HMX Purple Dawn: Review by Vere

Opening Words:

Hello everyone! It has been a long time coming for these switches ever since they were in development since 2023. I have always been excited for these switches as Dashan's concept for these switches definitely hyped me up as I really love switches that are full travel or near full travel. Although it is our first in-house designed switch, I will go over the objective parts of this switch as always. This switch is among the top 3 for my personal favorite HMX switches so I hope you will give them a try. 

 

Switch Introduction:

The HMX Purple Dawns are long-pole linears with a PA12 top housing, P4 bottom housing, and come with a modified UPE stem.

They carry a 22mm KOS single stage extended spring with an operating force of 55g and bottoming out at 62.5g. There is a variance of 2g among them.

They have a true 3.9mm travel which is much longer than your average long-pole. They bottom out on the pole and not the rails.

These switches were designed in-house by Dashan(DY), the owner of Unikeys, marking this as our very first custom switch.

(I said this jokingly before but Purple Dawn is a very dramatic name)

Short Summary

 

Stock Experience:

These switches use HMX's standard lubing process of a Krytox GPL 205 + GPL 105 mix in light amounts over the leaf, bottom housing rails, as well the the stem legs. The springs use a dry film lubricant.

(Usual coating over legs + stem sliders)

Overall, there is not much to go over as we see this same technique in all of HMX's switches. The main difference is that these switches do use a new mold in order to work with the modified UPE stem, which also has been adjusted to prevent any syringe effect from occurring with the heavier spring.

(Hefty amount over leaf legs)

The UPE stem also has a surprisingly low amount of wobble and is quite stable.

It is worth mentioning that I have been noticing some ticking noises from recent HMX switches I have been testing such as the Eva, Sunset Gleam, and even these Purple Dawns. Though it is barely audible upon actuation, it still exists.

(No issue with less lube on stem since bottom housing rails have lube too)

Would I re-lube them? Unless you have some ticking switches, there's not much reason to add more lube to an HMX switch as it may even reduce the performance of the switch.

 

The journey towards the Purple Dawn:

As mentioned previously, this switch has been in development for quite some time, as they have been in development from May 2023, and were first teased in August of 2023.

Dashan has mentioned that he was testing samples from several manufacturers, such as BSUN, Aflion, Keygeek, Huano, QTUO, and ultimately ended up with HMX as their molds were able to satisfy his desire for a flawless switch. That isn't to say that the other manufacturers were sub-par, but it has to do with not wanting to concede on any possible flaws or errors no matter how minor.

After a long wait, we finally ended up here with the HMX Purple Dawns, a custom in-house designed switch that offers specs that you won't be able to find elsewhere from HMX, true 3.9mm travel, a spring weight that is on the heavier side, and an actually balanced sound profile thanks to the UPE stem.

 

Notes on the modified UPE stem:

Although it has become a more common material in recent years, UPE might be a material that people still don't know much about. UPE or UHMWPE is a polyethylene with an extremely low coefficient of friction, it is a softer material that is fairly resistant to wear and damage and has been actively used in switches ever since releases such as the C3 Tangerines thanks to its smooth properties.

With a softer material for the stem, I expected these switches to sound quieter, but they seem to be modified in a way that keeps stiffness and generates decent volume, they also seem firm enough to prevent any issues with damage in the long-term.

After opening up the switch and inspecting the stem, the increased travel results from the elongated part of the stem being much shorter than other HMX switches. This elongation is usually what helps generate sharpness, so with the Purple Dawns having a duller tip, it helps to generate a rounder sound instead.

(Purple Dawn vs fellow UPE stem user Caramel Pudding)

My hypothesis is that the modified UPE and this stem tip play the largest factor in this switch's sound profile, as the Caramel Pudding also has the same stem material but sounds slightly thinner overall.

 

 

PA12 top housing and P4 bottom housing:

The Purple Dawns carry a PA12 top housing and P4 bottom housing, both materials often being seen in other HMX switches.

As one of the more common materials for HMX top housings, PA12 results in a subdued top-out sound due to the PA12 material being less stiff than its other nylon counterparts.

This allows the Purple Dawn and other HMX switches to sound more consolidated on the bottom out and reduces the overall noisiness of the switch.

