Blueshift chorus first not chorusing, then half-chorusing. BBD issue?

[PRR]

Whatever it is (two common organic acids in grease), it is not rosin. Sales/Safety sheets here:
https://termopasty.pl/en/produkty/solder-paste/    "Download"

[matopotato]

Whatever it is (two common organic acids in grease), it is not rosin. Sales/Safety sheets here:
https://termopasty.pl/en/produkty/solder-paste/    "Download"

Yes, I saw that too, in fact that is where I ended up first. But that product looks different from the one I have.
I assumed it was an update and then they might have tried to replace the rosin with something else.

Mine looks more like this one:



And there is says it is rosin based.

Anyway, for what it is worth, it smells really great. I took some resin from a pine or spruce I felled, just for fun, and used it on a joint for test.
And it kind of worked like rosin (where I think resin is one main(?) ingredient).
Although raw resin is not purified so I would not recommend anyone to use it for soldering.
But it smells the same.

And nice.

EDIT: Personally I rarely need to use it when building. Sometimes when desoldering some old TV or Radio or something similar, but rarely on the builds, so in my case, any rosin, resin, flux on my builds would come from the solder core I guess.

[matopotato]

To me this looks like Pb 60 Sn40 on the label upper left:



Yup, some googling confirms the article number.
Wouldn't that be even better than Sn60/Pb40 then?
Or can there be too much of the good stuff?
Anyway it is 2mm thick so OK for pots and switches I guess, but not the smaller stuff.

[PRR]

To me this looks like Pb 60 Sn40....Wouldn't that be even better than Sn60/Pb40 then?

The "good" (costly!) stuff is the Tin.
Tin: $27,000/ton, Lead: $2,100/ton

Electronics favors "eutectic" Sn63 Pb37: mostly Tin. It melts a bit cooler than any other, and freezes instantly.

Historically we buy "60:40" Sn60 Pb40 because a bit cheaper than 63/37. There is a slight "pasty" phase just before it freezes; motion here makes a "brittle, cold" joint.

Plumbers buy 40:60, more Lead than Tin, because they need a lot to fill pipe joints so they want cheep, pipes can stand the heat; also in older work they made "wiped joints" where they let the (80% lead 20% tin) wiping solder hover in the "pasty" phase and wiped it to fill gaps and make a smooth surface. (The 1910 poop-pipe in my 1830 house had a beautiful wipe job.) Before Bondo, auto body repair used high-lead 'solder' so it could be massaged into and over the dents; the 1966 Batmobile was one of the last of this craft.

We here do NOT want 40:60.

[matopotato]

To me this looks like Pb 60 Sn40....Wouldn't that be even better than Sn60/Pb40 then?

The "good" (costly!) stuff is the Tin.
Tin: $27,000/ton, Lead $2,100/ton

Electronics favors "eutectic" Sn63 Pb37: mostly Tin. It melts a bit cooler than any other, and freezes instantly.

Historically we buy "60:40" Sn60 Pb40 because a bit cheaper than 63/37. There is a slight "pasty" phase just before it freezes; motion here makes a "brittle, cold" joint.

Plumbers buy 40:60, more Lead than Tin, because they need a lot to fill pipe joints so they want cheep, pipes can stand the heat; also in older work they made "wiped joints" where they let the (80% lead 20% tin) wiping solder hover in the "pasty" phase and wiped it to fill gaps and make a smooth surface. (The 1910 poop-pipe in my 1830 house had a beautiful wipe job.) Before Bondo, auto body repair used high-lead 'solder' so it could be massaged into and over the dents; the 1966 Batmobile was one of the last of this craft.

We here do NOT want 40:60.

Thanks!
Will be passing that one over to the next plumber then.

[duck_arse]

as a great man once said,

"Should have breadboarded it first".

[matopotato]

as a great man once said,

"Should have breadboarded it first".

I usually try to breadboard, but there is a limit somewhere.
Not sure where I draw the line but something like the Blueshift is definitley on the "Breadboard it? Nah, I'm just gonna have to take my chanses on this one straight to PCB..."

Of course, mods and tweaks, put another option switch in there usually needs breadboarding to know what is worth the effort and not.

[duck_arse]

ahh, but, you see - the rule is breadboard the circuit, then use the parts off the BB, because you know they work. with a flinty big circuit, say, break it into blocks, breader an oscillator circuit and test all your opamps there. and there is some very basic bbd tester about, I think Kevin or Lacky. that way, you learn breadbord, you learn circuit blocks, mods, additions, parts, measures, oscilloscopes and what to expect where, all sorts of stuff.

all the time you waste on the breadboard is the time you save wondering what is wrong with the build, or reading my stupid troubleshooting blah blah blah.

[matopotato]

Thanks,
Yes, that is another thing I would have to learn: How to build a circuit in sections and how to verify if a section or block works as expected.
Any good reads on section/block testing?

