The Pro-Ject Phono Box E BT5 combines two functions in one compact unit: an MM phono preamplifier and a Bluetooth transmitter. It lets you connect a compatible turntable to wireless speakers or headphones without replacing the turntable, while also providing a conventional wired line-level output.
Its main appeal is convenience rather than a guaranteed improvement in sound quality. If your turntable already has a suitable built-in phono preamp, the BT5’s value is primarily its wireless transmission and additional line input.
Pro-Ject Phono Box E BT5 Quick Specs
| Specification | Detail |
|---|---|
| Phono cartridge support | Moving magnet (MM) |
| Phono gain | 34 dB |
| Phono input impedance | 47 kΩ |
| Phono input capacitance | 100 pF |
| Inputs | 1 × RCA phono, 1 × 3.5mm line |
| Outputs | 1 × 3.5mm line, Bluetooth |
| Bluetooth | Version 5.2 on current manufacturer specification |
| Supported codecs | aptX, aptX HD, aptX Adaptive |
| Wireless range | Up to 10m in direct line of sight |
| RIAA accuracy | Within 0.5 dB, 20Hz–20kHz |
| Signal-to-noise ratio | 74 dB A-weighted |
| Dimensions | 120 × 32 × 100mm |
| Weight | 280g without power supply |
| Power supply | External 18V / 500mA |
Bluetooth revision note: Some earlier Pro-Ject documentation lists Bluetooth 5.0, while the current product specification lists Bluetooth 5.2. Check the documentation supplied with the exact unit you are buying. The supported codecs also need to match the receiving speaker or headphones to be used.
Who Is the Pro-Ject Phono Box E BT5 For?
The BT5 makes sense if you:
- Own a turntable without Bluetooth transmission.
- Have an MM cartridge and need an external phono preamp.
- Want to listen through Bluetooth speakers or headphones.
- Prefer having both wired and wireless output options.
- Want to transmit audio from another line-level source, such as a CD player.
It is particularly useful for a traditional turntable that you want to use with modern wireless audio equipment.
Who Should Skip It?
The BT5 may be unnecessary if your turntable already has Bluetooth transmission or if you only plan to use a wired connection.
It is also not designed for every cartridge type. Pro-Ject specifies MM cartridge compatibility, so it is not the right choice for a low-output moving-coil cartridge that needs an MC-compatible phono stage.
If your turntable already has a built-in phono preamp and you only need Bluetooth, a dedicated line-level Bluetooth transmitter may be a simpler alternative.
How the Two Inputs Work
One useful feature is that the BT5 has separate phono and line-level inputs.
Phono input
Connect a turntable with a passive MM cartridge to the RCA PHONO input. The BT5 applies RIAA equalization and amplifies the signal to line level.
This is the normal connection for a turntable without a built-in phono preamp.
Line input
The 3.5mm LINE input accepts an already amplified line-level signal from another source.
You can use it with equipment such as a CD player or a turntable whose built-in phono preamp is enabled.
When the line input is selected, the analogue line output acts as a direct bypass. Bluetooth transmission remains available for wireless playback.
Bluetooth Connectivity and Supported Codecs
Bluetooth is the feature that separates the BT5 from a conventional phono preamp.
The transmitter supports several codecs:
| Codec | What to Know |
|---|---|
| SBC | Basic Bluetooth audio compatibility |
| aptX | Higher-quality option when supported by both devices |
| aptX HD | Supports higher-resolution Bluetooth transmission |
| aptX Adaptive | Adjusts transmission to suit supported devices and conditions |
The receiving speaker or headphones determine which compatible codec can actually be used. Having aptX Adaptive on the BT5 does not mean every Bluetooth speaker will receive aptX Adaptive.
For example, if your headphones support only SBC, the connection will use a mutually supported codec rather than automatically upgrading to aptX HD or Adaptive.
Pro-Ject specifies a wireless range of up to approximately 10 metres in direct line of sight. Walls, interference and the receiving device can affect the practical range.
Bluetooth also introduces wireless compression and potential latency. It is convenient for casual listening, but a wired connection remains preferable when you want to avoid Bluetooth transmission and its associated delay.
Setup: Connecting a Turntable to Bluetooth Speakers
The basic setup is straightforward.
- Connect the turntable’s RCA cables to the BT5’s PHONO input.
