Note that this is a discontinued product. You may want to visit the brand's page here to browse their newer products.
What reviewers think
Bloggers and YouTubers have tried this product—so we've summarized their strongest opinions below. Links to full reviews follow.
Product Strengths
- Adjustable loading and impedance options provide setup flexibility
- Fully discrete design, with no op-amps, reduces unwanted noise
- Polystyrene capacitors and a split RIAA circuit are used for accurate equalisation
- Solid, high-quality all-metal casework
- Neutral, detailed, and clear sound quality doesn't heavily color the sound
Product Considerations
- Dip switches for adjustments are very small and fiddly to adjust
- Gain can be lost when increasing gain settings
- Experimentation with grounding may be required to minimize hum and noise due to increased connections
- Moving coil operation can introduce some noise during idle and quiet passages
- Some gaps exist in the settings for moving-coil cartridges
Comparisons (according to reviewers)
- Vs Sutherland KC Vibe: The S2 Ultra is less expensive, but Sutherland has more flexibility of settings for future investment in a cartridge
-Vs iFi Zen Phono: The iFi Zen Phono sounds very similar to the Pro-Ject Phonobox S2 Ultra
Takeaway: The Phono Box S2 Ultra is a versatile and well-built phono stage that delivers neutral and detailed sound, working well with a range of cartridges. It's a worthwhile upgrade to improve the sound of a vinyl setup and maximize what a cartridge can do.
All
Phono Box S2 Ultra
reviews

Manufacturer details
- Input impedance: 10 Ohm/100 Ohm/1 kOhm/47 kOhm
- Input capacitance: 100 pF/220 pF
- Gain switch: 40dB/43dB/60dB/63dB
- Subsonic switch: -18 dB @ 20 Hz
- Signal-to-noise ratio: 89 dB V (MM)
- THD: 0.00052%
- RIAA accuracy: < 0.4 dB / 20 Hz - 20k Hz
- Power consumption: 18 V / 80 mA
- Outboard power supply: 18 Volt DC/ 500 mA
- Dimensions (W x H x D): 103 x 37 x 119 mm
- Weight: 570 g without power supply
Brand highlights
Taking a step back to look at reviewers' thoughts of the brand's entire lineup—not just this product—what stands out most is the following:
- Pro-Ject offers a range of turntables and components that focus on simple setup and ease of use, often arriving pre-configured, making them particularly appealing to beginners.
- They prioritize sonic performance, often incorporating higher-end components like carbon fiber tonearms and Ortofon cartridges, even in their more affordable models.
- Pro-Ject is known for its all-in-one audio systems that combine a turntable, amplifier, and receiver into a single unit, aiming to provide component-like sound quality in a smaller, more convenient package.
Select products
A2
- Positioning: The entry-level, fully automatic turntable designed for ease of use and convenience.
- Description: Offers a fully automatic operation with a sub-chassis design that isolates the tonearm and platter from vibrations, making it ideal for small spaces where speakers are close to the turntable. Unlike the more manual and high-end models like the Signature series, focuses on user-friendly features and affordability, making it suitable for those with a limited budget who still want quality sound.
The Classic Reference
- Positioning: Positioned as a mid-range turntable, combines traditional design with modern technology.
- Description: Features a high-end EVO 9 AS HG tonearm and a precision motor control system, providing excellent sound quality with a touch of luxury. It offers more advanced features compared to the A2, such as a balanced XLR output.
RPM 10 Carbon
- Positioning: A high-end turntable known for its innovative design and superior sound quality.
- Description: With its carbon fiber chassis and 10" Evo tonearm, delivers exceptional sound clarity and stability. It stands out from the Classic Reference with its advanced materials and design.
Signature 10
- Positioning: A premium turntable that combines mass-loading with magnetically-floating principles for high-end audio performance.
- Description: Features a 10" single-pivot tonearm and a magnetically decoupled platter, providing a resonance-free listening experience. It offers more precise adjustments and a higher level of performance compared to the RPM 10 Carbon.
Signature 12.2
- Positioning: The flagship model, representing the pinnacle of Pro-Ject's turntable lineup.
- Description: Boasts a groundbreaking 12" 3-point pivot tonearm and a flywheel belt drive system, ensuring the most accurate and stable playback. It surpasses the Signature 10 with its larger tonearm and enhanced stability.
