Herbs and Stones Liquid Foam review

From the north of Italy comes what we can only describe as a box of inspirational happy accidents

  • £369
Herbs and Stones Liquid Foam
(Image: © Future)

MusicRadar Verdict

Liquid Foam remains a rewarding and musical module. Investing time to learn its features is a must and, once done, will pay you back in spades.


  • +

    Great sound.

  • +

    Lots of functions for the size.

  • +

    Easy to find happy accidents.

  • +

    Works well in a rig.


  • -

    Takes a little learning.

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Herbs and Stones Liquid Foam: What is it?

We first reviewed the Liquid Foam back when it was a standalone instrument, cased in a wooden box and connecting to other devices via banana plugs. We loved it back then and it has remained a constant source of inspiration, churning out slightly unpredictable sequences and gorgeous tones. The only real downside we could see to it was that it wasn’t the easiest to use as part of a studio workflow.

Herbs and Stones has now released the Eurorack version of Liquid Foam and we're so pleased they have, as having the wonderful output in an easy to integrate module makes this even more of a sound investment.

Herbs and Stones Liquid Foam

(Image credit: Future)

Herbs and Stones Liquid Foam: Performance and verdict

Liquid Foam is a single VCO module that can output PWM, variable saw and triangle, all of which can be output singularly or together. There is a versatile two-pole 12db filter, which is buttery smooth in both low pass and high pass, plus a cmos-based drive circuit for added grit. Tones range from soft and delicate to thick and squelchy.

Churns out unpredictable sequences and gorgeous tones

The envelope generator is a bit quirky, in general terms, but its decay-only (invertible) output works well, especially when paired with the sequencer, which is perhaps the quirkiest feature here. There are two of them, each with four patch points and here is where the fun begins.

As we’ve said of Liquid Foam before, it isn’t the type of module that you programme for repeatable results, that stick to a grid, but is an absolute hoot to play with. It can generate all manner of tones and patterns, by mixing voltages from the LFO, envelopes, clock (which it has in and out jacks for) and pitch controls. 

The options for interoperability here make for surprises and once a few hours have been spent experimenting, it all falls into place and patching becomes more natural as the mental muscle-memory connects the dots. Pairing this with the rest of a rack turns the whole thing into a more experimental adventure, which we give high praise for.

Physically the Liquid Foam is very similar to the standalone version, as you’d expect, just on a smaller scale. It’s a shallow module so will fit in any skiff. Roadworthiness is high too, as everything feels secure, well constructed and should withstand the rigours of gigging. Labeling is clearly printed and although some functions are mysterious, navigating is easy.

All in all, Liquid Foam is unchanged, other than to congratulate its developers on making a Eurorack version, meaning less power cable clutter and desk space needed and closer interaction with other modular gear. Liquid Foam remains one of the most oddly rewarding modules out there. It continues to inspire and that is a hallmark of a great groovebox. 

MusicRadar verdict: Liquid Foam remains a rewarding and musical module. Investing time to learn its features is a must and, once done, will pay you back in spades.

Herbs and Stones Liquid Foam: The web says

"The strength of the Liquid Foam lies in the fact that you can patch very complex, wild patterns without a built-in sequencer. All of this is now available in Eurorack and I think the possibilities are even wider."
Synth Anatomy

Herbs and Stones Liquid Foam: Hands-on demos


Bogdan Raczynski

Herbs and Stones Liquid Foam: Specifications