cave dweller early oscillations

[copachino]

hi, i just build a cave dweller, and finally fixed all, but on dwell poti dont even past from = to 1 and starts oscillating, so im not sure what may be the problems, here are what i change from the real values, on R6 instead of 2k i used a 2.2k, and onc6, instead of 47nf, i used 2 22nf in parallel, and the dwell pot its 100Kb, delay sound nice on echo, but on dwell, oscillations make it impossible to used, does the values i change has something to do??, or its something else??, also, the pt2399 its wonking ok on a sea urching, so its no a bad IC problem.

also i still have a real hot reg, its normal??, its working ok, but it comes real hot just when i plug it, so for longer times, may be a problem or its normal that the reg its hot??

[jimilee]

Nope, it's no normal for the regulator to get hot. Try a different 2399 chip and also check your resistor values. Look for any tiny solder bridges also. Some one should be along shortly to tell you to post clear sharp well lit photos and check the voltages and post them too. .

[ggarms]

Check this thread if I understand your issue correctly. Midwayfair for the win:

"fter some breadboarding, I found that just putting a 10K across lugs 1 and 2 of the Dwell pot @ 50K (stock value) was adequate. It still oscillates on the very last of the pot's sweep; the infinite repeats happen much later on the dial, and there's a slightly smoother control in the middle.

I found a 100KA with the 22K resistor on it, just awkward. Almost the entire first half of the sweep was a single repeat, and it was very tough to dial in anything above 3 repeats without going into oscillation.

Anyway, that's what worked for me. I want to do a little more experimentation with the dwell pot before boxing this one up. I also did the bright mods this time around.

Edit: i've done this one each of my dweller builds and it has fixed the early oscillation issue. Also, +1 on the regulator not being hot. Sorry, I saw the oscillation issue and got excited because I knew of the fix for that. The resistor on the dwell pot won't solve that. Like Jimi said, check your values and look for golden gates.

[copachino]

Nope, it's no normal for the regulator to get hot. Try a different 2399 chip and also check your resistor values. Look for any tiny solder bridges also. Some one should be along shortly to tell you to post clear sharp well lit photos and check the voltages and post them too. .

i just checked, and there its no short, my voltages seem ok, my supply its 9.35V
1: 4.8v
2: 2.35V
3: 0v
4: 0v
5:4.8
6:2.5
7:135mv
8:180mv
9:2.30v
10:2.35v
11:2.40v
12:2.40v
13:2.5v
14:2.5v
15:2.5v
16:2.5v

still reg its too hot to touch, an dwell oscillate too early, echo its perfect, and i saw schematic, the changes i made only affect the echo filtering and not the dwell, what would happen if i change R8 for a 1M resistor?, IMO that will help a bit, i dont think its a bad chip since its working on other delay, and echo repeats are really clean, also i have notice that if a stop right before oscillations, a really low low range of the pot, i get infinite repeats, and they are fairly clean, so, probably, there its something on the range of the pot i can change like i said, the filtering resistor may help, but im not so sure

[copachino]

Nope, it's no normal for the regulator to get hot. Try a different 2399 chip and also check your resistor values. Look for any tiny solder bridges also. Some one should be along shortly to tell you to post clear sharp well lit photos and check the voltages and post them too. .

damn, how could i just mistake a 470k with 47K, that whay its oscillates so fast since the filter was setted to low with the 47k resistor, i have to replace it now