- Connect the turntable’s grounding wire to the grounding terminal on the BT5, if provided.
- Connect the supplied power adapter.
- Select the PHONO input.
- Put your Bluetooth speaker or headphones into pairing mode.
- Follow the BT5 pairing procedure in the manual.
- Start playback and adjust the listening volume on the receiving device.
The turntable must provide a passive phono-level signal for this connection. If it has a built-in preamp, switch that preamp off or select PHONO output before connecting it to the BT5’s PHONO input.
Do not feed an already amplified LINE signal into the PHONO input.
Wired Connection: Using the BT5 as a Phono Preamp
The BT5 can also operate as a conventional phono preamp.
Connect the turntable to the RCA PHONO input, then connect the BT5’s 3.5mm LINE output to a line-level input on your amplifier or powered speakers.
You may need a suitable 3.5mm-to-RCA cable, depending on the equipment.
The analogue and Bluetooth outputs can operate simultaneously, so you can use a wired system and a Bluetooth receiver at the same time.
Can You Use Both Inputs and Outputs?
The BT5 offers two inputs and two outputs, but they serve different purposes.
| Connection | Function |
|---|---|
| RCA PHONO input | Accepts a passive MM turntable signal |
| 3.5mm LINE input | Accepts an already amplified line-level signal |
| 3.5mm LINE output | Sends analogue line-level audio to an amplifier or powered speakers |
| Bluetooth output | Transmits audio to compatible wireless receivers |
The input selector determines which source is used. The analogue and Bluetooth outputs can both carry the selected source.
This makes the BT5 more flexible than a phono preamp with only one input and one output.
Is the Pro-Ject Phono Box E BT5 Better Than a Built-In Turntable Preamp?
Not automatically.
The BT5 provides a dedicated MM phono stage with published gain, input loading and RIAA specifications. However, those specifications alone do not prove that it will sound better than the built-in preamp in a particular turntable.
Its clearest advantage is the ability to transmit a turntable’s audio over Bluetooth while retaining a wired output.
If you already own a turntable with a built-in preamp, you can compare the two options, but remember that the BT5’s PHONO input is intended for an unamplified phono signal. For an existing LINE output, use the BT5’s LINE input instead.
For more options, see our guide to the best phono preamps.
Final Verdict
The Pro-Ject Phono Box E BT5 is a useful two-in-one solution for listeners who want to add Bluetooth transmission and phono amplification to a compatible MM turntable.
Its separate phono and line inputs, simultaneous analogue and Bluetooth outputs, and support for aptX HD and aptX Adaptive make it more versatile than a basic phono preamp.
However, it is not a universal cartridge solution, and its Bluetooth codec advantages depend on the receiving device. It should also not be treated as an automatic sound-quality upgrade over a turntable’s existing phono stage.
If wireless listening is the main reason you are considering it, the BT5 has a clear purpose. If you only need a wired phono preamp, a simpler model may be more appropriate.
Frequently Asked Questions
Does the Pro-Ject Phono Box E BT5 work with moving-coil cartridges?
Pro-Ject specifies the BT5 for moving-magnet cartridges. It is not designed as a dedicated low-output MC phono preamp.
Does the Phono Box E BT5 support aptX Adaptive?
Yes. The current Pro-Ject product specification lists aptX, aptX HD and aptX Adaptive. The receiving Bluetooth device must support the same codec for that format to be used.
Can I use the Phono Box E BT5 with wired speakers?
Yes. Its 3.5mm LINE output connects to a line-level input on an amplifier or powered speakers. You may need a 3.5mm-to-RCA cable.
Can I connect a turntable that already has a built-in phono preamp?
Yes. Switch the turntable’s preamp to LINE and connect its output to the BT5’s 3.5mm LINE input. Do not connect that line-level signal to the BT5’s PHONO input.
Can I use Bluetooth and the wired output simultaneously?
Yes. Pro-Ject specifies that the analogue and Bluetooth outputs can operate simultaneously.
Does the Phono Box E BT5 receive Bluetooth audio?
No. It is a Bluetooth transmitter. It sends audio from its phono or line input to compatible Bluetooth speakers, headphones or receivers.
How far does the Bluetooth connection reach?
Pro-Ject specifies up to approximately 10 metres in direct line of sight. Actual range depends on obstacles, interference and the receiving device.