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Well, I haven't been able to pinpoint the problem.  Not having a continuity checker on my DMM is preventing me from identifying where there might be an issue.  Going to get with my building buddy here in town on Thursday, he's going to bring his MM and expertise and help me figure out why this thing won't fire up properly.  Between the time I finished the build and started troubleshooting up to now, he's already built one from start to finish and it fired right up no problem.    Here's hoping he can help me get my working before week's end!

Here's another vote for the low-wattage Weller.  Guy on another message board shipped me one for free as he "can't stand the thought of someone using a Radio Shack soldering iron for PCB work."    I still have the Radio Shack one, usually reserve it for bigger jobs as it's a bit hotter.

[Love]

Dude.  Fantastic build, killer job.  Very impressed!  Love the etch job on the enclosure, and I'm also mega impressed with your wiring job!!  Clean, clean, clean! 

Pin 3 IC1: 3.43V is madbeans reading, mine was closer to 4V

Josh

Gotcha.  I should be able to get back to my office tomorrow and check on those points.  Thanks.

1.) Color bands look fully accurate. 

2.) What should the value be for Pin 3 on IC1?

3.) I'll have to consult my DMM's manual to determine how to get to the continuity mode, otherwise I'll look for 0.00. 

Thanks again, Josh!  Really appreciate the time you've been taking to assist me on this.

IC1 (TL072)
Pin 1: 4.78
Pin 2: 4.78
Pin 3: 1.24
Pin 4: 0.00
Pin 5: 4.60
Pin 6: 4.77
Pin 7: 4.76
Pin 8: 9.49

IC2 (TL072)
Pin 1: 4.86
Pin 2: 4.77
Pin 3: 4.73
Pin 4: -8.34
Pin 5: 4.71
Pin 6: 4.76
Pin 7: 4.67
Pin 8: 16.49

IC3 (LTC1044 - MAX1044 equivalent)
Pin 1: 9.49
Pin 2: 4.88
Pin 3: 0.00
Pin 4: -3.99
Pin 5: -8.34
Pin 6: 0.03
Pin 7: 4.76
Pin 8: 9.48

I also checked all the resistors between IC1A and IC2A, and all the values appear to be correct except for the two 68k resistors that are part of the DPDT switch: R28 is about 34k, and R29 usually goes to 0.00. 

Thoughts?

[same exact]

Yes, Josh, you are correct in that bypass mode sounds just fine and dandy.  I was afraid I may have ended up with a resistor that wasn't the right value.  The stock at my local shop tends to get mixed a little bit from time to time.  I do have a bookmark of a color band calculator, found it my first build as Smallbear doesn't frickin' label their frickin' bags of resistors.  

My solder joints all look pristine, but I'll go over them again.  I'll let you know if I find anything weird between those ICs!  Thanks, Josh!

BTW, just read this thread and it sounds like the same exact problem I'm having... but I've been over my solder joints with a fine-toothed comb!...

I'm highly intrigued by the addition of the blend control and wonder if it's something I could add to my MXR Dyna Comp as a mod...

If your voltages seem correct I think that the problem may be in IC1.  Try swapping in another TL072...  If that doesn't work at least you can rule it out...

Josh

I've already switched out all the IC's, so I don't think it's any of them.  I'll see if I can post IC values today, should have a bit of time to do that.

Thanks for being so thorough, Josh.  Send that Sunking my way!    Nah, I want to get my workin'.

I'm curious what the deal is with Lug 2 on Gain 2 and Lug 3 on Gain 1.  One thing's for sure, I'm definitely not getting anywhere near the right response when the gain pot is turned.  I just got back from New Orleans this evening, so later this week I should have the opportunity to continue checking the rest of the build with the audioprobe.  Just not brainy enough to know how the signal goes through the schematic and why it should respond in a particular way at particular points along the signal path.  Going to keep at it, will keep you posted.

Have you tried testing the pots that you are not sure about with a DMM? Then you can rule that out at least.

I did, but the one in question appeared to behave exactly like the other two, and the other two are working just fine.

Thanks, Josh.  Makes sense on those no-audio lugs. 

Didn't get a chance to continue testing with the audio probe today, and I won't for the next several days.  Headed to New Orleans with the wife tomorrow through Sunday.  Maybe the wonderful eggheads around here will be able to come up with a few different troubleshooting options that I can work through upon my return. 

Thanks all!  See you in a few days.

In your description above instead of top set, bottom set could you label it gain 1, gain 2 so we know what's going where.

Done, see updated reply above.

[LOVE]

Brilliant build!  Oh, and BTW...

I LOVE the Yip-Yips!!!

yip yip yip yip yip yip yip yip yip uh-huh uh-huh

Could you post a pic of your gain pot wiring?  It's hard to see in your previous pics.

josh

Not currently in a position to post a closeup of it, but I can describe it for ya in über detail if that's okay:  

Looking at the front of the pot with the shaft up and the lugs facing you, I've got from left-to-right as 1-2-3, color coded Orange-Green-Blue.  They attach to the board from the component side, but in reverse order as on the board it's labeled 3-2-1 from left-to-right (Blue-Green-Orange): top set of lugs connects to Gain 2 and bottom set to Gain 1 (this lines up with what I saw in other users' Build Report pics).

I quadruple check all my wiring and polarity during assembly these days as not doing so bit me in the butt on my first couple builds and forced me to disassemble numerous times.  However, now looking closer at the Gain 1 and Gain 2 wiring, it's possible that my wiring is only 90% accurate, but from what I can tell, I've got it wired exactly like the other builds I've seen in the Build Reports threads.