Man O War, stuck. please help

[half_smith]

I posted on this in another category but the only responses I've had were to repeat my due diligence (reflow, check values, etc). If it turns out I did miss something I will kick myself, but honestly, I've got a half dozen working pedals (among my other electronics projects) and this one is just not playing nice.

Has anyone completed a Man O War (not dlx)?

I just can't find anything wrong with my build, it gets to the NE571N and just stops.

The voltage on the output (pin7) is 11.11v when it should be only 2.97v.

also voltages on Q2 are 12v, 10.75v, 10.4v and should be 11.71v, 2.96v, 2.39v (Q3, Q4 are likewise high on B, E pins)

All the other voltages seem within acceptable range, but the signal basically stops at inside the 571 and becomes a helicopter.

I've tried different OPAMPs, Transistors, and another compander, same result.
What else can I do?

Thanks!

[harryklippton]

This may not be helpful but when I get really stuck on a build, i set it aside and go on to something else so I can reset with a little success from something else. It gives me a much needed morale boost.

[half_smith]

thanks Harry
It's already been over a month this thing has been on the desk. I've had some fun in between working on my '68 Bassman and socketing parts in my Klon and MXR Dist+ getting really cool results XD

Also, as I mentioned in another post about this project, I don't think it is possible to fit in the enclosure as designed. I followed the drill pattern exactly and there is just no way that the DC Jack will fit, I had to start over with a bigger box.
Is it possible Brian just moved onto the DLX and there's something amiss with this design?

[Zerro]

Sorry, but the best way for such a problem is to visit somebody with oscilloscope, and to bring there printed schematics of circuit. To help by another way without sufficient chance to observe your "manowar" is very problematic. By the way, ICs are ok? I have schematic with NE570, not 571. It may be slightly different (pin 3 and 14).

[half_smith]

Aha! I had a breakthrough.
I realized that R18, R19 are a voltage divider affecting the pin7 of my bane. I tried many things, different values, etc.
Finally discovered the trace in the PCB was bad.

I actually had to jumper 2 different traces on the PCB that are on the layout but were not making continuity.
Either my usual very careful build style was too rough for the PCB or the QC on it was questionable.

I'm moving on to the next step and hopeful again!

[madbean]

Aha! I had a breakthrough.
I realized that R18, R19 are a voltage divider affecting the pin7 of my bane. I tried many things, different values, etc.
Finally discovered the trace in the PCB was bad.

I actually had to jumper 2 different traces on the PCB that are on the layout but were not making continuity.
Either my usual very careful build style was too rough for the PCB or the QC on it was questionable.

I'm moving on to the next step and hopeful again!

Sorry for the lack of response on my behalf. The last week has been consumed by getting this latest release out. Do you have the ability to post a very close up pic of the area where you think the bad trace is? I can cross check against the PCBs I have here. I do look at every PCB when I get them to ensure there are no obvious problems but it's not impossible for there to be an issue. Unusual, but it happens. I'll also check in on your other thread.

[half_smith]

No worries Brian! I may have been a little rough on some joints that I desoldered while debugging, and the pads just kind of lifted off the board, not something I've experienced with other pcbs (doesn't mean it's not my fault).
However the 2 spots near the NE570 (R18 to pin7, and down to C13) were never stressed, just not connecting for some reason.

I've got signal up to pin7 of the XVive 3005, but alas, it's not coming out pin3, 4 and the voltages are off on the 3005 and 3101... I'm digging in again to look at continuity over every connection in that area...

Is there another voltage divider up near the 3005 that would cause pin2 to be weak and 3, 4 to be super high?
Is it possible the voltage on the 3005 is a matter of the trimpots?
-something I read on another forum:
"As you trim the pin 7 "bias" voltage, pins 3 and 4 should follow, but about 2V lower. They are MOSFET source followers. The exact input/output difference depends on MOSFET threshold voltage, which depends on chip-maker and wafer processing." PRR