Visual Vector Curve Generator in Eurorack Format
Splines
Splines is a visual vector curve generator in Eurorack format, with a wide frequency range and built-in quantizer, CV scope and CV processing capability. It can be used in ways similar to a wavetable VCO, LFO, step sequencer or envelope generator.
Onboard quantizer scales, backups and firmware updates are managed just as you would with an external USB drive. It's a small, shallow, multifaceted addition to any setup — and for touring rigs, it can fill many roles in exchange for very little space and weight.
In Depth
In the technical sense, "splines" are most commonly used in 3D modelling, animation and vector graphics. They're essentially a way of creating a curved path from one point to another.
In this module, you have up to sixteen user-configurable points, or nodes, which function much like a step sequencer, where the X axis represents time and the Y axis represents voltage. When the phase (time) reaches the X position of a node, the 1V/oct output changes to the Y position value of that node. Each of the sixteen nodes also has a configurable trigger setting, determining whether the gate output goes high when the phase crosses the X position of the node.
The nodes are connected by a spline, and the shape of this spline is determined by three parameters:
- Tension — changes how extreme the curve between the nodes is
- Continuity — sets the angle of the spline at the node
- Bias — shifts the tension to the left or right of the node
The spline output gives you a voltage following this curve. You can adjust which part of the full spline is output by changing the Zoom and Scroll parameters. The curve loops at the end, so when zoomed all the way out, the last node connects to the first.
The speed at which the phase progresses through the nodes can either be set fluidly using the "frequency" parameter, or quantized to fixed frequencies listed in .scl files in the "scales" directory on the module. Cycle frequencies range from 16 minutes per phase to 20kHz — from very slow LFO rates all the way up to the limits of hearing.
The output amplitude can be changed using the level parameter and CV input, allowing the module to be used without a dedicated VCA. When the spline shape goes higher or lower than the ±5V limits, a few different clipping options are provided, such as wavefolding or soft clipping — since all parameters can be overdriven substantially, this makes for some interesting effects.
The sync input is also configurable, letting you manage timing as you would a tap-tempo LFO, an envelope generator, or a step sequencer.
For working with control voltages, a basic rolling oscilloscope is available for each of the six CV inputs, including scaling and offset settings, so you can adapt the control voltage signal visually, directly in the module.
Developer resources such as drivers, templates, pin configs and best practices are also provided, in case you'd like to use the module as a development platform for your own ESP-32 based DSP projects. Firmware and quantizer scales can be updated easily by drag-and-drop via the front-accessible USB-C port.
Inputs/Outputs
- Output resolution: 1–16 bits
- Output sample rate: 192kHz
- Output voltage range: ±5V
- CV input resolution: 12 bits
- CV input sample rate: 1kHz
- CV voltage range: ±5V
- Trigger duration: 7ms
- Input trigger: 0–5V
Power
- +12V: 50mA/170mA
- -12V: 50mA
- 5V: 170mA/0mA (5V source switchable)
Dimensions
- Depth: 31mm
- Width: 10HP
- Height: 3U
How much is my shipping?
Shipping is automatically calculated before you submit your payment information. Simply add items to your cart and proceed to the checkout page, where you'll be offered shipping options and their prices. In the UK, 'next working day' shipping is free to most parts of the UK if the order value is over £150, and £5 otherwise. We can also ship on a 'next working day before 12pm' service, which costs £6 for orders over £150 and £7.50 for orders under £150.
Certain areas of the UK, including the Scottish Highlands and Islands, Northern Ireland and other offshore islands, may have higher shipping charges and slightly longer delivery times due to surcharges applied by the courier and reduced service availability in those areas. We try to keep these costs to a minimum.
Do you ship to my country?
Almost certainly - the site will give you an estimate of shipping costs if you add an item to the cart and then enter your country and postcode. If you have specific requirements (such as if you prefer UPS over FedEx, for example) then let us know in advance and we'll try to work something out for you.
Shipping methods
We use a combination of DPD and Royal Mail for the UK, and for international orders it's either DPD, DHL, FedEx, UPS or Royal Mail depending on where you are in the world. If you have a particular preference then try to let us know BEFORE you order so we can look into it for you. Please note that there may occasionally be additional shipping charges if you live in a remote area, depending on what surcharges are applied by the shipper. We'll get in touch to discuss this with you in such cases.
Dispatch times
For UK orders, we normally dispatch the same working day if we get the order before 16:00. If you have a really urgent situation then of course drop us an email before ordering and we'll always do our absolute best to accommodate you.
For international orders, we normally dispatch the same day if we get the order before 13:00 but again, occasionally it might be the next day before we can send it out, and sometimes the couriers may come to collect a little earlier than scheduled which would also push an order into the next day.
Saturday/Sunday delivery
If you're in the UK and you order before 16:00 on a Friday then we can send something for a Saturday or Sunday delivery with DPD. This is FREE for order values over £350, £5 for order values between £75 and £250, and £7 for order values under £75. (NB: this applies to UK mainland addresses only). Please note that any orders placed after 16:00 on a Friday will ship on the Monday.
International shipping times
Most orders are delivered within 3 to 5 working days if sent on a courier service. Royal Mail services can take a lot longer and are often less secure.
Pre-orders
If a product is listed as a pre-order, it means we've ordered it from the supplier but it's not physically in stock yet. The product listing will include an estimated shipping date based on the best information we have from the supplier, but do bear in mind this is subject to change and is not a guaranteed date.
If you place an order containing a mixture of in-stock and pre-order items, we'll normally hold off on shipping anything until the pre-order item(s) have arrived, rather than splitting it into multiple shipments. If you need the in-stock items sooner, we'd recommend placing separate orders. As always, please get in touch if you have questions.
