I'm working on a SLO clone with dual EQ stack on a ampclones SLO100 PCB. I followed the BOM list and official SLOcone schematics. I've built many regular SLO clones before so this baffles me!!
Overdrive channel works OK, all controls work. When I switch to Clean I only get a pop and faint sound at Max gain (probably a bleed from the OD channel) The Volume and EQ controls have no effect.
Troubleshooting
1. I ran line from FX loop send to another amp and had same result. loud/normal overdrive signal and faint clean/bleed signal
2. replaced V1 tube -no effect
3. replaced C7-22nf Coupling cap - no effect
4. replaced LDR5 and LDR4 VTL5C1 - no effect.
5. Bypassed clean/crunch switch circuit going from board to gain pot -no effect
6. Bypassed LDR5 with jump from R17 to R21, I got a boost in volume but still not much. still very low compared to OD
7. Checked voltage at V1a Pin 1 & 3 to be normal range
8. cant be heater issue since OD sound awesome
9. Since running 7 LDR's changed switching circuit power suppply resistors R64 from 47ohm to 15ohm & R65 33ohm to 15ohm.
I've traced the board out and this channel is to small to give me such a big headache.
Any Ideas how to resolve this.
HELP! No sound on Clean Channel on Dual EQ SLO clone
Moderators: pompeiisneaks, Colossal
HELP! No sound on Clean Channel on Dual EQ SLO clone
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Re: HELP! No sound on Clean Channel on Dual EQ SLO clone
If that is the same method as the original it is a brute force way of toggling the vactrols and it can be a balancing act but it does work. Extra energy and heat is thrown away. You need to trace the transformer specs and your wiring. Personally though I would use a different method of toggling the Vactrols maybe driven by a simple 4049 driving transistors.
That way it is also way more compatible with switching.
Did you try and switch without the LED in the footswitch
You could also have a dead vactrol, seen it many times. You have a scope and ohm meter? It shouldn't be too hard to track it down
That way it is also way more compatible with switching.
Did you try and switch without the LED in the footswitch
You could also have a dead vactrol, seen it many times. You have a scope and ohm meter? It shouldn't be too hard to track it down
Re: HELP! No sound on Clean Channel on Dual EQ SLO clone
I have a ohm/voltage meter but no scope. I have a bypass front panel channel switch connected to switch without LED pedal. No change!! What do I look for on the dead vactrol?