Sparkle boost build problem

[Hepcat]

Hello I was wondering if anyone could help me get this thing to work?


1. What does it do, not do, and sound like? 
    -- Doesnt pass any guitar signal even when effect is bypassed.

 
2.Name of the circuit = 
  --- Dragonfly sparkle boost

3.Source of the circuit (URL of schematic or project) =
  --http://aronnelson.com/gallery/album88

4.Any modifications to the circuit? Y or N
  -- No mods
5.Any parts substitutions? If yes, list them.
---No substitutions
6.Positive ground to negative ground conversion? Y or N
-- ?
7.  Voltage at the circuit board end of the red battery lead = 9.78
Voltage at the circuit board end of the black battery lead = 0

I have two differnt readings for the transistor, first with trimpot turned all the way up

    D=9.81
    G=.69
    S=9.81

next with trimpot turned all the way down

   D=8.97
  G=.68
  S=8.97

Any help would be much appreciated,  I have been at this all day,  I think its making me crazy .

  -Josh--

[Meanderthal]

 Look for a solder bridge or other short between the drain and source...

[Dragonfly]

Check your grounds.

Also...look for solder bridges.

AC

[Hepcat]

I was just checking the schematic and realized i used a 100k audio taper for the volume insted of a 100k log, could that be the problem? Also when i was opening the package for the.022 cap i scratched it with a razor blade    does that matter?--Josh--

[Dragonfly]

I was just checking the schematic and realized i used a 100k audio taper for the volume insted of a 100k log, could that be the problem? Also when i was opening the package for the.022 cap i scratched it with a razor blade    does that matter?--Josh--

NOPE...shouldnt cause the problems youre seeing with voltages...

you "likely" have a ground issue or a solder bridge...check for solder bridges with a magnifying glass.

also...did you make the proper "trace cuts" on the vero board ? (the places where you see a red square with a dot in the center)

AC

[Hepcat]

also...did you make the proper "trace cuts" on the vero board ? (the places where you see a red square with a dot in the center)

AC

When i made the trace cuts i counted spaces with the green side up and then cut out corresponding hole on the copper side , is this the right way? I also checked for solder bridges, i just scraped inbetween every row with a razor.   -Josh-

[Pushtone]

Are you using an isolated DC jack?

The aluminum box conducts ground.
The DC jack needs to be plastic or isolated from the box.

Does the circuit work when not installed inside a box, just laying out on the table?

[Hepcat]

 I am not using any DC jacks, this is the layout I used. [urhttp://aronnelson.com/gallery/album88/SPARKLE_BOOST_LAYOUTl][/url] . I originally had wired up the deluxe version but when it wasnt working and i looked at a messy pile of wiresand decided to start all over and just try the non-deluxe version, that didnt work either. I may just start over with a new board I dunno.  ---Josh---

[Dragonfly]

a coupe questions...

did you use a NTE458 ?  did you check the pinout ?  (flat side facing you is D-G-S)
or.....
did you use a J201 (flat side facing you is D-S-G)

did you double and triple check your grounds with a multimeter, verifying that they read 0 volts ?

also, when i do the trace cust, i use a 5mm drill bit...insert the point into the hole that i want to have a "cut" at, and twist gently by hand...its quick, easy, and removes the copper around the holes quite nicely.

AC

[MikeH]

You said it doesn't pass signal even when bypassed?  That could be an issue with your off-board wiring.  Double check how you've wired your jacks and switches.  Make sure you haven't soldered to the wrong lug of a jack.  I prefer to build the circuit first, then hook it up on my breadboard and make sure it works.  Then I solder in the switches and jacks.

[Hepcat]

Dragonfly, I used an NTE 458 i have it positioned so the flat side is facing the left side of board. I checked the wiring, maybe it is wrong . in the diagram where it shows the green wire, basically I soldered a wire inbetween bottom lugs of input and output then connected the wire from bottom left of the board to bottom lug of input then the wire from bottom lug of 100k pot to bottom lug of output, is this right?


Mike H I just got a breadboard for christmas and am still figuring out how to use it , thats a great idea prolly save you a bunch of headaches. know of any good breadboard tutorials?  ---Josh---

[Dragonfly]

Dragonfly, I used an NTE 458 i have it positioned so the flat side is facing the left side of board. I checked the wiring, maybe it is wrong . in the diagram where it shows the green wire, basically I soldered a wire inbetween bottom lugs of input and output then connected the wire from bottom left of the board to bottom lug of input then the wire from bottom lug of 100k pot to bottom lug of output, is this right?

