NANO Modules ST IN & ST OUT: the gateway for line-level signals in and out of your modular

July 30, 2025 Synth Anatomy Eurorack, Hardware, News 0

NANO Modules ST IN & ST OUT are new stereo interface modules with clever additions that bring line-level signals in and out of your Eurorack modular.

Eurorack systems are often instantly connected to classic Synthesizer structures like oscillators, filters, etc. But you can do much more with them. For example, use them as a modular FX. For this, you need an interface module to convert the line level to Eurorack level. I’ve been using the Befaco InAmp and Output modules for this for many years.

NANO Modules, also from Spain, is showing new interface modules with the ST IN & ST OUT, which are significantly more interesting in direct comparison.

NANO Modules ST IN & ST OUT

ST IN and ST Out are new stereo interface modules for Eurorack. Both have 6HP and offer a very similar design.

NANO Modules ST IN brings external gear into your modular system with proper gain and impedance. For example, it helps bring hardware synths, drum machine sounds, or other instruments into the modular world and further process them.

The module offers two balanced 6.3mm mono line inputs that give you a stereo line-to-modular conversion. A dedicated knob sets the gain that goes from -∞ to up to +30dB.

There are also some very clever additions. The developers added a built-in envelope follower with three selectable ranges (slow, mid, fast) that is linked to the gain knob. It is especially useful to turn the amplitude into a CV signal.

Then, it also offers a one-knob tilt EQ, a volume fader, and a peak LED meter with a clipping indicator. Plus, it is DC coupled, 0dB = 10Vpp.

Output Module

An input, here the ST IN, rarely comes alone, so NANO Modules has also developed an ST OUT module. The latter takes over the reversed task and converts modular signals back to line level. They promise with clarity and punch.

The ST Out offers two 6.3mm balanced mono outputs, giving you stereo connectivity. Like on the input module, it also features a volume fader, a peak LED meter, and a tilt EQ for final tone shaping.

As a nice addition, NANO Modules also added a drive circuit to it, offering soft and hard analog saturation with a simple click on the switch. This adds warmth and extra grit to your signals. Further, the module has a headphones output with a dedicated volume knob.