The One

"The boss of the overdrive pedals"



The One overdrive rack effect module compares to the original Boss OD-1 Overdrive that was made in Japan with quad op amps, before the circuit was updated to use dual 4558 op amps. The original was great, preferred to the later versions by those that have had a chance to hear one.



The Boss OD-1 Overdrive was released around 1977, making it one of the first overdrive pedals on the market.  The first two versions of the circuit used quad op amps.  The circuit was later updated to use dual 4558 style op amps.  At the same time as the op amp change, several other component values were also changed.  The warm tube-like sound became thinner and less pleasing.  Most players find the quad op amp versions to be much superior to the later dual op amp versions. 

The sound change is due more to the other component changes than the op amp change.  The 4558 op amps are used in many great pedals, and can provide great slightly warm tone.  That original OD-1 tone can be recreated using the 4558s if you make other changes to go back to the original circuit.  The One compares to that original OD-1 circuit with the quad op amps.  We use the quad op amps, just like the original.  The specific quad op amps used in the original are becoming very difficult to find, and most are counterfeits.  We have some in stock, along with some other quad op amp models that offer great tone, too.  But eventually we expect to move to the dual op amps, utilizing the old circuit to maintain the superior tone it offers.

The One is a simple module, with only Level and Overdrive controls.  The circuit is similar to some Ibanez pedals that were available at roughly the same time, including the Overdrive II and Tube Screamer.  We also make available some options that provide a few more tone possibilities, but staying close to the original sound of the circuit.



  • The One - compares to early quad op amp versions of the Boss OD-1 Overdrive.



Input and output buffers



  • Fat Mod - Permanently thicken the tone.  Normally the tone thins out a bit as the drive is increased.  This mod retains a bit more bottom end as the drive is increased.
  • Fat Switch - Same as the Fat Mod, but lets you switch between the original circuit sound plus two other settings.
  • Gain Mod - This mod provides a slightly wider range of gain than the stock circuit.  It allows both a lower minimum gain and a higher maximum gain.  The original range is all still there, just extended.
  • Custom Clipping - The original circuit uses asymmetric silicon clipping diodes, 1S2473.  Those diodes are not particularly special.  We use 1N914 by default.  The 1S2473 are getting pricey and difficult to find, but we usually have some if you prefer them.  Or you can choose something else.  Asymmetric silicon will keep you close to the original sound.
  • Clipping Switch - This option provides a switch to allow you to select one of two different clipping configurations, along with the possibility of no clipping diodes.
  • Fizz Mod - Removes some very high end treble content and noise.
  • Fizz Switch - Same as the Fizz Mod, but on a switch.
  • Custom Op Amp - We use the TL074 JFET quad op amp by default.  It sounds virtually identical to the original op amps.  The original circuit used RC3403 and uPC4147 op amps.  We try to keep those stocked, but real ones are expensive and difficult to find.  There are several other worthy quad op amps that will sound fine, too.
  • Custom Components - We use metal film resistors and a selection of capacitors that provide good tone and low noise.


Front Panel

  • Level
  • Overdrive
  • (optional) Fat switch
  • (optional) Clipping switch
  • (optional) Fizz 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 and 1.5" right wing available for 2-4 control configurations


Power Consumption (aprox)

10 - 20mA


Base Configurations

Part # Description List Price
MOD-ONE The One module $199



Part # Description List Price
MOPT-ONE-SWFAT Fat Switch $19
MOPT-ONE-CLIP Custom Clipping $0 - TBD
MOPT-ONE-SWCLIP Clipping Switch $19 - TBD
MOPT-ONE-SWFIZZ Fizz Switch $19
MOPT-ONE-OPAMP Custom Op Amp $0 - TBD
MOPT-ONE-CC Component Changes TBD



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