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KTT Purple Star vs. HMX SU

An in-depth look at the KTT Purple Star and the HMX SU switches—which one is the best fit for you?

Overview

When it comes to choosing a mechanical keyboard switch, the differences between the KTT Purple Star and the HMX SU become evident, despite both being linear switches. The Purple Star is renowned for its all-POM construction, which provides a remarkably smooth typing experience complemented by a neutral sound signature, making it a fantastic option for light typists thanks to its very light 45g bottom-out force. This characteristic is particularly appealing for those who prefer a mild, low-pitched, and easy-to-press switch, enhancing comfort during extended typing sessions. In contrast, the HMX SU features a robust PA12 housing and a T5 stem, delivering a subtle yet comparatively deep sound profile. This switch appeals to users who appreciate a solid build and a more resonant acoustic experience. Both switches cater to different typing preferences and styles, making it essential to consider your specific needs when selecting one. However, let's dive in a bit deeper beyond generalities so you can best decide on the best switch for you.

By the numbers

Technical specifications

Actuation force

43g

Actuation force

45g

Bottom-out force

50g

Bottom-out force

50g

Pre-travel

1.80 mm

Pre-travel

1.80 mm

Total travel

3.50 mm

Total travel

3.60 mm

Factory lubed

Yes

Factory lubed

Yes

Stem construction

Partial box

Stem construction

Standard

Stem material

POM

Stem material

T5

Top housing material

POM

Top housing material

Nylon

Bottom housing material

POM

Bottom housing material

Nylon

Mount type

PCB (5-pin)

Mount type

PCB (5-pin)

Spring

Stainless steel

Spring

22mm single-stage spring

Housing materials

The KTT Purple Star and the HMX SU switches utilize different materials for their housing, which ultimately influences their sonic characteristics. The Purple Star features POM (polyoxymethylene) for both its top and bottom housings. POM's unique acoustic properties are said to produce a pleasing and distinctly muted sound profile, leaning towards the deeper side. Conversely, the HMX SU switches use nylon for both the top and bottom housings. Nylon, being a classic switch material, offers its own deeper and fuller sound profile, primarily due to its softer plastic composition that absorbs sound, resulting in a more rounded and duller auditory experience. This distinction in housing materials sets the two switches apart in terms of sound, while also impacting their tactile feedback during use.

Despite their differences in materials, the Purple Star and HMX SU switches can achieve similar results in terms of sound profile due to the fundamental principles governing acoustic responses in switch designs. Both POM and nylon, while contrasting in hardness and acoustic properties, contribute to creating deeper sound profiles that provide a satisfying typing experience. The impact of these materials is significant; for instance, while the Purple Star's POM housing generates a unique muted sound, the nylon in the SU can achieve a comparable auditory experience through its natural sound absorption capabilities. In both cases, the sound produced at the bottom-out and release stages of a key press is crucial, and each housing material contributes to that experience in different ways.

When considering the interaction of each housing's material properties, it's essential to understand their roles within the switches. The POM housing in the Purple Star is designed to produce a distinct sound profile during key release, while also adding to the resonance felt during bottom-out. On the other hand, the nylon of the HMX SU significantly influences the auditory feedback and tactile feel, particularly upon bottom-out due to its softer nature. Overall, while the KTT Purple Star and HMX SU switch materials are different, they are engineered to create complementary results in terms of sound depth and typing feedback, highlighting how diverse housing materials can cater to specific user preferences while still aligning in their performance outcomes.

Weight

The KTT Purple Star linear switch and the HMX SU linear switch both exhibit light actuation and bottom out forces, making them suitable for extended typing sessions. The Purple Star has an actuation force of 43 grams, while the SU requires a slightly heavier actuation force of 45 grams; thus, the Purple Star is the lighter option. Both switches share the same bottom out force of 50 grams, indicating that while the actuation forces differ slightly, users will experience a similar resistance when fully bottoming out. Ultimately, for those who prefer a more responsive and easier keystroke, the KTT Purple Star may be the better choice, whereas the HMX SU provides a marginally firmer press at the actuation point, catering to users who enjoy a bit more resistance without sacrificing comfort.

