need help reading schematic

[snz728]

what is the VB+ on the neutrino schematic?

I desoldered some wrong parts on mine, lost the pads, and now am soldering points directly together and  it doesn't work so I'm debugging with an audio probe but don't recognize this symbol.

Thanks for any help or advice in how to debug with an audio probe and schematic.

[gtr2]

VB is the used as a reference voltage point after a voltage divider.  In this case from the power supply section in the upper right of the schematic.  It's not an actual pad or component, it just makes the schematic much easier.

So, for example the VB side of R2 on the schematic is connected to the positive leg of c8 and the VB side of r10 and r9.  c3 (via the vb) is also connected to c8, r9, r10

Hope that makes sense...  It's hard to put some things into words.  If you need help with the exact areas you can always post pics or just draw in paint on the pdf file and we'll do our best to help out.

Josh

[snz728]

Thanks Josh,
I appreciate the help
let me see if i can figure this out now

[gtr2]

Ok cool.  If you need anymore help just refer to the component via the schematic (ex. c3) and I'll do my best to help.

Josh

[snz728]

I need some help because I am going from debugging to bugging out of my mind with this neutrino.  I don't have much experience so any help/advice you can give will be helpful. 

I used red to mark the schematic where the audio probe produced sound and yellow on the pcb layout.  I included a picture of my board, schematic and pcb layout in this document.

I removed C5, C3, R3, and R5 and lost the pads so I soldered the new parts point to point and then soldered R2 to R10 thinking that would help and Vol2 to Out.  The red stuff on the board is marker.
I need some help because I am going from debugging to bugging out of my mind with this neutrino.  I don't have much experience so any help/advice you can give will be helpful. 


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[gtr2]

If you could be a little more specific that would help.  What sound are you getting at lug 3 of the volume pot?  Are you getting the desirable overdrive guitar signal there?  If so then there is a problem at the volume pot.

Josh

[snz728]

I just hooked my audio probe up and had the kids strum.  The output at Vol3 is weak (but may be distorted I'm not sure it's so quiet).  I put the amp volume up to 7 and it is a weak distant sound compared to the strong sound that comes out of the IN, C1, or R1

[snz728]

have sound now
volume and tone work
new problem : no distortion, it's the same as the clean signal

anyone have an idea??

[gtr2]

can you show all the wiring?  pots, switches, & jacks

Josh

[snz728]

no sound again

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[gtr2]

Can you be more specific.  It's hard for us to help unless we have all the details.  Are you talking about no sound at the output jack?  What about the audio probe?

It really sounds like you have a couple intermittent solder joints in your build.  You could try retouching up all the joints in your build and report back.

Josh

[snz728]

Thanks Josh, I have LED, bypass signal, and the audio probe sound varies in strength (strongest at the Input to a whisper at the VOL3)

I had a moment where I had clean output when the effect was engaged but that might have been a loose wire on the switch that broke loose from twisting around.  When I resoldered the wire I have no output only LED and Bypassed signal.

I am going camping today through the weekend and maybe thinking of reheating all the joints on the board when I get back Sunday.  Does this sound like a good idea?? 

[gtr2]

If you haven't left yet.  Can you give us the IC voltages for each pin?  Sorry I should have asked for that earlier in the thread.

Josh

[snz728]

IC voltages (using a 9v battery if that matters) are:
1=4.4
2=4.4
3=4.4
4=0
5=2.2
6=4.4
7=4.4
8=8.9

[jkokura]

Instantly pin 5 makes me curious. That should be at 4.4 like the rest. Check things out and see if there's a bad joint or bridge around that.

Jacob