negetive ground prob

[clamup1]

i started out using this schem


then i found it it was for npn. i am using ac 128's that are supposed to be picked for fuzz faces
i was then shown a schem from scruffie that switched around two of the resistors and hooked the black wire to the sleeve of the in jack.

i have a ? about neg ground wiring.  with the rest of the offboard jacks do they hok up the same as when you hook up  the red wire to the 9v+ on the board. 

[Scruffie]

Wire it with the Diagram Posted and like this -


Make sure the Electrolytics and transistors are orientated as shown in that diagram, not in the one you posted.

http://www.generalguitargadgets.com/diagrams/switch_lo_3pdt_tb_dcj_pnp_gi.gif?phpMyAdmin=78482479fd7e7fc3768044a841b3e85a

You cannot use a Normal Negative Ground Power Supply for the DC Jack.

[clamup1]

thanks scruffie. i etched the board from fuzz central
http://fuzzcentral.ssguitar.com/fuzzface.php

im still having the same prob. different set on trannies(still ac128) i was thinking i have something not wired right. ill check again

oh and are the 1n4001 and the 1n4003 compatable? i checked a data sheet at mouser and it listed 1n4001-1n4007. so i guessed they were compatable. the 1n4003 just has a higher volt rateing

[clamup1]

substitutions- 1n4003 for 1n4001, 1m for 2m2, 20k res for 10k trim pot

numbers:
1m- -4.1
2.2 uf  -4.1
q1 e 4.1 b 4.1 c 4.1
22uf -0
100uf  -133.8
1n4003 -133.1
100k -11
33k -12.7
470r -127.5
.01uf 0
20k 127.3
q2 e -10.9 b -12.5 c -29.1
the dashes arent seperators they are neg

[petemoore]

numbers:
1m- -4.1
2.2 uf  -4.1
q1 e 4.1 b 4.1 c 4.1
22uf -0
100uf  -133.8
1n4003 -133.1
100k -11
33k -12.7
470r -127.5
.01uf 0
20k 127.3
q2 e -10.9 b -12.5 c -29.1
  I figure 'numbers' to mean pin voltages such as the 3 x 4.1 readings of Q1 pins e/b/c. If this is the case check for shorts between the pins.
  If this is an NPN Neg. Gnd circuit, connect the black wire to ground and all the - readings invert to+ readings, even though it is only a 'distance measurement', it helps to assure that the circuit polarity is correct, with black DMM lead to Gnd. in Neg Gnd circuit, all the readings should be + from there.
  Now, reading further...not sure what we've got here, the pin voltage measurements and battery [the battery is the reference point by which all the pin voltages refer to, ie necessary to equate where they sit-of-supply in order to analyze the bias. So...29.1 doens't make sense as a battery voltage, and ask what does ''numbers'' refers to?

[GP]

With respect to the fuzz central layout...

1. You should reverse all of the electrolytic capacitors 22uF, 2.2uF & 100uF.
2. The diode 1N4003 (that you used) should be reversed also.
3. Reverse the + and - leads from the power supply/battery

A 20K resistor instead of the 10K trimmer is going to make it very difficult to bias the transistors so you really ought to get yourself a trimmer.

If you have trouble after this, post voltages again but it's quite important you let us know the units... to paraphrase pete "29.1 what?". I think you mean mV here.

[clamup1]

With respect to the fuzz central layout...

1. You should reverse all of the electrolytic capacitors 22uF, 2.2uF & 100uF.
2. The diode 1N4003 (that you used) should be reversed also.
3. Reverse the + and - leads from the power supply/battery

this schematic is supposed to be pnp. do i still need to switch the caps and the diode?

petemoore

ive seen lots of people post their numbers and they never had wacked out numbers. but thats what i got so i put them in. my pedal sounds gated and you have to turn the guitar and amp up all the way. so my noob gut is telling me something is either wired wrong or like GP says ive got the caps and the diode in wrong. but why would the schem tell you to put them in like that if it was wrong. the schem is posted as pnp neg ground. i did read RG's debugging page. putting the meter to a board for me dosnt do any good b/c i dont know what the numbers mean. ive never read up on any of that. any good links on that?

