Retro-King Amps Announces The Addition Of The Plexi 50 To Its Line Of Custom-Made Hand-Wired Amplifiers

The Plexi 50 is a replica of the 1960''s 50 watt plexi with a solid state rectifier (you can order this with a GZ34 rectifier tube if you want).

It uses two EL-34 output tubes and a heyboer 50 watt plexi output transformer. The filtering consists of a double 50mf cap and a double 32mf cap. Unlike the 45, which uses a shared cathode, the 50 watt uses a separate cathode arrangement on the first tube, which adds pre-amp gain. A .68 bypass cap on the second stage 33k slope resistor and 500pf cap gives that classic British midrange crunch of the original. The output tranny built for me by heyboer has the correct 3.4k primary plate load.

Hand wired on a vintage style turret board just like those great amps of the 60's. Also available is the optional negative feedback control. In these amps the negative feedback resistor varied from 47k to 100k depending on the year. With the control (mounted on back of amp) you can adjust this from 47k to 100k. This will give you more or less gain. Also available in a 2x12 combo.

Retro-King Amps are hand built by Chuck Dean, a guitar player for most of his life who has owned most of the best amps made during the 50's and 60's. He knows what they should look and sound like. Chuck builds these amps with the same quality and tone as you would expect from these great amps, at a fraction of the cost of the originals. He uses the best components available in production today and takes the time to test and tweak each amp he builds, as if it were his own.

The Plexi 50 features:

  • 2 channel 4 inputs (high & low)
  • High treble & normal channels
  • 2 Volume, Treble, Mid, Bass and presence
  • 2 Matched Svetlana EL34 power tubes
  • 3 JJ 12AX7 preamp tubes
  • 1 Solid state rectifier (GZ34 tube by request)
  • Heyboer transformers (120/240 volt primary)
  • Output Tranny has correct 3.4k primary
  • 4, 8 or 16 ohm selector
  • Two speaker outputs
  • Optional negative feedback control (47 to 100k)
  • Plexi panels
  • Original 50 watt Plexi specs
  • Mallory caps allen bradley carbon comp resistors
  • Aluminum chassis
  • Hand wired point to point (Teflon wire)
  • Baltic birch cabinet (black Levant Tolex)

For more information, visit their web site at