Maxon - 808OD Reissue Help
Posted: 22 Jul 2014, 19:40
Hello,
I am a longtime lurker first time poster. I have a question concerning a Maxon 808 OD pedal. I am an amateur tinkerer, and have fixed several of my own pedals over the years, and I decided to try to install a 3PDT true bypass switch. I was able to glean a lot from the following thread:
viewtopic.php?f=1&t=1903&p=49249&hilit= ... ors#p49249
My thanks to smanq for the schematics and knowledge imparted.
I successfully removed Q1, Q2, R17, R18, R19, D3, D4 & TR3, as well as linking the source and drain on Q1 with a small jumper wire.
I wired up my 3PDT switch as follows using the following layout:
A1 B1 C1
A2 B2 C3
A3 B3 C3
A1: PCB Input (Also Jumpered to B3)
A2: Input Jack Tip/Signal
A3: Jumpered to C3
B1: LED w/ 2.2k resistor
B2: Output Jack Ground
B3: Jumpered to A1
C1: PCB Output
C2: Output Jack Tip/Signal
C3: Jumpered to A3
After removing the afore mentioned parts and wiring up the 3PDT, everything seemingly worked great. LED comes on/off in correlation with the switch and effect. However, I noticed that there was an audible popping sound that would occur when engaging the pedal, especially at higher volume and brighter tone settings on the pedal. It's not as noticeable at lesser volumes or with the tone on darker settings. Also, it seems if you allow ample time between using the effect, it's less or nonexistent.
I did research here and elsewhere, and I realized I may need a pulldown resistor. So, I installed a 1M resistor before C1 on the input that connects to ground. I read that placing a pull down resistor on the input side alone may do the trick, and the out put side already had a resistor, R16 (100k) running to ground and R15 (470 ohms) in series with the output after the last capacitor, C9, before the PCB output. I hope I stated that correctly. Please see the schematic in the linked thread above for better clarity. Do I still need to add a 1M resistor on the output side after C9 to match the input side?
Even after all that, I still have the pop. I understand that it may be the LED. I was going to disconnect the LED and see if the popping remained. But after wiring and rewiring for the past day, I need a break for clarity. I also need to run to my local electronics store as my solder suction tool has finally broken, and I need an assortment of parts.
Anyway, I am not certain where to turn next and any expertise of guidance would be greatly appreciated. Thanks a million in advance.
I am a longtime lurker first time poster. I have a question concerning a Maxon 808 OD pedal. I am an amateur tinkerer, and have fixed several of my own pedals over the years, and I decided to try to install a 3PDT true bypass switch. I was able to glean a lot from the following thread:
viewtopic.php?f=1&t=1903&p=49249&hilit= ... ors#p49249
My thanks to smanq for the schematics and knowledge imparted.
I successfully removed Q1, Q2, R17, R18, R19, D3, D4 & TR3, as well as linking the source and drain on Q1 with a small jumper wire.
I wired up my 3PDT switch as follows using the following layout:
A1 B1 C1
A2 B2 C3
A3 B3 C3
A1: PCB Input (Also Jumpered to B3)
A2: Input Jack Tip/Signal
A3: Jumpered to C3
B1: LED w/ 2.2k resistor
B2: Output Jack Ground
B3: Jumpered to A1
C1: PCB Output
C2: Output Jack Tip/Signal
C3: Jumpered to A3
After removing the afore mentioned parts and wiring up the 3PDT, everything seemingly worked great. LED comes on/off in correlation with the switch and effect. However, I noticed that there was an audible popping sound that would occur when engaging the pedal, especially at higher volume and brighter tone settings on the pedal. It's not as noticeable at lesser volumes or with the tone on darker settings. Also, it seems if you allow ample time between using the effect, it's less or nonexistent.
I did research here and elsewhere, and I realized I may need a pulldown resistor. So, I installed a 1M resistor before C1 on the input that connects to ground. I read that placing a pull down resistor on the input side alone may do the trick, and the out put side already had a resistor, R16 (100k) running to ground and R15 (470 ohms) in series with the output after the last capacitor, C9, before the PCB output. I hope I stated that correctly. Please see the schematic in the linked thread above for better clarity. Do I still need to add a 1M resistor on the output side after C9 to match the input side?
Even after all that, I still have the pop. I understand that it may be the LED. I was going to disconnect the LED and see if the popping remained. But after wiring and rewiring for the past day, I need a break for clarity. I also need to run to my local electronics store as my solder suction tool has finally broken, and I need an assortment of parts.
Anyway, I am not certain where to turn next and any expertise of guidance would be greatly appreciated. Thanks a million in advance.