Mad Professor Kosmos Review: Ambient Reverb Without Menu Diving
The Mad Professor Kosmos is one of those pedals that looks fairly simple until you start going through everything it can do.
You get 11 different programs covering traditional sounds like plate, room, spring and hall reverb. From there, things get considerably more ambient. There are three shimmer modes, combinations of reverb and delay, two swell programs, a freeze function and even a wet-only mode.
Despite all of that, the pedal never really feels complicated.
There is no screen, no preset system and no collection of hidden menus. You choose a program, turn a few knobs and start playing.
That simplicity is probably one of the things I like most about the Kosmos.
One important thing to mention before getting deeper into this review is that the Mad Professor Kosmos has been discontinued. Mad Professor currently has the pedal listed in its archive under the Kosmoz name. Still, these pedals occasionally show up used. I think there is plenty here that remains interesting today.
For my original video, I ended up using the Kosmos on every guitar part in the intro song. Rather than running through all the modes with the same chord progression, I used different sounds as part of the arrangement.
That turned out to be a much better way to understand what the pedal actually does.
What Is the Mad Professor Kosmos?
The Kosmos is a compact ambient reverb pedal with 11 different programs.
Its main controls are Level, Tone, Time and Control. A rotary selector lets you choose between the different algorithms.
Level controls the amount of effect in the signal. Tone changes the brightness of the reverb, while Time controls the length of the tail.
The interesting one is the Control knob.
Its function changes depending on the selected program. On some modes, it adjusts ducking. On others, it controls the shimmer balance, delay amount or the rise time of the swell effect.
Normally, this kind of multifunction control can either make a pedal clever or make it frustrating.
Here, I think it works.
You get enough control to shape the sounds without turning the Kosmos into a small computer sitting on the floor.
Sometimes I just want to turn a knob and hear what happens.
My Setup for the Demo
For the original demo song, I recorded the guitar parts through my Victory Sheriff 22 into a Two Notes Torpedo Live. I used a closed-back REVV 4×12 IR for the cabinet sound.
Most of the guitar parts went through the first channel of the Victory with the amp set very clean. This gave the Kosmos plenty of room to do its thing. There wasn’t already a lot of distortion in the signal.
For the solo section, however, I did pretty much the opposite.
I switched to the second channel of the Sheriff and added gain. Then I ran the delay and reverb directly into the overdriven amp.
The result was slightly nasty, messy and very enjoyable.
Usually, delay and reverb are placed after distortion. That keeps the repeats and ambience nice and clean. But sometimes clean is not what you want.
Driving reverb and delay into an overdriven amp can get chaotic very quickly. In the right context, though, that chaos becomes part of the sound.
It ended up being one of my favourite tones in the entire demo.
Breaking Down the Intro Song Sounds
For the intro song, I didn’t simply choose one Kosmos setting and leave it there.
Instead, I treated the different programs almost like separate instruments. Some parts needed a short and controlled space around the guitar. Others worked better with huge shimmer tails or delay mixed into the reverb.
That also shows one of the pedal’s strengths.
The Kosmos isn’t only useful for making everything sound enormous.
It can do the practical stuff too.
Spring Reverb
The Spring setting was one of my favourite classic-style sounds in the pedal.
It can get into that familiar splashy spring territory, including surf-like sounds. Increasing the Time control makes it considerably more ambient.
For one of the song parts, I used a longer decay. That produced a really nice spacious spring sound that worked far beyond traditional surf guitar.
I also used the Spring setting with a shorter decay for some of the more rhythmic parts.
That worked particularly well because the reverb added space without washing away the rhythm. You still hear the attack of the guitar clearly. Meanwhile, the tail adds just enough atmosphere around it.
That’s exactly what I want from this kind of reverb.
Room Reverb
The Room setting has a shorter, more natural decay. It worked really well with rhythmic guitar parts.
You get space without immediately making the guitar sound like it’s sitting inside an enormous hall.
I especially liked the tails on this setting. They remain musical and present but don’t start competing with the guitar part itself.
When I wanted something less dry without making the reverb obvious, Room was one of the easiest settings to use.
Shimmer 2
Things get considerably more ambient with Shimmer 2.
This mode has a really moody character. I especially like how it works with long chords.
It’s also useful for atmospheric soundscapes. In those situations, the guitar starts turning into a background texture instead of sitting clearly at the front of the mix.
