Winterbloom! Design, philosophy, tips/tricks

Winterbloom’s third module, Castor and Pollux, is here! I just got mine yesterday.

This is one of the most interesting modules I’ve gotten my hands on, both in terms of design, with the translucent panel reminiscent of Make Noise, and operation. I generally dislike minipots but this module is quite easy to use, despite the relatively small size and controls.

I also really like this user guide; I think built-in sound samples and waveform visualizations should become a standard in oscillator and LFO user guides.

I’m currently looking at putting together a tiny system for a few pieces with just the Sol, the BHB, and Castor and Pollux, plus a filter and a few utilities.

Who else uses Winterbloom modules? What are your thoughts? How do you use them, and what codes are your running on your Sol/BHB?


Castor and Pollux looks amazing and I’ve been trying to resist, just broke down based on how smart the LED lighting looks in your second photo :sweat_smile: Love the night vibes.

This in-depth article that touches on the module’s circuit design and inspiration is one of the most approachable explanations of circuit design decisions I’ve seen, again with lots of inline visualization to help: Stargirl (Thea) Flowers - The Design of the Roland Juno oscillators

Love what Winterbloom is doing in terms of open source and sharing knowledge, and the modules look delightful and smart. Looking forward to it :smiley: !


I also really like her article explaining how the big honking button worrks, definitely helped me understand how modules with microcontrollers in them work more, I recommend checking it out if that’s interesting to you Stargirl (Thea) Flowers - Designing Winterbloom's Big Honking Button

Massive respect and thanks to all those who open source their designs, write stuff like this, and help out people who are interested in learning about how these things work but aren’t sure where to begin.


I think I said this to you @NoraCodes once before, but I think Sol is the best companion to modulation systems like those found in Bitwig and in M4L.

While Sol and Crow are only somewhat comparable, I think that how simple Sol is to program in comparison makes it a no-brainer for doing something like taking complex modulation and clock/trigger sources, assigning them to midi CCs in Sol’s firmware, and then just pumping that out to a modular system makes for an efficient way of putting together a hybrid system.

If/When she makes a Sol 2 (or Luna, etc), my only hopes are that it’s bidirectional and that the ‘gate’ outs can also be CVs.


Yeah, I would love to see a CircuitPython powered module that has even just one CV/gate input. I’ve been looking at the Daisy Patch but it doesn’t support anything nearly as simple as the CircuitPython platform, which makes me hesitant to spend a lot of time developing for it as distributing firmwares is a bit of a pain.

I’m quite tempted to throw something together with a Teensy 4.1, which has more than enough power for a decent DSP platform as well as supporting MIDI, CAN, and CircuitPython, and has an SD card slot, but I don’t think I could realistically do manufacturing and distro.

That said, I am currently looking at a building a guerilla expander for the Sol which gives at least a clock in, so I can more easily send MIDI clock from my Pam’s.


My Castor and Pollux is sitting at my post office back home. Can’t wait to pick it up!

I’m planning on running it through Optomix and making some third-interval piggy stabs first!


Here’s a little something I threw together this evening to demonstrate the module’s utility as a lead and bass voice; of course, combining the two oscillators into one voice is extremely cool too, but for my fairly small system, having two such lovely voices is a real luxury.

This is Castor through Ripples, Pollux through Forbidden Planet, and Plaits doing all the percussion as sequenced with the magic of Sol generating MODEL input voltages from MIDI drum commands.

I also munged up the same basic melody with Ripples - Castor is the carrier, Pollux is FMing the filter cutoff and resonance. Very fun stuff.


Apologies for the double-post, but this is pretty cool news: Winterbloom have updated their Big Honking Button hardware with additional sample storage and a larger and more stable CV range, as well as issuing a firmware update porting some of the stability improvements back to the original version.


I am so jealous that you already have yours. I’m glad the production run looks just as amazing as the initial prototype posted on Instagram. I can’t wait to be able to get that Juno sound from my modular!


Yes! I’m so excited for these things to make it out into the market - the amount of beautiful Juno pads, chords, and lead lines we’ll see going forward makes me very, very happy.

Jeremy from Red Means Recording did a great jam with his the other day: (there’s a follow-up patch notes video as well)


Winterbloom has taken receipt of the boards; everyone with a pre-order, rejoice :slight_smile:


Even more reason to rejoice: we’ve tested the first 5 units of this run and they’re all wonderful. :slight_smile:


Great vid on the C&P from RMR: Winterbloom Castor and Pollux, a Juno-Inspired Friend - YouTube


More fun with the C&P:

In this case, sequenced with the Tracker, and paired with samples of itself and some sparse percussion. It takes really well to aggressive filtering and layering.


I have never pre-ordered a module, but decided to pre-order a Castor & Pollux. :slight_smile:
Super excited for it!
Sounds so lush from the examples i have seen :smiley:


So, Castor and Pollux bleeds significant LED light out the sides, as is the nature of such a beautiful backlit Euro module. This generally doesn’t do much, since the light is blocked by other panels, but I got my hands on a NLC Lux, which generates voltages based on the light coming into its photodiodes, and placed it next to my C&P, and now the LED lighting generates some lovely, subtle, and fairly complex LFOs that I mostly use for PWMing the C&P.


How cool is that!!!

Will you put one on the other side of C&P as well?



I have only one, but if I get another one I definitely will! I might tape over the sensors too, to get a more consistent result.


I got a shipping notice yesterday :smiley:
So excited that Batch 2 are finally going out :smiley:

Just messing around with the first noodle :slight_smile:


My very first Eurorack module arrived this morning and has received feline approval. My case arrives next week, then I’ll be slowly, gently falling down the rabbit hole…

Being serious for a sec, I got Sol because I think it’ll help a beginner like me experiment a lot before I settle on specific modules for specific functions. And also, I love the design! :slight_smile: (Edit: And thank you for the cool pin!)