Audio T Verdict
The Pro-Ject CD Box S3 is refreshingly straightforward. It plays CDs, it is small enough to fit into systems where a conventional full-width player would be cumbersome, and it gives you the choice of using its own DAC or sending the digital signal to another converter.
There is more substance behind that simplicity than the compact dimensions suggest. The slot-loading mechanism is optimised specifically for Red Book Audio CD playback, the internal PCM5102 DAC feeds a proper 2V line-level RCA output and the electronics sit inside a torsion-resistant full aluminium enclosure rather than a lightweight plastic case.
For someone with a CD collection who wants a neat, dedicated player without streaming, SACD or unnecessary complexity, the CD Box S3 makes a lot of sense. And if you later upgrade to a better external DAC, the coaxial digital output means the player can remain useful as your disc-reading source.
Pro-Ject CD Box S3
The CD Box S3 is an ultra-compact dedicated CD player from Pro-Ject's S Line, designed specifically around conventional Red Book Audio CD replay.
Unlike the transport-only CD Box RS2 T, the S3 contains its own digital-to-analogue converter, so it can connect directly to any suitable line-level analogue input on an integrated amplifier or preamplifier.
- Dedicated Red Book Audio CD player
- Slot-loading disc mechanism
- 1:1 bit-accurate CD playback
- PCM5102 digital-to-analogue converter
- RCA stereo analogue output
- 2.0Vrms analogue output level
- Coaxial S/PDIF digital output
- External DAC upgrade capability
- 1.54-inch display
- Display colour inversion
- Full aluminium casework
- Torsion-resistant enclosure
- Remote control supplied
- External 9V power supply
- Less than 0.5W standby consumption
- Made in Europe
- Black or Silver finish
A Proper CD Player in a Compact Chassis
The CD Box S3 is only 206mm wide, making it less than half the width of many conventional Hi-Fi separates.
That does not make it a portable or lifestyle CD player. It is intended to form part of a separates system and provides a fixed line-level analogue output for connection to an amplifier, alongside a digital output for customers using an external DAC.
Dedicated Red Book CD-DA Playback
Pro-Ject optimises the disc mechanism specifically for Red Book CD-DA, the conventional Audio CD format.
Rather than adapting a DVD or Blu-ray mechanism designed to handle several different optical-disc standards, the CD Box S3 concentrates on stereo Audio CD playback.
1:1 Bit-Accurate Disc Reading
Pro-Ject describes the CD Box S3 drive as providing 1:1 bit-accurate playback of the Audio CD data.
The aim is to recover the information from the disc accurately before it is either converted by the internal PCM5102 DAC or passed through the coaxial digital output to another DAC.
Why Use a Dedicated CD Mechanism?
A CD may store digital information, but reading the disc remains an optical and mechanical process.
The laser has to follow the data track accurately while the disc rotates, and the mechanism must deal with disc condition, tracking and error correction in real time.
Pro-Ject therefore approaches the CD Box S3 as a dedicated Audio CD source rather than simply using a general-purpose computer or video-disc drive.
Slot-Loading Mechanism
Insert the disc label-side upwards and the slot-loading mechanism automatically draws it into the player.
After the disc has been read, the display shows the total number of tracks and total playing time.
Pressing Stop once stops playback; pressing Stop again ejects the disc.
Simple Everyday Operation
There is no drawer to open or magnetic puck to position. Insert the disc into the slot, allow the mechanism to load it and playback can begin from the front panel or supplied remote control.
Designed for Full-Size Circular CDs
Pro-Ject specifies standard round 12cm CDs.
Cracked, chipped, warped or otherwise damaged discs should not be inserted, and shaped discs are not recommended.
The operating instructions also warn that self-recorded discs which do not comply with the Red Book standard may not operate correctly.
Disc Compatibility
The manufacturer's current specification guarantees Red Book CD-DA playback. Pro-Ject does not advertise the CD Box S3 as an SACD, DVD, Blu-ray or general data-disc player.
No SACD Playback
The CD Box S3 is not an SACD player.
Its purpose is conventional stereo Audio CD reproduction rather than universal optical-disc playback.
PCM5102 DAC
Digital-to-analogue conversion is handled by a Texas Instruments PCM5102 DAC.
The converter itself is a high-resolution DAC architecture capable of operating at significantly greater bit depths and sample rates than the Red Book CD format requires.
What Does the 32-bit/384kHz DAC Specification Mean?
