An alternative to replacing it (since it's probably hard to get an exact physical replacement) is to replace R18 with a large value. The volume control pot is a B50K which I assume means that it's linear as opposed to audio taper. There's a blog article where someone used a pair of 1N34As. I'll look into replacing the leds, either with a single one of different color or with a couple of germanium diodes. Roly, thanks for the suggestions and the schematic. That should work, although you could always mount another socket somewhere for an external speaker and retain the headphone/Line Out option. Quote- Remove/short the headphone resistors and use the headphone jack as a speaker out jack Quote- Zeners to 'control' the supply voltage for the op-ampsĭo you have a reason/problem? If you don't actually have a problem then I wouldn't bother, most op-amps have about 120dB of power supply rejection. If it's a linear taper then it will be about 25k to each end, but if it's quite different then it's already a log pot. Set it to 5/10 and measure the resistance from the wiper to each end. Quote- Use an analog taper pot for volumeĪll pots are by their nature analog - I think you mean 'audio' taper or log pot, which the volume control should already be. You may find some tonal advantage in playing around with one of these LED's trying one with a different forward voltage (generally a different colour) with will give you asymmetric clipping of +ve and and -ve parts of the signal, which can produce a nice 2nd harmonic. The overdrive from this stage is clipped by the following back-to-back red LED's. Quote- Change the gain resistor of the second stage to reduce the gain when the drive switch is on A six inch speaker is worth replacing just because it's six inch, and a buzzy six inch speaker.

Vox pathfinder 10 led mod