Tangible Waves Bob Filter 904A is a new adaptation of the analog Moog Ladder filter for the AE Modular systems.
Diving into modular synthesis in hardware form can be expensive, and getting started is anything but inexpensive. If you’re interested in modular synthesis but you can do it without the Eurorack world, take a look at the AE Modular System from the German company Tangible Waves.
AE Modular is an affordable modular Synthesizer format with module prices well under 100€ or even under 50€, and beginner systems are available for 268€. Unlike Eurorack, the modules are patchable with minicables, but they are on the same feature set level.
And now Tangible Waves offers the legendary Bob Moog Ladder filter for a low price for the AE Modular.
Tangible Waves Bob Filter 904A
The Bob Filter 904A brings the legendary Moog transistor ladder filter to the AE Modular world. Tangible Waves Bob Filter 904A is a recreation of the iconic analog circuit with all the same characteristics and features. But it’s more than just a simple clone/replica.
In addition to the classic 24dB/oct lowpass filter, this new AE Modular module also features outputs of each filter stage, including 18dB, 12dB, and 6dB, each with its own sonic qualities.
The filter can be tweaked with classic cutoff and regeneration (resonance) controls. On the front panel, you have three signal inputs, two of which have attenuators with dedicated controls.
Alongside manual control, you can also animate the filter with three CV inputs, two of which feature hardware attenuator controls. According to Tangible Waves, the module sounds best with analog sources.
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First Impression
The AE Modular is a fascinating system that lets you explore modular synthesis affordably. Even though it’s been on the market for many years, it still flies somewhat under the radar.
I’m delighted to see that Robbie Langer (the brain behind tangible Waves) is now bringing the Moog filter to the AE Modular. More classic vibes for the system are always welcome.
Tangible Waves Bob Filter 904A is available now in two styles: the classic AE look for 49€ (excl VAT) and in the Moog-style look for 55€ (excl VAT).
More information here: Tangible Waves


Super cool! Nice to see more attention being given to AE modular. The format has come a long way in the past few years and seems a great choice for beginners, would love to see it become widespread in the way that eurorack has. While I understand the need to keep costs low, I think adding more unique visual identity to the modules (as they have done here) is a nice way to make building a rack feel more ‘fun’.
apart from the price, the look of AE modules is one of the most appealing things about them. They have a consistent visual language. Systems look clean and technical like a lab instrument. Like the random*source Serge stuff. They make you want to experiment with sound. Eurorack cases full of different manufacturers all with different design languages look ugly and messy. I really hope AE don’t start making their modules look more ‘fun’.
Fair enough, then it’s good that they offer both versions. Keeps everyone happy 🙂
Haha, no worries; our look will remain like you know it. But in this case, I couldn’t resist to make it Moog-ish – and still, a classic AE version is available too.
Looks great Robert.