How to Change the Tube in a Le-Series Preamp Pedal?

How to Change the Tube in a Le-Series Preamp Pedal?

This article describes how to change the vacuum tube in a Le-Series Preamp Pedal including Le Bass, Le Clean, Le Crunch and Le Lead,

WARNING: Changing the tube is a simple process and does not void the warranty; this should only be actioned by a qualified technician considering the presence of high voltages within the unit. This procedure requires the tube to be cold and the unit disconnected from any power source, audio devices and MIDI peripherals.

The tube used in a Le-Series Preamp Pedal is a Ruby 12AX7AC5 HG. You can also use any standard 12AX7 tube as a replacement.

Changing the Vacuum Tube in a Le-Series Preamp Pedal | Step by Step Guide

  1. Disconnect the power cable and all other audio / MIDI connections from the device
  2. Install the device upside-down on a soft, clean and protective surface to avoid scratching the unit
  3. Using a Philips-head screwdriver, remove the 4 screws retaining the bottom cover
  4. Remove the cover. Please note, this can sometimes be stuck and hard to remove. Loosen the 5 X 1/4" jack connector hex nuts using a 11mm socket wrench. If needed, you can also use a small flat screwdriver as a lever through the screw holes, again to avoid any cosmetic damage to the unit
  5. You should now have access to the tube, through the big hole in the center of the PCB:

  1. Grab the tube and move it from side to side while pulling it out of its socket to remove it from the device
  2. Before inserting a new tube, first locate its missing pin. Then, insert the tube so as to match this missing pin with the indicated location on the tube socket:

  1. Finally, install the cover and screw the 4 retaining screws back into place. If loosened, please also tighten the 5 X 1/4" jack connector hex nuts, by hands at first, then with a socket wrench (a 1/8 or 1/4 turn should be sufficient).

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