Product Overview
Visual Vector Curve Generator in Eurorack Format
Splines
Splines is a visual vector curve generator in Eurorack format, with a wide frequency range and built-in quantizer, CV scope and CV processing capability. It can be used in ways similar to a wavetable VCO, LFO, step sequencer or envelope generator.
Onboard quantizer scales, backups and firmware updates are managed just as you would with an external USB drive. It's a small, shallow, multifaceted addition to any setup — and for touring rigs, it can fill many roles in exchange for very little space and weight.
In Depth
In the technical sense, "splines" are most commonly used in 3D modelling, animation and vector graphics. They're essentially a way of creating a curved path from one point to another.
In this module, you have up to sixteen user-configurable points, or nodes, which function much like a step sequencer, where the X axis represents time and the Y axis represents voltage. When the phase (time) reaches the X position of a node, the 1V/oct output changes to the Y position value of that node. Each of the sixteen nodes also has a configurable trigger setting, determining whether the gate output goes high when the phase crosses the X position of the node.
The nodes are connected by a spline, and the shape of this spline is determined by three parameters:
- Tension — changes how extreme the curve between the nodes is
- Continuity — sets the angle of the spline at the node
- Bias — shifts the tension to the left or right of the node
The spline output gives you a voltage following this curve. You can adjust which part of the full spline is output by changing the Zoom and Scroll parameters. The curve loops at the end, so when zoomed all the way out, the last node connects to the first.
The speed at which the phase progresses through the nodes can either be set fluidly using the "frequency" parameter, or quantized to fixed frequencies listed in .scl files in the "scales" directory on the module. Cycle frequencies range from 16 minutes per phase to 20kHz — from very slow LFO rates all the way up to the limits of hearing.
The output amplitude can be changed using the level parameter and CV input, allowing the module to be used without a dedicated VCA. When the spline shape goes higher or lower than the ±5V limits, a few different clipping options are provided, such as wavefolding or soft clipping — since all parameters can be overdriven substantially, this makes for some interesting effects.
The sync input is also configurable, letting you manage timing as you would a tap-tempo LFO, an envelope generator, or a step sequencer.
For working with control voltages, a basic rolling oscilloscope is available for each of the six CV inputs, including scaling and offset settings, so you can adapt the control voltage signal visually, directly in the module.
Developer resources such as drivers, templates, pin configs and best practices are also provided, in case you'd like to use the module as a development platform for your own ESP-32 based DSP projects. Firmware and quantizer scales can be updated easily by drag-and-drop via the front-accessible USB-C port.
Inputs/Outputs
- Output resolution: 1–16 bits
- Output sample rate: 192kHz
- Output voltage range: ±5V
- CV input resolution: 12 bits
- CV input sample rate: 1kHz
- CV voltage range: ±5V
- Trigger duration: 7ms
- Input trigger: 0–5V
Power
- +12V: 50mA/170mA
- -12V: 50mA
- 5V: 170mA/0mA (5V source switchable)
Dimensions
- Depth: 31mm
- Width: 10HP
- Height: 3U
Technical Specs
Shipping Details
How much is my shipping?
Shipping is automatically calculated before you submit your payment information. Simply add items to your cart and proceed to the checkout page, where you'll be offered shipping options and their prices. In the UK, 'next working day' shipping is free to most parts of the UK if the order value is over £150, and £5 otherwise. We can also ship on a 'next working day before 12pm' service, which costs £6 for orders over £150 and £7.50 for orders under £150.
Certain areas of the UK, including the Scottish Highlands and Islands, Northern Ireland and other offshore islands, may have higher shipping charges and slightly longer delivery times due to surcharges applied by the courier and reduced service availability in those areas. We try to keep these costs to a minimum.
Do you ship to my country?
Almost certainly - the site will give you an estimate of shipping costs if you add an item to the cart and then enter your country and postcode. If you have specific requirements (such as if you prefer UPS over FedEx, for example) then let us know in advance and we'll try to work something out for you.
Shipping methods
We use a combination of DPD and Royal Mail for the UK, and for international orders it's either DPD, DHL, FedEx, UPS or Royal Mail depending on where you are in the world. If you have a particular preference then try to let us know BEFORE you order so we can look into it for you. Please note that there may occasionally be additional shipping charges if you live in a remote area, depending on what surcharges are applied by the shipper. We'll get in touch to discuss this with you in such cases.
Dispatch times
For UK orders, we normally dispatch the same working day if we get the order before 16:00. If you have a really urgent situation then of course drop us an email before ordering and we'll always do our absolute best to accommodate you.
For international orders, we normally dispatch the same day if we get the order before 13:00 but again, occasionally it might be the next day before we can send it out, and sometimes the couriers may come to collect a little earlier than scheduled which would also push an order into the next day.
Saturday/Sunday delivery
If you're in the UK and you order before 16:00 on a Friday then we can send something for a Saturday or Sunday delivery with DPD. This is FREE for order values over £350, £5 for order values between £75 and £250, and £7 for order values under £75. (NB: this applies to UK mainland addresses only). Please note that any orders placed after 16:00 on a Friday will ship on the Monday.
International shipping times
Most orders are delivered within 3 to 5 working days if sent on a courier service. Royal Mail services can take a lot longer and are often less secure.
Pre-orders
If a product is listed as a pre-order, it means we've ordered it from the supplier but it's not physically in stock yet. The product listing will include an estimated shipping date based on the best information we have from the supplier, but do bear in mind this is subject to change and is not a guaranteed date.
If you place an order containing a mixture of in-stock and pre-order items, we'll normally hold off on shipping anything until the pre-order item(s) have arrived, rather than splitting it into multiple shipments. If you need the in-stock items sooner, we'd recommend placing separate orders. As always, please get in touch if you have questions.