Our take on the brand
Look inside the brand
Our interview with the brand
What are two key technological innovations or strong opinions that differ you from other brands?
Pro-Ject Audio Systems was founded with a passion for analog audio reproduction. Our very first product, introduced in 1991, was a record player – a time when the entire industry was turning its back on vinyl. We didn’t jump on the bandwagon when vinyl became hip – we were instrumental in bringing vinyl back.
We manufacture – not only assemble – 95% of our products in the EU. Raw materials come in – finished products leave the factories. Since we make everything ourselves, we are able offer a 25 year spare part availability!
Today, we offer one of the broadest ranges of high-fidelity products in the world, including turntables, CD players, DACs, streamers, phono preamps, amplifiers, speakers, and a variety of accessories designed to enhance your system and vinyl care.
What's your approach to customer support?
Pro-Ject Audio Systems has a worldwide network of dealers and distributors. We ensure that our team members are highly knowledgeable in the field of high-fidelity audio setup and repairs. In the event of a need for support, the first point of contact is the local dealer. If the dealer cannot handle the problem, the second tier is the distributor in the respective country. By handling as many problems as possible locally, we can ensure the quickest and smoothest resolution.
What are your favorite tracks for showcasing the strength of your products?
Aside from one of the audio industry’s widest range of high-fidelity products, Pro-Ject also produces limited runs of high-quality vinyl records. 7Ray’s Jazzy Zoetrope is a double album of fine Jazz standards played by 7Ray and his quartet. One of the two records was recorded live at our headquarters in the Weinviertel region of Lower Austria. We produced the whole album in AAA for the highest analog purity. Here’s a link to the records we offer, which double as fine reference recordings across multiple musical genres.
What other products pair best with yours?

Used
Pro-Ject
What if you spend more?
Our summary
Product Strengths
- Balanced connections improve sound, though stellar audio is available via RCA inputs
- Tighter and continuous control over load impedance via a potentiometer control
- Discrete circuit design offers a more neutral sound than integrated circuits
- Two turntables can be connected at once, one with XLRs and one with RCAs
- Expanded soundstage and individual instrument placement both horizontally and vertically
Product Considerations
- Turntable with XLR outputs needed to experience its best features
- More expensive if balanced connection features are not being used
- Tube box will push coloration into the mix, so tubes need careful system matching
- Balanced outputs and moving coil cartridge are needed to reveal the sort of detail that vinyl aficionados champion
Comparisons (according to reviewers)
- Vs NAD Phono Preamp PP-1: Allows for markedly more detail and separation between instruments
- Vs Phono Box S3 B: Integrates all the technology from the SB3 and adds in a few extra features, as well as a potentiometer
- Vs Projects Tubebox DS3: The sound is far more clear, and the weighted treble and upper spectrum sound more pronounced
Takeaway: The Pro-Ject Phono Box DS3 B unlocks the potential of a turntable, enhancing the listening experience with more dynamics, details, and soundstage. It's a versatile phono preamp with remarkably neutral and detailed sound.
Video review
Our take on the brand
Product Strengths
- Offers a versatile range of adjustments, including nine input impedance choices and four gain options, to match various cartridges
- Offers three different equalization curves (RIAA, Decca London, and American Columbia), unusual for phono stages in its price range
- Produces a clean, smooth, lucid, and well-balanced sound that is uncolored and neutral, allowing for greater transparency and speed
- Musical, smooth, coherent and dynamic, with a very good pace, rhythm, and timing
- Touchscreen interface is easy and intuitive to use
Product Considerations
- Moving magnet capacitance is set at 220pF and is not adjustable
- Some reviewers express concern about potential RF interference from the digital display affecting the analog circuitry, particularly with sensitive MC cartridges
- Instrumental images may be smaller than with other phono stages
- May sound a little weightless compared to significantly more expensive phono preamps
- Reviewers note the forthcoming PSU-5 power supply
Comparisons (according to reviewers)
- Compared to a similarly priced phono stage, the Gold Note PH-5 provided greater insights into how Miles Davis played each note, and was more full-bodied and dynamic
- The Pathos In the Groove was more spacious and shapely sounding but lacked the PH-5's sense of control and smoothness
- Compared to the Gold Note PH-10, there's a remarkably similar sound, with a tad more weight to recordings played through the more expensive PH-10
- The PH-5 sounds closer to the GrandiNote Celio MK IV—a bit richer, smoother, and more saturated—whereas the ESE Lab Nibiru is more about speed, precision, and transparency
Takeaway: The Gold Note PH-5 is a versatile phono stage that sounds musical and natural. It provides many options to adjust the sound, and it is an affordable way to get great performance from vinyl records.