USING THIS LAYOUT, the NTE458 will face to the left.

The green wire is GROUND. It connects to the ground lugs of the input and output jacks, lug-1 of the volume pot, and the bottom row of the veroboard.

if youre not getting sound in "bypass", check your switch wiring as well.

AC

[Hepcat]

Dragonfly, are the bottom lugs on the input and output jacks the ground?  I also used a 3pdt switch and just used the two outside lugs is that right?Maybe I have the switch oriented wrong its  a rectangle so wich side is up?  Thanks for helping answer all these basic questions ,its been a little while but I have built several other pedals most of them just worked right away . I have been trying to read here every day and learn as much as i can .... guess ill have to read more. The music stuff is taking over the house, my wife thinks im going crazy.    Thanks again ---Josh---

[Dragonfly]

Dragonfly, are the bottom lugs on the input and output jacks the ground?  I also used a 3pdt switch and just used the two outside lugs is that right?Maybe I have the switch oriented wrong its  a rectangle so wich side is up?  Thanks for helping answer all these basic questions ,its been a little while but I have built several other pedals most of them just worked right away . I have been trying to read here every day and learn as much as i can .... guess ill have to read more. The music stuff is taking over the house, my wife thinks im going crazy.    Thanks again ---Josh---

INDISPENSABLE READING MATERIAL ! 

AC

[petemoore]

Dragonfly, are the bottom lugs on the input and output jacks the ground?
  The jack ground...test for it using DMM beep mode, it's the lug on the jack that connects to the jack threads, also called the 'sleeve' connection..clip the DMM to a ground, test that all ground points [on schematic] connect.
I also used a 3pdt switch and just used the two outside lugs is that right?
  I'd check GGG for bypass wiring diagrams, I get lumpy trying to word it.
  Maybe I have the switch oriented wrong its  a rectangle so wich side is up? 
  Say you have a DPDT blue, each lug will have an 'eyelet' or needle threadhole, look through the threadholes on one 'column'...now 'north is north', if the eyelets are facing L/R, rotate the switch 1/4 turn.
  Not a bad idea to look at a DPDT wiring, then with DMM, chart what gets connected/disconnected when switch is hit.
  if you have
1  EFkt IN      Efkt out 4
2  InJack        Outjack 5
3  Bypass___ Jumper 6
  [if not you may have to turn the switch 1/4 turn and rewire]
  2/3, also 5/6 should connect when switch is 'one way', disconnect when hit, once...aslo and then 2/1 and 5/4 should connect.
  In bypass mode, signal goes in switch lug #2 from input jack, connects to lug 3, jumper and lug 6, lug 5 and out...it's like a wire from input jack to output jack.
  with switch in effect mode, input jack of course still soldered via wire to switch lug 2, but only goes to lug 1, throught and, out of the circuit to lug 4, which connects to lug 5 and the output jack.
  Hope this helps.
7.  Voltage at the circuit board end of the red battery lead = 9.78
Voltage at the circuit board end of the black battery lead = 0

I have two differnt readings for the transistor, first with trimpot turned all the way up

    D=9.81 [probably a minor typo, D can't be greater than supply V, 9.78
    G=.69
    S=9.81
  Source should be above Gate, this source is at same voltage as Drain, I would suspect/check for a misconnection between S/D using DMM beep mode, it looks like they may somehow have become connected. Source resistor...you should be able to read a 'small' resistance between Source and ground, see schematics value for source resistor.
next with trimpot turned all the way down

   D=8.97
  G=.68
  S=8.97
   I would apply that DMM every way, read resistor values, check connections, check where connections shouldn't be too, test all grounds, count number of connections at a node and verify them...the drain should be about 1/2v [IIRC this is a gain stage] the gate should be ...low...like 'near ground, and the source needs to be a bit above the gate [something like 1v or 2v from ground?

[Hepcat]

Wow , Thanks petemoore , that was a very informative post. Well I finally got it working I had the switch positioned the wrong way,  turned it i/4 turn and rewired and it fired right up, I just spent the last hour playing it  , its a really nice sounding pedal , cant wait till tomorrow when i can crank the amp. Thanks Dragonfly for designing a great boost , and Thanks to all who helped.  ---Josh---