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help debugging Man 0' War, bad IC? voltages seem high.

Started by half_smith, April 14, 2021, 01:05:56 PM

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jimilee

Quote from: half_smith on April 27, 2021, 02:05:56 PM
Haha thanks Jimilee.

I don't know how, but I think I have it working! I just swapped out the ICs again, different NE570, different 3101, different places, and started fiddling the trims by instinct... the probe inside the circuit is whiny, noisey, or no delay, but the OUTPUT SOUNDS GOOD.
I'm going to mess with it a little more, but I think it might be ready to go in the box. holy cow what a journey.
I'll report back, or share my Build Report in the next couple days.
Thanks for the support and guidance :)
Good on you. I went through some of this with the DMM pedal before I started over. While building the second I realized where I went wrong on the first one.


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Pedal building is like the opposite of sex.  All the fun stuff happens before you get in the box.

half_smith

Yeah, it's not quite right. I'm getting 1 nice sounding repeat, but the T1 trim or FDBK pot don't give me more repeats.
It's a huge relief to have anything coming out, but only a single repeat is kind of lame.

Any help with this?

Zerro

My advice now: if you made proper welding with sufficient amount of tin and rosin, clear now ALL PCB points around with sharp needle from dirt from welding. I found there problematic points as I showed below (red pointers). Do it at both sides of PCB for all points. Maybe your problems will dissappear. Good welding and clarity is important. And PCB controll from crackles.
"Nudíte se? Kupte si našeho cvičeného ježka! Pobaví vás svými veselýmí kousky!"

half_smith

I managed to think clearly on this, and since I had 1 single repeat and no feedback, I traced the feedback loop and found that the same joint I had jumpered earlier (R17-IC2p5), probably my damage to the pad, needed a jumper to C37 to connect the FDBK loop.
Did that and it totally works and kicks major ass. After tweaking on the trims for a while (I found that bal1 can be set for full self-oscillation btw)
It's good. It's going in the box.

Brian, thanks for your help, I didn't mean to assume the board was faulty, I was lost in hell.
In the end I had to make 4 jumpers due to somehow losing traces, I will assume due to my roughness, and had to swap out 3 questionable components. All in all made this a real study, and I actually think I understand this circuit now and that was my ultimate goal anyway.

I'll post a build report eventually eventually eventually eventually

jimilee

Wow man, nice job. I'm super impressed.


Sent from my iPhone using Tapatalk
Pedal building is like the opposite of sex.  All the fun stuff happens before you get in the box.

half_smith

So, I have been rocking the Man O' War for a few weeks, it's pretty cool, but there's a bit of "fuzz" or pfff on the first transient, the repeats are very clean. Any idea how I can clean up the initial note?

Zerro

Try to play around Bias and Balance pots. Maybe too high or unbalanced values are going to output compressor NE570.
"Nudíte se? Kupte si našeho cvičeného ježka! Pobaví vás svými veselýmí kousky!"