Video review
Our take on the brand
Product Strengths
- Straightforward, high-quality preamp that does everything asked of it, very well
- Includes tone control knobs for bass and treble to personalize the listening experience
- Allows turntable users to switch between moving magnet (MM) and moving coil (MC) modes
- Features seven source audio inputs, a front-panel 3.5mm headphone jack, Bluetooth 5.1, optical and USB inputs, as well as a phono stage for turntables
Product Considerations
- Bluetooth 5.1 connectivity, while present, is not super high resolution compared with Wi-Fi and may not appeal to those seeking a more robust streaming experience
- Has no balanced inputs
Comparisons (according to reviewers)
- Against Rotel's RC-1572 MKII, the Adcom GFP-915 wins in many audiophile categories, such as a lower reported total harmonic distortion and noise floor
- The Schiit Freya S stereo preamp at $599 is another solid, no-frills audiophile option that can compare to the Adcom GFP-915
- The NAD C 3050 integrated amp's HDMI switching, internal DAC, Bluetooth 5.4 and phono stage might sway one to spend a few hundred more dollars than the Adcom
Takeaway: The Adcom GFP-915 is a traditional stereo preamp that delivers quality performance and offers a range of useful features for audiophiles. It is a worthwhile option for those seeking a simple and effective way to manage audio sources and volume control.
Video review
Our take on the brand
Product Strengths
- Features a fully discreet headphone amplifier built-in that sounds good
- Offers flexibility with passive, low gain, and high gain settings, not commonly found at its price point
- Build quality feels good, with a nice textured black finish
- Features a precise 128-step attenuator for accurate left-right balance, unusual for a $699 preamplifier
- Features a metal remote with volume, mute, and input selection
Product Considerations
- One reviewer experienced the Kara going into protection mode and muting the sound when adjusting the volume quickly—requiring a power cycle to resolve
- One reviewer said they prefer the RCA input and output sound
- XLR inputs for stereo mode are not available
Comparisons (according to reviewers)
- Vs Schiit Freya S: It replaces the Freya S and has significant upgrades, including a headphone jack and a more powerful power transformer
- Vs Pass Labs HPA1: The Pass Labs is a better-sounding pre-amplifier and headphone amplifier overall, but is significantly more expensive
Takeaway: The Kara preamplifier offers great flexibility with gain options and a good-sounding headphone amplifier. It's a well-built component that could be a good addition to an audio setup, especially if clarity is valued.
Video review
Our take on the brand
What competes at this price?
Our Summary
Product Strengths
- True balanced connections reduce noise and increase detail, dynamics, and musicality
- Settings are easily adjustable on the front panel, including impedance, capacitance, and gain
- Well-made metal chassis is compatible with both MM and MC cartridges
- Discrete circuits are used in its gain stages, which Pro-Ject believes delivers the best sound
- Offers both single-ended (RCA) and balanced (XLR) inputs and outputs
Product Considerations
- Balanced cables are required for optimal performance if using balanced connections
- Relay switching causes a time lag when switching impedance, capacitance, or gain
Comparisons (according to reviewers)
- The Lehmannaudio Black Cube had more power in the low end, while the Pro-Ject tended toward a drier character
Takeaway: The Phono Box S3 B is a well-designed phono stage offering balanced connections, making it a great choice for those wanting to upgrade their vinyl listening experience. The adjustable settings and solid build quality make it a versatile and worthwhile addition to any system.
