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Author Topic: millenium bypass+ range control questions  (Read 7626 times)
sometimes_called_green
Posts: 19


millenium bypass+ range control questions
« on: October 14, 2003, 01:43:34 PM »

Hi Aron, The millenium bypass shematic says you can use any silicon diode, can you name some easy to find and working names of silicon diodes? or show us where and how to find these informations?
i assume that we are in the N-channel JFET version of the millenium byhpass here.

About the range control, is the pot linear or log?
i know these are dumb questions.. but that's why you opened this forum right? :roll:
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aron
Administrator
Posts: 10226

Aron Nelson


Re: millenium bypass+ range control questions
« Reply #1 on: October 14, 2003, 02:51:37 PM »

Quote from: sometimes_called_green
Hi Aron, The millenium bypass shematic says you can use any silicon diode, can you name some easy to find and working names of silicon diodes? or show us where and how to find these informations?
i assume that we are in the N-channel JFET version of the millenium byhpass here.

About the range control, is the pot linear or log?
i know these are dumb questions.. but that's why you opened this forum right? :roll:


I used the typical 1N914 or 1N4148 diode, found everywhere.
The FET, either MPF102 or J201.

Here's a great picture of the millenium:



The range control can be either linear or audio, but I used linear.

I haven't tried the range control myself, but I will.
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sometimes_called_green
Posts: 19


millenium bypass+ range control questions
« Reply #2 on: October 15, 2003, 11:06:59 AM »

This is really great!!!
thanks Aron,
another thing.. is there an intelligent way to do wiring, i mean, this is really messy, how do you clean things up?
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Jake5
Posts: 1


millenium bypass+ range control questions
« Reply #3 on: October 15, 2003, 12:43:12 PM »

I might have missed something but since you have kind of touched on it here, there is some terminology I'm not to familiar with.
What exactly is a JFET? I'm totally lost when that guessed tossed around.
Thanks
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Play it like you mean it.
aron
Administrator
Posts: 10226

Aron Nelson


millenium bypass+ range control questions
« Reply #4 on: October 15, 2003, 01:01:05 PM »

Quote from: sometimes_called_green
This is really great!!!
thanks Aron,
another thing.. is there an intelligent way to do wiring, i mean, this is really messy, how do you clean things up?


Yes, it does look like a spider when out of the box.

The reason to use pre-tinned wire or solid core is that once it's in the box, you can bend the wire to make it look neat and it will stay.

Once you have a consistent method of putting things in a box, it starts looking neater and neater. Remember the basics:

Input and output wires as far apart as possible. Keep crossing wires at right angles (if possible).

All that being said, you can get away with a lot.
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aron
Administrator
Posts: 10226

Aron Nelson


millenium bypass+ range control questions
« Reply #5 on: October 15, 2003, 01:03:09 PM »

Quote from: Jake5
I might have missed something but since you have kind of touched on it here, there is some terminology I'm not to familiar with.
What exactly is a JFET? I'm totally lost when that guessed tossed around.
Thanks


Think if it as just a different type of transistor.

Instead of the usual collector, base and emitter pins, you have Drain, gate and source.

In many ways, it acts (and some say sounds) like a "mini tube".

It delivers a tube-like tone (pentode-like) and can be used for amplifying or switching etc....

http://www.americanmicrosemi.com/tutorials/junctionfet.htm
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sometimes_called_green
Posts: 19


millenium bypass+ range control questions
« Reply #6 on: October 19, 2003, 01:27:47 AM »

I went to my local store yesterday, and they don't have any FET i wanted, i'll have to try to find these from another way.
I added the range control mod, and it works fine,
then i tried to wire the switch. i saw that gus smalley's bluesbreaker shematic shows a dpdt with a led + resistor in series,as a led circuit. so i tried to wire my switch like this.
it actually works, but the led lights up when the effect is off.. what did i do wrong?
i'll do the millenium bypass as soon as i can get my hands on some FET..

would the bluesbreaker be a simple enough projet? there's only one op amp, and lots of the parts can be monted on the pots, it seemed quite easy to me.(but my opinion is surely not the best...:? )
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aron
Administrator
Posts: 10226

Aron Nelson


millenium bypass+ range control questions
« Reply #7 on: October 19, 2003, 02:11:11 AM »

I only know how to wire up things with either DPDT and Millenium ( or other variations) or 3PDT.

I haven't had time to try othe methods.

