I’ve seen a lot of reviews of these keyboards, but they’re not that useful. They usually record what they sound like when typing and talk about how they look and feel. I’ll try to provide a bit more objective info here.
The keyboards I’m comparing are a Durgod with Cherry Blue switches, and a Unicomp Mini M with buckling springs. Both are 87-key layouts (tenkey-less). I find this more ergonomic, as it puts my right hand closer so I don’t have to stretch to reach the trackball. More on that here.
Sound
I recorded both keyboards with my Rode NT1A mics while typing the sentence, “Now is the time for every good man to come to the aid of his country.”
Here are the cherry blues
Here are the buckling springs
They sound quite different. Cherry blues go “click-tick-click-tick” with a thin high pitch while buckling springs go “clock-tock-clock-tock” with a thicker lower pitch. Perceptually, the buckling springs sound louder but the difference is belied by the recordings. According to the recording. peak levels for the buckling springs are only 0.3 dB louder than the cherry blues. Perceptually, it’s hard to compare relative loudness of sounds having such different frequency profiles.
Next, frequency spectrum analysis of these sounds:
Here are the cherry blues
Here are the buckling springs
If you look closely you can see differences that are consistent with subjective perceptions. The buckling springs have more energy at lower frequencies: 50-70 Hz, 310 Hz, and 750 Hz. They have less energy at high frequencies, as the cherry blues have bigger spikes at 1200 and 9500 Hz.
Compatibility
Like every other keyboard I’ve used, the Unicomp works on both Linux & Windows, and through my IOGear electronic KVM switch. However, it behaves differently with Numlock.
Most 87-key TKL keyboards don’t have Numlock, and they ignore the Numlock signal. Not the Unicomp. It supports Numlock! The ScrLk key becomes NumLk when you use Shift. It has 12 keys dedicated to the keypad: 7-9, u-o, j-l, m-.. It seems nice to have even though I would never use it. However, it can also cause problems.
Most computers’ system BIOS have a setting to set the Numlock state when the computer boots. By default, this is ON. This doesn’t work well with an 87-key like the Unicomp, because it changes important alphanumeric keys into numbers. So you may need to alter your BIOS to set the default state to OFF.
Furthermore, Linux enables Numlock when it boots and when you log in (even when you set the BIOS state to OFF). So you’ll have 2 more places you need to reverse the Numlock state. The Linux command “numlockx” is useful for this.
At first I thought this was an annoying bug in the keyboard firmware, as the Numlk got enabled every time I booted my Linux system, and every time the desktop timeout lock kicked in. But as sometimes happens, it turns out to be a feature. Once I figured out how to set the default state to OFF, this is no longer a problem.
Typing Speed
An accurate way to assess typing speed is to look at the keyclicks in the sound waveforms as I typed the same sentence. So here they are:
cherry blues
buckling springs
You can see from the clicks in the waveform that my typing speed was almost exactly the same: about 6.5 seconds to type that sentence (distance from first to last click).
The sentence has 68 characters and 16 words. For typing speed, nominal word length is taken to be 5 characters, so this sentence is only 13.6 nominal words. This amounts to 125 words per minute. That is, form the ratios 13.6/6.5 = X/60, then X = 13.6*60/6.5 = 125.5.
As typing speed is the same, one might assume the difference between these keyboards is purely subjective: which do you think feels or sounds better? Yet such is not the case. We must consider typing accuracy.
Typing Accuracy
Here, the Unicomp wins, and it’s not even close. And it’s not for what might perhaps be the most obvious reason: mechanical switch accuracy. Neither keyboard’s switches produce missed or double characters. The reason is more subtle. It’s about the key switch actuation force and the shape of the keycaps.
Key Actuation Pressure
Blues are not the heaviest cherry switches (greens are). Blues are heavier than the popular Browns, yet still much lighter than buckling springs. The difference is not subtle; it is big and obvious. The Cherry switches are so light, I find that they actuate with incidental finger movement. Just lightly resting my fingers on the keys to find the home keys, I sometimes accidentally press a key. And while typing, if my finger is even slightly misaligned from the exact center of the keycap, if my finger even slightly brushes the key next to it, that key also activates.
