millenium bypass

[mccready]

hi guys,

well, there goes a simple question..

the layout of 'millenium bypass' there are at www.geofex.com... u know.. looking at the board for top (on the side of the components), should the led be on the right side (as the layout, with the positive for right) or should it be on the left side (with the positive for left)?

www.geofex.com/article_folders/millenium/mill2bd.gif <-- layout...

thanks a lot of!

[zener]

Sorry, I really didn't get your question.

First, you're looking on the layout with the components in your sight. So, the led is in the right as what you see.

Are you going to mount the LED directly into the pcb of the millenium? I don't think so. :roll:

[mccready]

humm..

[mccready]

First, you're looking on the layout with the components in your sight. So, the led is in the right as what you see.

yes! that´s ok...

and I would mount the led directly into the pcb of the millenium... but now, I can see that it´s wrong, right? hehe
so, even if I don't mount the led into the pcb.. (leaving the led 'suspended' into the enclosure)...
what I really want to know, is if the pcb of the millenium - looking at the top -, stays just like the layout of geofex, or if the layout stays 'inverted' on the pcb?
(sorry about my english... I´m not a north-american)

thanks man!  

[zener]

Now I get it :wink:

When you're looking at the layout in geofex, you're looking into it as if the the pcb is transparent and you can see the copper traces underneath.

Just print the pcb layout as how you see it. I assume that you already know how to transfer the layout in a pcb.

The process of transferring the layout into a pcb will do the inverting or "mirroring" of the layout.

Once you you have transferred the layout in the back (copper side) of the pcb, you will notice that the layout in geofex was inverted or "mirrored". Since you will solder on the other side, you have to flip the pcb around, and there you go. The layout and the pcb with layout are now the same in orientation.

With that, all single sided pcb layout are done with components' side in perspective.

I hope that made it all clear.

[mccready]

thank you for the help zener!

I was mirroring the board before transferring...
now I made it right...

but two more question...
the LED just don´t turn off..

I´m using a resistor 4k7, a transistor C5492 and 2 diodes 1N4148.. is that right? Should it work?
and..
Is the positive side of the led, it what has that flat mark in the light? I will try to draw | )
where | is +
and ) is -

I hope that made it all clear!

[R.G.]

When you're looking at the layout in geofex, you're looking into it as if the the pcb is transparent and you can see the copper traces underneath.

Actually, the parts are mounted on the *copper* side of the board for the Millenium Bypass PCBs. These are the only board illustrations there that this is true for, and it's noted in the information in the illustration.

The parts *and* copper sides are up. There are no holes drilled in the board for leads to go through. This is "surface mount" with normal parts.

I´m using a resistor 4k7, a transistor C5492 and 2 diodes 1N4148.. is that right? Should it work?

The "C5492" is, I believe, a 2SC5492. If I remember my Japanese semiconductors, that's an NPN transistor. All of the MOSFETs have 2SJ- or 2SK- prefixes. So no, if that's an NPN transistor or a JFET, the circuit won't work.

Also, no, you cannot use two 1N4148's. The diode from +9 to the MOSFET gate must be a 1N4148. The other diode must not. Get an ordinary NPN bipolar transistor, cut off the emitter lead, and use the collector base junction for the gate-to-ground diode. You may also leave off the ground-to-gate diode, as it's a protective component, not needed for normal operation.

Finally, you MUST get the pinout of the parts correct. One of the most common mistakes in the Millenium 2 is to get the MOSFET backwards. That leaves the LED always on.

[zener]

I haven't used the millenium bypass before. From what I've known, there are two different diodes, one of which is 1N4148. The other one, I don't know. Also, it specifies a mosfet, BS170 or 2N7000 will work. The tranny you specified doesn't return any match in google.

This is the DPDT w/ LED circuit I've used a lot.


This only works if the pedal has a vol control. If there's none, there should be at least 1M (not sure about the value) resistor between the effect's output and ground (pulldown resistor, I think that's what they call it).

[zener]

When you're looking at the layout in geofex, you're looking into it as if the the pcb is transparent and you can see the copper traces underneath.

Actually, the parts are mounted on the *copper* side of the board for the Millenium Bypass PCBs. These are the only board illustrations there that this is true for, and it's noted in the information in the illustration.

The parts *and* copper sides are up. There are no holes drilled in the board for leads to go through. This is "surface mount" with normal parts.

Oh... :roll:  I didn't read that. Anyway, with only 4 components, I'll just go with copper side soldering. But it will work either way as long as the mosfet is in correct orientation

[R.G.]

I'll just go with copper side soldering. But it will work either way as long as the mosfet is in correct orientation

Yes, it will work either way as long as the parts get connected to the right pads. The hidden beauty of the single-side copper and components is that you can stick it to the box in some out of the way spot with double sided foam tape and thus add it to any effect easily.

[mccready]

I would never imagine that it would be solder on the same side of the copper...anyway it should work, because the connections are correct (as if it was really on the same side that the copper)
thanks for the info!

about that...

I´m using a resistor 4k7, a transistor C5492 and 2 diodes 1N4148.. is that right? Should it work?

well, I´m sorry
I typed wrong, I wanted say C549, the '2' in the end came out for my mistake! But at really, I used the BC549C... should it work? perhaps, that´s causing the fact of the LED don´t turn off...

other question!

I´m building the TS-808 (from the tonepad.com), the fx already is working! And sounds great! But to make him work, I put a jumper among two legs of the one transistor (2N3904)...then it worked! Is that normal?

I will try to draw / |-\
/|\ = the legs of transistor
- = 'jumper'

zener:
this 'led trick', should work in the ts-808 from tonepad??


thanks a lot of guys!

[R.G.]

well, I´m sorry
I typed wrong, I wanted say C549, the '2' in the end came out for my mistake! But at really, I used the BC549C... should it work? perhaps, that´s causing the fact of the LED don´t turn off...

No problem. I'm a self taught typist and I make lots of mistakes.

No, the BC549 will not work. The BC549 is an NPN bipolar transistor, not a MOSFET. The circuit requires a MOSFET. You *can* use the BC549 for the low leakage diode by clipping off the emitter lead. But it will not work for the main switch. Yes, that may be why the LED won't turn off.

Note that if you cannot find a suitable MOSFET like the BS170 or 2N7000, you might be able to use the Millenium 1. This uses a JFET, and the BFxxx series should work.