Typically, Moog Synthesizers are rather expensive, being that they are hand made for a rather substantial, albeit niche market. Therefore, I can't say I've spent any time with a real Moog. As much as I'd like to say I have a couple kicking around in the spare room of my house, I don't. So, unfortunately, I don't know a great deal about the sounds of Moog hardware other than what I've heard off recordings. And, I suspect, that's how most other users will approach Filtatron, too.
Thankfully, Filtatron goes a long way to helping users understand what it does and how it does it by including a built-in user guide and glossary. After you've had an initial play, I highly recommend you have a good read over these to get the most out of the app. It certainly helped me out. There's also a whole bunch of presets to show you exactly what Filtatron can do, and how to get there.
At this point, you may be wondering what Filtatron actually does. In a nutshell, let me try to explain. Using its filter ladder -- a four-pole resonant ladder filter modeled after the filter found on analogue Moog hardware -- Filtatron shapes sound, giving it characteristics akin to a real Moog filter.
In Filtatron, there are two different ways of using this filter. You can either shape the sound using the knobs and dials found on the main tab of the app or by using the two "hands-on" pads provided -- allowing you to swipe and move your fingers around the pads to adjust and control most of the parameters found in Filtatron. To provide further character to the sound, there's a FX module, with fully featured delay, and an amp with distortion and controlled feedback, too.
A large part of what you get out of Filtatron is actually what sounds you put into it. Although you can generate your own sound using the on-board oscillator, Filtatron shines best when you feed sound through it. This is demonstrated with the preloaded samples and presets.
The Sampler heads up this department, allowing you to record your own samples either by line input (unfortunately not directly from the iPhone mic) or transferring .WAV files between Filtatron and your computer using some FTP software and a Wi-Fi connection. Likewise, you can transfer your modified Filtatron'd loops back to your computer to use further in a DAW. Although it took me a little while to setup the FTP client (mainly because I'm not used to it and I had to download some free FTP software -- try CyberDuck), once it was up and running it worked easily enough. I transferred a rough acoustic piano loop into Filtatron which is what I mainly used to test out its capabilities. The Sampler can also record sound being produced by the app, you can then save this for further sculpting at a later stage, layering on top of what you've already done.
So what can you expect to get out of Filtatron? Well, at its essence, Filtatron is a filter for sound to be pushed through. Either sprinkle a few textures on your sound or go full steam ahead and manipulate the sound until it's unrecognizable from what you started with. I can imagine it being particularly interesting to use in a live context, on a vocal or some drums. Moog says FIltatron will model the same "classic warm, thick character" that its Moog instruments produce, and for the most part (in my limited Moog experience), I can say that I produced some definite Moog-like tones. Between the filter itself, the FX module and the Sampler, there are literally dozens of ways to manipulate the sound -- creating rip-roaring distortion to eerie ghost-like melodies.
Filtatron works how you'd expect it to on the iPhone. Its well laid out interface, with beautiful graphics that illustrate exactly what's happening and where, is intuitive and a pleasure to use. However, I did wonder whether the iPhone's 3-axis gyro and accelerometer could have been used to aid in some of the manipulation of the sound, but perhaps this would have been more of a gimmick than a useful feature. Still, waving an iPhone in the air whilst turning around on the spot to produce varying sounds would definitely be a sight to behold.
The slogan that accompanies Filtatron reads, it's not a toy -- but go ahead and play with it. I'm inclined to agree with most of this statement. There's loads of depth and mileage in Filtatron, to the degree with which you can edit, sculpt and manipulate sound -- and the incredible results you can get out of it. Certainly, Filtatron is a lot of fun to play with. But for me, aside from sketching ideas and using the app in a live setting, I actually wanted Filtatron to be on my Mac (as a plug-in for my DAW) rather than on my iPhone. And that's a positive reflection on Filtatron. If I was to take it seriously, I'd be frustrated with the way audio has to be moved off of my Mac to the iPhone and then back again (though Filtatron supports audio copy and paste with other compatible apps). Having said that, if Filtatron was a plug-in for my DAW, it would probably cost 50 x as much as it does on the App Store. So, maybe I'm reading too far into what music production apps on the iPhone are all about, at this stage anyway.
At £2.99 on the iTunes App Store, Filtatron puts some warm, thick and slightly eerie-but-very-dreamy Moog tones in the palm of your hand. So much so, that I wish I could have it straight up on the Mac. Filtatron is definitely worth checking out and gets a big thumbs-up from us here at TUAW.