Eight Ball Overdrive

OD is Glorious

Active member
I populated the PCB today. Got some help with one item: the 2sk209g orientation. FYI: I used an adaptor and did not consider the girth of a 220u cap. It was a tight fit and something to consider. I decided to go with the N4148 diodes that the build called for and I made no changes in the directions. There are quite a few components involved in this build and I am going to have it up on the PedalPCB auditorium platform tomorrow and then get it boxed up probably Monday because of the Superbowl tomorrow.

Right now I am deciding of my graphics choice here is too risqué. I see most people use the pool reference for their graphics.

It will be all gold, the footswitch, Stompbox powder coated enclosure, LED bezel, output jacks, and knobs. I am including images of my board and soldering..
 

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Well, I got it up on the platform didn’t work. Checked all the resistors and caps redid all of the solder. No time for further testing today because of that Super Bowl I got a party to go to. I did have trouble with one cap the 100 and in the upper right. So I gave that a little more attention. I had initially put the wrong cap there and had to really jag around to open up the hole so hopefully I didn’t damage the board too bad maybe that’s why it doesn’t work. I’ll certainly be back to this tomorrow.
 

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for what it's worth, you can actually just sub the JFET for a 2N5089 (or probably a 2N5088) and it doesn't sound any different. (per breadboard investigations).
it's just an input buffer.

Where did you get those MC33178 opamps?
good call.
maybe drop in something guaranteed genuine like a 4558 or whatever and see if it works (opamp choice isn't really critical to the sound)
 
Looks like I got them
Let's start with the easiest stuff first...

Did the LED light up?

Where did you get those MC33178 opamps?


Now I want to mount a battery on my Auditoriums..... :unsure:
Yes, the light works. And you get a little bit of a extremely muffled sound. I haven’t tested it since I redid all the solder and I just checked where I got those chips from... Amazon. I got some good ones that I purchased from pedal PCB but I decided to try these Amazon ones because they were less work.The second image below shows the ones from PedalPCB and they just require a bit more fussing so I tried the others. What other chip you think I could stick in there? I do have many others and some I know are great. I have some 4558s that I will try tomorrow. They are from Stompbox.

Note: OK, I just got home. Put it back on the auditorium platform. If I put everything at 10, I get just some far away distortion.
 

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I got those chips from... Amazon.
unfortunately buying opamps from amazon will be as likely to land genuine units as me shooting a 3-point basket blindfolded.

it's probably the only component type (ICs) in this entire game where using genuine parts matters.

please install some genuine opamps.
 
unfortunately buying opamps from amazon will be as likely to land genuine units as me shooting a 3-point basket blindfolded.

it's probably the only component type (ICs) in this entire game where using genuine parts matters.

please install some genuine opamps.
Thanks. And looking at the images in the Amazon ad they are not the same as the chips
TL072 / RC4558 will work perfectly fine.

It may or may not sound identical, but it'll help you identify (or eliminate) your opamps as the problem.
I failed at a video, but I put the 4558s in, and it was the same. Odd that I turn everything on ten and the volume A100 only allows the pedal to spit out some sound once it gets turned to 9. Once I turn volume to ten I can here the other knobs controlling tone. It is not right and something is holding it back.
 

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Yes the Auditorium is used with all builds. I used to box them and then have trouble, so now I always use the platform first. I do have a multimeter, but I’ve never traced. Looks like I’m gonna have to learn about settings and how to.. my trouble was with the 100n
 

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Have you used your Auditorium with other builds successfully? (Just want to make sure it's not the issue)

Do you have a DMM to take some continuity measurements? If so, make sure no traces are damaged from removing that capacitor.

View attachment 110798
Hey Robert, do you think I might have a bad potentiometer? When I test the A100 volume it goes only to 9 when you spin the knob clockwise. When I go counterclockwise, it goes all the way to 100.
 

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Keep your leads in the left/center eyelets (don't move them) and measure both conditions again.
I tried this three more times rotating the dial when I go clockwise. It starts out at one, and it only goes to nine.
Note: just checked all of the pots. The other three have the correct readings. This one: when I put the leads left and center the MM reads 1.1 all the way counterclockwisse and 9.4-10 all the way clockwise. Is this Eureka? Or should I keep looking?
 
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I sent Robert a private message. Very very helpful builder. I thought I had a bad potentiometer at the A100 volume. It had a very low reading of nine so I asked Robert and he said the concentrate around C 14. He said a potentiometer was rarely bad but it does happen. So on my own I unsoldered the A100 post and I also un soldered the A1M because it had a low reading. Then I went about concentrating in the C14 area. I removed C102 which I had already replaced once and replaced it again. The soldering on that cap looked suspect. C14 C103 and C100... as I remember one of the electrolytic capacitors was not registering on my meter. I think it was the 220u or the 100u.I replaced them all. I reinstalled the potentiometers double checked all of my work - reflowing solder. You can see now I’m getting a full reading on the volume and it was not the potentiometer. While the potentiometers were out, I tested them both and they were perfect. The 220 U at C 100 may have been the culprit because of my ham fisted installation of the 2SK209. I had it installed and then when I put in the breakout for the 2SK209 it pushed the 220U.

So I put it up on the Auditorium Platform and it worked! I very much appreciate the solid help of people like Robert. I was hoping I wouldn’t have to throw this board on the pile with the other broken dreams. Lol.
 

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Well, I boxed it and then it went back to fair away sputtering. This has happened with a few pedals so maybe tomorrow I can take a little video so you can hear what this thing sounds like. Maybe someone on here would be able to advise me what I’m doing wrong when about one and three pedals ends up like this for me. Thanks and have a nice night.
 
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I sent Robert a private message. Very very helpful builder. I thought I had a bad potentiometer at the A100 volume. It had a very low reading of nine so I asked Robert and he said the concentrate around C 14. He said a potentiometer was rarely bad but it does happen. So on my own I unsoldered the A100 post and I also un soldered the A1M because it had a low reading. Then I went about concentrating in the C14 area. I removed C102 which I had already replaced once and replaced it again. The soldering on that cap looked suspect. C14 C103 and C100... as I remember one of the electrolytic capacitors was not registering on my meter. I think it was the 220u or the 100u.I replaced them all. I reinstalled the potentiometers double checked all of my work - reflowing solder. You can see now I’m getting a full reading on the volume and it was not the potentiometer. While the potentiometers were out, I tested them both and they were perfect. The 220 U at C 100 may have been the culprit because of my ham fisted installation of the 2SK209. I had it installed and then when I put in the breakout for the 2SK209 it pushed the 220U.

So I put it up on the Auditorium Platform and it worked! I very much appreciate the solid help of people like Robert. I was hoping I wouldn’t have to throw this board on the pile with the other broken dreams. Lol.
FYI.... Robert is pedalpcb. He's pretty good...lol. He's traced and made a few pcbs around here...
 
Well, I boxed it and then it went back to fair away sputtering.

If it works out of the enclosure but doesn't work when you put it back in the enclosure something is making contact with something it shouldn't.

The most likely cause is a component lead touching the back of one of the pots.

When it's out of the enclosure the pots aren't grounded and are floating, so it doesn't cause any issues... once you mount it back in the enclosure (which is grounded by the 1/4" jacks) the metal pot housing also becomes ground and shorts whatever is making contact to ground.
 
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