LPB1 from Tonepad LED is ALWAYS ON

[audioguy]

OK this is an odd one... Or maybe not... I don't know..
I built an LPB1 from Tonepad.com, didn't use the PCB, just used a blank board. The box sounds great but for some reason the LED is lit but extremely dim when not in use. When I kick it on, it lights up as it should, but when off its stays lit, again extremely dim.
So I built another, just for grins.. and now on the 2nd, the LED is solid bright all the time. This unit sounds great as well, but the LED is always lit. Then I rebuilt THAT one, on a new board, with new leads and a several new parts, but still its the same, always on solid.
At first I thought it might be because I wasn't using the prescribed FET in the milbypass, I was instead using... oh I don't remember exactly... but I researched it here and it looks like something that is a usable alternative to the suggested part.
Then I found where someone had wired the FET backwards, so I experimented with that possibility, and still get the solid LED.
I know this is an extremely vague posting, but can anyone offer up any suggestions?
Thanks!!

Audioguy

[Samuel]

What types of diodes are you using for Mill. bypass?

[audioguy]

Thanks for the quick reply!
Great question... I wish I could answer. The diode in the MilBP is the only thing I havnt tried swapping. These were my first builds, so I dont know exactly what I used. I'll have to look into it when I get home. On these 2 builds I will say that I went to a guitar/amp repair shop for my parts (where I got raped) and told him that I needed a 1N914 diode, but he didnt have any but gave me 2 that he said would work. They are not identicle, but agian, he said it would work.
I have since ordered a real 1N914 from Smallbear, should I try it out?

Thanks!

Audioguy

[Torchy]

GEO says to use a 1N914 and the C-B junction of any npn transistor.

[Samuel]

You need one 1n914 and one "low leakage" diode, for which I believe a 1n4001 fits the bill. Try and get your hands on these two - I've used them to build a mill bypass that worked for a circuit where Joe Davisson's "LED Trick" did not work (stayed bright the whole time). I think the diodes are the really key part of the mill. bypass equation, from what I've read of other people's experiences. (BTW - if you can only find 1n4002 or 1n4003 or something, I think these will work as well, they're basically the same as the 1n4001, jsut with higher voltage tolerance...) If you plan to stock parts as opposed to just buying what you need on a per-project basis, 1n914s are a good diode to stock up on as they are frequently used as clipping diodes and for other things...

[audioguy]

Shoot... no luck. I replaced the questionable diode with the recomended 1n914, nd Imgetting the same thing, solid LED.

Any other possibilities?

[Fp-www.Tonepad.com]

There is an error in the millennium part...

Change the 4k7 resistor to 2k2, remove the 22k resistor. Add a 4k7 resistor across the LED.

Also make sure the Gate of the FET is in the correct pad.

Fp

[audioguy]

AWESOME, let me try that! Any idea why the 1st one came out to function almost correctly?

[audioguy]

There is an error in the millennium part...

Change the 4k7 resistor to 2k2, remove the 22k resistor. Add a 4k7 resistor across the LED.

Also make sure the Gate of the FET is in the correct pad.

Fp

Im not sure I understand what you mean when you say add a 4k7 across the LED. Excuse my ignorance, but could anyone explain it to me in a little more detail?

Thank you all so much!

[Fp-www.Tonepad.com]

In parallel with the led.

Fp

[audioguy]

So what I need to do is put the 4k7 across the 2 leads to the LED?

Thanks again for all of your help!

[Samuel]

Yeah that's what he means, one leg of resistor soldered to one leg of diode, and the same on the other side. Like sitting next to each other and soldered together on each side.

[audioguy]

:cry:
No luck same thing. Solid LED.
I think I'll just rip ot the MillBP since I cant make it work. I guess I dont need an LED...
Its just so odd that he first one I built exactly as the PCB shows works fine.... extremely confusing.  :?
Thanks for everyones help!!

[Samuel]

When it gets to that point with something I'm building, I'll usually just start over from scratch. There's not too many parts involved, so it's not like you're wasting a ton of money...

[audioguy]

funny thing is... I did that already. But no biggie, its practice... and when it works, its fun!

[Samuel]

You've got a way better attitude than I do when I'm on the losing side of a circuit !