Video review
Our take on the brand
Our Summary
Product Strengths
- Good starting point for a decent phono stage at an affordable price
- Offers a dual-mono structure, which is rare at its cost
- Provides a warmer tonal balance, which can help balance out the sound of cheaper turntables and cartridges
- More refined in the highs, cleaner, and weightier in the bass compared to some competitors
Product Considerations
- Dynamics are a bit slow and compressed compared to higher-end options
- MC option might be useless, as not many audiophiles with an MC cartridge would use a budget phono preamp
- Lacks adjustability, especially for MC impedance input load and MM input capacitance
- Has a resonant top cover that could benefit from damping
Comparisons (according to reviewers)
- Compared to the NAD PP-1, the PhonoBox is more refined in the highs, cleaner, and weightier in the bass
- Compared to the Lehmannaudio Black Cube SE, the PhonoBox is slower and more compressed dynamically
Takeaway: The Pro-Ject PhonoBox E is an affordable way to play vinyl, and it improves the sound relative to some similar devices. It is a good option to consider if the amplifier does not have a phono input.
Video review
Our take on the brand
Our Summary
Product Strengths
- Premium build quality with internal shielding to eliminate electromagnetic interference
- Advanced Bluetooth 5.2 with aptX Adaptive and aptXHD support for high-resolution audio transmission
- Dual-input configuration (phono and 3.5mm line-level) for maximum versatility
- Precise RIAA equalisation and low noise performance for pure analogue sound
- Compact, space-efficient design and easy setup/operation
- Limited to MM cartridge compatibility
- The 10m Bluetooth range might not suit larger homes
- Single 3.5mm line output
Takeaway: The Pro-Ject Phono Box E BT5 offers a blend of vinyl warmth and wireless convenience. It's a versatile option for vinyl enthusiasts wanting to connect to modern Bluetooth speakers.
Video review
Our take on the brand
Our Summary
Product Strengths
- Good sound quality, warm with lows and highs present, and a quiet noise floor
- Supports both Moving Magnet (MM) and Moving Coil (MC) cartridges
- Adjustable gain settings to match different cartridge output levels
- Metal construction for durability and shielding
- Offers DIY upgradeability with a socketed op-amp that can be swapped to change the sound signature
Product Considerations
- The ground post is positioned close to the power input, which can be inconvenient
- To power it off, one must press and hold the power button instead of pressing it quickly to turn it on, which is not intuitive
- Lacks a headphone jack
- Does not have a subsonic filter or capacitive loading switch
Comparisons (according to reviewers)
- Compared to the Schiit Audio phono preamp, the Fosi Audio Box X5 is on par or better than the Schiit Audio phono preamp generation one version
Takeaway: The Fosi Audio Box X5 is a great value phono preamp that provides good sound quality and versatile features for both MM and MC cartridges. It is a solid choice for anyone looking to upgrade from a built-in preamp or start with their first turntable.
Video review
Our take on the brand
Our Summary
Product Strengths
- A very low noise floor, even with high gain settings for moving coil cartridges
- Various gain settings for moving magnet and moving coil cartridges, making it versatile
- An 'intelligent' subsonic filter effectively reduces rumble without negatively impacting bass frequencies
- A balanced 4.4mm output, which is uncommon in phono stages at this price point
- Impressive sound quality for its price, including a wide soundstage and good dynamics
Product Considerations
- Large diameter RCA plugs may not fit due to the small chassis
- The number of load settings is stated inconsistently across sources, with some stating four and others stating three
- Connecting RCA and balance output together simultaneously to two different amplifiers can result in noticeable humming noise
- One reviewer mentioned a 'clinical' sound that might pair better with warmer cartridges, though this was addressed by changing the setup
Comparisons (according to reviewers)
- The ZEN Phono 3 has a wider soundstage and better dynamics than the iFi Zenfone Stage
- The ZEN Phono 3 has deeper bass than the Accuphase AD-60, but slightly less clarity and definition in the bass region
- The ZEN Phono 3 delivers a larger, beefier—and more rhythmic sound than the built-in phono stage in the U-Turn Orbit Special
- The ZEN Phono 3 produces significantly less noise than the Musical Fidelity M5SI phono stage
Takeaway: The ZEN Phono 3 is a valuable phono stage that provides a clean and dynamic sound, along with features typically found in more expensive units. It is especially useful for those looking to upgrade from a basic phono stage or for vinyl enthusiasts who want to explore different cartridge types.
Video review
Our take on the brand
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