Build Your Own Clone Message Board

Hello,

I’ve been working a building the Analog Chorus pedal. This is my third BYOC build and the first one with issues.

I’ve gone over the board and everything seems correct. I had a left over capacitor (224J63V) when I finished. During the build I realized I installed a few transistors backwards but quickly caught the mistake before continuing. When I went to test out the pedal, the LED quickly went on then off. I had no sound either on or off. I realized several ICs were backwards too, so I placed them correctly. I was getting no sound on or off, except when the switch was halfway pressed. I ended up redoing the off board wiring and replacing the switch and checked over the board again and realized two film capacitors were switched, so I corrected the mistake. On my second test, I get sound on and off, but no effect or lit LED.

I just got a multimeter, but I don’t know how or what to check. Maybe I damaged the ICs? I have replacements coming.

Any help would be greatly appreciated. My first two builds, the Russian muff and harmonic tremolo were successes. Hope to get this figured out before moving on.

Here are photos of my build:
https://ibb.co/Nm3y8sZ
https://ibb.co/FHbGms1
https://ibb.co/8mGNbkf
https://ibb.co/JxTnKbC
https://ibb.co/HpbHK4C
https://ibb.co/sJVz3TN

Thanks!

Update: I went over and reflowed all the joints. The pedal is same as before, except the LED lights up momentarily whenever the power plug in inserted or removed. Sound but no effect or LED.

If you had the ICs in backwards, you've likely damaged them. Probalby not the 3207 or 3102, but most likely the 4558 and TL022.

_________________
*patience is a virtue*

Please do not PM me. email is prefered. keith@buildyourownclone.com

I’m in the process of learning how to check voltage with a multimeter. While checking the TL022 IC, the LED suddenly turned on when I accidentally touched pins 1 and 2. If I touchthe pins again in turns off. There is sound but no effect.

Any thoughts on whats happening?

Someone else may be able to point you toward a specific solution based on those symptoms. I'm not sure about what could be causing them. I'm just chiming in to request some better photos. What you've uploaded gives us a little info, but if you could take them in much better lighting, that would make it easier to see what's happening. We need the whole image to be in focus and not washed out by your flash, so we can see little details like the color bands on resistors and small solder bridges.

Also, if you copy the info in the field that says "BBCode" and paste it into your post, the photo will display as an embedded image, which makes it a lot easier to troubleshoot because we don't have to keep changing tabs to see everything.

_________________
Scott

My band, Austin Hollow

If you look at the Analog Chorus schematic (HERE), you'll see that the LED is driven off the LFO/Clock Driver portion of the circuit. This is how the LED flashes in time with the chorus rate setting. The TL022 IC is a key part of this sub-circuit, and the LFO output changes the voltage bias on transistor Q4, which then turns the LED on and off. So apparently you touching/shorting those two pins together caused enough of a voltage change to turn the LED on and off "manually."

To measure the DC voltage level on the IC pins, set your multimeter to the DC voltage mode, indicated by a solid line above a dotted one. Use the 20VDC range setting if it's not an auto-ranging meter. Your power source needs to be connected and there needs to be a cable in the input jack. If the pedal is assembled into the metal enclosure, put the black probe into one of the corner screw bosses of the enclosure--this is your ground connection. If the "guts" are out of the enclosure, use the sleeve tab of the input jack for the ground connection. Then touch the red probe to each point that you want to measure. See left side of the image below for the numbering of the pins.

_________________
“My favorite programming language is SOLDER” - Bob Pease (RIP)

My Website * My Musical Gear * My DIY Pedals: Pg.1 - Pg.2

Here are the IC voltages as measured along with better pictures of the build. The voltages for the 4558 definitely look off! I even remeasured it again just to make sure, lol. Any further support would be very helpful.

No. The 4558 voltages look perfect. Is your LED blinking?

_________________
*patience is a virtue*

Please do not PM me. email is prefered. keith@buildyourownclone.com

No, it flashes on for a quick second when power is connected, otherwise the LED is off.

That means your problem is at the TL022. Only pins 2, 4, 5, and 8 will have a constant voltage and those all look correct. This is the oscillator, so all the other pins will have varying voltages, so it's difficult to say, but it doesn't look like the TL022 is faulty. My first assumption would be that you simply have a cold solder joint at one of the resistors, or cap, or rate pot that are part of the oscillator circuit. Or on the TL022 socket. Or maybe you have a value out of place...I can't really tell from the pics.

_________________
*patience is a virtue*

Please do not PM me. email is prefered. keith@buildyourownclone.com

When the TL022 is removed the LED lights up. Ill reflow the joints and go over and make sure parts are installed correctly, this will take some time.

Do you have any suggestions on what else to check to help narrow down the issue?

Please reflow and double check your components and well go from there if need be.

Also, try replacing the 4558 with the TL022. BUT do not swap them. Leave the TL022 socket empty and just use the actual TL022 chip in place of the 4558. If the chip is good, you should get dry signal but no chorus signal, and your pin voltages should be exactly the same as with the 4558

_________________
*patience is a virtue*

Please do not PM me. email is prefered. keith@buildyourownclone.com