That’s where the Kosmos becomes more than simply a reverb pedal.
The sound itself begins influencing what you want to play.
Shimmer 3
Shimmer 3 was another highlight.
This one is great for enormous sustained chords that seem to keep going forever and ever and ever.
More importantly, it can still remain musical.
Using the Control knob, you can adjust the balance between normal reverb and shimmer. Therefore, you don’t have to completely drown everything in the pitch-shifted effect.
Of course, you can.
In the original demo, I described one of the more extreme settings as sounding like a bunch of unicorns and rainbows appearing behind the guitar.
I still think that’s reasonably accurate.
Room Reverb With Slapback Delay
The Room plus slapback mode was another really fun sound.
It immediately gets into rhythmic territory. The delay gives the guitar extra movement, while the room reverb makes everything feel wider.
There is something slightly Edge-like about some of these sounds. However, the Kosmos still has its own ambient character.
I used this setting for a rhythm part behind the solo in the demo song. The timing happened to work surprisingly well with the track.
You can start with something relatively normal here and then push it much farther if you want.
Room Reverb With Multi-Head Delay
The Room plus multi-head delay mode gets considerably more complicated.
Compared with the slapback setting, there is more movement and a much denser texture around the guitar.
I used this setting for the solo near the end of the intro song.
As I mentioned earlier, I also ran it into the overdriven channel of the Victory Sheriff.
The result wasn’t particularly clean.
That was the point.
Instead of having pristine delay repeats sitting politely behind the guitar, everything started interacting with the amp distortion. Both the repeats and reverb became part of the gain structure.
It was messy in exactly the way I wanted it to be.
The Controls Are Simple, but There Is Plenty to Explore
One thing Mad Professor did really well is getting a lot out of a relatively small number of controls.
The Level knob is straightforward. Keep it lower for subtle ambience, or increase it until the effect becomes a major part of the sound.
With larger ambient programs, the Tone control becomes especially important.
Darkening the reverb helps it sit behind the guitar. A brighter setting makes the effect more obvious and brings out the shimmer.
This is particularly useful because bright shimmer can go from beautiful to “is my guitar being abducted?” surprisingly quickly.
The Time control changes the length of the reverb.
Shorter settings work nicely for practical room, spring and plate sounds. Turn it up and the reverb tail becomes part of the performance.
What Does the Control Knob Do?
Then there is the Control knob.
Its job depends on the selected program, which is one of the cleverer parts of the Kosmos.
On some conventional reverb programs, it changes the amount of ducking. This lets the effect move out of the way while you’re playing. Afterward, the reverb blooms into the spaces between phrases.
For ambient guitar, that’s extremely useful.
You can have a lot of reverb without every note immediately turning into soup.
On other programs, Control adjusts things such as shimmer balance, delay amount or swell speed. As a result, the same four-knob layout gives you much more control than it initially appears to.
Plate Reverb
The Plate program gives you the more traditional studio-style side of the pedal.
It has a smooth, dense character that works well on clean guitars and melodic leads. It’s also useful when you want extra space without creating the impression of a huge room.
With sensible Level and Time settings, Plate can be fairly restrained.
Push those controls harder and things get considerably more dramatic.
For general guitar use, this would probably be one of the first Kosmos settings I’d try.
It isn’t the most outrageous sound in the pedal.
That’s a good thing.
Not every reverb needs to sound like a portal is opening behind you.
Room Reverb
Room is probably the most natural reverb in the pedal.
Rather than creating an enormous tail, it makes the guitar feel like it’s sitting in a physical space.
That works well when a recorded guitar tone feels too dry. At the same time, you don’t necessarily hear an obvious reverb effect.
A good room reverb probably isn’t the thing that sells pedals.
It’s also unlikely to make your pedalboard look more expensive on Instagram.
But this kind of effect can quietly make a guitar part work much better in a mix.
The Kosmos Room mode also handles rhythmic playing nicely because the shorter decay doesn’t get in the way.
Spring Reverb
Spring reverb is always an interesting thing to reproduce digitally.
Real spring tanks have their own splash, bounce and slightly mechanical quality. Some pedals try to recreate that very literally. Others use “spring” more as a general description for a brighter and tighter guitar reverb.
The Kosmos falls somewhere toward the latter category.
I wouldn’t buy it specifically as a replacement for a massive vintage spring tank.
As a lively guitar-friendly spring sound, however, it works really well.
