Grand Fromage build (and thanks to R.G.)

[mrsage]

Well, I just finished my Great Cheddar / Big Cheese build, and it sounds awesome. The build itself actually wasn't all that difficult...just a high part count to keep track of.

The debugging process is always a pain, so I wanted to extend my thanks to R.G. for his sticky. Although I usually follow the exact same debugging process each time I build something, it definitely helped to read through it anyway just to calm myself down.

I was getting weird voltages at pins 2, 3, and 6 of my TL072 opamps. One of the opamps was okay, but the other was way off. So I went through methodically and found a bridged trace that I had missed before. It was so neat and tidy that I had originally thought it was part of the PCB!

So I went back to my multimeter and....

...Now both TL072s had even weirder voltages!

The voltages at Q1 and Q2 were as they should have been, but the opamps weren't getting the right readings. I tried replacing one or two key capacitors, but to no avail.

So I sat back, took a break, read the Sticky, and decided to use the "search" function before posting. I read all about others' problems, but they weren't quite the same as mine. Then someone asked what they could substitute for a TL071 in this circuit.

Dammit. Classic me.

I was using the wrong kind of opamp from the start. Sure enough, when I replaced the TL072 with an LM741, everything got the proper readings. Plugged it in this morning, and there's sweet, cheesy fuzz!

So all this is mostly to say thanks to R.G. for being so patient with us newbies in the past, and another word of thanks for taking the time to put together the sticky. It always helps to go through methodically and make sure everything is in order. (although it's a lot easier to run to the forum and post "HOLY CRAP!! I JUST TRIED MY CIRCUIT AND IT DOESN'T WORK!! WHAT DO I DO??")

:lol:

Thanks again!

(build pics below)
http://www.voxblues.com/guitar/cheesecase.jpg
http://www.voxblues.com/guitar/cheeseguts.jpg

[jmusser]

Yes, RG is the man! Whenever I get a chance, I like to extend my thanks to him and all the other people who actually know what they're doing for teaching us. I have huge amount of things to get a grasp on, but it's filtering in a little at a time because of the patience the gurus have with us along the way. He and Mark Hammer have posted a wealth of information which I collect in a binder and pour over to try to make sense of it all. The detailed description that RG gave of the Super Fuzz, and Mark Hammer's in depth descriptions on the characteristics of diodes were absolutely wonderful, and help to clear the fog a little at a time on what is going on inside these circuits. we appreciate you guys very much!

[Samuel]

tidy-looking solder bridges are a curse of trusting the PCB too much I spent days and days trying to track down switch popping in my trem. lune before figuring out i had bridged the leads of the output cap. d'oh.

[mrsage]

One last bump in case anyone wants to see the pics!

[airhole]

thanks! i almost missed it..

Yeah thanks to RG for his sticky... i betta go read it one more time!

[mrsage]

i betta go read it one more time!

Yep...once is definitely not enough...

[R.G.]

Thanks for all the kind words! I'm glad I can help.