[matopotato]

I finally got the spare 3207 and put it in place. All works!
I feel happy. I also have a new 2N5087 in Q8, so I cut its legs to fit.
I then take out the wires that connect the two boards together, but with some space apart.
And clean out the box.
There I find the "broken" old Q8 I replaced and decide to test it out, it turns out to be a 2N5088...
Aha, so I must have, as part of my errors managed to swap an 87 for an 88 and I find that in Q2 there is indeed a 2N5087 that should have been an 88. (Some were loose and I might have gotten them mixed up at some stage).
I swap.
And all becomes flat-line on the TPs. (with tone generator and scope).
So perhaps it was a bad 88 after all, and I put the "wrong" but working 87 back in Q2 since that constellation did produce a result at least, but still flat line.
I get some kind of interesting signal from input and to IC3 and IC9 pins 3, so signal seems to go in to those sections at least.

I will have to probe and go through a bit organized once I bounce back. (The happy feeling went away needless to say)
So Q2 (in the middle, high up in the schematics) needing to be an NPN, but was PNP for a bit, and the circuit still worked.
How can this be? (This is my main question in this post)

The Q8 having possibly been an NPN instead of required PNP did not seem to have affected the IC9 problem, since IC9 in IC3 position never worked either, so that IC did not perform even in proper conditions. (Of course it all interacts, so I could probably be wrong there too, can test again if I get it working).

Will let it rest a little before I start probing, but since it did actually work, I think it should be solvable although the circuit is a bit complex to troubleshoot.

[matopotato]

After some thought I suspect that the smaller board is not getting power. I never checked voltage last time, only signal.

Still I do not understand how Q2 being NPN or PNP seemingly had no impact?

[duck_arse]

what are the voltages on Q2 now that the correct polarity is installed? and how do they compare with your Q2 volts from page 1? it might be that the effect of the bum transistor was not noticed as such, but was there.

we often ask posters what transistors they have used in their non-functioning build, and, sometimes, they argue with us. tsk.

[matopotato]

I found a broken wire. A ground wire that went from signal In to the GND on the smaller board, middle down next to TR2.
I was suspecting first that 9V wasn't reaching the smaller board so I tested the RG1 and the values were too high and D8 wasn't grounded.
The wire had partially gone off the jack itself so I re-soldered it, but it was on the other side close to the PCB where it was failing.
Turns out the wire (a multi threaded one, not the single core type cause they break to easily for me.) had gone off 4mm in and the plastic kept it hidden and in place.
Never happened before. I guess all the testing over time wore it down. In a way happy it happened before boxing.
So I managed to get that fixed and could calibrate with the scope again.
Also removed the wires between the pinned contacts between the boards and still plays.
Now decal and boxing before I know if I manage to break yet another one close to the finish line or not.

About Q2: I didn't play with the wrong transistor in place, which I realize I should have to try it out. But I do not plan to go back and test that now.

With a 2N5087 in Q2 (faulty selection)
C=9.21
B=8.61
E=7.04

With a 2N5088 in Q2 (proper selection)
C=9.21
B=4.51
E=3.94

I can't tell if either would work or what effect that would have to the full circuit by looking at the schematics though.

So at some point I had managed to swap a 5088 with a 5087 (Q2 and Q8)
For sure having the wrong in Q8 made that signal path not work.
As I had found one 3207 was faulty, I kept moving the good one between paths but having the wrong Q8 in made that part not work regardless, until I decided to test with "another fresh" 5088 in Q8, which became "putting the proper one in", and then both paths worked and only the 3207 was broken.
(How and when that happened I will leave for now)

Still while Q8 was sensitive enough to stop that path when selection was wrong, the Q2 position didn't seem to mind which one it got.
A bit strange and the remaining unsolved part for me.

[matopotato]

Closure:
I ordered the kit from Das Musikding in late December 2021. I knew it would be a challenge, but wanted to set the bar high to see what I could accomplish (and not). And it was set high.
After the final fix described in the post above, I put it in the "ready for decal" queue. Then a few weeks ago I started the creative journey which for some reason feels like an uphill one for me. Not clear why, since I often get things as I want them.
Anyway, printed, water-slided, varnish-coated (despite a few near curls) I made final assembly today. Only to discover a thumping background sound when engaged in the mono out (second out was mostly ok). And it varied with the settings of the switches. There was also some scraping as if a wire had frayed and touched something.
The assembly is really tight and has to be done in the right order. A few "as short as it will allow" wires made by a guy who felt that was ok a few years ago, I now regretted that self-imposed additional challenge.
Still. Everything out again but problems persist. I pushed around a bit to see if anything wiggled, and apparently it did because it snapped into position and the crackle and thumping went away with it.
So assembly again, jack by jack, screw by screw with a new audio test between each step. And it kept obedient all the way. Tightening the last enclosure lid screw in and hearing that it still works was a huge relief.
Again thanks to anyone who helped me out during this long journey, couldn't have done it without your help, support and encouragement!

Purple Rain, here we come...

[tootsMcgee]

That design is dope! I love the spectra. Glad you got it working.

[matopotato]

That design is dope! I love the spectra. Glad you got it working.

Thanks!
My day just got off to a good start