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London Power Electronic Relay Kit (ERK)
Have you tried this relay kit? Post your questions and comments here!

[Image: erk-kit_sq.jpg]

The Electronic Relay Kit (ERK) features:
  • A, B exclusive selection
  • ground-referenced jfet shunt switch elements
  • silent operation
  • can be used with push-on push-off remote switch (not included)
  • easy wiring for panel control (switch not included – order our PSW)
  • can control panel LEDs (LEDs not included)
  • 6-poles included; infinitely expandable
  • use for channel muting or selection
  • use for gain selection via cathode-bypass caps
  • low current consumption of <2mA
  • operates from -12Vdc or high-voltage AC

This kit uses “shunt” switch elements for silent, reliable channel selection or gain stepping. Three transistors create and control two control lines that respond to a remote foot-switch. You can connect any required number of jfet switches to these lines. 

For example, you can use the ERK to select the channels of the LP-PRE Preamp Kit or the FPM Fender Preamp Mod by using one jfet on the control line to mute the ‘Clean’ channel, and two jfets on the second control line to mute the ‘Lead’ channel. Because jfet gates create almost no loading on the control lines, there is no true limit on how many jfets you tie on.

ERK has a fourth BJT to control one or two LEDs, or a bicolour 3-lead LED, to indicate which channel is ‘on’. If you use LEDs, ERK should be supported by a proper -12Vdc supply rather than the high-AC voltage.

ERK also has wiring accommodation for a front panel switch, which will be over-ridden if a foot-switch cable is inserted into ERK’s 1/4″ jack. 

More information here:

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