August 18, 2019 at 9:20 pm #6657
Successfully built an Ancenstral Apparition. The 125B is a little too small, so I ordered a larger enclosure. I am curious about the pots though – see if y’all can give me some advice.
It seems the effect of the knobs is extreme – I can’t push them past a tiny amount from full counter clock wise. Is there a way to adjust the amount of “action” in the dial?
pgAugust 18, 2019 at 10:46 pm #6658
Especially if this observation is as extreme as you say you should consider it is quite possible there could be a build issue. Visually recheck and verify all values by color band and part number. For example R11 is 470 ohm sometimes mistaken for 470k ohm. Since I have not previously heard anyone suggest an issue like this and it was not my experience this makes it worth a serious re-check.
If we have pictures we can take a look as well.August 19, 2019 at 6:36 pm #6665
Great thanks I will. Besides confusing 470R and 470k, what should I be on the lookout for?
One things I goofed up is I used a 1/2 W resistor in one case – would that matter?
I’ll work on getting a photoAugust 19, 2019 at 8:09 pm #6668
1/2 watt is fine other than fit. With that in mind besure to re-flow any suspect solder joints. Especially dull grey instead of shiny. Check that every capacitor matches the BOM and that they match the exact location on the board.
Finally visually inspect and verify every resistor with an online calculator.August 19, 2019 at 8:27 pm #6669
roger that, thanks Barry!August 19, 2019 at 11:20 pm #6673
My, my. Didn’t even bother checking components, saw these two macked up solder points on the pots. Oddly enough the (top) one has continuity to ground. Checked the bottom one and the resistance sweeps across the pot. However, the last photo shows the ground solder point has NO continuity to ground…
ugh.August 20, 2019 at 11:47 pm #6683
Ya think this PCB is gorked?August 21, 2019 at 8:38 am #6691
The decay pot lug 1 does connect directly to ground
The depth and attack pots don’t, attack is connected to ground via R19 If you look at the schematic you’ll see how they’re wired and where you should expect continuity
If I understand correctly you are saying that all pots don’t have much range across thier rotation and they go from min to max very quickly?
Double check you have the correct value pots in the correct positions there’s not a huge difference in pot values but if you put a B2K were a B10K should go then the range would be affected
As Barry says check all component values and orientation it’s very easy to use an incorrect value in a fairly high parts count build
This is what I use to check resistor valuesAugust 21, 2019 at 7:56 pm #6700
OK, cool. I will. Thanks!August 23, 2019 at 7:41 pm #6721
pots look good.August 24, 2019 at 10:14 am #6727
Well, the components seem to check out. I’ll put it all back together and test it. Outside of the enclosure, it seemed to work fine, although a tad bit of a lower signal. I think the build is prolly ok, I wonder if I had shorted out or compromised something when I had it jammed in the smaller enclosure…August 24, 2019 at 1:25 pm #6729
Well folks, Good news. I checked out all the components, did a re-flow on the pots a couple of joints, and plopped it into a larger enclosure, and it works much better. Erm, the wires are a bit long on the pots, oh well…
Prolly dinged something jamming it in the smaller box, or the re-flows improved something or other.
Anyway, thanks!! On to the next project!
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