Wampler Black 65- No sound Doesn't work

[Strat68okc]

I built this with the vero layout on IVIark's blog. I have re-flowed all my solder joints and checked repeatedly (7 times) for solder bridges. As a matter of fact, I've run my exacto knife between the rails so many times I'm almost afraid they'll separate...I've checked the cuts at least that many times.

http://tagboardeffects.blogspot.com/2012/08/wampler-black-65.html





I had no 240k resistors so I used 220k's. The Treble pot is an A500k with a 12k resistor across lugs 1 and 2. I wasn't sure about that being correct but I tried it anyway. Mids pot is a B5k and the Gain is an A500k but its old and from my guitar parts bin. It measured out to be 493k actually. The 470uF is an axial lead one from RatShack, and its huge. I've got it flying above the board with insulation on the legs. Looks like crap really. The 1nF cap is recycled ceramic. The 10pF caps are tantalum and I'm not 100% sure the polarity is correct. Everything else is new Greenies from Tayda or new ceranics from RatShack. I almost forgot. There is no bypass. I intend to use it as a preamp, the switch is a 3PDT wired to the boost. My DPDT stomp switches haven't arrived as yet.

Battery is 10.01 volts
V+ = 9.76v
V- = 0

I've got a 10r bias resistor as per the layout.

FETs are j201 from Aron here, matched as best I could with my DMM. I seemed to have misplaced that sheet of paper though....

Q1
D=1.82
S=1.13
G=1.14

Q2
D=1.93
S=1.23
G=1.35

Q3
D=2.03
S=1.26
G=1.27

Q4
D=2.06
S=1.29
G=1.31

I'm lost at this point. I'd appreciate any help, this thing has me pulling my hair out. Not that I had a lot left to begin with. Sorry for the huge pics, I hoped y'all would be able to see them.

Brent

[IvIark]

Those drain voltages are very low.  What voltage are you getting at the bottom of the 10R resistor in series with the supply?

[Strat68okc]

Looks like .58 and .59 at the top. err. no. Sorry. 9.45v at the top and 9.39v at the bottom

[IvIark]

You've got the FETs the wrong way round

[IvIark]

Actually I'm not sure if you have, the whole thing looks mirrored.  Did you build it backwards to the layout or take a photo with a mirror?

[Strat68okc]

I swapped the FETs. I seem to remember doing that before... Oops.
Voltages are now
Q1
D=7.54
S=0.26
G=0

Q2
D=8.37
S=0.12
G=0

Q3
D=7.16
S=0.32
G=0

Q4
D=8.20
S=1.42
G=0

I suppose I could have built it backwards this is my first vero attempt. Everything else I used perf on. I had it lined up at one point. The cuts are all in the same places as on your layout. I think. I'm looking at it and the components that are supposed to be near the cuts are the same as the layout. Now I get a really loud hum, and I can hear it through my amp if I touch the board. Sounds a little like tapping on a pickup. Make sense?

[IvIark]

Yes if you've mirrored the components then the fets will definitely need to be the opposite way shown in the pic, and those new voltages, whilst definitely not right, look more like what you would expect.  Just for future reference, the layouts are always component side up and so the parts are laid out exactly as shown in the layout.  People often mark the track cuts on the component side first and then drill through, or alternatively if like me you turn the board over to cut the tracks with a drill bit, then the cuts layout needs to be mirrored from left to right to shown exactly where the cuts should go track side.

[Strat68okc]

Okay, so let me be sure I got this right. On your layout, the left hand image and the right side image are of the SAME side of the board? Left has components, Right does not, but its an image of the same side of the board?

I'm going to tear this one down and rebuild it. Its not like it was working anyway. Thanks for the help and the education.

[IvIark]

Yes.  I always include a bare board layout without components so that any cuts obscured by parts can be clearly seen.  But if you have to translate that to real cuts on the reverse copper side, then you'd need to mirror the bare board layout from left to right.

[kristopher612]

did you match your FETs to use those 5k6 resistors on the drian?  that's how wampler does it.  you should have about 4V there.  i built this on perf and biased using trim pots at somwhere between 4 and 4.5 V, and it sounds great. there was something said on the other forum about how to match them, but i didn't have enough to even try that, so i popped in some 100k trimmers

[Strat68okc]

Okay y'all its working. Sounds awesome. A Blackface Twin is one of my Holy Grail amps and this thing sounds pretty damn close. Its not as drivey as the demos but I like the clean just at the edge of break-up sound this has. The J201's are biased between 4.5 and 4.8 volts... Sweet. Thanks for the layout and the help IVIark!!!