"Clean, tube-y JFET boost with dirt options"



The Sabre boost rack effect module compares to the Keeley Katana and other cascaded JFET boosts.  It is a big, tube-y boost that lets you stay clean or add in a bit of grit or a little fat.  It might become one of those "always on" effects once you start using it.



JFET transistors can provide a powerful clean boost that can sound more tube-like than other types of solid-state boosts.  They can easily push a tube amp from clean to overdrive, producing some very nice tonal options along the way.  That's great, but sometimes you want to add a little grit and get dirty.  The Sabre allows you to do just that.  You can keep it clean, add some grit, or add some hard clipping crunch.  It sounds great on its own or giving a nice push to whatever comes after it.  

Over the years, there have been some minor variations to the circuit, but they sound very similar.  Different JFETs have been used, and some of the capacitor values have been tweaked to trim off some bass and leave in more highs.  By default, we build the earlier version but you can select the later one if you prefer it.



  • Sabre - Compares to Keeley Katana and other cascaded JFET boosts.



No buffers



  • Version - By default, we build an early version of the circuit, but we can also build a later, more recent version.  The early version uses 2N5484 or 2N5458 JFET transistors.  The later version uses J201 JFETS and has slightly less bass and slightly more highs.
  • Custom Transistors - Comes with 2N5458 standard.  Can substitute other JFETs of your choice.
  • Custom Clipping - Comes with symmetric red LED crunch clipping standard.  Can substitute other diodes of your choice.
  • Components - We use metal film resistors and a selection of capacitors that provide good tone and low noise


Front Panel

  • Volume
  • Clip / Clean / Grit switch


Rear Panel

  • Audio In
  • Audio Out
  • On/Off Footswitch
  • On/Off Override
  • DC Power
  • DC Power LED


Module Width

  • 1.5"
  • 2" left wing available
  • 1.5" right wing available


Power Consumption (aprox)

25 - 30mA


Base Configurations

Part # Description List Price
MOD-SABRE Sabre Boost module $199



Part # Description List Price
MOPT-SABRE-VERSION Early or later version of the circuit $0
MOPT-SABRE-TRANS Custom Transistors $0 - TBD
MOPT-SABRE-CLIP Custom Clipping $0 - TBD
MOPT-SABRE-CC Component Changes TBD



Part # Description List Price
MPT-SABRE-CA Replacement pot, switch, jack, LED cable assembly $19
MPT-SABRE-KNB Replacement control knob $2
MPT-SABRE-PB Replacement power board $29
MPT-SABRE-SB Replacement switching board $29