Sabotage and newfangled LED advice

[mybud]

Hi everyone and all best wishes for 2022. I’ve trying out these new foot-switch LED rings from Tayda. 

I noticed with the Sabotage (great circuit BTW) that there’s a small but noticeable low frequency loss when the LED switch is connected (no CLR, since there’s a resistor built in). So two questions regarding options: one, to run the drive at 12V (all elcaps are rated 50V) to make up the missing headroom or: two, to use the 1k8 CLR called for in the original circuit to dim the LED and hopefully again make up the slight bass loss.

I wanted to consult the collective wisdom for advice before removing jumpers and making permanent changes to the PCB. Hope this is clear, thanks in advance, and again best wishes for the year to come.

Best, mybud

[Cybercow]

Dunno how you have yours connected. (Photos would help.) Personally, I ALWAYS take the DC supply for my bypass LEDs (and CLR where needed) from a point BEFORE the first power filtering cap – directly off the DC jack.

[mybud]

Hi CC: Greetings and many thanks for the speedy response. I wired it exactly like the schematic.

I’m going to try a trimmer in series to supply an adjustable voltage to the LED. Interesting that there’s actually a subtle tonal difference with the LED in circuit. I’ll update with a pic when our power’s back, big storm in progress.

All will be revealed in time. Thanks again. Best, M

 

[mybud]

[mybud]

So, S4 and S5 connected for test purposes. Same for LED, as per schematic.

[Anonymous]

FIrst, there is NO audio signal passing through the LED.  The LED only serves as an indication that the signal is passing through the circuit.  Any change in the bass response occurs within the circuit itself.

There is a change in the bass response at several points in the circuit.  The largest change occurs at the RANGE control.  Increasing the value of C2 will let more bass pass that point.

Increasing the values of other blocking caps through the circuit will also allow more bass to pass.

Finally, the PRESENCE control affects the apparent bass response as well.

I hope this helps.

[mybud]

Greetings and thanks, wilkie1. I fear that I have expressed myself rather poorly in this case.

What I observed was this. When testing the circuit, I noticed that switching in this new LED contraption causes an apparent change in the bass response (minimal but noticeable). I assumed that this is because the LED draws some current away from the circuit, hence the suggestion to run it at 12V (more overall headroom) or use an additional CLR in series to lessen the draw from the LED. At the moment it’s too bright anyway so the CLR route might be better than running it at 12V (even brighter).

But I absolutely understand that this is not a design fault in the Sabotage drive itself but merely the complication of the new LED arrangement. I wanted to try to solve this for future reference regarding other builds that might be similarly affected. Hope this now makes sense and thanks as ever.

[Author]

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