Wampler Pinnacle help

[mikestahlme]

Hi, I just built a Wampler Pinnacle from IVIark's blog here>
http://tagboardeffects.blogspot.com/2012/07/wampler-pinnacle.html?showComment=1352688177449#c4938724400783111757

I want to try and get more opinions on what the problem could be. If you scroll all the way to the bottom you'll see my comments.
Thanks in advance,
Mike

Just a run through of what I know so far...

For some reason as soon as I plug in the pedal the 10R resistor on the left side of the layout starts to burn up. I also get no sound when it isn't bypassed.
Mark suggested I replace the resistor with a higher value, and also to try omitting the resistor and moving the power supply three rows up on the vero. I tried both, using a higher value did nothing, and at least nothing got warm when moving the power up three rows. But still no sound.

I then realized I had confused the Volume and gain pots and had them filp flopped. I re wired them the correct way, tested it , and still the resistor gets hot, and there's still no sound. I tried Mark's suggestion and got the same results as before.

I'm afraid to plug it in to start testing voltages because of the burning resistor. So now I'm taking out the Jfets one at a time to see if I can get the resistor to not get hot.

Thanks again,
Mike

Note: I should probably mention I had a similar problem a few months ago while building a bluesbreaker project with mods to turn it into a KOT. I ended up just rebuilding the thing and it worked fine after that. I would really like to get down to what's causing the problem this time so I can avoid it in the future. This is my third build, first on vero/stripboard.

[PRR]

Power supply polarity.

Capacitor polarity.

Missing cut.

Use a 330 ohm resistor where the 10 ohm is. It won't burn-up with 9V. The circuit may not work (not enough information on that page to know what's what), but if you get dead-zero where you should have something, you know there's a short.

[mikestahlme]

I took out Q4 and it stopped getting hot when I plug it in....
could it be a bad transistor? or am I just getting closer to the problem?

the cap and power supply polarity is correct. I'm 90% certain I have all the cuts and jumpers in correctly.

[mikestahlme]

When put Q4 back in it doesn't heat up as long as the gain pot is disconnected. So I took out Q3 and re connected the gain pot. Again the resistor did not overheat.
I replaced Q3 with a new J201 and it started heating up again. I then replaced the the 100n(0.1uf) cap going from the gate of Q4 to the drain of Q3 and it still heats up.
The only other thing that I can think of is the two 1M resistors because they seem to be in the path from the 10R to Q3.

I'm still a noob at this so any suggestions are greatly appreciated.

thanks
Mike

[mikestahlme]

here is the schematic if that helps  http://....org/viewtopic.php?f=7&t=14966&hilit=pinnacle&start=40#p198689

[rockhorst]

Is the diode in the power supply part oriented correctly (with the stripe pointing away from ground)?
[Edit: I just noticed that the schematic does show the diode, but the layout doesn't, so that probably isn't the problem ]

[Pyr0]

I took out Q4 and it stopped getting hot when I plug it in....
could it be a bad transistor? or am I just getting closer to the problem?

the cap and power supply polarity is correct. I'm 90% certain I have all the cuts and jumpers in correctly.

Keep checking until your 100% certain. Assuming you have all the correct value components in the right places this problem is more than likely a short of some sort. Are you certain all the cuts really do cut the vero, make sure there are no hairline threads of copper still connecting a trace that is supposed to be cut. If need be, use a DMM to meter all the tracks and cuts out one by one checking for shorts between cuts and adjacent tracks.

Maybe post a photo of the component side and copper side of your build.
Transistor voltages would also help.

[mikestahlme]

I've gone through with a multimeter and tested to see if any track cuts weren't complete. Never hurts to double check though.
Just to warn you, about half of my solder joints are getting cloudy from heating them so many times: just making sure they aren't cold or taking parts out to test or replace.

IVIark suggested that I omit the 10R resistor and move the power supply up three rows. The circuit still doesn't work, but will my voltage measurements be accurate with that change? (I don't think it's a good idea to let the resistor sit there and go up in smoke as I test voltages! ha

I'll try to have a photo soon.

[PRR]

Use a 330 ohm resistor where the 10 ohm is. It won't burn-up with 9V

> will my voltage measurements be accurate

You are looking for ZERO where there should be some voltage.

[mikestahlme]

Ok I made up a 300R resistor and replaced the 10R with that. I tested on every single joint and track.

Here's what I found while testing:
The top and bottom tracks are ground so of course, I get 0
The track just above the bottom track is completely shorted.
Everything on the left of the track cut is shorted on the track just below the top track.

The only other place I get 0 is on the 9v power rail between the two track cuts, which I think is correct since there's supposed to be a jumper going there from ground.

[mikestahlme]

and here's a pic of the board.
https://dl.dropbox.com/u/54382528/DSC_1962.JPG

[Pyr0]

Run a knife blade or the edge of a small flat head screwdriver between the tracks to remove any possible lodged solder splashes. Set your DMM to the Ohms range and measure the two tracks to ensure there is no short.

[mikestahlme]

I don't have time to check it now, but just for educational purposes, why would there be the possibility of it reading 0 volts but not shorted when set to ohms?

[Pyr0]

Well just looking at it again, both sides of the track 2nd from the bottom goes to 3 and 6 of the boost switch, so depending on if the boost switch is on or off it will ground those tracks. So I guess that's not the problem.

I'm trying to tell from your picture which is top/bottom left/right. Have you reversed that image ? I could be wrong, but it looks to me like you put all the holes for the track cuts on the wrong side of the board i.e. you had the copper side of the board facing you and put the cuts in just like the layout. Did you then mirror all the components to the other side ? Normally vero board layouts are shown from the component side, so when doing the track cuts you have to reverse them.

[mikestahlme]

AH! I did not know that! I made the cuts exactly like the picture shows with the copper facing up (towards me). Then I built it so when looking at the component side, the 1k resistor that is on the right side of the layout is on the left side of the board. So yes I made all the components a mirror image of the layout picture.

This is my first time using a vero layout. I've only built two pedals before; one just by schematic and one on pcb.

Thank you so much! I have four more of IvIark's layouts lined up to build, this could have been a disastrous project!

[Paul Marossy]

I had a real Wampler Pinnacle once. It's a great sounding pedal if you like that kind of sound.

[mikestahlme]

Although, if my version is a mirror image shouldn't it be correct? And why would part of the second rail from the top get zero voltage?

[mikestahlme]

it appears that C16 (33n) isn't passing any voltage to contour 1&2. So far that's the only suspicious thing I've found. I think I'm just going to tear it apart and rebuild it the right way...

[Pyr0]

It's probably best to rebuild it - I would imagine that trying to mirror the components would be prone to error.

Also, capacitors block DC voltages, so you won't see any voltage on Contour 3 & 2.

Also, if you had taken voltage measurements of all the FET transistors and posted them it might have helped someone debug it.