SMSL PH-1 is the perfectly pragmatic phono pre-amp

An ideal phono preamp for beginners but also a perfect upgrade for enthusiasts

The SMSL PH-1 is a compact MM phono preamplifier that represents a fantastic upgrade for first-time turntable users over the built-in phono preamps found in entry-level turntables. With its minimal design choices, impressive technical specifications, and exceptional sound quality, the PH-1 delivers performance that punches well above its price point.

So I have been using the PH-1 for a few weeks now, and A/B testing in different setups with various turntables. I have also been comparing it with other external MM phono stages, in some of my other audio devices like my Denon AVR, my Argon Forte MK2 Active Speakers, and even with my beloved WiiM Ultra. In pretty well all these use-cases the PH-1 is a significant upgrade in audio quality. But I do have some nitpicks which I will get into during the review.

But before I get into the sound quality, let’s have a quick look at the unboxing experience:

Unboxing and Build Quality

The SMSL PH-1 arrives in a simple but well-designed package that protects the unit during shipping:

Opening the box reveals the PH-1 securely nestled in protective packaging:

The package includes:

• SMSL PH-1 phono preamplifier
• USB-C power cable
• User manual

The build quality of the PH-1 is impressive for its price point:

The unit features a CNC-machined aluminum chassis that looks premium and reminds me a little of the equally excellent SU-1. You can see how closely the design matches:

The PH-1 is nicely compact, making it easy to integrate into any audio setup without taking up much space.

You will notice that large 6.5mm headphone jack and the Volume pot on the front of
the PH-1. More information on this feature later on in the review.

The rear panel houses all the necessary connections: RCA inputs for your turntable, RCA outputs to your amplifier, a ground terminal, and a USB-C power input. The front panel features a 6.35mm headphone output and a power button with an LED indicator.

The included USB cable is functional, though as I’ll discuss later, this is one area where a minor upgrade could potentially yield even better performance:

Features and Performance

I thought I would pick a few of the key features of the PH-1 for a brief discussion.

Optimized Gain Structure

I believe the PH-1’s standout feature is its optimized gain structure. Most entry-level MM phono preamps set their gain at 38-40dB, resulting in output signals of only about 300mV, which is gives underwhelming performance for many modern amplifiers. The PH-1 addresses this by providing a fixed 46dB of gain, which produces an output of approximately 1Vrms from typical MM cartridges (which output 3-6mV).

This higher output level makes the sound fuller, more energetic, and more dynamic without introducing distortion in the next stage of amplification.

Power Supply and other components

Another excellent feature at this price point is the isolated power supply. I believe the power supply is isolated in the box on the lefthand side of this photo from a tear-down video I found on Youtube:

This design significantly reduces hum noise and eliminates common problems like AC sound and grounding interference that plague many phono preamps in this price range.

But the external power supply design also provides flexibility for users who might want to upgrade to an even better DC power supply in the future to further improve performance.

Headphone Jack

This was a very interesting feature to include, and I found it worked pretty well for most of my headphones, but I did notice with some more sensitive headphones I could hear more hum that I would have liked. I believe ultimately in most setups there will be a much higher quality headphone amplifier later in the audio chain, so this feature won’t be used, but I can imagine it is a nice way to have a simple headphone amplifier in a basic vinyl setup.

Note: The volume only controls the headphone output, so you will still need a separate preamp to control the volume from the RCA outputs.

MM-Only - A feature or limitation?

SMSL has made a deliberate choice to focus exclusively on MM cartridges with the PH-1. As they explain, “Better be the best single MM than compromise MM+MC.” SMSL mention in their material that this decision was made for the following advantages:

• It allows for a more cost-effective product
• It caters to the 90% of users who use MM cartridges
• It simplifies the user experience with fewer switches and settings
• Removing the MC amplifier circuit improves overall circuit performance by 50%

As a pragmatic guy, anything that cuts down on the price and increases the sound quality is welcomed and I doubt many first-time turntable users buy MC enabled turntables. But it does make me slightly wonder why include the headphone jack if the design choice was the simplifying the internals and controls.

Sound Quality

The sound is characterized by a natural, detailed presentation with excellent dynamics and a noise floor that’s impressively low for a unit in this price range. Both the lower noise floor but also a fuller sound were the real upgrade I felt when swapping between the PH-1 and other phono preamps during the past few weeks.

Bass

The bass response is tight, controlled, and extends deep with excellent definition. The optimized gain structure ensures that bass notes have proper weight and impact without becoming bloated or overwhelming. This is particularly noticeable on bass-heavy tracks where the PH-1 maintains composure and clarity even during complex passages.

Midrange

The midrange is where vinyl often shines, and the PH-1 does an excellent job of preserving the natural warmth and presence of vocals and instruments. There’s a wonderful transparency to the midrange that allows the character of different recordings to shine through without coloration.

