data audio or water rating; not for speaker-level or microphone-only sockets.
- Does not guarantee uninterrupted wireless service through metal, walls, crowds or heavy 2.4GHz interference.
- Does not repair a damaged source, USB port, AUX socket, amplifier or speaker.
- Does not make a connector compatible merely because it fits physically.
- Does not prove ANC, aptX, LDAC, multipoint or microphone return from the Bluetooth version number alone.
What to do
Check the label
Confirm SKU, model and stored revision on the product or box before relying on a specification.
Begin with one endpoint
Pair and test one path before adding any supported second device or output.
Lower volume first
Protect hearing and speakers when changing mode, output, codec, call profile or device.
Keep connections dry
Inspect USB and audio plugs, remove debris without metal tools and dry completely before power.
Use official drivers/manuals
Use the CM/BT model instructions; related UGREEN revisions can use different buttons and radios.
Pause before switching
When two sources are connected, pause the current programme before starting the other.
What not to do
Do not infer features
Bluetooth 5.x/6.0 alone does not establish codec, ANC, microphone, multipoint or delay.
Do not force plugs
Stop if a connector does not align; check port type, direction, damage and case clearance.
Do not use speaker-level output
AUX/RCA receiver inputs are line-level; passive speakers still need an amplifier.
Do not pair while moving
Configure car and aircraft audio before movement and follow local/crew instructions.
Do not charge damaged cells
Stop for swelling, leakage, odour or abnormal heat and seek proper battery disposal.
Do not borrow reset timing
Battery, charging and realistic runtime
Battery/power: Up to 15 hours of music/calls and about 200 hours standby are shown in media, measured under UGREEN conditions. Volume, calls, age, temperature and signal strength affect results.
Charging/connection: USB-C charging; about 2 hours is the listed full-charge time. This is a battery-powered receiver, not a permanently bus-powered USB audio interface.
- Published runtime is normally a controlled maximum; volume, calls, codec, temperature, range and battery age can shorten it.
- USB-powered models have no reserve runtime and stop when vehicle/computer power stops.
- Use compliant, undamaged power sources and disconnect any product that becomes unusually hot.
- Do not leave rechargeable products empty for months; follow the manual for long-term storage.

Warnings and limitations
- Hearing: begin at low volume, limit exposure and stop if you notice discomfort or ringing. Bluetooth features and noise processing are not hearing protection.
- Battery: never crush, puncture, short, burn or charge a swollen, leaking, wet or unusually hot rechargeable product. USB-powered models still require a sound, compliant 5V source.
- Aircraft: follow crew instructions, use only permitted headphone outputs and keep wireless devices off whenever directed. Carry lithium products in accordance with airline rules.
- Driving: pair, mount, select sources and set volume while parked. Hands-free calling does not remove attention or legal responsibilities.
- Water: This product does not has a IP rating. Keep adapters, plugs and charging ports dry; never connect power while damp.
- Heat and storage: do not leave the product on a hot dashboard, near a heater or in direct sun. Keep small adapters and cables away from children and pets.
- Audio ports: connect only to the stated headphone/AUX line-level role. Never connect a 3.5mm/RCA port to mains, passive-speaker output or an unknown industrial signal.
Troubleshooting and reset
No pairing
Bring devices close, verify power/mode, disconnect competing saved devices and pair one endpoint first.
Connected but silent
Check source playback, OS output, TX/RX direction, AUX input selection, cable seating and both volume controls.
Audio but no microphone
A built-in microphone supports hands-free calls. media describes DSP processing that reduces environmental noise for clearer speech; it does not make the cabin silent and is not listening ANC. Confirm the call app input and permissions only where a microphone path is documented.
Drop-outs
Reduce distance and metal/body obstruction, move from crowded 2.4GHz radios and test one connection at a time.
Delay
Compare with a wired path; no unstated codec or Bluetooth version can remove all source and endpoint buffering.
Reset path
If reconnection fails, disconnect the second source, forget the receiver on both hosts, power-cycle the unit and pair one host again at close range. Use only the CM596 reset timing in the supplied manual.
Technical specifications
| Product / model | UGREEN Bluetooth car audio receiver / CM596 |
|---|---|
| SKU / colour | 90748 / black |
| Bluetooth version | 5.3 |
| Wireless role | Receiver only |
| Codecs | SBC and AAC; no aptX |
| Wired audio | 3.5mm AUX output |
| Microphone | Built in for supported hands-free calls |
| Simultaneous sources | Two connected; one programme at a time |
| Runtime | Up to 15 hours under stated conditions |
| Standby | About 200 hours shown in media |
| Charging | USB-C; about 2 hours |
| Dimensions | Approximately 60 × 35mm shown in media |
Listed ranges and runtimes are qualified maxima in suitable conditions, not universal guarantees.
Package contents
Package: Bluetooth receiver, 3.5mm audio cable, USB charging cable and documentation, as shown/listed for SKU 90748.
Pre-purchase checklist
- Confirm this SKU/revision on the sealed product.
- Confirm TX, RX or Windows-host direction.
- Confirm every wired input/output and required power source.
- Confirm call/microphone, codec and second-device needs separately.
- Check whether any cable, charger or flight adapter you require is actually listed.
Product-specific FAQ
What exactly is UGREEN 90748?
It is a rechargeable receiver that adds Bluetooth music and hands-free calling to a car stereo, powered speaker or home audio system with a 3.5mm AUX input.
What does this receiver connect to?
A phone, tablet or computer is the Bluetooth source. SKU 90748 receives that programme audio and sends it from its 3.5mm plug or supplied cable into an AUX input. It cannot transmit television or seat-screen audio to Bluetooth headphones.
Which codecs does SKU 90748 support?
Is low latency guaranteed?
No millisecond latency figure or gaming mode is verified. Bluetooth delay varies with the source, codec, application and radio conditions.
Do microphone and calls work?
A built-in microphone supports hands-free calls. media describes DSP processing that reduces environmental noise for clearer speech; it does not make the cabin silent and is not listening ANC.
Can two phones or outputs be used?
Two Bluetooth source devices can remain connected. Only one programme should play at a time; pause the first source before starting the second.
What battery life or power does it use?
Up to 15 hours of music/calls and about 200 hours standby are shown in media, measured under UGREEN conditions. Volume, calls, age, temperature and signal strength affect results. USB-C charging; about 2 hours is the listed full-charge time. This is a battery-powered receiver, not a permanently bus-powered USB audio interface.
Which devices and systems are compatible?
Bluetooth-audio phones, tablets and computers as sources; car stereos, powered speakers, amplifiers and home audio equipment with a 3.5mm AUX input as destinations.
What should I do if pairing fails?
If reconnection fails, disconnect the second source, forget the receiver on both hosts, power-cycle the unit and pair one host again at close range. Use only the CM596 reset timing in the supplied manual.
What is in the package?
Bluetooth receiver, 3.5mm audio cable, USB charging cable and documentation, as shown/listed for SKU 90748
What should it not be used for?
receiver only; no Bluetooth-headphone transmission, aptX, LDAC, optical/RCA output, USB data audio or water rating; not for speaker-level or microphone-only sockets.