The P4 material shows up in several other HMX switches as well, though most of these switches exhibit a thinner and less powerful sound profile. This P4 material uses less fiberglass in its composition and uses more PTFE (Teflon) material instead. 

(The other P4 users share the same trait of being less sharp than other HMX)

This source of the thinner sound profile is due to PTFE being very soft, a little too soft for switches. This is why it is often used as a modifier and not a standalone material. It has the lowest coefficient of friction of any solid material which can obviously boost the smoothness of any switch.

Thanks to the small amount of fiberglass still present in this switch, the Purple Dawns still retain a hint of HMX's usual sound profile but it is not as strong. 

 

Type-feel discussion:

The most notable part of this switch is the considerably altered type-feel that I received from using the Purple Dawns. I find the increased travel to feel much more substantial, but this is just one of the factors that make this switch more pleasant to type on.

To clarify, I have tested the 62.5g variant of the HMX Xinhai and have also spring swapped other HMX switches before. The Purple Dawns feel slightly different and I believe there are a few reasons as to why that is.

First, travel distance has a large effect on springs, as the more you need to "travel" with a stem also means that there is more spring to press in, especially for longer springs at something like 22mm. This means that long poles at 3.5mm travel require less force to bottom out thanks to the fact that you don't need to fully compress the spring at all. With these sitting at 3.9mm, it allows for a more accurate feeling of 62.5g weight.

Second, the tolerances being less tight actually allows for a more comfortable typing experience depending on your typing method. There are actually a few demerits to having an overly tight housing and it depends on each person's typing strength/cadence, I will go over how this can affect type-feel.

For example, when typing on Dustproof box stems, if the housing is too tight for the tolerance of the stem, you may even feel that the stem itself won't smoothly travel or even may return at an angle which leaves a very uncomfortable "jamming" feeling. This is largely due to the fact that we don't exactly type by pressing the keys straight down on a vertical axis, normally we lay our hands over the keys and then extend over the keys with our fingers, which means that there is a slight angle at which we press down on our keys.

This is how we often feel stem wobble in the first place, if the wobble is considerable, then we can easily feel the keycaps moving all over the place because of the slight angle at which the average person types as well as the typing angle of the keyboard. Dustproof box stems by nature allow for almost no breathing room for the stem, which means that overly tight housings can cause a feeling of the stem being jammed when pressed off-center.

Another example would be the previous syringe effect that plagued some of HMX's earlier releases caused by overly tight housings that caused air to be trapped inside the switch. Due to the tightness of the tolerance, any air that was caught inside the stem pole of the switch would have to be pushed down alongside the spring which adds an artificial weight to the switches, this also caused the return to become sluggish due to the air being trapped inside the center post.

In comparison, the HMX Purple Dawns feel extremely consistent with the combination of heavier weight and slightly more comfortable tolerance. With the heavier operating force requirement, there are less chances that you will mistype, and the snappy return along with the stem not being overly tight will allow for the switch to feel more natural on the upstroke.

Ultimately this boils down to preference, as some people do enjoy the super lightweight springs with short travel and tighter tolerances, meaning that you barely need to exert any force to bottom out, but I personally feel more in control of my typing with a normalized spring weight and near full travel, I feel like I wouldn't get fatigued after typing on these for a while. (Just personal preference!)

 

Note on 3.9mm travel:

There is a simple reason as to why we don't often see 3.9mm travel for long-pole linears: shrinkage calculation.

To remind people about shrinkage, this occurs in the molding process of plastics in which the plastic cools down and a percentage of the plastic itself will shrink in the process. Some plastics are more susceptible than others but is something that exists in all plastics processing. (PBT is a big offender here)

When it comes to switch production, manufacturers have to keep this in mind during the molding process and calculate ahead of time the amount of shrinkage that will occur. (Though they will usually find this out through sampling) This means that in order to obtain a true 3.9mm or 4.0mm travel, they will need to calculate the shrinkage ahead of time to ensure that it aligns perfectly with the projected distance. In most long poles, you would expect the stems to be exactly 13.5mm length to hit the 3.5mm travel, but many stems are actually slightly off like 13.45mm length due to the shrinkage that occurs. (This is usually referred to as deviation)

(Side note: this is what caused the major issue with the Meirun Pleiades stems due to the initial prototype batch unknowingly being 13.9mm length due to an accident, then shrinking to 13.6mm. They had no idea it was actually longer than the original length which led them to officially produce them at 13.6mm which they thought was fine, but then the stems ended up at 13.4mm length after the shrinkage which was much shorter than the initial prototype batch.)

