Review: Moog Model 15, A New Standard for iOS Audio Apps

We are undoubtedly living in the golden age of synthesizers. Many vintage synths are being reissued. Many analog synth manufacturers are creating newer models at a very affordable price. The Eurorack format has opened up the modular world to the masses with more than 200 manufactures (https://www.modulargrid.net/e/vendors) creating all kinds of modules for every possible permutation and combination. Let’s also not forget the plethora of software emulation plugins of analog synthesizers along with modern digital synths. Since the Apple iPad’s release in 2010, there has been a significant number of synth manufacturers also developing iOS versions of their synths. Now Moog has entered the world of iOS modular synthesis with a faithful recreation of their Model 15 modular system specifically for the iPad, iPhone & iPod Touch. 

Moog Model 15 Ribbon Controller

User Interface

This is one of the more aesthetically pleasing & ergonomic iOS synths I have used. The interfaced can be zoomed into and navigated around using the standard 2 finger pinch & scroll gestures. Considering the amount of controls packed into the interface, it’s very helpful to have such zooming capabilities. Comparatively, the Korg iMS-20 app lacks in this department and can seem quite intimidating to new users. In fact, when using the iPad with a keyboard connected, you can even use key commands for zooming and navigating the interface of the Model 15. The built-in manual has all the available key commands listed. Double-tapping on the interface will dim all the connected patch cables, making it easier to look at control labels. What you will also notice while zooming into the interface is that the detail in the background, knobs and patch cables is astounding. It also doesn’t feel sluggish while scrolling around. This is all possible because it uses the relatively new Apple Metal API for Graphics (https://developer.apple.com/metal/). With this technology all the graphics related processing is offloaded to the GPU which leads to a more optimized performance for the CPU. So the CPU is dedicated to taking care of all the audio calculations and it does not have to worry about the graphics.

Moog Model 15 in portrait mode.

One drawback of this app is that it’s not true multitouch when it comes to knob control. You can’t control multiple dials simultaneously. This is quite a common way of using a real modular where both your hands are used to control 2 different parameters of the synth. I hope in a future update Moog implements true multitouch for at least up to 2 pots being controlled simultaneously.

Moog's Model 15 Synthesizer is a game changer. A fantastic app that will only get better.

Modules Included

This app is a recreation of the Moog Model 15 hardware modular synthesizer. These are the main modules of the Model 15:

• 921, 921A & 921B: Voltage Controlled Oscillators
• 904A: Voltage Controlled Low Pass Filter
• 907A: Fixed Filter Bank
• 923: Non-Resonant Low Pass & High Pass Filters, White & Pink Noise generator
• 995: Attenuators
• 902 (2 modules): Voltage Controlled Amplifier
• 911 (2 Modules): Envelope Generator 
• Mixer Panel: 4 Inputs, 2 original and 2 polarity inverted outputs & Multiples 
• Reversible Attenuator: Polarity inverted attenuator & Multiples

Control Modules:

• Keys: Standard Keyboard module similar to the original 952 Keyboard Controller.
• Animoog: Animoog’s controller with options for setting scales.
• Arp: 8-step tempo syncable Arpeggiator
• Ribbon: Ribbon controller based on the original 1150 Ribbon Controller

Additional Modules:

• Audio Bridge: Receive external audio to be processed by the Model 15 or send audio out to other apps.
• MIDI Bridge: Send and receive MIDI CC messages to control or be controlled by external controllers.
• Delay Effect: A clock syncable Delay module that processes the main output(Trunk Lines) of the Model 15.
• Recorder: Record, loop, overdub and export audio.

Audio Engine

It's hard to find words to explain the feeling one gets when listening to the audio from this device. Even if you have never heard a real Model 15, listening to the audio coming out of this app is a joyous experience. It’s almost hard to believe that such sounds can originate from an iOS device!

Since this app models all the saturation and nuances of each of the modules from the original hardware synth you get a very true representation of what a Moog modular sounds like. I would recommend listening to the output of this app through a high-quality audio interface like Apogee’s Duet for iPad or an audio pass through device like the iConnectMIDI. But even if you can’t do any of that and listen to the app through the iOS device’s headphone out, you will still hear some of that analog goodness which you may not on other apps.

Moog Model 15 Arpeggiator.

Here’s an example of a 921B sawtooth oscillator running through the 904A Low Pass Filter with an envelope modulating the filter cutoff and some delay on the overall sound.