Thus, the cherry blues require more finger placement precision when typing, which means either (A) making more mistakes, or (B) slowing down. Because the buckling springs are a bit heavier, they are more forgiving. If your finger is slightly off the exact key center, and gently brushes a key next to it, they key doesn’t actuate. This enables faster typing.
Keycap Shape and Feel
The buckling spring keys feel like they are further apart from each other, slightly bigger spacing. Yet they measure the exact same dimensions, so I assumed this was just my imagination. But the feeling was so persistent that I took additional measurements, and discovered that the keycaps are the same overall size but they have slightly different shapes.
Here I’ll call them “Unicomp” and “Durgod” rather than “buckling spring” and “cherry blue” because we’re talking about the keyboard’s keycaps, not the switches.
Unicomp’s keycaps have slightly smaller top faces and slightly more taper to the base. In comparison, the Durgod keycaps (which are the same shape as the standard keycaps we get on any keyboard that uses cherry switches) are a bit more squarish: the top face is slightly bigger with slightly less taper to the base.
In millimeters, the Unicomp keycap tops measure 11×11, vs 12×12 for the Durgod. Of course, if the keycap tops are slightly smaller while the overall key spacing is the same, the gaps between keycap tops must be slightly larger. And this is true. That spacing measures 7 on the Unicomp, vs 6 for the Durgod.
Both keycaps top faces are curved so you can feel when your fingers are perfectly centered. But the key actuation force of the cherry blues is so light, I can’t actually feel that curvature because doing so incidentally presses the key. To avoid incidental presses, I must hover my fingers just above the keys instead of on them. This reduces the precision I can get by feel.
How does this affect the feel of the keyboard when typing? With the Unicomp you can tell if your fingers are slightly off the keycap center, and keep them centered as you type. I find I do this automatically, probably from all that time typing on original IBM keyboards all those years ago. In comparison, the Durgod keycaps feel the same whether you hit direct center or are slightly off.
Typing Accuracy: Conclusion
These two factors combine to make my typing less accurate with the Durgod keyboard. First, the cherry blue switches are so light, I get accidental strikes on adjacent keys when my fingers aren’t positioned exactly right. Second, the shape of the Durgod keycaps make it harder for me to tell when my fingers are perfectly centered.
In contrast, the Unicomp is more forgiving of sloppy finger positioning when typing, and the keycaps give better tactile feedback to improve that positioning by touch as you type.
Postscript: Cherry Greens
Greens are just like blues, but with a heavier spring / actuation force. Only slightly heavier, the difference is subtle. Many keyboards with blue switches use a green for the spacebar. As mentioned above, the (slightly) stronger force protects against accidental strikes and boosts accuracy. However, greens still feel lighter than buckling springs, and less tactile. Also quieter, but with a less satisfying higher pitched click.
I use greens (with o-rings) at work and buckling springs at home. I prefer the buckling springs but the greens are the best compromise I can find that won’t torture my co-workers with the noise.
Postscript: O-Rings
Installing small o-rings around the stem of each keycap is a popular mod. I’ve seen them available in 2 hardnesses and thicknesses:
- Hardness: 40A (soft) or 50A (firm)
- Thickness: 0.2 mm (thin) or 0.4 mm (thick
What the o-rings do:
- They make the keyboard quieter, especially if you bottom-out the keys (which I always do).
- They soften the bottom-out so it’s less jarring on your fingers.
- They don’t make blues or greens less clicky or tactile.
I find these effects subtle and easy to exaggerate. They make a difference for sure, it’s just not a huge one. They are not necessarily “better” or “worse” — it’s just different and a matter of taste. O-rings are inexpensive, you can get a 200 pack for around $5 – $10. And they can easily be removed if you don’t like them. So if you’re curious then jump right in – there’s no real reason not to try them.