Pro-Ject describes the PCM5102 implementation as capable of up to 32-bit/384kHz conversion. This describes the capability of the DAC chip and should not be confused with the resolution stored on an Audio CD. The CD Box S3 remains a Red Book CD-DA player rather than a 384kHz disc source.
Use the Internal DAC
For the simplest system, connect the stereo RCA outputs directly to a conventional line-level input on your amplifier.
The internal DAC then handles conversion and provides a fixed analogue signal at 2.0Vrms at 0dBFS.
Suitable amplifier inputs might be labelled:
Do Not Connect It to a Phono Input
The RCA output is a standard line-level signal. It should not be connected to an MM or MC turntable phono input, which is designed for a much lower signal level and different electrical characteristics.
2.0Vrms Analogue Output
The fixed analogue output is specified at 2.0Vrms at 0dBFS.
This is a conventional line-level source output intended for connection to an amplifier or preamplifier that provides the system volume control.
Fixed Output, Not a Preamplifier
The CD Box S3 does not provide an adjustable analogue listening-volume control.
Your amplifier or preamplifier should therefore control playback level.
The volume and mute symbols visible on the multi-product-style handset should not be taken as evidence that the S3 itself functions as a variable-output preamplifier; Pro-Ject specifies the player with a fixed 2.0Vrms line output.
20Hz to 20kHz Frequency Response
Through the analogue output, Pro-Ject specifies a frequency response of 20Hz to 20kHz within ±0.15dB.
This covers the conventional audible frequency range with very little published level variation.
Low Analogue Distortion
Pro-Ject specifies analogue-output total harmonic distortion below 0.005% at 1kHz.
The manufacturer-published noise-floor figure is greater than -120dB across 20Hz to 20kHz.
Coaxial S/PDIF Digital Output
A rear RCA coaxial digital output allows the disc signal to bypass the internal PCM5102 DAC and feed another compatible converter.
This gives the CD Box S3 an important upgrade path: you can use the built-in analogue output initially and later add a higher-performance DAC without replacing the CD mechanism.
Use an External DAC
An external DAC can connect between the CD Box S3 and your amplifier:
- Connect the S3 coaxial digital output to the DAC.
- Connect the DAC's analogue output to the amplifier.
- Select the corresponding input on the DAC and amplifier.
The external DAC then performs the digital-to-analogue conversion instead of the S3's internal PCM5102.
Use a Proper Digital Coaxial Cable
The coaxial output uses an RCA socket, but it carries a digital S/PDIF signal rather than conventional analogue audio.
A purpose-designed 75-ohm digital coaxial cable is the appropriate connection.
Internal DAC or External DAC?
Start with the S3's own analogue output if you want the simplest setup. If your amplifier contains a good DAC, or you already own a dedicated converter, compare the coaxial digital connection. There is no need to buy another DAC simply because the digital socket is available.
No Optical Digital Output
The current CD Box S3 provides one coaxial S/PDIF output only.
There is no optical TOSLINK output, USB audio output or AES/EBU connection on this model.
CD Player or CD Transport?
The S3 can perform either role depending on how you connect it.
As a Complete CD Player
- Use the stereo RCA outputs
- Internal PCM5102 performs conversion
- Connect directly to a line input
- No external DAC required
As a CD Transport
- Use the coaxial S/PDIF output
- Internal DAC is bypassed
- External DAC performs conversion
- S3 remains the disc-reading source
No Network Streaming
The CD Box S3 is deliberately a dedicated disc player.
It does not contain:
- Wi-Fi
- Ethernet
- Network streaming
- Spotify Connect
- Qobuz Connect
- TIDAL Connect
- Internet radio
If streaming is required, a separate network player can simply be added to another input on the amplifier.
No Bluetooth
Bluetooth is not part of the CD Box S3.
That keeps the player focused entirely on physical CD replay.
No USB Music Playback
There is no USB socket for memory-stick playback or computer audio.
Digital connectivity is output-only through the coaxial S/PDIF connection.
1.54-Inch Display
The front panel incorporates a compact 1.54-inch display.
It shows the information required for normal CD operation, including track number, elapsed time and playback status.
Display Colour Inversion
The display can be inverted between light and dark presentation modes.
With the player switched on, press and hold the Stop control to change the display scheme.
Front-Panel Controls
Essential playback functions are available directly from the player without needing the remote.
- Previous track
- Play / Pause
- Stop
- Next track
- Fast scanning by holding Previous or Next
- Disc eject by pressing Stop again after playback has stopped
Repeat Playback
The supplied remote provides three playback modes:
- Normal playback
- Repeat current track
- Repeat all tracks
Remote Control Included
A remote handset is supplied and operates from two AAA batteries.