HMX was able to properly lock this down after several attempts as the initial batches that Dashan received were 3.7mm or 3.8mm due to the slight miscalculation for shrinkage (Macchiato/Cloud/Swift). It is because of this shrinkage factor that it is difficult to create a perfect switch that follows the imagined design and tolerances to a tee.

 

Overall Design:

In short, this is an HMX switch that is an outlier among HMX switches.

With a different type-feel than your usual HMX switch, as well as a more rounded sound that differentiates itself among the rest, it almost feels like you could have hidden the fact that it was an HMX switch if not for the excellent stock form and slight HMX traits.

A great stock form with no issues for smoothness and minimal transient noise.

A crisp bottom out that isn't overly sharp and is consolidated thanks to the material choice for top and bottom housing.

A moderate pitch resulting from a balance between soft and stiff materials, allowing this switch to reach the higher pitches of sound, or touch the deeper notes that most HMX switches will never reach depending on your build.

A long-pole switch that also allows for enjoyers of full travel to appreciate the type-feel provided by these switches.

Dashan's vision of a "perfect" switch is almost realized with the Purple Dawn, it has a great stock experience with smooth travel, clean bottom out, and has a sound profile that can become bright or deep depending on your setup. It is a high quality product resulting from the desire to remove all flaws and to be used by anyone.

That being said, "perfect" is a word that is difficult to use in this hobby as everything is preference, but I would dare say that this switch isn't that far from the goal.

 

Smoothness: Phenomenal

You already know what's going to be here, these switches are as smooth as can be with HMX's quality. 

There's nothing much else to say about their performance as adding more lube wouldn't have any effect. I would say they are one of the smoother HMX options.

 

Sound Profile:

With a more subtle bottom out resulting from the softer materials, these switches finally lean towards an average long-pole's sound profile.

Part of their brightness results from the small amounts of fiberglass within the bottom housing, the increased travel also helps for a more substantial feeling in creating a crisp bottom out.

Overall, the sound of the Purple Dawn is rounded and full.

In my opinion, most of the HMX switches are perceived as clacky because of their sharp and thin sound profiles. This isn't exactly wrong since those switches definitely have a higher pitch, but part of what makes the switch itself sound brighter than other options is the concentrated thinness of HMX. (After recording most of them, it seems that some HMX options aren't as loud as I thought in reality)

Since most HMX switches have a concentrated bottom out, you can hear and perceive the sharpness very clearly without any scratch, ping, or ticking noises, most of them also have quiet top-out sounds. In truth, there are plenty of switches that are louder than HMX when it comes to actual volume in decibels, but the type of thin sharpness that results from HMX switches just "sounds" more bright to our ears.

It's because of this thin sharpness that we can easily identify an HMX switch, this sound tends to overwhelm other sounds in a board and isn't easily altered by modifiers like foam. If you've tested many HMX switches, you'll know exactly what I mean. 

That's where this switch comes in, the overall tone of the Purple Dawn is balanced and leans towards a sound profile with more depth to it. With a more rounded tone, it can be altered quite easily to how you would want to mold it, albeit it does have a slight hint of HMX's sound traits. The Purple Dawn keeps the clean consolidated bottom out that we know, but without being sharp.

Rounded refers to having a balanced sound profile that isn't too quiet or loud, nor deep or sharp.

Crisp refers to having a solid bottom out that is clear and is easy to hear, doesn't necessarily mean loud and bright.

Clean refers to a sound profile that is mostly one-note or consolidated, lacking excess noise from factors like scratch or having a top-out that is much quieter than the bottom-out.

Full refers to a sound profile that doesn't sound shallow to our ears, or isn't dull and empty. (To be more specific, it has all kinds of frequencies in the sound, lows, mids, and highs.)

