Alllllmost finished with Small Clone build but having a little trouble...

[deadlyshart]

I agree with the 3007 being the problem. I have bought hundreds of chips from sellers with fine feedback that were fakes. Getting very tough to find real chips in China/Hong Kong/Taiwan. Do you have a pedal you can test one in? Good luck!

It would make the most sense at this point if it were the 3007. Something I actually haven't tried yet, that I should, is just powering it without any 3007 in the socket. As I mentioned above, the voltage after the 47 Ohm resistor (which should basically still be about the same as the input voltage) is often significantly lower. If the 3007 is causing this cause it's a dud, measuring that same voltage without it might give me info.

I unfortunately don't have another pedal I could test it in, all my pedals are DIY from here

I've now ordered these: https://www.amazon.com/MN3007-bucket-brigade-delay-socket/dp/B01MFC9Y51/ref=sr_1_1?ie=UTF8&qid=1483319857&sr=8-1&keywords=mn3007

which have the same markings (so could really be the same exact ones I got from ebay), but it's amazon which usually means a little more legit.

[Jdansti]

Hopefully the Amazons will do the trick. If not, I'll bet someone would volunteer to test a few of your chips in their working pedal. You'd have to mail them back and forth unless you get lucky and find someone in your area. I'd do it for you if I had a pedal that used the 3007.

[deadlyshart]

Sorry, but things got super busy for me. A quick check of IC, electrolytic cap, diode and transistor polarity looks good. The only thing that looks iffy is the damaged ceramic cap near the output, but it's most likely ok. The individual values of the two sets of parallel caps should summed to achieve the desired value. You probably did it that way, but just mentioning it for completeness.

If I can get some time tomorrow, I'll check the resistor values.

Regarding the MN3007, maybe someone who has a known working one can give you a good deal on it or swap it for something.

Hey, thanks for the check. You really don't need to check the res. values, they're most likely correct and I'll just do it myself. I was more curious if you just saw any higher level stuff I might be missing.

I think the 'damaged' cap (if it's the same one you mean) is actually just some sharpie ink on it, I just looked at it and it doesn't seem chipped or anything.

The two combined caps are the 180pF and the 2.7nF ones from the schematic, because I didn't have those actual values. They're made from (150pF + 33pF) and (2.2nF + 470pF), so slightly off, but very close (probably within their tolerance anyway).

I'll report back when I get those amazon ones, thanks for all the advice.

[Cozybuilder]

Time to bite the bullet and get a real 3007 from Small Bear, like John suggested in posting #12

[deadlyshart]

Time to bite the bullet and get a real 3007 from Small Bear, like John suggested in posting #12

I'll probably do that, but I'm just gonna wait a couple days until I find out whether these amazon ones are ok or not

[deadlyshart]

WELP!

Got the ones from Amazon this morning. Same "sigma" markings, though different production number. Popped the first one in, and lo and behold, it works beautifully. For future reference, it was these ones, that came in a weird little test tube:

https://www.amazon.com/MN3007-bucket-brigade-delay-socket/dp/B01MFC9Y51/ref=sr_1_1?ie=UTF8&qid=1483730453&sr=8-1&keywords=mn3007

$10 for 5. I wasted all this damn time because I skimped and bought shitty Chinese ones for $5 for 5. Let this be a lesson for posterity: if a given chip is relatively expensive everywhere else, and then you find a single really cheap source, chances are it's too good to be true.

Anyway it sounds amazing so thanks for the help everyone! I did a fun etching job on this one so I'll upload pics soon.

[Jdansti]

Yea! Glad you got it figured out and it works!

[deadlyshart]

Thanks dude. Sorry for wasting your time, when it was such a simple thing I should have tried earlier!

[Jdansti]

No waste!  I enjoy debugging. The answers aren't always obvious. It's always a simple thing when you figure out what the problem was. There are a lot of things that can go wrong. At least now you have a build that works and you can use it to test other 3007 chips if you ever use them again. I made a basic PT2399 reverb/delay and mounted the board on the outside of the enclosure so I could quickly test new chips to make sure they work since there were a lot of reports of bad PT2399s being sold. I look forward to seeing your end product!