It provides standby, play/pause, stop/eject, track stepping, scanning and repeat functions.
Full Aluminium Casework
The complete player is housed in a full aluminium enclosure.
Pro-Ject describes the case as torsion resistant and uses the metal structure to provide mechanical rigidity while also shielding the internal electronics from external interference.
Why Aluminium Rather Than Plastic?
The enclosure forms the mechanical reference for the slot-loading mechanism and electronics.
A rigid metal case also provides significantly greater shielding than a lightweight plastic enclosure, which is particularly useful in a compact Hi-Fi system where multiple power supplies and electronics may sit close together.
The Compact S3 Format
The CD Box S3 introduced Pro-Ject's revised S3 chassis dimensions.
The player measures:
- Width: 206mm
- Height: 55mm
- Depth: 153mm
- Depth including sockets: 160mm
That makes it particularly easy to combine with Pro-Ject's other compact electronics or incorporate into a system where a full-width CD player would simply take up unnecessary space.
1.33kg Without the Power Supply
The player weighs 1.33kg excluding its external power supply.
That is relatively substantial for a component of its dimensions and reflects the extensive aluminium casework.
External 9V Power Supply
Power comes from the supplied 9V/2A DC external supply.
Keeping the mains conversion outside the main CD-player enclosure reduces the amount of mains-voltage hardware that needs to share the compact chassis with the disc mechanism and audio electronics.
Use the Correct Power Supply
Pro-Ject instructs users to use the supplied power supply. Do not substitute another adapter simply because the connector appears to fit.
Low Standby Consumption
Standby power consumption is specified at less than 0.5W.
Operating current varies between approximately 250 and 1500mA DC according to the manufacturer's current technical data.
Made in Europe
Pro-Ject specifies the CD Box S3 as Made in Europe.
The player continues the company's approach of manufacturing compact Hi-Fi electronics in Europe rather than treating the small chassis format as disposable consumer electronics.
Black or Silver
The CD Box S3 is available in:
Both use the same full aluminium enclosure and front-panel layout.
CD Box S3 or CD Box RS2 T?
These two Pro-Ject CD products serve quite different systems.
CD Box S3
- Complete CD player
- PCM5102 DAC built in
- RCA analogue output
- Coaxial digital output
- Slot-loading mechanism
- 206mm compact chassis
- Designed for straightforward system integration
CD Box RS2 T
- Transport only
- No internal DAC
- No analogue output
- CD-Pro 8 mechanism
- Coaxial, optical and AES/EBU
- Pro-Ject I²S plus Master Clock
- Designed around high-end external conversion
The S3 is the more obvious choice if you simply want a compact player that connects directly to an amplifier. The RS2 T is intended for a much more elaborate system built around a separate DAC.
Who Is the CD Box S3 For?
The CD Box S3 is particularly attractive if you:
- Still own and regularly play CDs
- Want a dedicated player rather than a universal disc machine
- Need something substantially smaller than a conventional full-width component
- Want simple RCA connection to an amplifier
- Would like the option to add an external DAC later
- Prefer straightforward physical controls
- Do not need SACD, streaming or Bluetooth built into the player
- Want a matching source for compact Pro-Ject electronics
Key Features
- Pro-Ject CD Box S3
- Dedicated Audio CD player
- Red Book CD-DA support
- 1:1 bit-accurate playback
- Slot-loading mechanism
- PCM5102 DAC
- 32-bit/384kHz-capable DAC architecture
- 2.0Vrms RCA line output
- Coaxial S/PDIF output
- External DAC compatibility
- 20Hz - 20kHz frequency response
- Less than 0.005% analogue THD at 1kHz
- Less than 0.001% digital-output THD at 1kHz
- 1.54-inch display
- Display colour inversion
- Front-panel controls
- Repeat current track
- Repeat complete disc
- Remote control supplied
- Full aluminium enclosure
- Torsion-resistant casework
- 9V/2A external power supply
- Less than 0.5W standby consumption
- 206mm-wide S3 chassis
- 1.33kg weight
- Made in Europe
- Black finish
- Silver finish
Frequently Asked Questions
Is the Pro-Ject CD Box S3 still current?
Yes. Pro-Ject continues to list the CD Box S3 in its current S Line and Hi-Fi electronics range.
Is it a CD player or CD transport?
It is a complete CD player because it contains its own PCM5102 DAC and stereo RCA analogue output. Its coaxial digital output also allows it to be used as a transport with an external DAC.
Which discs does it support?
Pro-Ject specifies Red Book CD-DA Audio CDs.
