Hi everyone.
I've been working on a project that I think is finally ready to share. Out of curiosity, a while back I bought a BMP-1 Blackouts Modular Preamp and installed it in a guitar with a Nazgul and Sentient set. The Nazgul output was super hot, as expected, but it wasn't too muddy and I liked the tone. I did however, miss the original Nazgul tone and thought it would be a fun project to see if I could somehow set up active/passive switching with the existing control routing on the guitar (two pots, blade switch).
For proper operation, the BMP-1 requires a pickup's coils to be wired in parallel and out of phase. To do this in the context of a traditional series wiring with a Duncan pickup (green->ground, red->white, black->hot) means at the very least, the black, red, and white leads have to be changed (black->ground, red+white->hot). So to switch two humbuckers between series and active, you have to at a minimum be able to switch 6 leads in total.
I first tried this a couple different ways with 4P3T rotary switches and 4PDT mini toggles, but I wasn't really satisfied with what I was able to make. I had resigned myself to giving up on this, but then one day I came across a 6P5T blade switch (https://axlabshardware.com/products/axlabs-5-way-blade-2-pole-switch-copy) and I saw some possibilities. By combining this with two push-pull pots, I was able to get active/passive switching with a volume control for each mode, as well as optional coil-splitting in passive mode. Rather than going through everything in detail, here's the final diagram:
The positions are as follows:
The final result is a bit of a rat's nest, but it fits. You may also notice that the preamp isn't the BMP-1. I ended up using a different preamp (https://analogworkshop.eu/products/doublediffamp/) that I believe is based on the Bajaman design (https://www.freestompboxes.org/viewtopic.php?t=31532), but this method will work with the BMP-1 or any other similar device.
Anyways, if you got this far, thank you for reading. I hope this was useful for everyone and inspires more projects!
I've been working on a project that I think is finally ready to share. Out of curiosity, a while back I bought a BMP-1 Blackouts Modular Preamp and installed it in a guitar with a Nazgul and Sentient set. The Nazgul output was super hot, as expected, but it wasn't too muddy and I liked the tone. I did however, miss the original Nazgul tone and thought it would be a fun project to see if I could somehow set up active/passive switching with the existing control routing on the guitar (two pots, blade switch).
For proper operation, the BMP-1 requires a pickup's coils to be wired in parallel and out of phase. To do this in the context of a traditional series wiring with a Duncan pickup (green->ground, red->white, black->hot) means at the very least, the black, red, and white leads have to be changed (black->ground, red+white->hot). So to switch two humbuckers between series and active, you have to at a minimum be able to switch 6 leads in total.
I first tried this a couple different ways with 4P3T rotary switches and 4PDT mini toggles, but I wasn't really satisfied with what I was able to make. I had resigned myself to giving up on this, but then one day I came across a 6P5T blade switch (https://axlabshardware.com/products/axlabs-5-way-blade-2-pole-switch-copy) and I saw some possibilities. By combining this with two push-pull pots, I was able to get active/passive switching with a volume control for each mode, as well as optional coil-splitting in passive mode. Rather than going through everything in detail, here's the final diagram:
The positions are as follows:
- bridge - active
- bridge - passive - series or split
- bridge and neck in parallel - passive - series or split (same for each humbucker)
- neck - passive - series or split
- neck - active
The final result is a bit of a rat's nest, but it fits. You may also notice that the preamp isn't the BMP-1. I ended up using a different preamp (https://analogworkshop.eu/products/doublediffamp/) that I believe is based on the Bajaman design (https://www.freestompboxes.org/viewtopic.php?t=31532), but this method will work with the BMP-1 or any other similar device.
Anyways, if you got this far, thank you for reading. I hope this was useful for everyone and inspires more projects!
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