Increasing the Time control takes it into more ambient territory. Shorter settings, meanwhile, are particularly useful with percussive guitar parts.
It’s a nice middle ground when Plate feels too smooth and Room feels too small.
Hall Reverb
Hall is where the Kosmos starts opening up.
This setting works beautifully for slower chord progressions and melodic leads. It also suits volume swells, worship-style sounds and more cinematic clean parts.
Importantly, it still sounds like a conventional reverb.
You haven’t entered shimmer territory yet.
And I like shimmer territory.
It’s just nice to visit by choice.
Hall is also a good place to experiment with the ducking control. You can dial in plenty of ambience while keeping the original guitar part clear.
Shimmer 1
Shimmer 1 is where the Kosmos starts leaning properly into ambient guitar sounds.
This type of reverb adds pitch-shifted content to the tail. The result is that familiar floating texture behind the dry guitar.
Used carefully, it can be beautiful.
Push it less carefully and things can become completely ridiculous.
Naturally, I enjoy both.
In the original demo, I turned the Time and Level controls up fairly hard. I simply wanted to hear how far the sound would go.
That’s part of the fun with a pedal like this.
You can use it subtly.
But it also encourages you to stop being sensible for a moment.
Shimmer 2
Shimmer 2 feels noticeably moodier.
For me, it worked particularly well with longer chords and atmospheric soundscapes.
Instead of feeling like a bright pitch effect sitting on top of the guitar, it can become more like a pad. The shimmer starts surrounding the notes.
Tone becomes especially important here.
If the shimmer gets too bright, it can start fighting the guitar.
Darken it slightly and everything settles farther into the background.
I probably wouldn’t use Shimmer 2 as an everyday reverb.
When a normal hall sound feels too plain, though, it’s fantastic.
Shimmer 3
Shimmer 3 might be the most obviously magical program in the Kosmos.
Using the Control knob, you can balance the standard reverb against the shimmer component. That lets you keep the pitch-shifted effect subtle or make it the main event.
This is the setting that produced my previously mentioned unicorns-and-rainbows moment.
It can get huge.
For the intro song, I particularly liked Shimmer 3 on long sustained chords. The tail can seem to hang around forever. Even so, it remains musical if you dial things in carefully.
This sound would work well for intros, outros, worship guitar and post-rock textures. It’s also useful whenever the guitar needs to become more of a layer than a traditional guitar part.
Just maybe don’t leave it on for the entire song.
Unless the song specifically requires unicorns.
RSB: Room Reverb With Slapback Delay
The RSB program combines room reverb with slapback delay.
With the Control knob, you decide how much slapback gets mixed in. This lets you move from something close to a normal room sound into a noticeably more rhythmic effect.
One limitation is the lack of precise timing control. You don’t get what you’d expect from a dedicated delay pedal.
However, I don’t think the Kosmos is trying to replace one.
Here, the delay feels more like another texture inside the reverb sound.
For rhythmic guitar parts, that can be a lot of fun.
RM: Room Reverb With Multi-Head Delay
The RM mode combines room reverb with a multi-head delay effect.
Compared with RSB, the repeats are more complex. They also produce much more movement around the guitar.
Once again, Control changes the amount of delay.
Keep it low and you’re mostly dealing with room reverb.
Increase it and the multi-head delay becomes a much bigger part of the sound.
I used this setting on the overdriven solo near the end of the demo song. It remains one of my favourite Kosmos sounds.
It isn’t particularly polite.
That’s why I like it.
Swell 1
Swell 1 makes the footswitch part of the performance.
Instead of simply turning the effect on and off, you use the footswitch to bring the sound in gradually.
Control changes how quickly the swell rises.
Faster settings bring the sound in more immediately. Slower settings create a softer, pad-like fade.
That gives you volume-pedal-style ambient swells without dedicating extra pedalboard space to a volume pedal.
For ambient transitions and cinematic guitar parts, that’s genuinely useful.
Swell 2
Swell 2 takes the same basic idea and adds a more sparkling, shimmer-like character.
If Swell 1 is the practical ambient pad, Swell 2 is where the unicorns start returning.
Used carefully, it creates beautiful background textures.
Push it harder and it can become the background, foreground and probably most of the surrounding countryside.
Depending on your music, that might be exactly what you want.
For me, the swell modes help make the Kosmos more interesting than a normal multi-mode reverb pedal.
You actually interact with them while playing.