Does it play SACD?
No SACD playback is specified.
Does it play DVDs or Blu-rays?
No. It is a dedicated Audio CD player.
Does it play MP3 data discs?
Pro-Ject specifies Red Book CD-DA rather than general data-disc playback, so Audio T does not advertise MP3-CD compatibility.
Can it play home-recorded CDs?
The operating instructions warn that self-recorded CDs which do not comply with the Red Book standard may malfunction. Pro-Ject does not publish broader CD-R or CD-RW compatibility as part of the current specification.
Can I use shaped CDs?
Pro-Ject recommends standard fully circular 12cm discs and does not recommend shaped CDs.
Is it slot loading?
Yes. Insert the disc label-side upwards and the mechanism draws it in automatically.
How do I eject a disc?
Press Stop once to stop playback and press Stop again to eject the disc.
What DAC does it use?
A PCM5102 digital-to-analogue converter.
Does it really play CDs at 32-bit/384kHz?
No. Pro-Ject specifies the DAC chip as capable of up to 32-bit/384kHz conversion, while the player itself reads Red Book CD-DA. The DAC specification should not be confused with the resolution stored on the disc.
Does it have analogue outputs?
Yes. One stereo pair of RCA line-level outputs is provided.
What is the RCA output level?
2.0Vrms at 0dBFS.
Can I connect it directly to an integrated amplifier?
Yes. Connect the RCA output to a suitable line-level input such as CD or AUX.
Can I connect it to a phono input?
No. A phono input is intended for a turntable cartridge signal rather than the S3's 2V line-level output.
Does the CD Box S3 have a volume control?
No variable analogue output is specified. System volume should be controlled by the connected amplifier or preamplifier.
Does it have a digital output?
Yes. One coaxial S/PDIF digital output is provided.
Can I add an external DAC?
Yes. Connect the coaxial digital output to a compatible external DAC.
Does it have optical output?
No.
Does it have USB output?
No.
Does it have AES/EBU?
No.
What is the analogue frequency response?
20Hz to 20kHz within ±0.15dB.
What is the analogue THD?
Less than 0.005% at 1kHz.
What is the published digital-output THD?
Less than 0.001% at 1kHz under Pro-Ject's published measurement specification.
What noise-floor figure does Pro-Ject publish?
Greater than -120dB across 20Hz to 20kHz.
Does it have Bluetooth?
No.
Does it have Wi-Fi?
No.
Can it stream Spotify, Qobuz or TIDAL?
No. It is a dedicated CD player.
Can I play music from a USB memory stick?
No.
How large is the display?
1.54 inches.
Can the display colours be inverted?
Yes. Press and hold Stop while the player is switched on to change the display presentation.
Can I scan forwards and backwards within a track?
Yes. Press and hold the previous or next control.
Does it repeat tracks?
Yes. The remote provides repeat-current-track and repeat-all-tracks modes.
Does it have shuffle playback?
Shuffle is not documented in the current CD Box S3 manual, so Audio T does not advertise it.
Is a remote supplied?
Yes.
What batteries does the remote use?
Two AAA 1.5V batteries.
What is the case made from?
Aluminium.
What power supply does it use?
A 9V/2A DC external power supply supplied for the appropriate market.
What is the standby consumption?
Less than 0.5W.
How large is the CD Box S3?
206mm wide, 55mm high and 153mm deep, or 160mm deep including the rear sockets.
How much does it weigh?
1.33kg excluding the external power supply.
Where is it made?
Pro-Ject specifies the CD Box S3 as Made in Europe.
Which finishes are available?
Black and Silver.
Related Pro-Ject Products and Audio T Guides
Why Buy the Pro-Ject CD Box S3 From Audio T?
The CD Box S3 is easy to use, but there are still useful choices to make around the rest of the system. You can use its own PCM5102 DAC, compare it with the DAC inside your amplifier or add a standalone converter later through the coaxial output.
Audio T can demonstrate those options, help match the player with the right amplifier input and show whether stepping up to a dedicated transport such as the CD Box RS2 T makes sense for your CD collection and wider system.
- In-store demonstrations
- CD player and amplifier matching
- Internal versus external DAC comparison
- Coaxial digital connection advice
- Digital cable guidance
- Compact-system planning
- Pro-Ject S Line system matching
- CD Box S3 versus dedicated transport advice
- Existing CD collection demonstrations
- Ongoing after-sales support
Contact your local Audio T store to arrange a demonstration or discuss how the Pro-Ject CD Box S3 could fit into your existing Hi-Fi system.