n00b ALERT - PNP POSITIVE GROUND AND MILLENIUM BYPASS

[Renegadrian]

I know it can sound so n00b, but hey it's the first time I have this in mind...
Say I have a PNP positive ground circuit to put in a box - an ac128 FF
Say I want to use a DPDT with millenium2 (bs170) switching for the led...
So how do I have to wire it!? 

[Scruffie]

I know you're a vero users so is this any good to you http://www.aronnelson.com/gallery/main.php/v/TheBigMan-Layouts/mb.png.html?g2_imageViewsIndex=1

[Renegadrian]

THX man! Yeah I love vero! but For what I understood there is no way to use a bs170, I should go with a bs250...
I have some 170, but no 250...Else, I could finally use Millenium1 - that image calls a 2n3904 for NPN - so I believe a 2n3906 can be used on the PNP circuit!? I got some of them around...

[Scruffie]

Oh I didn't notice it said BS250... perhaps R.G can chip in with a better answer but I think it does have to be a P-Channel J-FET.

[frank_p]

Adriano, perhaps try this if you have trouble finding the semiconductor (?)

http://www.diystompboxes.com/smfforum/index.php?topic=71408.msg575926#msg575926
http://www.geofex.com/Article_Folders/Millenium/The%20Next%20Millenium.pdf

[Renegadrian]

Yeah I read that - so no way to use a 2n3906?! I have seen a Joe Davisson layout using 2n3904, so I guess its PNP brother can be used...

[petemoore]

  IIRC there are caveats to what the various LED bypass indicator switching does, the Mil Bypass article and Joe Davissons state what is required for the switching to occur.

[Renegadrian]

So any chance to use those frekin 3906 lying around?! 

[Renegadrian]

Maybe I have to try the upper part with a 3906...

[Renegadrian]

.

[Renegadrian]

yes it works, I made it!
I only had to put a 10M, and it works ok!

[Renegadrian]

obviously the transistor symbol is wrong, as it is a PNP

[Skruffyhound]

Good news man!
Only took a little over a year to build too 

[Renegadrian]

  well, I didn't need it anymore after I built that first PNP FF, So I just didn't care anymore. Now I built a four knobs fuzz (ggg) and the need resurfaced. I then tried it, 5 minutes assembling and minor tweaking and that's it! Strange nobody else tried and reported it! But may someone else need it, here it is!!! 

[profgoop]

I just built this for a pnp fuzz and I used a 3906 for the bypass and it works however it is very dim, and suggestions on how to fix that?

[Renegadrian]

Do you have 1k resistor to the led?!

[merlinb]

For what I understood there is no way to use a bs170,

I think this should work. Note the MOSFET drain is connected to ground.

[mateusborges]

Heyas!

Sorry for reactivaing such an old topic but this one is exactly what I'm trying... and failing!

I have a positive ground fuzz face built and tried wiring this millenium true bypass using 2N3096 as shown here but I'm just failing miserably, could someone please shed some light over this again?

Here's what I want
Only DC power, no battery.

How to do it?
Cheers!

[R.G.]

Use a P-channel MOSFET, reverse the directions of the diodes and the power supply connections.

The real magic, if there is any, is that a reverse biased signal diode leaks enough current to turn on a MOSFET.

Note that you can use a CMOS inverter IC as in http://www.geofex.com/Article_Folders/Millenium/The%20Next%20Millenium.pdf, which shows the positive ground variant in one of the diagrams.

[duck_arse]

I did this in a rangemaster-alike recently. the 1N60A is not a germanium. the 9k1's were on hand, you'd use 10k instead.