Adding A Switch For Components

Lytt Effects

Active member
Hey All,

As usual, I come bearing a novice question of a gift for you all. My next build is going to be the Son Of Ben (Benson Preamp), and there is a thread about general modifications for the circuit. Two of the modifications involve either omitting a cap, changing the value of the cap, or combining all three using either a SPDT or DPDT on/off/on switch. How exactly does this work, and how exactly does it need to be wired up? I've attached a picture of the schematic, as well as the PCB, and the cap in question is C10. Ideally, I'd like to combine them all and be able to switch from the C10, to omitting C10, to a lower value for C10.

While I am curious about it for this build in particular, I would like to apply this knowledge to future builds as well, so any help would be greatly appreciated. I did some digging through searches, but didn't come up with anything as a direct how-to that breaks it down for a novice like myself. Thanks in advance!

sob pcb.jpg sob schem.jpg
 
I had to think about this for a moment. I don't think you can get all 3 options unless someone chimes in here since (we don't want to short it to ground). 2 options, definitely. You'll need a regular DPDT switch. Solder the positive end of C10 to lug 2 and the negative end to lug 5. For your switchable caps, solder the 10u cap between lugs 3 and 6 or lugs 1 and 4 (dealer's choice). The remaining cap (we'll say 1uf for discussion) on the remaining lugs. Kind of like this. The switch will be 100% off board and mounted somewhere else in the enclosure.

1711992192934.png

This tutorial may help with switches in general.
 
I had to think about this for a moment. I don't think you can get all 3 options unless someone chimes in here since (we don't want to short it to ground). 2 options, definitely. You'll need a regular DPDT switch. Solder the positive end of C10 to lug 2 and the negative end to lug 5. For your switchable caps, solder the 10u cap between lugs 3 and 6 or lugs 1 and 4 (dealer's choice). The remaining cap (we'll say 1uf for discussion) on the remaining lugs. Kind of like this. The switch will be 100% off board and mounted somewhere else in the enclosure.

View attachment 72063

This tutorial may help with switches in general.
This is perfect, thank you. The visual representation helps a ton.

For achieving all three, could it be done with a DPDT on/off/on switch? So the middle position just wouldn’t be making a connection to either cap on lugs 1-4 and 3-6, thereby omitting it altogether?
 
For achieving all three, could it be done with a DPDT on/off/on switch? So the middle position just wouldn’t be making a connection to either cap on lugs 1-4 and 3-6, thereby omitting it altogether?
I had to think it over again, and yes - you can get all 3! In my head I was thinking that in the off position there would be a connection through C10 to ground, but that is not the case. The connection will be severed. Use an on-off-on switch.
 
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