US Customers

Please ignore the generic shipping warnings from Lectronz regarding tariffs and delays in shipments. All volume knob kits are shipped from us with tariffs pre-paid (the tariff is included in the shipping cost) resulting in no delays and no border clearance issues

EU Customers

As of 26/06/2026, B2C shipments to some EU countries are to be sent from New Zealand using Delivered Duties Paid (DDP). NZ Post is in the process of adding support for this, but for now, shipping to some countries in the EU is unavailable. This includes Austria, Belgium, Denmark, Estonia, Finland, France, Germany, Luxembourg, Portugal, Cyprus, Czechia, Netherlands, Malta, and Spain. We apologise for the inconvenience and will update our shipping options when we can resume shipping to these countries.

Features:

• Simple, plug-and-play solution. Mount the volume knob to a panel in the car, solder two wires into your stereo's steering wheel control input and you are good to go
• Compatible with major headunit brands
  • JVC1
  • Kenwood2
  • Alpine
  • Pioneer
  • Android Headunits (solderless control via USB!)3
  • Sony
  • Any headunit with resistive steering wheel control learning
• 5V USB powered. Most headunits have USB outputs for you to plug this into and power up
• MCU: WCH CH32X035 with Arduino firmware support
• Interrupt-driven firmware results in a smooth, user-freindly experience
• Firmware updates via USB upload
• All inputs remapable using the Configurator Tool
• Fully open source hardware and firmware. This includes all design files, BOM, firmware, etc

1 JVC forces incremental volume control above certain values on select models. I am yet to find a way to bypass this.

2 Kenwood forces incremental volume control above certain values on select models. I have found a way to bypass this and have implemented it by default in the firmware. This may or may not work for your unit and your miles may vary.

3 Some Android headunits do not allow USB volume control. If that is the case with your unit, you can default back to using the resistance SWC mode of this kit for control input

RESWC Impact Map

Check out where our volume knob kits are in use around the world! >> RESWC Impact Map <<

What's in the box:

• 1pc Volume Knob Kit - includes controller board, encoder board and required connectors/cables

Optional Accessories:

• Black Aluminium volume knob cover/cap (large and small)
• 0.5m Braided USB C to A cable (data & power)
• 3.5mm jack pre-terminated SWC patch connector
• USB A Data & Power Splitter: The volume knob kit only requires power from the USB port (unless running in USB HID mode). Use the USB splitter to power the volume knob kit while also charging and running Android Auto or Carplay on your phone through just one port on your headunit

Default SWC Outputs

INPUT	OUTPUT
Volume Knob CW	Volume +
Volume Knob CCW	Volume -
Button Short Press	Mute
Button Long Press	Next Track
Button Double Press (Gen. Resistive Mode)	Enable Learning Mode
Button Double Press (Other Modes)	Previous Track

Remapping Outputs

Your kit can be configured on the fly! Use the Volume Knob Kit Configurator Tool and truly make your Volume Knob Kit your own. Map all the inputs to any of the supported outputs.

Note: Output remapping is supported on firmware version 4.0.0 and later

Documentation and Source Code

• User Guide
• Video Demos
• Hardware Documentation and Source
• Firmware Source

Why did I make this?

No kits like this exist: a plug-and-play solution to add a volume knob back into your car. Mount the volume knob to a panel in the car, solder two wires and you are good to go

My headunit does not have a USB socket to power this??

No worries, purchase an automotive 12V to USB adapter and plug this into it.

• Note: The 12V rail in cars is harsh. Do not cheap out on this component

Is this just as good as a volume knob built into my stereo?

Unfortunately, no. The knob built into car stereos control the "absolute" volume and allows for cool functions such as acceleration of the volume when you really wrench on the knob.

This kit taps into your car stereo's steering wheel control input. Using this input, the Volume Knob Kit can only request volume increments or decrements at a pre-defined rate (dependent on the protocol overhead of each brand).

We have tuned the encoder and MCU for this product to be as responsive as possible to your input! If you are not happy with the end result, let us know and we will action a response asap!

Volume Orders

If you would like to purchase more than one kit, please get in contact with me! I am happy to provide a discount for volume orders and combine them into a single shipment :)

Installer or Shop?

We are scaling and keen to work B2B as well! Let us know if you are interested with this short Google Form

Shipping

Please note, the price of this item is exclusive of GST and/or VAT etc. Any import taxes and duties shall be borne by the customer.

• Note: Only US shipping price includes prepaid tariffs (DDP) as this must be paid by us on behalf of you before shipping
• NZ customers: We are Auckland based (Rosedale). If you would like to pick up your order, please let us know beforehand and we can provide you a free pick up option with the site!

Warranty and Returns

I will happily accept warranty claims for products that are DOA. If your headunit is listed as Compatible - Unconfirmed and it ends up being incompatible, I will also happily provide a refund. Buyer's remorse will not be warrantied or refundable.

FCC Compliance Statement

This device complies with Part 15 of the FCC Rules. Operation is subject to the following two conditions:

1. This device may not cause harmful interference, and
2. this device must accept any interference received, including interference that may cause undesired operation.