Treble Boost

Vintage VOX Treble Booster

 

 

The Treble Boost rack effect module compares to the vintage VOX Treble Booster.  The original had no controls other than an on/off switch.  The fixed boost worked well in dark setups, but could be very bright in other setups.  We offer a switchable boost frequency to make it more useful in a wider variety of setups.

 

Description

Although this is in the Boost category, it isn't really a boost.  It is really a tone shaping tool aimed at brightening up dark setups.  The original was just an on/off effect, with no controls.  It left the apparent volume at about unity but boosted the high end to give a much brighter output.  It does that by cutting everything below a cut frequency, then restoring the original level to the combined cut and uncut frequencies.  The low cut alone would lower the apparent volume.  It is a bit like using a 7-band equalizer pedal set to cut all but the highest frequency band, although the cut point is higher even than the midpoint of that 7th band of a normal 7-band EQ, and then raising the output volume.

The treble boost works well with a dark amp and humbucker pickups, a popular early British combination.  However, with single coils or a brighter amp, the treble boost can make the tone really bright.  That may be exactly what you want, but if it isn't, we have an option to tame it a bit.  The optional Pickups switch will allow you to switch between the original "Humbucker" treble boost, or a "Single Coil" treble boost.  The Single Coil setting lowers the frequency of the cut point so that you get some more mids coming through.  This also gives an apparent volume boost.  For that reason, there is also a Level control that will let you dial the volume back down to unity.  Or leave it up there and get not only a treble boost, but a volume boost, too.

The original used an input cap to cut everything except mid to high treble.  With the Level control, this seems like a volume cut if you set the Level at less than max.  With Level at max, it seems like a treble boost at about unity volume, as intended.  You may notice a little extra hiss, but that is only because you aren't covering up with lower frequencies the hiss that would be there anyway.  The noise becomes a larger percent of your signal once you cut the lower frequencies.  That is the nature of most treble boost effects.

The Pickups switch gives you a choice between the original (Humbucker) cut frequency and a lower cut frequency (Single Coil) further down in the upper mids.  Or if you prefer, you can move the original cut point down a bit, too - depends on your setup and what you want. 

The default is to add the Level control and the Pickups switch, with the choices for the Pickups switch to be the original value and a second value that moves the cut frequency down into the upper mids.

The standard cut frequency is pretty extreme, which may be just what you want.  The optional second Single Coil setting adds a second capacitor to the first to lower the cut frequency.  You don't want to make the sum of the two capacitors too high, or you won't really have a treble boost.  By default, the second capacitor is twice the size of the original (first) capacitor.  If you don't need extreme treble boost, we can just flip the two capacitors.  That leaves the Single Coil cut frequency the same, since the sum of the capacitor sizes is the same.  But it puts the larger capacitor in the Humbucker position, moving that cut frequency down to the high midrange/low treble range.  That might be more appropriate if your setup isn't overly dark.  That means the difference between the two settings is smaller, so you won't notice a massive change when switching between the two settings.  The change is still substantial, but with the default config, it is more "massive" than "substantial".

 

Configurations

  • Treble Boost - Compares to VOX Treble Booster

 

Options

  • Custom Transistor - We'll use a 2N2924 by default, like the original.  Other NPN silicon transistors are available.
  • Custom Capacitors for Single Coil / Humbuckers Switch - (described above)
  • Remove Single Coil / Humbuckers Switch - remove the switch and use the original cut frequency
  • Components - We use metal film resistors and a selection of capacitors that provide good tone and low noise.  Carbon comp resistors sound good in this circuit, providing a little bit of good noise or vintage mojo, whichever name you prefer.

 

Front Panel

  • On/Off indicator LED
  • Boost
  • Single Coil / Humbucker 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)

10 - 15mA

 

Base Configurations

Part # Description List Price
MOD-TBOOST Treble Boost module $194

 

Options

Part # Description List Price
MOPT-TBOOST-TRANS Custom Transistor $0 - TBD
MOPT-TBOOST-SCH Remove Single Coil / Humbucker Switch -$10
MOPT-TBOOST-SCHCC Custom Capacitors for Single Coil / Humbucker Switch $0 - TBD
MOPT-TBOOST-CC Component Changes $0 - TBD