Pandora's Box Bass Toggle

megatrav

Well-known member
Hello,

I am going to build one of these sometime soon. I have seen the mod of adding a bass contour control, but I was wondering if anyone has done the bass switch like the JHS Kilt v2?
If so, please let me know!
 
Actually I found the info! Looks like a toggle to add in an additional 100n cap at c1 is the way.

Ive never done that before..
Can someone tell me how to wire the toggle with the caps and board?
 
There're a few ways to approach this.

For a blank PCB that's never been populated, here's how I would do it for 3 EQ settings:

DPDT ON-OFF-ON

Wire from the board's cap-in pad to lug 2 of DPDT
Wire from DPDT lug 5 to the board's cap-out pad.

Solder the smallest value cap (Cap A) across lugs 2 & 5.
Solder a larger value (Cap B) across lugs 1 & 4
Solder an even larger value (Cap C) across lugs 3 & 6.

When the toggle is in the OFF position, you've got just Cap A [treble]
When the toggle is in the DOWN position (connecting lugs 1&2, 4&5), you've got the sum of values from Cap A and Cap B. [mid]
When the toggle is in the UP position (connecting lugs 2&3, 5&6), you've got the sum values of Cap A and Cap C. [bass]

You can swap the outer lugs caps if you prefer having the bassiest setting in the DOWN toggle position.

Use whatever values rock your world, but if you want STOCK, BRIGHTER, BASSIER and 100n is the stock setting, stick 47n in the middle (lugs 2&5), 56n across one set of outer lugs and 100n across the opposite outer lugs.

You'll then have 47n BRIGHT in the middle toggle position ("off"); 103n in the MID (close enough to stock); and 147n in the BASS position.
Of course, adjust values to taste, maybe you want 120n or 150n for Cap C, which with the centre's 47n gets a combined bassiest setting of 167n or 197n respectively.


As a bass player, for a guitar-oriented circuit I usually go stock value in the middle, and then just keep adding bigger values for BASS up & MORE BASS down.



JUST TWO SETTINGS:
If you want just bass/treble, use an ON-ON type switch, either SPDT or DPDT.

The DPDT is just like the three-settings one above, you just use the on-on type and omit the cap across lugs 2&5.

For SPDT — Run the cap-in wire from the board to the middle lug. Solder one end of the bass cap to an outer lug, do the same for the treble cap to the remaining lug. Solder the floating ends of the caps together and run a wire from them back to the board's Cap-out pad.


For a board already populated, you need only attach the bass-cap to the SPDT.
 
A picture is worth more than a 1,000 words of my gibberish!


Yes, same-same as what I described, as what Music6000 posted — just drawn from a different angle. Not a different method, but same method.
 
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