Dating mxr pedal
The first Script Logo units does not include this component, later schematics (Block Logo) added it, finally the EVH model has an additional potentiometer to adjust the intensity of this factor.
The x-axis of the plot was modified to include the year 2000, and the date code of three final-series pedals (a FX25B, FX84, and FX91) that had been previously assumed to have a date code of late 1999, were revised in April 2011.As the FX15 was a slow seller, it is reasonable to assume that many circuit boards were assembled but not immediately housed in an enclosure, which would explain why the component date was about two years younger than its serial number.Five related pedals (represented as red circles, including four Digi Tech PDS-series twin pedals and one DOD Master Switch 225, each of which used the same type of serial number sticker) fit very well with the FX-series data.With respect to component date codes, the rollover of two-digit year codes from 1999 to 2000 was not clearly understood at first, but started to make more sense as we re-examined component-side circuitboard pictures of those pedals.For example, we now believe that a pot stamped "2009" is a date code meaning the 9th week of the year 2000.Last models include smd components and pcb mounted jacks.
Using the Elementary Shifting Unit concept, the Phase 90 uses an inverting operational amplifier with the RC shifter at the ( ) input.
used 6 single op-amps while the latest utilize 3 dual op-amps.
The layout and jacks/switches placement changed during the different productions.
At the same time other frequencies will get the opposite effect, being reinforced when the input and phased waveforms have 0 or 360 phase difference.
Feedbacking part of the output signal into the Shifting Stage chain will reinforce keeping the cancellation points.
Some early DOD FX-series pedals have stickers with the date of final assembly, but unlike Boss pedals, the month and year of manufacture is not encoded in its serial number.