November 12, 2023 at 2:30 pm #30038Big OParticipant
This project is a “pedal” to insert between an effects pedal such as a Wah or OD and an old style fuzz circuit such as a Fuzz Face. Typically, many have found that there can be problems when using a Wah placed before a fuzz face. I decided to place this discussion in the DIY section as it really is not a GPCB pedal, but some might find this topic useful.
Why can there be problems with Wah’s and other pedals in front of a vintage fuzz circuit? It is because Fuzzes usually have a Low Input Impedance, which usually means they sound not so good after other pedals (unless the pedal in before it has a High Output Impedance). Passive guitar pickups can be seen as having a fixed High Impedance and that is why a guitar plugged directly into a fuzz face sounds good. However, as previously stated, effects circuits will respond differently to an input from a Low Impedance signal source output (e.g. op-amp OD) than when driven directly from a High Impedance guitar pickup. This Low Impedance pedal output problem may be especially noticeable with certain types of simple transistor circuits such as the classic fuzz face, and the FF can sound significantly different when connected directly to a guitar pickup than when it is preceded by some other Low Impedance output effects box. Wahs will provide a variable output impedance depending on where the wah pot is positioned and of course there will be some Low Impedances provided from some treadle positions.
A way to help with this problem is by placing a Pickup Simulator (with its High Impedance) in front of the vintage fuzz circuit (e.g. Fuzz Face). What better way to build a pickup simulator than using an actual pickup? Jack Orman on the AMZ site has a short article regarding how to do just that. All I needed was a 10K Pot, 330pf Capacitor and a spare single coil pickup I had laying around in my guitar parts box. I built it in an electrical box that cost about 2 bucks and added the input and output jacks. The result is the Impedance Machine!
The page/article from Jack Orman and the AMZ site.
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