Millenium Problem - Slow LEDs

Started by ClenchedTeeth, May 25, 2008, 04:36:03 AM

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ClenchedTeeth

Sorry if this has been posted elsewhere, I am sure I have heard of this problem before but I couldn't find any mention of it.
I just mad a dual SHO/2in1 clone and used two millenium 2 circuits for the LEDs. It works as it should, except the LEDs turn on far too slowly (fades in over say 5 seconds), and the behaviour is exactly the same on both channels. I have checked the wiring/layout and parts orientation and everything. I've built the circuit many times before using the same veroboard layout and never had a problem. I'm using 2n7000 and a 2n3904 for the low leakage diode. I presume the 100k output resistance on the effect is enough to work with the millenium?
As I say, I'm sure I've heard of this problem before so if anyone wants to just link to an explanation elsewhere that would be a great place for me to start.

R.G.

The high leakage diode (1N914 or 1N4148) is not quite leaky enough. Put another one or two of them in parallel.
R.G.

In response to the questions in the forum - PCB Layout for Musical Effects is available from The Book Patch. Search "PCB Layout" and it ought to appear.

ClenchedTeeth

Thanks! Will try that tonight. Seems strange though since they are from the same batch as all the others that I have made, and I happen get two of them at once. Will report back.

ClenchedTeeth

Well, I came home and fired it up and the problem had disappeared. The LEDs are still a little slow to turn on, but certainly fast enough to be usable. This might be because I used a fresh battery however. I will report back if the problem pops up again.