 All in all, this switch's sound profile is one that is more in-line with the average switch and that's honestly a good thing in my opinion. After all, HMX could be seen as the extreme side of linear switch sound profiles depending on how you look at it. This means that that there will definitely be people who cannot enjoy or make use of HMX even if they wanted to use a HMX switch in a more controlled environment. I think this switch may be just slightly louder than what you would want for the office, but it's not a bad option.

 

Special HMX Comparison:

For our first in-house switch, I decided to do a special comparison since this switch has been hyped up since forever and everyone probably keeps a picture of KeebTaro's HMX Chart framed in their bedroom. 

Sound is subjective, and what I pick up from my ears could be affected by many different factors such as keyboard build, desk, desk-mat, and even temperature.

I directly recorded each switch in the same conditions, and played back the recorded audio back and forth for this comparison.

This comparison is not definitive. I used 12 HMX switches here, as some HMX switches are extremely similar to one another, I decided against testing every single HMX switch I own.

HMX Deep Navy (P3/P3/LY Stem) 3.6mm Travel

• The Deep Navy is slightly louder than the Purple Dawn.
• These both sound full amongst HMX.
• The Purple Dawn is lower pitched.
• The Deep Navy has slighty more N/S wobble.

HMX Canglan v2 (P3/PA66/T2 Stem) 3.5mm Travel

• The Purple Dawn is slightly louder than the Canglan v2.
• The Canglan v2 is thinner in sound.
• The Purple Dawn is slightly lower pitched.
• The Canglan v2 has slightly more N/S wobble.

HMX Sunset Gleam (PC/Mod. PA66/LY Stem) 3.5mm Travel

• The Sunset Gleam is slightly louder than the Purple Dawn.
• The Sunset Gleam is much thinner in sound.
• The Purple Dawn has a much lower pitch.
• The Sunset Gleam has slightly more N/S wobble.

HMX Eva (PA12/P4/T2 Stem) 3.6mm Travel

• The Purple Dawn is slightly louder than the Eva.
• The Eva is thinner in sound.
• The Purple Dawn is slightly lower pitched.
• They share similar wobble.

HMX Jammy (PA12/P4/POM Stem) 3.7mm Travel

• The Purple Dawn is slightly louder than the Jammy.
• The Jammy is much thinner in sound.
• They just barely share the same pitch.
• The Jammy has slightly more N/S wobble.

HMX Hyacinth v2 (PC/Mod. Nylon/POM Stem) 3.5mm Travel

• They share a similar volume.
• The Hyacinth v2 is slightly thinner in sound.
• The Purple Dawn is much lower pitched.
• The Hyacinth v2 has slightly more N/S wobble.

HMX Macchiato (PA12/Mod. Nylon/POK Stem) 3.8mm Travel

• The Macchiato is slightly louder than the Purple Dawn.
• These both sound full amongst HMX.
• The Purple Dawn is slightly lower pitched.
• They share similar wobble.

HMX Xinhai (PA12/Mod. Nylon/POM Stem) 3.5mm Travel

• The Xinhai is slightly louder than the Purple Dawn.
• These both sound full amongst HMX.
• The Purple Dawn is lower pitched.
• They share similar wobble.

HMX Blue Topaz (PC/P4/LY Stem) 3.7mm Travel

• The Purple Dawn is louder than the Blue Topaz.
• The Blue Topaz is much thinner in sound.
• The Purple Dawn is lower pitched.
• They share similar wobble.

HMX Caramel Pudding (PA12/PA66/Mod. UPE Stem) 3.6mm Travel

• The Purple Dawn is slightly louder than the Caramel Pudding.
• The Caramel Pudding is slightly thinner in sound.
• The Purple Dawn is slightly lower pitched.
• They share similar wobble.

HMX Swift (P3/PA3.0/LY Stem) 3.7mm Travel

• The Purple Dawn is louder than the Swift.
• The Swift is slightly thinner in sound.
• The Purple Dawn is slightly lower pitched.
• The Swift has slightly more N/S wobble.

