Millenium Bypass problem

[MmmPedals]

I built a Brian may TB from here http://www.generalguitargadgets.com/pdf/ggg_geb_bmay_sc.pdf?phpMyAdmin=78482479fd7e7fc3768044a841b3e85a
And used a Millenium bypass (1 Plus)  for the led. When I put the peal in bypass the LED starts off and slowly turns on. When the LED is not fully lit the boost pot will dim it when turned up.
Any idea what's going on?

[Mike Burgundy]

Could you show exactly how you hooked everything up? Connecting a Mil bypass to this schematic's output will not work - the Mil relies on some kind of pull-down resistor on the effect's output (most often the output volume pot, R3 here) but this is isolated for DC by the output cap C2 in the stock schematic. That said - the MIL1 does fade in the LED over a short amount of time when working correctly. That's just what it does - the Mil2 and C correct this.

[MmmPedals]

Hooked it up as I would to any other circuit. When the effect was on the light turned on immediately. then I would turn it off and the light would very slowly (30 sec?) turn on.
This was when it was plugged into the amp. Not plugged into the amp the light would fade on when the battery was connected and then would not go off.

I added a pull down resistor on the output and it works fine. any possible ill affect from the added resistor?

[R.G.]

The Millenium Bypass is a very sensitive detector of the difference between some real resistor (say, 1M or lower) and an open circuit.

It will not work right if there is no DC path to ground to turn it off. I believe that you had no DC path to ground and were seeing the very small current of the Millenium's bias charging the output cap. It started working right when you put a pull down resistor on it to satisfy the DC path.