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Smoothie and Pork Barrel not working

Started by Axe_34, October 28, 2012, 05:05:50 PM

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Axe_34

Hi all.

Got my Smoothie populated and on to the test rig.

It passes signal at unity volume (although a little thin -- there`s quite a bit of bass loss).

No phasing -- I'm using exactly matched 2n5952s. I tried both orientations with no effect. In fact, when I took one of them out, it was still passing signal unaffected. I also tried three different pairs.

Trim pot does nothing.

I only had one TL072 so I used it in IC1 and a TL062 in IC2.

I can hear a very faint clock noise when not strumming the guitar.

I`ve got C5 on a couple of flying leads because I want to eventually add the mod vibe to it.

Here are the voltages:

v: 9.17

IC1

1: 4.45
2: 4.45
3: 4.21
4: 0
5: 4.42
6: 4.43
7: 4.41
8: 9.18

IC2

1: 4.45
2: 4.43
3: 4.42
4: 0
5: oscillates
6: oscillates
7: oscillates
8: 9.18

Q1

1: 4.41
2: 4.42
3: 4.45

Q2

1: 4.45
2: 4.43
3: 4.32





All ideas and suggestions are welcome. Thanks!

Axe_34

My brain just fell out of my head. I thought I'd take a break and give the Pork Barrel a whirl.

SAME THING!! Signal passes through but no chorus.

I had almost a dozen straight builds with no problems -- including a Dirtbag Deluxe -- and now two duds in a row. I've double-checked the values, orientation and wiring. All correct. I've checked continuity and haven't found any sneak bridges.

Again, even when I pull transistors, the signal continues to pass on my test rig.

Using an audio probe, I can hear the clock noise on both of the boards and the LFO LED is working as it should on the Pork Barrel.

There's got to be bridges on both of them -- I can't find them and have reflowed both of the boards to no avail.

I'm stumped. If I wasn't already bald, I would've ripped all my hair out by now.

***Deep breath**



madbean

Pinout on the 2n5952 is opposite of the 2n5457, so you need to have those 180 deg from the package drawing on the silk screen.

Do you have any 2n5457s handy? What I'm thinking is just try sticking a couple of those (or J201) in there at random and see if any pair gives you any type of phasing at all.

On your trimpot---is it labeled "254"?

For your Pork Barrel--what type of BBD are you using and clock?

Axe_34

Yeah, I tried both orientations for the transistors on the Smoothie. Trim pot's 254.

I don't have any other transistors to use but I think I can get some locally today.

Pork Barrel's using the v3102 and v3207.

It just seems weird to me that both builds would end up with the exact same results:

1. Signal passes but no effect.

2. No effect from trim pot or even taking out transistors.

3. LED works on both.

4. Clock noise audible on both with audio probe.

GermanCdn

Not too ask the obvious question, but is there a chance there's a problem with your test rig?  Only reason I ask is I had a streak of vero builds a while back that went straight to the bin of fail for no real good reason, then I smartened up and traced my test rig and found that I needed to replace the output clip.  Box of fail emptied fairly quickly after that.
The only known cure in the world for GAS is death.  That's my story, and I'm sticking to it.

Axe_34

Welp, just threw some 2n5458s in the Smoothie and we have phase!

Looks like bad transistors.

I'm going to replace the 2n5088s in the Pork Barrel too and see what that does.

Thanks for your help!

Axe_34

Replacing the transistors in the Pork Barrel didn't do anything but I know I'm close. I can hear a throbbing hiss that changes pitch and speed when I turn the depth and speed controls. It sounds like a nice chorus trying to get out.  :D