El Sol - Gating Issue

[ckendall924]

I know this has been posted previously and resolved, but I'm having this same issue and cannot resolve it using any of the suggestions on the previous post.

I get clean bypass. LED turns on, great big Acapulco Gold sound when I dig in. But the sustain dies abruptly with a fuzzy gated sound. The signal even dies completely and back on in a sort of swelling sound as a chord is allowed to ring out. (It's kinda cool, but also not the intended sound with this circuit.)

I've posted some pics below. (Just one thing to note, the pic of the back of my pcb should've been updated. I reflowed all of my solder joints as a good measure. Also, I have 2 sets of the JRC386 chips. I swapped out the IC's to see if that would do the trick. No success.)

Any ideas would be helpful.

 

[Nostradoomus]

I can’t explain why exactly but using the LM386N-4 has always solved this issue for me.

 

[ckendall924]

I can’t explain why exactly but using the LM386N-4 has always solved this issue for me.

Alrighty... I'm going to have to order some of those and give it a try. Thanks!

 

[Nostradoomus]

If you’re in Canada I can send you some.

 

[ckendall924]

If you’re in Canada I can send you some.

Very kind of you! I’m in US. (Don’t hate me for that)

I just ordered a few variants of the LM386 (N1, N3, and N4) from StompBoxParts.com

I’ll play around with them and see if that solves it.

 

[Sturdag Lagernathy]

Where did you get the chips that are in-circuit in the pic? At first glance, printing seems odd.

 

[ckendall924]

Where did you get the chips that are in-circuit in the pic? At first glance, printing seems odd.

StompBoxParts.com

Just looked up the receipt, and it says the brand is New Japan Radio.

 

[Sturdag Lagernathy]

Lol, yeah Stomp Box Parts sell legit stuff.

 

[ckendall924]

I received my replacement IC's and gave it a sound test. Still gating and scratchy. Maybe it's the pot?

 

[hamerfan]

A LM386-3 helped here:

M

SOLVED Post in thread 'Paradise Overdrive (Gain Pot Motorboating)'

Mar 14, 2020

Hi first time on the forums, how ya'll doin?
I've tried to solve this problem quite a few times already but to no avail, so now I'm here hoping that one of the wiz's can help me out.

So as the title suggests I have a problem with the Paradise Overdrive, mainly the gain control. At all the knobs in the 12 o'clock position everything seems fine. I can even push the volume and it seems to be okay. The gain however in the last 1/10 of a turn starts motorboating quite a bit. If i back off the gain knob a bit the motor boating goes away but seems to have a faint noise (which is what I'd...

• music6000

• 

 

[GizzWizzKing]

I assume you checked the values for your components. I can't read your resistor stripes or cap values.



I don't see any solder on the component side of the 4n7 cap which is fine but maybe something to check if your reflow didn't fix it.

 

[darwin999]

Hard to tell, but some of the solder joints look like they might be cold joints - i.e., the solder doesn't flow smoothly onto both the pads and wires, but instead have some dark pits in them. So maybe there's an oxide layer in between. I've highlighted a few questionable joints here (compare them to the others under magnification):

What solder do you use? I'd stick with a top brand like Weller or Kester, cheap solder isn't worth the pain of debugging bad joints.
And when you reflow the joints, do you touch the joint just with the soldering iron or also with a little touch of new solder (so flux is present, which helps solder flow better and clean up the connection). I recommend the latter.

Another thing to try is to check the signal path and find where the fuzz occurs. You might work backwards from the output until the signal looks clean. You can do this with an oscilloscope, if you or a friend are fortunate to have one.

Just my 2 cents, I wish you luck in getting it fixed.

 

[ckendall924]

Hard to tell, but some of the solder joints look like they might be cold joints - i.e., the solder doesn't flow smoothly onto both the pads and wires, but instead have some dark pits in them. So maybe there's an oxide layer in between. I've highlighted a few questionable joints here (compare them to the others under magnification):
View attachment 88743
What solder do you use? I'd stick with a top brand like Weller or Kester, cheap solder isn't worth the pain of debugging bad joints.
And when you reflow the joints, do you touch the joint just with the soldering iron or also with a little touch of new solder (so flux is present, which helps solder flow better and clean up the connection). I recommend the latter.

Another thing to try is to check the signal path and find where the fuzz occurs. You might work backwards from the output until the signal looks clean. You can do this with an oscilloscope, if you or a friend are fortunate to have one.

Just my 2 cents, I wish you luck in getting it fixed.

Appreciate that… I’ll look at them again. I did go back over them and flowed new solder after that photo was taken, but I can triple check them.

And yes, I’m using Weller.

Wish I had an oscilloscope!

 

[ckendall924]

I assume you checked the values for your components. I can't read your resistor stripes or cap values.

View attachment 88740

I don't see any solder on the component side of the 4n7 cap which is fine but maybe something to check if your reflow didn't fix it.

Yeah, I had reflowed solder after those photos were taken, but I’ll triple check them.

 

[ckendall924]

A LM386-3 helped here:

M

SOLVED Post in thread 'Paradise Overdrive (Gain Pot Motorboating)'

Mar 14, 2020

Hi first time on the forums, how ya'll doin?
I've tried to solve this problem quite a few times already but to no avail, so now I'm here hoping that one of the wiz's can help me out.

So as the title suggests I have a problem with the Paradise Overdrive, mainly the gain control. At all the knobs in the 12 o'clock position everything seems fine. I can even push the volume and it seems to be okay. The gain however in the last 1/10 of a turn starts motorboating quite a bit. If i back off the gain knob a bit the motor boating goes away but seems to have a faint noise (which is what I'd...

• music6000

• 

I did get some LM386-N3 chips, so I can give that a whirl also.

 

[ckendall924]

Something is definitely not right with my pcb... I went over the values of the components and wasn't getting a read on R1, which is a 1M resistor. I've decided to replace that resistor, but I'm having a terrible time getting the solder out of one through hole.

In the interim, I decided to breadboard this circuit and see if I got a different sound. I was able to get this thing working beautifully on the breadboard!

It's making me think of just building this circuit and power section on a perf board and putting it in a pedal enclosure. (Maybe even do one of the mods that exist out there and include a separate tone control?)