The Freeze Function
The footswitch can also control the freeze effect on compatible programs.
It’s worth understanding what “freeze” means here, though.
In my experience, the Kosmos doesn’t capture a chord and hold it forever as a completely static sound.
Instead, the frozen texture gradually becomes darker and quieter.
So, if you’re planning to sustain one gigantic chord for five minutes while making meaningful eye contact with a fog machine, there are probably better tools available.
For normal musical use, I actually like the way this behaves.
You can create a pad underneath another guitar part or fill transitions. Another option is leaving a texture hanging behind your playing.
All of that works without needing another guitarist, keyboard player or backing track.
The multifunction footswitch is one reason the Kosmos feels playable. It doesn’t simply feel like a box containing lots of algorithms.
What I Like About the Mad Professor Kosmos
The biggest strength of the Kosmos is its balance between variety and simplicity.
You can move from practical room, plate and spring reverbs to huge shimmer sounds. Delay combinations, freeze and swell effects are available too. Yet none of this requires screens or menus.
I also really like the Control knob.
Its changing function gives the pedal much more flexibility than the small control layout initially suggests.
Another highlight is the multifunction footswitch.
Freeze and swell effects make the Kosmos something you can interact with during a performance. You’re not simply switching the reverb on before the song starts.
Finally, the normal reverbs are genuinely useful.
That’s important.
An ambient pedal isn’t much use to me if its only trick is creating giant soundscapes.
Sometimes I just need a little room or spring reverb.
The Kosmos can do that too.
What I Don’t Like About the Mad Professor Kosmos
The biggest limitation is the lack of presets.
In the studio, I don’t really care. I can stop, turn a few knobs and continue recording.
Live use can be different.
If one song needs Shimmer 3 and another needs a short room sound, you have to change the settings manually. Add one of the swell modes to the set and there is another adjustment to remember.
For complicated live setups, a more modern reverb with preset storage will probably make more sense.
The delay-based programs are intentionally limited too.
You don’t get deep timing control. There is also no tap tempo for locking everything precisely to a song.
However, that limitation connects directly to one of the Kosmos’ strengths.
It’s simple.
Adding presets, MIDI, tap tempo, screens and deeper editing would certainly make it more powerful.
At the same time, it would turn the Kosmos into a completely different pedal.
This design clearly chooses immediacy instead.
Is the Mad Professor Kosmos Still Worth Buying?
I think so, with a couple of obvious caveats.
The pedal is discontinued. Therefore, you’re probably looking at the used market rather than walking into a shop and buying one new.
Ambient reverb pedals have also moved forward considerably.
If you need stereo operation, extensive preset storage, MIDI control and deep editing, newer options make more sense.
None of that suddenly makes the Kosmos sound bad, though.
If anything, its simplicity has helped it age quite well.
You still get 11 useful programs covering practical reverbs and shimmer sounds. Reverb and delay combinations are included too, along with freeze and footswitch-controlled swells.
More importantly, you can access all those sounds without spending the evening reading a manual.
If I found one used at a sensible price today, I’d still consider it.
Mad Professor Kosmos Review: Final Thoughts
The Mad Professor Kosmos sits in a really nice middle ground.
It isn’t a simple three-knob reverb pedal, but it also isn’t an enormous ambient command centre.
Instead, you get useful plate, room, spring and hall reverbs. Three shimmer programs expand things further, along with reverb and delay combinations, freeze and swell effects.
The controls remain simple enough that you can start experimenting immediately.
For me, the standout sounds are still the shimmer modes and reverb-plus-delay programs. I also really like the footswitch-controlled swells.
Those are the things that make the Kosmos feel different from a normal reverb pedal.
At the same time, the more conventional sounds are genuinely useful.
You don’t have to summon unicorns every time you switch it on.
If you need presets, stereo operation, MIDI and precise delay timing, this probably isn’t the pedal I’d choose.
However, the Kosmos still has a lot going for it if you want something simple, creative and easy to use.
It’s discontinued now, but if you find one used, I think it’s absolutely worth checking out.
You can check out the gear mentioned in this post through the affiliate links below. Using them does not cost you anything extra, but it helps support isthisgeargood.com and keeps the lights on around here.
It is discontinued now, but if you find one used, it is absolutely worth checking out.
Interested in any other pedals? You can check out some of my favourites pieces of gear here: https://thmn.to/thocf/to75kzs7bv