Duende Booster Problems Part Deux

[modsquad]

Okay thanks to those that helped with the Schematic.  Now I have a quiet pedal with no sound when DPDT switched on.  I have the LED wired to the bottom legs of the switch.  That seems to work.  I have the jacks wired like this.

http://aronnelson.com/gallery/album18/DUENDE_JFET_BOOSTER_VERO

I am using the PCB and not the vero board.  Here are the volt readings I am getting:

Battery - 7.99
R1 - 2.84
C1 - 7.91
C2 - 7.91
Q1:
   D - 4.58
   G - 7.28
   S - 7.98

D1 - .44
VR1 - 7.99 In
         4.58 Out

Help...I am so close I can feel it. 

Thanks,

Stan

[modsquad]

Bump.

Could it be just a bad switch.  I am using one of the x-wing switches from hell.  I have some new ones on order.

[petemoore]

Q1:
   D - 4.58 
   G - 7.28
   S - 7.98
  Do the - marks mean negative voltage to ground?
  Assuming they dont...
  Source needs to be farther from ground than the gate with Jfets.
  G/S voltages are nearly at a supply rail, the bias needs attention.
  First tho, I would reference the data sheet pinout to the schematic to the circuit board,  Jfets are common source of miswire.
 

[modsquad]

Do the - marks mean negative voltage to ground?

   I am fairly new and still learning the electronics lingo...Not sure what you mean

Source needs to be farther from ground than the gate with Jfets.

   By that do you mean the difference in the voltages

First tho, I would reference the data sheet pinout to the schematic to the circuit board,  Jfets are common source of miswire.

   Are you referring to the J201 datasheet?

Stan

[Jay Doyle]

Check the pinout of the JFET. I'm almost certain that you have it wrong.

[modsquad]

As I am new to JFETs here is how I pinned the JFET

http://aronnelson.com/gallery/album32/DUENDE_JFET_BOOSTER_PCB

Looking at that orientation you would have:

   G---S---D

Is this not correct?

[modsquad]

I AM A COMPLETE NOOBIE IDIOT...After spending 2 days trying to debug this thing, I just noticed I have the diode where the capacitor should be and vica verse.

Geez

Stan

[Jay Doyle]

Stan,

Don't worry about it, there have been several projects, many more than one or two, where I have done everything and fired it up only to find out that there weren't any voltages anywhere. I never could understand what was going on!

Then I noticed I didn't have a battery attached.

We are ALL idiots.

Jay

[modsquad]

Actually switched them around but still no sound.  Its kind of interesting though when I play with the volume on the guitar the light dims.  Oh well back to looking at the circuit again.

stan

[QSQCaito]

Stan,

Don't worry about it, there have been several projects, many more than one or two, where I have done everything and fired it up only to find out that there weren't any voltages anywhere. I never could understand what was going on!

Then I noticed I didn't have a battery attached.

We are ALL idiots.

Jay

I had my blues breaker done everything perfect.. but wasnt getting any sound at all when activated i went very mad, revised everything.. the following day, that i was calmed, i realized i forgot to put the opamp

things need to be donde very calmly i have found.. i put one piece at a time revise it twice and solder it. 3 projects fired right up, and the 4th well, the bluesbreaker issue, as soon as i put the opamp.. my best pedal

sorry for the offtopic-ness

bye bye

dac

[Ed G.]

Stan,

Don't worry about it, there have been several projects, many more than one or two, where I have done everything and fired it up only to find out that there weren't any voltages anywhere. I never could understand what was going on!

Then I noticed I didn't have a battery attached.

We are ALL idiots.

Jay

Yep, I've done stupid things that eclipse that. Sometimes when you're focused on getting it to work you get tunnel vision and not noticing obvious things...

[petemoore]

  GEO has info on biasing Jfets.
  Yes I mean the source should have an idle voltage farther away from groung than the Gate.
  If you are using N channel Jfets, likely, so I assume you are, and connecting the black DMM Lead to Gnd/Neg., the voltage readings should be + [probably indicated by *absence of a 'pre' mark like +, - voltage readings would be marked by having a - line, pre to the numbers].
  I'd be going through and verifying the topology first [how the resistors and parts are 'mapped'], then test the Actual Resistor Values with the DMM.
  I hook to a place, verify all places it IS to be connected to, are in fact connected, also, while I"m there, I just randomly poke around with the other lead of the DMM, to verify *No Extra 'stray' connections from that point exist.
  I see the Jfet SBG connections on the layout, but no data sheet on the Jfets you are actually using, Jfet pinouts vary from one part # to the next.

[modsquad]

Thanks to everyone who helped out.  I now have a fully functional first project and it works as designed.   

Stan