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Sonar Recording Light


FYI, this product is no longer available.  Page here for historical purposes only.


Cakewalk/Sonar users, how many times have you had people walk into your studio in the middle of a recording session? Don't you just want some kind of automatic recording in progress light right outside the door? I sure did! Searching the web, turned up nothing. So what does a good engineer and maker do? Make one! It worked great for me, so thought I'd make some for other folks too. Problem was, the controller used the PC's parallel port to control the lights. Nowadays, you're hard-pressed to find a new PC with a parallel port, but they all have USB ports!

Thus the birth of RecLightUSB...

RecLightUSB uses Sonar's Control Surface interface to access Sonar's transport control. This means when Sonar records, the Red recording light automatically comes on and when Sonar plays, it automatically switches to the Green playback light.


These two pictures show the RecLightUSB LED light box. You can watch a video of the RecLightUSB in action here


There are two versions of the RecLightUSB controller module. Both versions connect to a USB port on your recording PC and control a recording light, a playback light or both.

The RecLightUSB LED model can control up to 2 LED light boxes like those show above and only requires a small "wall wart" power supply connected to the RecLightUSB controller to drive either 1 or 2 LED Light boxes. Each LED Light Box is a 5.63"L x 3.25"W x 1.51"H black plastic box and has one red and one green multi-LED light. The controller connects to the LED Light box(s) via standard Ethernet cabling.

RecLight USB with LED display


RecLightUSB-LED variant circuit diagram

RecLightUSB-LED variant circuit diagram

RecLightUSB-LED circuit board

RecLightUSB-LED circuit board

Unsupported firmware for the RecLightUSB
Unsupported Sonar Control Surface in Visual Studio for RecLightUSB

The RecLightUSB Power Switch model, rather than controlling LED's, can be used to switch normal A/C lighting on and off. Play and Record each have their own solid-state relay. Each solid-state relay is rated for 4A @ 110/220VAC.

For 110VAC power, "recording" light only there's a complete RecLightUSB Power Switch model which is effectively a USB switchable extension cord.


RecLightUSB Power Switch
Here's the complete 110VAC "recording" light only configuration. Plug the USB connector into your PC, the one end of the extension cord into a handy 110 outlet and your favorite "recording" lamp into the other end of the extension cord.


For other voltages or other A/C configurations, only the 'bare' Power Switch model without any A/C wiring or enclosure is available. In that case, you must supply your own wiring and enclosure and assemble the unit to meet all your local electrical code regulations.

RecLightUSB Power Switch controller
This is how the two relay RecLightUSB Power Switch is delivered. No enclosure, no A/C wiring. Just the USB cable (power for the controller comes from the USB port on your PC)


One potential way to assemble the RecLightUSB Power Switch is to put the switch and an A/C outlet into an outlet box. The circuit board is sized such that it should fit inside a single gang outlet box, though a dual-gang outlet box would give you a bit more room to work with.

RecLightUSB Power switch

In this example configuration, I removed the jumper between the two A/C outlets so they can be controlled independently. The "record" relay output is then wired to the one outlet and the "play" relay output is wired to the other outlet. The A/C power comes in via the power cord, through the two relays, and applied to the A/C outlets. You would then plug your "recording" and "playback" lights into the two A/C outlets.

The major concern with this configuration is you must be absolutely certain that there is no way for any of the A/C wires to contact the low voltage side of the board. Plus, if you use a metal gang box as shown in this example, you must insulate the bottom of the circuit board from the metal box. Similar insulation material could then be used to ensure none of the A/C wiring can contact the low-voltage side of the board. Warning - if any of the A/C wires come loose and contact the low voltage side of the board, A/C power will likely be applied to the USB port on your PC and that's the end of your PC. Worse, that A/C power will likely run through YOU as well with all the hazards that implies. Safely wiring and using this device is your own personal responsibility.

No official kits, if you are interested in one-offs, contact me at: .

The 4 configurations plus kits we looked at producing (but never did):

  1. RecLighUSB LED module with power supply and 1 Red/Green LED light box
  2. RecLightUSB Power Switch module with 2 solid state relays (can control both a "record" and "play" light),no enclosure, no A/C wiring
  3. RecLightUSB Power Switch module with 1 solid state relay (can only control a "record" light), no enclosure, no A/C wiring
  4. RecLightUSB Power Switch module with 1 solid state relay (can only control a "record" light), with enclosure, with modified extension cord (US only)
  5. Circuit board good for either LED or relay configuration and pre-programmed MCU

Below prices are approximate, contact me at for accurate one-off pricing:

  1. $75 - RecLightUSB LED module with power supply and 1 LED light box, you supply Ethernet cable
  2. $55 - 2 relay RecLightUSB Power Switch module, assembled board, no A/C wiring or enclosure
  3. $47 - single relay RecLightUSB Power Switch module, assembled board, no A/C wiring or enclosure
  4. $60 - single relay RecLightUSB Power Switch complete, with enclosure and modified extension cord (US only!)
  5. $15 - circuit board and pre-programmed MCU, circuit board can be used for either LED's or power relays


RecLight Software is available for download below.

After installing the RecLight software, connect the RecLightUSB module. The software installs a "Test Driver" utility, located in the RecLightUSB Start menu. Run the "Test Driver" after plugging in your module. The "Test Driver" utility should cycle from "record" to "playback" to off and repeat. This will verify that the driver and module are properly installed.

Once you've verified the hardware and driver, launch Sonar and under Options menu, select "Control Surfaces..." In the Control Surfaces dialog, click the "Add New Control Surface" button. Select RecLightUSB in the Control Surface drop down. The Input Port and Output Port can be set to --None--. Then click OK and Close the Control Surfaces dialog.

At this point the Control Surface toolbar should show "RecLightUSB" and "USB OK". If you do not see the Control Surface toolbar, use Sonar's View / Toolbars... menu to enable the "Control Surfaces" toolbar.

That's it! recording something, the "recording" light will automatically come on. Play it back and the "playback" light will come on.


  1. The LED Light Box connects to the RecLightUSB Controller via a simple Ethernet cable connection. No, it's not Ethernet based, so don't even dare trying to plug this into a router! Using Ethernet cable for the interconnect just means it's easy to get or make a cable of whatever length is necessary.
  2. The install kit is configured to install 64 bit control surface and drivers on 64 bit windows and 32 bit control surface and drivers on 32 bit windows. If you're running 64 bit windows, but 32 bit Sonar, contact us for specific instructions for manual installation.

RecLightUSB software and driver