Travel distance

When comparing the travel distances of the KTT Purple Star linear switch and the HMX SU linear switch, the Purple Star has a travel distance of 3.5 mm, while the SU switch has a slightly longer travel distance of 3.6 mm. This means that for users seeking a more responsive experience, the KTT Purple Star may be the better choice due to its shorter travel distance, which can facilitate quicker key presses, particularly beneficial for gaming. On the other hand, the HMX SU, with its travel distance of 3.6 mm, offers a more pronounced depth, appealing to those who prefer a more tactile feedback and a less abrupt feeling when bottoming out. Therefore, while both switches provide a relatively short travel distance compared to traditional switches, the KTT Purple Star is shorter, making it more suitable for fast-paced actions, whereas the HMX SU caters to those who appreciate a bit more travel for a hearty feel.

Price comparison

Which switch is more bang for your buck?

The HMX SU has an MSRP of $3.50 per 10 switches. At Milktooth, we are able to pass on savings to our customers and offer the SU for $3.29.

The KTT Purple Star comes in at $4.88 per 10 switches.

Here at Milktooth, we offer the best prices on switches (on average, 27% lower the competition). In addition, we offer free shipping on orders over $49.00. We also offer free returns and exchanges, so you can shop with guaranteed satisfaction.

That said, while price is an important piece of the puzzle, our opinion is that you should ultimately pick the option that most suits your unique preferences since you’ll be using these switches for years to come. In other words, finding something perfect for you is, in our view, the most important criteria.

Typing experience

When it comes to sound, the KTT Purple Star linear switches are known for their low-pitched, buttery smooth quality, producing a mellow and bass-heavy tone that is generally pleasing to the ear. This neutral sound signature can make typing feel more enjoyable without drawing too much attention, making them ideal for users who prefer a subtler acoustic profile. In contrast, the HMX SU linear switches are characterized by a relatively deep sound profile, though specific descriptors about their acoustics are less defined. As sound quality can vary significantly based on factors like the keyboard construction and keycap selection, both switches are likely to offer a satisfying auditory experience, albeit with different nuances.

In terms of feel, the KTT Purple Star excels with its mild response, which provides a gentle and comfortable typing experience. The light 45g bottom-out force makes these switches particularly appealing for lighter typists, allowing for a relatively effortless key activation that reduces finger fatigue during long typing sessions. The easy-to-press nature of the Purple Star gives it a responsive feel, making it accessible for users who may not want to exert much effort while typing. The characteristics of the HMX SU linear switch, however, remain unspecified regarding their tactile feedback or overall sensation during use. This lack of detailed information means that potential users may need to test the SU switch to gauge its feel personally.

In summary, the KTT Purple Star and the HMX SU linear switches cater to different tastes, with the Purple Star standing out for its low-pitched sound and mild, easy-to-press feel. Both will provide a unique typing experience, but the Purple Star’s specifications allow for a clearer understanding of its auditory and tactile characteristics. The SU’s performance in these domains lacks the same level of detail, leaving some unknowns that may influence your decision. Ultimately, both switches can lead to satisfying results, but personal preference will play a key role in choosing between them.

Conclusion

To conclude, when deciding between the KTT Purple Star linear switch and the HMX SU linear switch, your preference will largely depend on your typing style and the experience you seek. If you prioritize a buttery smooth typing experience with a low-pitched sound profile, the KTT Purple Star is an excellent choice, especially if you’re a light typist or someone who types for extended periods as the light 50g bottom-out force minimizes finger fatigue. Its mild feel and easy-to-press design will keep your hands comfortable during long sessions. On the other hand, if you appreciate a slightly deeper sound that doesn’t compromise on smoothness but still provides a satisfying tactile response, the HMX SU might be the better option for you. With a solid PA12 housing and a T5 stem, it offers a unique character suitable for those who enjoy a bit of depth in sound combined with comfort. Ultimately, both switches are light and smooth, but your choice should reflect whether you lean towards a mellow, neutral typing sound with the Purple Star or a subtly rich sound experience with the SU.

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