Build Your Own Clone Message Board

Hello! Finished up putting the Analog Chorus together and I have the following issues:

1. Chorus effect is not modulating / rate pot does nothing. You can manually modulate or sweep the chorus effect with the depth knob and the internal trim pot for circuit bias does work. I was able to dial in a chorus sound, but it is static unless you move the depth knob. I assume this is a problem in the LFO section of the circuit.

2. LED worked fine first time I powered up and plugged in, clicked the switch a few times and now it only flashes on/off quickly when you insert the power supply jack or cable into input jack.

I went over all the solder joints and touched up anything that looked off, this solder I am currently using at home does not seem to finish as shiny as the Kester stuff I use at work so I am second guessing myself about cold solder joints. Thank you very much for any troubleshooting suggestions. Please excuse my lack of colour coded wiring for the Power, I/O & Switch section.

You did the fix for the 56k resistor that you only need to do if you have a Rev3.0 PCB. You have a 3.1, so you didn't not need to do that. You need to remove the 56k resistor that is tack soldered on the back and put it in its normal space on the top of the PCB.

This has no bearing on your issues with the LFO, however.

Please take voltage reading for the TL022 chip.

_________________
*patience is a virtue*

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

Thanks for the quick response Keith. I have soldered the 56k resistor in the correct place. I get a reading of -8.67v measuring across pin 4&8 on the TL022. I checked the pots with the meter as well and they are reading properly.

Describe the voltage readings on pins 1 and 7 of the TL022 please. You should be getting a fluctuating voltage at these pins. Pin 1 should be square wave and pin 7 should be a triangle wave....athough, I doubt you'd be able to see that with a multimeter. Anyhow...you've likely got a cold solder joint somewhere with one of the LFO components. Reflow the solder joints around the TL022. If that doesn't fix it, then tell me the voltages at 1 and 7.

_________________
*patience is a virtue*

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

I have reflowed the solder joints around the TL022. Pin 1 measures 8.00v and is static / no fluctuation. Pin 7 measures 0.663v also static / no fluctuation.

Swap your 4558 and TL022 and see if it starts modulating. The 4558 isn't the most ideal op amp for this LFO, but it will work. See if you get a fluctuating voltage now. If you do, then we know the problem is with the TL022. If not, then we know the problem is somewhere in the rest of the surrounding LFO components.

_________________
*patience is a virtue*

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