EEVblog Electronics Community Forum
Electronics => Beginners => Topic started by: Scornn on May 29, 2024, 05:07:10 am
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I tried to make one of these a few weeks ago and I decided it would be best if I started again. Everything was much cleaner and I had an overall smoother process putting this one together. However this one also doesnt work. Bypass and power works but when I click my footswitch I only get signal if I flip the switch from VIB to CHORUS and even then, its dry signal, the same as the bypass. Any help would be appreciated. Thanks!
https://www.diyguitarpedals.com.au/shop/boms/Lich%20King%20Chorus.pdf (https://www.diyguitarpedals.com.au/shop/boms/Lich%20King%20Chorus.pdf) - Build, schematics, components.
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I don't know about the circuit but isn't there a short on right side of SW2?
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i see what you mean but unfortunately not, as much as the picture makes it look like there is
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Looks like a very well documented piece of kit.
You mention that with the switch in VIB position it gives an output signal, so that means the input amplifier (U1A) is working. This means there is either a problem with the output filter, the bucket brigade, LFO or the PLL.
You can test the output filter by removing the bucket brigade IC and connect pin 3 to pin 7 on the now empty ic socket. If there is sound on the output with SW1 in the open position, it narrows it down to the bucket brigade, LFO or the PLL.
These are harder to test without some test equipment. The LFO could be tested with a LED in series with a resistor, and maybe a FET to drive it and lower the load on the LFO. On low frequency you should see it turn on and off. The PLL most likely needs an oscilloscope to check if it is working. When both these generate the needed signals it leaves the bucket brigade, and there is nothing to check on that. If it does not work it will be dead.