Chuck D. Bones
Circuit Wizard
HamishR asked me if I had tried the Basic Audio Alter Destiny. I hadn't. Just another BMP, right? Maybe not. I liked the bright cap on the FUZZ pot and the FAT knob (I can hear you snickering). The gain is somewhat reduced in the distortion stages and there is the familiar variable MID knob in the tone stack. Not a bad Muff on its own, but you know me...
I wanted to be able to vary the gain of the distortion stages and I had been thinking about using a MOSFET for one of the distortion stages. Here's what I ended up with. I tweaked the gain and EQ slightly in the 1st stage. I wanted the 1st stage to run transparent and clean, but be responsive to the guitar's knobs. The FAT knob does a good job of reigning-in the bottom end, but I wanted a little more sludge available when FAT is dimed. Because your knob can never be fat enough, right? So I increased C3 & C6 to 220nF. I left the 2nd stage pretty much intact, I just lowered R12 to increase the gain a bit. The 3rd stage is where the magic happens. With a MOSFET, the biasing is easier and we don't need a cap in series with the clipping diodes. The SUSTAIN knob varies the 3rd stage gain from unity up to almost 40dB. I changed the clipping diodes to LEDs so that when SUSTAIN is at zero, there's no clipping in the 3rd stage. The signal goes straight thru. The tone stack is right outta my Hoof mod and works pretty well here. The last stage is a JFET with enough gain to make up for any signal lost in the tone stack, and then some. Maximum output level is over 5.5Vp-p. I could have used a MOSFET there, but went with a JFET because I felt like it.
With two gain knobs, the range of tones is immense. Turn SUSTAIN down and there is plenty of dynamics. Turn SUSTAIN up and we get the classic BMP compression. Dime LEVEL & TONE, set MID to noon, SUSTAIN & FAT to zero and we have a treble booster. Use DRIVE to control the volume and MID to fine-tune the tone. Or dime FAT, DRIVE & SUSTAIN for some thick saturated fuzz. Dime TONE & back off on MID for some vintage sizzle. The SUSTAIN knob will scratch, that's normal. As usual, all component values are negotiable. If you don't have a particular component value, make like EHX and use the next closest value. The circuit is sensitive to some component values and indifferent to others. Check the clipping LEDs for leakage and use ones with lowest leakage for maximum gain. The ones I have installed indicate 10nA reverse current on my CCTT. Definitely one for the breadboard.
The 1st stage is at the bottom right, distortion stages bottom center, tone stack & output stage at the upper left.
Knobs (L-R): LEVEL - TONE - MID - SUSTAIN - FAT - DRIVE
I wanted to be able to vary the gain of the distortion stages and I had been thinking about using a MOSFET for one of the distortion stages. Here's what I ended up with. I tweaked the gain and EQ slightly in the 1st stage. I wanted the 1st stage to run transparent and clean, but be responsive to the guitar's knobs. The FAT knob does a good job of reigning-in the bottom end, but I wanted a little more sludge available when FAT is dimed. Because your knob can never be fat enough, right? So I increased C3 & C6 to 220nF. I left the 2nd stage pretty much intact, I just lowered R12 to increase the gain a bit. The 3rd stage is where the magic happens. With a MOSFET, the biasing is easier and we don't need a cap in series with the clipping diodes. The SUSTAIN knob varies the 3rd stage gain from unity up to almost 40dB. I changed the clipping diodes to LEDs so that when SUSTAIN is at zero, there's no clipping in the 3rd stage. The signal goes straight thru. The tone stack is right outta my Hoof mod and works pretty well here. The last stage is a JFET with enough gain to make up for any signal lost in the tone stack, and then some. Maximum output level is over 5.5Vp-p. I could have used a MOSFET there, but went with a JFET because I felt like it.
With two gain knobs, the range of tones is immense. Turn SUSTAIN down and there is plenty of dynamics. Turn SUSTAIN up and we get the classic BMP compression. Dime LEVEL & TONE, set MID to noon, SUSTAIN & FAT to zero and we have a treble booster. Use DRIVE to control the volume and MID to fine-tune the tone. Or dime FAT, DRIVE & SUSTAIN for some thick saturated fuzz. Dime TONE & back off on MID for some vintage sizzle. The SUSTAIN knob will scratch, that's normal. As usual, all component values are negotiable. If you don't have a particular component value, make like EHX and use the next closest value. The circuit is sensitive to some component values and indifferent to others. Check the clipping LEDs for leakage and use ones with lowest leakage for maximum gain. The ones I have installed indicate 10nA reverse current on my CCTT. Definitely one for the breadboard.
The 1st stage is at the bottom right, distortion stages bottom center, tone stack & output stage at the upper left.
Knobs (L-R): LEVEL - TONE - MID - SUSTAIN - FAT - DRIVE
