Hey,
I have a PT-80 that I built some time ago. Recently, the past few gigs I've played, the LED indicator on the PT-80 won't come on right away. It usually takes it about half an hour for the light to come up to full brightness.
I used a J201 as per the schematic to work with the ultrabright blue LED.
The indicator light never gave trouble before.
The pedal seems to work fine. I power the unit with an 18V danelectro power supply.
Only thing I can think of is perhaps the 100uf electro cap could be giving out. Any other ideas?
You may want to try subbing a different FET, a different J201 or perhaps try a 2N5485.
If the LED is turning on slowly (although a half hour is extreme), it may be that the diode that connects between V+ and the FET gate is not "leaky" enough, keep in mind the reverse leakage is what turns on the FET.
Thanks for the reply, Scott.
I'll try those suggestions. It's kind of funny in that it takes a long time to light up at first, but later it comes on instantly. Lately I turn it on when I'm setting up for a gig and after I get my rig set up, I leave it on while we set up the PA.
However, if there's a period of several songs where I'm not using it, it comes on kind of dimly before coming up to full brightness.