QRK-SR - Single Relay Controller Interface for QRK


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QRK-SR allows up to four voice control lines to interface with a a group of relays switched in tandem.  QRK-SR is equivalent to one-quarter of the QRK-RLY quad relay controller.

  • controls one relay group
  • function LED driver
  • requires 12Vdc
  • accommodates DIP switches for easy programming (order QRK-DIP)

Most guitar amp switching functions only require that one or two things in the actual audio path be switched. The amp might have three or more voices overall and benefit from the direct-random-access selection that QRK-LATCH provides, but may not need internal selection of as many things as there are voices. in such cases, being able to use one or two QRK-SRs plus QRK-LDV to drive the voice LEDs can save space and money compared to installing QRK-RLY that controls four relay groups and drives the voice LEDs.

Use RLY or similar mechanical relays located with the audio circuitry. More than one RLY can be switched simultaneously by QRK-SR. Each RLY requires 12V at 12mA, where QRK-SR requires about 10mA only if a LED is driven by it, otherwise no current for the driver itself.

An onboard LED driver allows an indication of the status of the function being switched.  The stock LED is 3mm round, green and standard brightness.

The relay controller can respond to up to four voice lines, determined by soldering in jumpers where the DIP switches would be. For easier programming, add QRK-DIP to allow changes any time without soldering.

Kit requires assembly.

PCB size: 1.35" x 1.1" (35 x 28mm)See also:

QRK-DIP - 4-way DIP switch

About London Power

London Power was founded in 1990 by Kevin O'Connor, after two decades of research into innovative audio amplification techniques. Kevin is an audio designer, author and speaker, known for his proprietary methodology called Power Scaling, and for his eleven books on audio subjects. Whether you seek amps, kits or information, you'll find useful answers here on not just the "how" but the "why" of audio amplifier design. Please enjoy the information on this site, and don't hesitate to contact us with questions.

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