ill switch out the caps and the diode. see what that does

[clamup1]

hey switched the caps around and it sounds great. still have the vol prob though. thanks GP

[petemoore]

  too sketchy for me to comment intelligently.
  I don't actually see a schematic, battery voltage [or supply, meausred], nor the type of transistors used...perhaps I got bored searching through the 'stuff' and missed these important points.
  Numbers can mean anything, pin voltages is what we can use.
  The 29.x voltage doesn't look like a supply for a Fuzzface or it looks like the meter is mis-reading or reading something else. Set the meter to 20vdc, and use a battery to test the meter, with the probes across the battery +/-, something in the ballpark of 9v should appear in the readout panel.
  Connect the black lead to ground using a testclip or hold it there, set the DMM for 'continuity check' so it beeps when the probes touch eachother, it should make a beep when touched to any point marked ground, nowhere else [especailly V+, if it connects to V+ don't apply power supply until the short is found and eliminated].
  Measure battery, connect battery to circuit [should be very small or undetectable voltage drop]. With the black lead on ground, measure every transistor pin, these voltages will all be no greater than the supply voltage or <9v.
  Post the voltages.
  This is all in the debugging thread, how well the instructions are followed = how effeciently the debugging proceedings go.

[clamup1]

thanks scruffie. i etched the board from fuzz central
http://fuzzcentral.ssguitar.com/fuzzface.php

im still having the same prob. different set on trannies(still ac128) i was thinking i have something not wired right. ill check again

oh and are the 1n4001 and the 1n4003 compatable? i checked a data sheet at mouser and it listed 1n4001-1n4007. so i guessed they were compatable. the 1n4003 just has a higher volt rateing

ill see if i can find continuity and see if my mv's have changed.

[clamup1]

heres my board

 

[GP]

I must apologise! Your original post and subject confused me somewhat - i thought we were trying to do a negative ground conversion (this isn't a good idea anyway).

Thanks for posting the pictures. they're a little bit small but they help a little bit to see what you've done.

First off, reverse all those electrolytic caps again...they are now oriented incorrectly...hence my apology.

With respect to the layout on fuzzcentral:

1. The black battery lead should go to "-9V" and the red to "Grounds"
2. Disconnect all of the wires you have (far too many) from the sleeve of the input jack and just run a single wire to "Grounds".
3. From the fuzz pot, disconnect either the yellow or black wire and just run ONE of them to "Grounds"
4. Run the black wire from the output jack to "Grounds"
5. Run the yellow wire from the the level/volume pot to "Grounds".
6. I can't see the diode very well in your picture but the silver band should be pointed north as we view the board in your picture.

This should now "work"... how well it works depends on the setting on the trim pot.

Do please follow Pete's advice and, if you have further problems, post some (meaningful) voltages. In particular, the pins of the transistors. To do this, place the +ve (red) terminal of your multimeter on one of the "Grounds" pads and use the -ve (black) terminal to connect to each pin in turn.

[clamup1]

thanks gp. i was looking at the fuzz central layout and that makes sense. the pos hooked to ground goes to the pos of the caps and the diode. black wire of bat completes the circuit.

[GP]

yes... sorry for the confusion earlier! you really don't want to connect electrolytics the wrong way round.

i guess the markings on the fuzzcentral board could be a little confusing: "-9V" is indicated that way because the positive terminal of the battery is your "ground" and therefore the negative terminal is referenced to that, i.e -9V.

Do let us know how you get on. If you do have problems, it would really help us if you follow the "DEBUGGING - What to do when it does't work" thread. Some bigger photographs would also help perhaps - both component and solder side of the board.

[clamup1]

thanks for your help. it works good. one prob is i have a 10k L hooked to the fuzz with a 4k7 to drop it to 2k. i know its wrong i dont have any 1k A. i get really good fuzz that last 2 percent of the pot. i dont know with the wrong pot if there is anything i can do. i have messed with the trimpot. i guess ill have to wait until i get some 1k a.

there is nooooooooooooooooo way that should be an intermediate pedal build good grief.

other than the pot thing the angels are singing with the mormon tabernacle choir. the sun is shining and skittles are raining from the heavens. thanks again