Good luck finding a FET.
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sometimes_called_green
Posts: 19


millenium bypass+ range control questions
« Reply #8 on: October 26, 2003, 11:33:04 AM »

Hi Aron, i finally got some 2n5457, i buildt the mill bypass circuit, and wired it, the problem is: the led never stops working.
i checked the wiring and soldering seems good.
i used the standart pinout from the faq.. maybe the 2n5457 don't have the same pinout..
i didn't used socket, do you think it could happen because i burned the fet?
how can i check this? thanks
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aron
Administrator
Posts: 10226

Aron Nelson


millenium bypass+ range control questions
« Reply #9 on: October 27, 2003, 01:31:07 PM »

You go find the pinout by using google and searching for:

2n5457 datasheet

Did you try a larger value resistor?
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sometimes_called_green
Posts: 19


millenium bypass+ range control questions
« Reply #10 on: October 28, 2003, 03:48:56 PM »

Hi aron, thanks for your help..
i found the 2n5457 datasheet, the fet was wired backwards..
i am now sure it is in the right direction, but it still doesn't work..
when it was backwards, the led lighted brightly , now that the fet is mounted right, it still doesn't switch off, but the led gives a really weak light..
i don't know what to do. i checked the wiring and it seems right to me, i can't see any bad soldering or misconnected elements.

i think i will desolder everything, and mount the bypass again from zero. after all, it's fun...Cheesy

if you have an idea about what the problem could be.. i'd appreciate any advice.. :wink:
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aron
Administrator
Posts: 10226

Aron Nelson


millenium bypass+ range control questions
« Reply #11 on: October 29, 2003, 01:42:21 AM »

That's strange about it not shutting off. Did you connect it like the diagram shows in this forum? Perhaps something's wrong with the connection on the switch?

As far as the brightness, yes, that's the only thing about the Millenium, you have to match the FET with the LED. You might want to try different LEDs with the circuit.

That's why I use 3PDT switches now. Since they now cost less than what I used to pay for DPDT, I use 3PDT now.
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sometimes_called_green
Posts: 19


millenium bypass+ range control questions
« Reply #12 on: October 29, 2003, 02:13:56 PM »

I desoldered the control wire, and it switches off when i put it directly to ground.

Here is how i understand the mill bypass:
when theres no current at the gate, the led switches off, when there is current, the led lights up..
that's why i tried to touch the ground with the control wire..
but it seems to me it isn't what we are doing with the switch wired the way everyone says it works.. i think there's something wrong in my comprehension somewhere..
i'll have to learn a little more before having a clear understanding of what happends i guess.

anyway, even when i wire everything correctly, it doesn't work..
i'll try to build a new mill bypass this weekend..
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aron
Administrator
Posts: 10226

Aron Nelson


millenium bypass+ range control questions
« Reply #13 on: October 29, 2003, 04:13:20 PM »

Quote
I desoldered the control wire, and it switches off when i put it directly to ground.


OK, what this means is that your mill 1 is working fine. It's your switch connection.

Can you measure from ground, the resistance of your switch lug when the circuit is bypassed?
Thanks,

Aron
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sometimes_called_green
Posts: 19


millenium bypass+ range control questions
« Reply #14 on: November 07, 2003, 10:36:54 AM »

Hi aron..
i rebuilded the mill bypass, and fixed the bright problem.. the led is now bright when it lights up.
and i resoldered the switch entierely,
but the led still doesn't switch off.
i measured 4.4 Kohms between the control lug of the switch and ground. with the circuit in bypass mode
and 4.6komhs when not bypassed.

There's something i don't really understand in the wiring. i thought the led would switch off when the control wire was wired to ground. but the wiring shows the control wire going to nothing or to the output of the circuit.
i guess there's no difference between the two, but mi mill bypass definately seems to need ground to switch off, and nothing else..
could you explain this to me?
and have you got an idea to fix it?
thanks..
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aron
Administrator
Posts: 10226

Aron Nelson


millenium bypass+ range control questions
« Reply #15 on: November 07, 2003, 01:40:19 PM »

Quote
i measured 4.4 Kohms between the control lug of the switch and ground. with the circuit in bypass mode
and 4.6komhs when not bypassed.


Something is still wrong.

When the circuit is engaged, the "change" line should be floating. So it should be infinite resistance.

When the circuit is bypassed, the "change" line should be grounded and have about 100K of resistance (the resistance of the output of the circuit).

hmmm.....
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sometimes_called_green
Posts: 19


millenium bypass+ range control questions
« Reply #16 on: November 08, 2003, 01:35:43 AM »

When the dircuit is bypassed, why should it be grounded?
i see the switch lug jumping to the central lug, witch is connected to nothing. and nothing is not ground to me..  i really don't get how you can obtain the conrtol wire to be grounded with a wiring like this..

Lets me explain what i did excatly to measure the resistances.
i first put the switch in bypass mode. but i found i couldn't measure the resistance with a signal coming in, and the battery, so i disconnected eveything. the the resistance between the control "leg" of the switch and ground was 4.4kohms. i pushed the switch then i found 4.6kohms.

maybe there's something obvious i haven't done.. i don't know..
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aron
Administrator
Posts: 10226

Aron Nelson


millenium bypass+ range control questions
« Reply #17 on: November 17, 2003, 12:44:14 AM »

well, take a look at R.G.'s picture:



To measure the resistance, put the black probe on ground and use the red to probe right on the switch.

You don't have to have input or a battery connected to measure the resistance.
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