Earlier power issue with 12V close to zero on board: fixed.
The PSU for some reason failed to give correct voltage on load, altough at 9V it worked fine. I bought a new one, a regulated switchmode supply, I hope it’s ok that it’s a switching one? I don’t remember now about all the earlier posts about PSUs for the Sammich.
Rotary encoder acting all crazy: partially solved.
I changed the head of the PSU connector to a more tight one, this made the encoder perform much, much better. Originally it was acting mostly randomly, now almost fine, still sometimes jumps a value or few. Strange that before the unit otherwise worked, only sometimes booted when I was moving this around, this prompted me to change the tip of the PSU.
Now it’s almost fine otherwise, but I need to troubleshoot my chips. They are dumpstered 6581s, and the filters are weird. First I thought they are broken, but I noticed that the resonance very noticeably changes the sound, only it’s that the cutoff value seems to do nothing mostly. There is maybe a VERY slight effect, but I’m not even sure about that…
Yeah, I wanted to use proper jumper caps too, but the ones I got were loose and I was impatient And my solder gun is totally unsuitable for electronics (way too big, I used it for tiffany glasswork…), so it was hard to make a good solder.
So the jumpers are not the same size than what computers use? Because that’s what I asked from the shop… Are they some standard size though? I’ll go today back to the shop, but I didn’t want to lug the device around with me, and I couldn’t get an accurate measurement about the width etc of the pins at home…
I removed the soldered shunts and SIDs… The ground connections are fine, 5V is 4,97, 9V is 9.03 and 12V is 10.81… The output of the transformer is 12.24V.
It says in the manual, 10.5V should be enough for the 6581s.
Anyway, without the shunts the device powers up, and also if J20 is set to 12V the 12V rating stays at 10.81, but as soon as I shut one of JPB jumpers, the 12V drops to about 2.5V, and with both shut 12V is around -0.47V… So something wrong with the power. I am now using normal jumpers.
So, what to check next. The device is before used on 6582s, so I think the previous builder never even probably checked the 12V operation…
Just a suggestion here: do not edit old posts except for adding a ‘solved’ to the title, because only then others can find the thread when doing a search and learn from your problem and solution. Open a new thread for a new problem.
Ah, good point. I tried to include the information about the original problem to the edited versions too, so some information is retained… But I’ll keep this in mind.
And my solder gun is totally unsuitable for electronics (way too big, I used it for tiffany glasswork…), so it was hard to make a good solder.
