Neurotic Drive

A vintage boost/overdrive/distortion with mods that make it a new classic for rock and roll

 

 

The Neurotic Drive overdrive rack effect module compares to the excellent Fulltone OCD.  It provides a full spectrum of tubey drive from mild boost to distortion, making it a very versatile effect.

 

Description

The Neurotic Drive compares to the Fulltone OCD, one of the more popular boutique pedals ever produced.  It has a wide range of gain and dirt from boost through overdrive to distortion.  It has good touch and tubey tone produced by a combination of JFET and MOSFET technologies.

It is unclear how many versions of the OCD pedal have been made, and what variations there may have been within those versions.  The circuits used to be physically obfuscated with goop, and have always been obfuscated with just enough truth and misleading statements to make it difficult to know which version is which.  However, a few things are likely true.  V1 and V2 differ only in the range of the Volume control.  From V2 to V3, the range of the Drive and Tone controls also changed, as did a capacitor in the tone stack.  From V3 to V4 and beyond it gets less clear.  It seems the curve of the Volume control changed.  In some units a Ge diode was added to the clipping.  The Ge diode was changed to another type of diode in at least the version 7.  Looks like the power filtering and maybe another cap or two have been adjusted.  Another transistor has also been added, probably for clipping.  It is difficult to tell the values of some components on the newer versions.

We offer V1, V2, and V3.  Our V4 will be a V3 with a Ge diode and a different type of Volume pot (same range, different curve).  V1 and V2 sound nearly the same, with maybe a touch more mids and a touch less bass in V2.  Don't expect much difference, though.  V3 is also not that different.  Maybe more mids.  Perhaps better Tone control.  V4 is a bit smoother, a little less bass.  None are radically different from each other.  None are radically different from original pedals we compared to.

The default configuration is V4, but without the Ge diode.  Removing the Ge diode is a popular mod to V4.  This makes it like a V3, but with a V4 Volume control.

 

Configurations

  • Neurotic Drive - compares to Fulltone OCD

 

Options

  • Custom Op Amp - We use the TL082, like the original.  You can choose a different pin-compatible op amp.  Choose carefully, since the circuit is based largely on the one dual op amp it contains.
  • Custom Clipping - We use a pair of 2N7000 MOSFET transistors as clipping diodes for V1, V2, and V3.  For V4, a single 1N34A is added to the original pedal, but we leave it out by default.  Again, if you choose something else, choose carefully.  Other than the op amp, the clipping diodes are the next biggest contributor to the effect.  This option lets you choose a different clipping diode configuration.
  • Clipping Switch - Add a second clipping configuration that can be selected by a switch.  Can make no clipping a third position on the switch.
  • Lower Gain - If you want to trim off a bit of gain, we can adjust some components to do that.  This is not switchable.
  • Fat Switch - Add a switched capacitor to thicken/thin the tone a bit.
  • Volts - The default voltage is 9V.  For a bit less distortion and more headroom, you can select 12V, 15V, or 18V instead.  18V is probably more popular to provide a bigger difference from 9V.
  • Volt Switch - Adds a switch to allow selection of 9V and either 12V, 15V, or 18V.
  • Custom Components - We use metal film resistors and a selection of capacitors that provide good tone and low noise.

 

Front Panel

  • On/Off indicator LED
  • Volume
  • Tone
  • Drive
  • HP/LP switch
  • (optional) Clipping switch
  • (optional) Fat switch
  • (optional) Volts switch

 

Rear Panel

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

 

Module Width

  • 1.5" standard
  • 2" with options
  • 2" left wing and 1.5" right wing available for 4 control configurations

 

Power Consumption (aprox)

31 - 35mA

 

Base Configurations

Part # Description List Price
MOD-NEUROTIC Neurotic Drive module $210

 

Options

Part # Description List Price
MOPT-NEUROTIC-OPAMP Custom Op Amp $0 - TBD
MOPT-NEUROTIC-CLIP Custom Clipping $0 - TBD
MOPT-NEUROTIC-SWCLIP Clipping Switch $19 - TBD
MOPT-NEUROTIC-GAIN Lower Gain $0
MOPT-NEUROTIC-FAT Fat Switch $19
MOPT-NEUROTIC-VOLTS Volts $0
MOPT-NEUROTIC-SWVOLTS Volt Switch $59
MOPT-NEUROTIC-CC Component Changes TBD