HMX Cloud (PA12/PA2.0/LY Stem) 3.7mm Travel

• They share a similar volume.
• These both sound full amongst HMX.
• They share a similar pitch (Slightly shocked here)
• The Cloud has slightly more N/S wobble.

After my comparison, it was quite shocking to find out that the Purple Dawns were actually able to be slightly louder than a lot of HMX switches just by looking at the dB levels. 

It likely has to do with the near full travel increasing the potential volume of these switches depending on how much force you exert to bottom out with them. 

That being said, it is a marginal volume difference as most of the HMX switches are extremely close in volume besides the louder switches such as Sunset Gleam, Xinhai, Macchiato, and Deep Navy.

Please take this comparison with a grain of salt as there are many different factors which can affect sound.

 

Flaws:

Time to go over the flaws.

First off, the only particular flaw to go over would be the minor ticking which seems to occur in some HMX switches, this could be a deal-breaker for some people who really care about transient noise.

Most HMX switches that are a bit louder can mask this sound, but the Purple Dawn is more in line with a normal long pole and perhaps it may not be able to.

Secondly, this is more of a minor nitpick which won't matter most of the time but may be an issue to some.

The spring weight and travel distance could be the opposite of what a die-hard fan of HMX switches may desire for their typing experience. After all, there were no HMX switches with such a spring weight on release, and that is further exacerbated by the near full travel, meaning that it would "feel" heavier than the common HMX switch.

This is really just a "what if" flaw that isn't even a real flaw, but keep this in mind if you strictly use lightweight springs.

 

Personal Build Recommendations: (Preference/Opinion based)

At first I used these on the Cycle7 with a FR4 plate but I felt that it sound slightly too bland.

I thought they sounded quite full in comparison to other HMX switches I had tested previously so I decided to try them on an O-Ring board with a POM plate. The resulting sound profile was very strong and leaned towards the deeper end.

Since they aren't quiet or loud, they can probably go well on any type of mounting system. I would recommend some of the more influential plates and mold the sound profile into what you desire.

For a brighter board, stick to Aluminum or Carbon Fiber.

To capitalize on a deeper HMX switch, stick to POM, as I think PP or PC may have higher notes than expected. Case foam may also be an option if you want to make these deeper.

 

Closing Summary:

Before we close up this review, I just want to mention that this switch can only exist thanks to your continued support. (Not sponsored!)

For $0.35 per switch, you will be able to experience a very unique HMX switch with a full and deeper tone, neither sharp nor thin. A definitive outlier among the bright and clacky HMX switches that we all know.

With a satisfying type-feel and crisp bottom-out, these are probably my personal favorite HMX switch to type on. With a 3.9mm travel that feels substantial, it should be a no-brainer for those that desire a switch close to full-travel. 

The HMX Purple Dawn marks a new beginning for Unikeys, it may be the first custom switch but it definitely won't be the last. If you've been following this project for a while, or perhaps you just wanted to get a new HMX switch, I have a feeling that you won't be disappointed with this offering. We hope you will look forward to exciting future releases designed to please!

 

Final Scoring: 8.4/10

Design: 10/10 

[The Purple Dawns have a design that is antithetical to HMX's usual products, however it is executed quite well. With a great material in the stem to balance the traits of fiberglass, the tone becomes even and rounded. The travel distance and heavier weight complement each other as well. This is the ultimate result of a lot of sampling and experimentation. Plus, they look amazing.]

Sound Profile: 8/10 

[Rounded and clean sound profile, a moderate sound that is in line with most long poles. This type of sound profile is great if you want to be able to enjoy both sides of the sound spectrum, but it doesn't exactly specialize in one or the other.]

Stock Experience: 9/10

[High quality stock experience that is normal for HMX, points are docked due to the slight tick, but there is nothing else to complain about, not even wobble. Smoothness is unmatched as usual.]

Uniqueness: 7/10

[The uniqueness of this switch comes from a true 3.9mm travel which is fairly uncommon in the switch market. It also happens to be the first HMX switch with a 60g+ spring weight. Lastly, it has some proprietary modifications and materials, though they are not exactly brand new.]

Flaws: 2/10 

[As this switch no longer has HMX's tolerance issue, the ticking is the only thing that is worth mentioning as a flaw, as minor as it may be.]