Now, there are some limitations to the sound. While modulating the oscillators or filter cutoff at audio rate the sound is a bit controlled and unlike what you would normally expect from an analog synth. In other words, the sound doesn’t really break apart and scream like it does on a hardware analog synth.

Here’s an example of an audio rate sine wave oscillator modulating an audible sawtooth oscillator. I am using an attenuator to control the depth, and I’m changing the rate of the sine wave with the octave switch and the frequency dial. 

Now personally, if this is the difference between a $30 iOS app and a $10,000 hardware synth, I’ll gladly accept.

Polyphony

The original Model 15, like most modular synths was monophonic. The Model 15 app can be literally switched to become 4-note polyphonic. So with this you essentially get 4 Model 15s running simultaneously! I don’t know much about iOS programming but the Moog programmers have achieved quite a feat by giving us this feature without compromising on the sound quality.

Here’s an audio example of the Model 15 in polyphonic mode with all 3 oscillators including the auxiliary out on the 921

Ableton Link

Considering that Ableton Link is a relatively new technology, it’s quite impressive to see the feature built-in the Model 15 app. With Ableton Link enabled the Model 15 can sync to any other devices with Link enabled. Any tempo changes will translate over to all the devices. All this is done wirelessly and without the hassle of intricate setting up and third-party applications. 

Audio & MIDI Bridge

It’s become a standard to see Audio Bridge & MIDI Bridge support on most iOS synths and audio apps. So with this you can route audio & MIDI in and out of the app. What is really great is that there is support for 14-bit MIDI, so you can get a much higher resolution while controlling the Model 15 with external controllers.

Educational Aspect

This is definitely one of my favorite features of this app. Moog has built in Tutorial Presets which guide you step by step on how to use the synth. There are currently only 2 Tutorial Presets (Signal Flow Part 1 & 2) but it is possible for end users to create these tutorial presets. Learning and teaching modular synthesis just got really intuitive and hands on. Expect to see a bunch of tutorial presets from me in the near future.

Competition

The Model 15 is definitely not the first modular synth iOS app. Jasuto and Audulus are a couple I have used. These two apps embrace the touch screen platform and give you a very futuristic user interface and almost endless patching possibilities. Since the Model 15 app is emulating a vintage hardware modular, we can’t really compare design attributes. But in terms of analog emulation and sonic quality, the Model 15 wins hands down. Comparing this app with some desktop plugins like the Modular V by Arturia, I would still put the Model 15 a step above, considering how buggy the Modular V is and also how uninspiring the user experience is when working with the computer mouse and trying to decipher the unintelligible labeling of the Modular V.

A good comparison with Model 15 is the Korg iMS-20. Personally I am a fan of the iMS-20. It too is a great emulation of a classic hardware semi-modular synth. The user experience is still much better on the Model 15 but the iMS-20 is also a great sounding app and it would definitely be worth having both. Keep in mind the iMS-20 is a semi-modular synth so you will be able to do a lot more with a fully modular synth like the Model 15. Also, the sound of a Korg synth is very different from that of a Moog synth which is generally attributed to the filter design so it would be again hard to compare the two. Lastly, the iMS-20 app is strictly monophonic while with the Model 15 you can get 4-note polyphony.

Moog have put a lot of care and attention to every aspect of the app.

 If you have an older device, it might just be worth upgrading just to use Model 15!

Compatibility

This is one area where some users might be disappointed. The Model 15 only supports 64-bit devices so iPad Air and above, iPad mini 2 and above, iPad Pro 12.9 inch, iPhone 5S and above, iPod Touch (6th Generation). I used the app on an iPad Air and surprisingly there were absolutely no issues. The only anomaly I observed was the iPad would get a bit warmer than usual. If you have an older incompatible device, it might just be worth upgrading just to use this app. Regarding the OS, it does require the most recent iOS 9.3.1. 

Conclusion

When Animoog was released there was a lot of excitement about the first synth app from Moog. In fact, my first course for macProVideo & AskAudio Academy was on the Animoog. Now, that excitement has doubled. The Model 15 is a game changer. A fantastic app that will only get better. Don’t think of this as a side-project that Moog would work on once in 5 years. Its only been a few days since the Model 15’s release and there is already an update available. Moog has a dedicated team working on iOS apps. You can contact them for any tech support needed for the Model 15 appsupport@moogmusic.com. They haven’t mentioned any future development plans but I wouldn’t be surprised if there are more apps released in the future. All in all, great news for everyone alive and making music with synthesizers today.