Kingslayer II OD Mod

[Droogie]

Orignally posted in the general questions section. Since it works well, I figured it belonged here in Mods.

I found I was missing the OD (soft clipping) option on the K II, and asked about putting it back in. Some advice from the Bean and a look at the K I schematic and voila, soft clipping!

I used back-to-back 1N4148s on a bit of vero connected to a DPDT  on/on (although I later realized that an SPDT would also work).

The mods that Bean suggested:

R11 = 1M (as on K I)

Bean: "Socket R9. Start with 2k there. Test out the range of overdrive using the soft clipping then the hard clipping. You want to minimize any oscillation you get when you start cranking up all three knobs in parallel. You will likely get this oscillation when you bring up the Tone pot when the Volume and Gain are cranked. To minimize this, increase the value of R9. Start with 4k7 and go up to 10k until you minimize or eliminate the oscillation."

I ended up using 10k, with no oscillation whatsoever.

To connect to the K II board, one wire from the center pair of lugs of the DPDT connects to the "bottom" leg of C11 (that connects to R11/C9 thru the via); the other wire from the DPDT connects to the "bottom" leg of R9 (that connects to R10).

I left the other side of the DPDT unconnected to take the clippers out of the circuit.

Totally worth doing if you're not so concerned about fitting it in a 1590B.

[jighead81]

Anybody have the K1 schematic? I was wanting to do this too.

Edit: good grief, it's on the projects page, my bad

[jighead81]

Did the mod with a On/Off/On switch with OA126's and 1S1588's, and the center position taking the whole mod out of the circuit.  I put in a 4K7 in R9 but I think I'm going to have to put in a 10K just like the OP because I'm still getting a little too much hair and borderline oscillation. 

I gotta say though, I love it.  This is my favorite OD, and I feel silly for not getting the K1 and building it a long time ago. 

I also just added in the "Thick" switch like on the SKII but haven't got to play around with it too much yet.  Seems subtle but more effective on certain settings.  Everybody should build this bad boy