Dating fender electric guitars
From looking at the version "A" photo, it appears the one op-amp is used per string to both amplify the signal and create the hex fuzz sound.If you look at IC6, at the top of the version "B" and "C" card, you can see resistors just to the left of the chip creating gain in the negative feedback loop, and additional diodes just to the right side of the chip for generating fuzz. After years of working with Roland vintage electronics, I finally noticed that there were two variations on the familiar hex pickup.I also have to add this: I picked up some G-707 electronics pulled from a guitar some years ago, and I did find a G-707 circuit board wired to support the older, narrow pickup.In the case of the G-707 guitar, you need to check to following resistors: R23, R26, R29, R35 and R38.When switching from the 80 ohm (narrow) to 900 ohm (wide) pickup, there is a 10:1 increase in impedance, likewise, it is necessary to change the negative feedback loop resistor by a similar ratio, from 330K to 33K, and from 1 M to 100K.
No doubt much of the popularity of the G-303 comes from Pat Metheny, who has played this guitar year after year on stages across the world, always amazing audiences with the moving and emotional quality of the G-303 and GR-300 rig.
These op-amps are the top three 4558 op-amps in line with the 24-pin ribbon connector.
IC4, IC5 and IC6 op-amps are used to create the hex fuzz sound. The line-level amplifiers are surrounded by resistors for a simple gain circuit, and the hex fuzz amplifiers have the network of diodes used to create the fuzz sound.
The other vintage controllers, the G-202 and G-505, are well-built, fine guitars.
But they cannot escape the feel of being really well made Fender copies, no matter how nice they are. The more expensive G-808 has through-neck construction and other nice features, like gold hardware.