Sea urchin strange sounds :(

[Gledison]

Hey guys.
just finish my sea urchin build and im having some weird sounds ....
basically, when i turn the "feedback" pot more than 50%, it goes crazily loud with a huge oscilation..
Does anyone have the measured values which i can check ?
thanks!

[garfo]

Check your solders and the component values.maybe you have changed resistor values by mistake.Anyway, the oscillation is normal to occur.There is a resistor that controls the amount of oscillation you can get at max

[jimilee]

I noticed some stuff like that as well but it's controllable. Still sticking with the cave dweller though. I am out if town or I would have posted the values.

[Gledison]

Thanks guys.
The solder points seems ok.
It has something to do with power supply. When using the battery it work like a charm. When i plug the 1Spot than the trouble starts.
By the way, the only mod i did was a 78L05 instead of the 7805. I had only to invert the position. Could be here a problem with a unregulated DC?
Cheers

[jimilee]

First have you switched the pt2399 out to see I it was consistent? Also have you jumpers pins 3 and 4? This seems to be a consistent fix for this pedal but only because the repeats seem to stop not runaway.

[Gledison]

First have you switched the pt2399 out to see I it was consistent? Also have you jumpers pins 3 and 4? This seems to be a consistent fix for this pedal but only because the repeats seem to stop not runaway.

Hey Jimilee,
i´ve seen some of your comments in other threads regarding this jumper. I didnt see this problem and i dont have this jumper but i did on the  TL072.
if im using battery there is no problem. The prob is only with my 1spot.
maybe something related to unregulated DC?
cheers

[jimilee]

Probably so. Measure it with your dmm and see if it's gone crazy on you. I had one that decided it was done and put put crazy power but it was only noticeable with a phaser. Then I bought an mxr power supply on eBay. My sea urchin is in a 1590b and I was too chicken to try to fit space for a battery in there.

[twin1965]

Looks like it could be the power supply. I have a couple of switch mode power supplies and my Stage Fright and Harbinger don't like them at all. They produce lots of noise and oscillation. The power supply introduces this noise into the audio path. That's why it works with a battery. Clean DC.

Sent from my GT-I9100 using Tapatalk 2

[Gledison]

Damn it! There is any way of regulate the dc? Im using a 1spot wallwart.
Cheers

[jimilee]

Damn it! There is any way of regulate the dc? Im using a 1spot wallwart.
Cheers

Regulate an un regulated dc? no, the answer to your question though would be to use a battery. Although that power distributor rej built recently promises to be less noisy. If you're playing shows invest in a regulated PS, if not, don't worry about it. 

[Gledison]

I noticed some stuff like that as well but it's controllable. Still sticking with the cave dweller though. I am out if town or I would have posted the values.

Hey mate, could you send me the values for the sea urchin components?
thanks a lot!
Gledison

[jimilee]

I noticed some stuff like that as well but it's controllable. Still sticking with the cave dweller though. I am out if town or I would have posted the values.

Hey mate, could you send me the values for the sea urchin components?
thanks a lot!
Gledison

like the build docs?

[Gledison]

I noticed some stuff like that as well but it's controllable. Still sticking with the cave dweller though. I am out if town or I would have posted the values.

Hey mate, could you send me the values for the sea urchin components?
thanks a lot!
Gledison

like the build docs?

Well, the IC pins voltages, voltage regulator values, etc...
Do u have it?
Thanks mate

[chromesphere]

Gledison, I followed the sea urchin doc exactly and didn't have these problems.  Mine will oscillate on max feedback and the volume gets mentally loud.  Like, block your ears loud.  If the delay time is on short, that feedback builds up very quickly.  If the delay time is on long, it takes longer.  I don't think its unregulated power that's the problem.  I reckon its a solder bridge or incorrect value.  Sounds like your feedback is on max at half turn of the pot or an incorrect value for a cap / res onboard that is having an equivalent effect.
Paul

[Gledison]

Gledison, I followed the sea urchin doc exactly and didn't have these problems.  Mine will oscillate on max feedback and the volume gets mentally loud.  Like, block your ears loud.  If the delay time is on short, that feedback builds up very quickly.  If the delay time is on long, it takes longer.  I don't think its unregulated power that's the problem.  I reckon its a solder bridge or incorrect value.  Sounds like your feedback is on max at half turn of the pot or an incorrect value for a cap / res onboard that is having an equivalent effect.
Paul

Heyyy the Master!
Paul, i have only the pcb layout, no full standard madbean doc:(
If was a solder bridge it wouldnt work with batery as well right? With battery i have no problem whatsoever! Only with the 1 Spot pluged in!
My only substitutiion is a 78L05 instead of the 7805! Ive checked the datasheet and i har to flip the regulator position, emmiter and collector have diff pinouts.
Could be this the cause?
Gledison