Pathfinder 15 LED mods : THE SOUND at room temperature

[bluesky6]

I managed to get my hands on a "fixer-upper" Pathfinder 15R with a couple of issues that required some resoldering and an op-amp swap (yes! An op-amp swap that actually fixed a problem!).

I was going to go germanium-clipping-diode on the Pathfinder but then thought that I was going to try the famous LED mod instead. The latter being an obvious misnomer since there are no LEDs post-mod.

I ran the amp through an external speaker with an attenuator. So I was able to max the gain while maintaining the volume at room temperature.

Anyway, I was surprised at the end result of the mod. The sound was pretty amazing: a very nice crunch with no fuzz/fizz. Wow!

The problem, I realized, was that you could only really get this nice sound if the gain controls were somewhat past 2 o'clock (with my Tele). Which made for a very loud amp if I were not using the attenuator.

So in typical Bluesky6 fashion, I changed the volume circuit:
1. Swapped out the linear taper volume pot for a similar value audio pot
2. Swapped out the 4.7K series resistor to the volume pot for a 470K. I know: it's high, but it was one value that gave me room volume with the volume pot set at 9 o'clock while the gain pot was at max
3. For good measure, I put in a 4.7nF tone bypass cap. I may yet swap that out for a slightly larger value

Once I had done this, I had reduced the main signal so much with respect to the reverb return signal that the latter basically overpowered the main signal. So I swapped one of the reverb resistors from 4.7K to 100K (after experimentation with different values).

The end result is a pretty simple amp with a very nice tone at reasonable volume.

The attached pic shows the changes I made. Apologies for the crude mouse-drawn tone bypass cap.