Description

‘Moyer Mod” Fender Vibrolux Reverb (blackface Vibroverb mod). Killer 35-watt combo with Reverb and Tremolo, $1199!

Fender Vibrolux Reverb with Moyer Mod

The Fender Custom Vibrolux Reverb is a 40-watt, 2×10″ tube amplifier known for its rich tonal qualities. However, some users have noted issues such as excessive hiss and a reverb effect lacking depth. The Moyer Mod, developed by Mark Moyer, addresses these concerns with several modifications to enhance the amp’s performance.

Key Modifications in the Moyer Mod

  1. Reverb Channel Adjustment:
    The stock amplifier features reverb on both the Normal and Bright channels, which can introduce additional noise. The Moyer Mod removes the reverb from the Normal channel, assigning it exclusively to the Bright channel. This change reduces hiss and aligns the amp’s functionality with classic Fender designs.
  2. Negative Feedback Loop Addition:
    The original design lacks a negative feedback loop, contributing to higher noise levels and reduced headroom. Adding a negative feedback loop decreases hiss and increases clean headroom, resulting in a more traditional Fender sound.
  3. Reverb Circuit Enhancement:
    The mod increases the value of certain capacitors in the reverb circuit, leading to a fuller and more vibrant reverb effect, reminiscent of classic Fender amplifiers.
  4. Removal of Protection Diodes:
    The stock amplifier includes protection diodes on the power tubes, which can sometimes cause fuse issues and affect high-frequency response. Removing these diodes improves reliability and tonal clarity.
  5. Ground Reference Resistors Adjustment:
    Changing the ground reference resistors in the heater circuit helps reduce hum and hiss, contributing to quieter operation.
  6. Adjustable Bias Installation:
    Adding an adjustable bias control allows for precise setting of the power tube bias, optimizing performance and extending tube life.

Impact of the Moyer Mod

Implementing the Moyer Mod transforms the Fender Custom Vibrolux Reverb into a more refined amplifier with reduced noise levels, enhanced reverb quality, and increased clean headroom. These modifications align the amp’s characteristics with classic Fender models, offering a more traditional and desirable tonal palette.