Treble

High frequencies are rendered with excellent detail and air without becoming harsh or fatiguing. The PH-1 strikes a good balance between revealing the detail in the music and maintaining a smooth, listenable presentation that works well for extended listening sessions.

Soundstage and Imaging

The PH-1 presents a well-defined soundstage with precise imaging; I believe the channel matching is excellent allowing the true nature of the vinyl recording to be transparently amplified. Instruments and vocals are placed accurately within the stereo field, creating an immersive listening experience that allows you to hear into the recording.

Real-World Testing

I found the SMSL PH-1 to be an excellent match with the new Fosi Audio Luna3 turntable (review coming very soon). This combination provides an outstanding entry point for newcomers to vinyl with 2 excellent products are very reasonable prices:

The PH-1 also paired beautifully with my Audio-Technica AT-LP60, offering a significant improvement over the turntable’s built-in phono stage, in A/B testing it was immediately obvious how well the PH-1 controlled the audio compared the built in phono pre-amp in the LP60:

Due to its size, the PH-1 will integrate seamlessly into any existing audio system, providing a clean, detailed signal to any amplifier:

Headphone testing

I also did some testing of the headphone jack with various headphones, it actually drove my Hifiman Ananda Nano’s pretty well with only minimal background hum, but with more sensitive headphones I did hear a little bit more of the background hum, so I while I do like this feature, depending on your headphone or IEM you may not want to use it.

Specifications and Measurements

The SMSL PH-1 boasts impressive technical specifications that contribute to its excellent performance:

Measurements

The measurements reveal the PH-1’s excellent performance characteristics.

First, the IMD is a smooth linear response:

The SINAD (Signal-to-Noise and Distortion) measurement shows impressively low distortion, contributing to the clean, detailed sound:

Note: These measurements would put the PH-1 near the top of the AudioScienceReview table of SINAD scores for phono preamps at any price, so getting this level of performance for $69.99 is pretty amazing.

The following is the raw published Frequency Response:

Note: This is before RIAA equalization.

For more detailed measurements beyond these frequency response and SINAD figures, you can visit the Aoshida-audio product page, which contains additional technical data.

Rating Explanation

The SMSL PH-1 earns a perfect 5-star pragmatic rating for several compelling reasons:

1. Exceptional Value: The performance-to-price ratio is outstanding, offering sound quality that competes with much more expensive phono preamps. Having a headphone jack adds to the value proposition.

2. Focused Design Philosophy: By concentrating exclusively on MM cartridges, SMSL has created a product that excels at its intended purpose rather than making compromises to accommodate every possible use case.

3. Thoughtful Engineering: From the optimized gain structure to the isolated power supply, every aspect of the PH-1 has been carefully considered to maximize performance.

4. Build Quality: The CNC-machined aluminum chassis provides excellent durability and EMI shielding in a compact, attractive package, and I love how it matches the SMSL SU-1, if only SMSL had a similar sized preamp to connect the output of both devices.

5. Real-World Performance: In practical use with various turntables and systems, the PH-1 consistently delivers excellent sound quality that enhances the vinyl listening experience.

While the PH-1 is nearly perfect for its intended purpose, there are two minor nitpicks worth mentioning:

1. Headphone Output: While the inclusion of a headphone output is convenient, it’s not particularly powerful at 90mW × 2 @ 32Ω. It’s adequate for casual listening but not ideal for driving demanding headphones. Given SMSL’s philosophy of removing unnecessary components to improve performance, the inclusion of a headphone amp seems somewhat at odds with their “do one thing extremely well” approach.

2. USB Power: While the USB power implementation is well-designed with its isolated power supply, I would have appreciated a dedicated power supply option for potentially even better performance. That said, the current implementation is already excellent, and the USB power makes the unit more versatile and easier to set up.

These minor points do not detract from the overall excellence of the PH-1 and are more observations than criticisms.

Conclusion

The SMSL PH-1 is a perfectly pragmatic phono preamplifier that delivers exceptional performance at an affordable price. By focusing exclusively on MM cartridges and optimizing every aspect of the design for this specific purpose, SMSL has created a product that represents a significant upgrade for vinyl enthusiasts without breaking the bank.

Whether you’re looking to upgrade from the built-in phono stage in your entry-level turntable or seeking a compact, high-quality phono preamp for a new setup, the PH-1 offers outstanding sound quality, build quality, and value. It’s particularly well-matched with the Fosi Audio Luna3 turntable, creating a synergistic combination that delivers performance well beyond its price point.

For anyone looking to enhance their vinyl listening experience without spending a fortune, the SMSL PH-1 is an easy recommendation and a perfect example of pragmatic audio design done right.