Chuck D. Bones
Circuit Wizard
Another design from Steve's contest. BtR did a mash-up of the SHO, a BMP clipping stage and a tone control from the BD-2. You can see his original schematic and write-up here. Did I mention that this design won?
I liked the basic circuit, so I tweaked it by removing a few unnecessary components and adjusting the values of a few others. On the breadboard, Q1 is on the right, Q2 in the middle, spare parts on the lower left. I gave the gain (HAIR) control more range and adjusted the bias on Q1 for maximum headroom. C1 & C2 determine how much bass gets thru. The values shown below produce a fairly tight bottom end. The toggle switch in BtR's circuit was subtle and I had only one favorite setting, so I removed it. I tweaked Q2 for a little more gain. The tone (SHAVE) network was retuned for a slight treble boost above noon. As usual, all component values are negotiable. You might think that the 1N4148/LED clipping diodes would produce asymmetric clipping. Turns out they don't because C4 blocks DC and causes their clipping thresholds to balance. With HAIR above 8 or so, we get some asymmetry because Q1 is driven to saturation. Good tones all across the control ranges and good volume clean-up too. The breadboard matches the schematic except for R11 & RLED.
Knobs: Black - MUFF; White - SHAVE; Red - HAIR
Check out my new breadboard set-up. I grew tired of buying crap breadboards from China. On some, the plastic part was warped. Many of the contacts were too loose to make reliable connections. I had ICs literally popping out of a couple of them. I found a good source
here in the US for the solderless boards. I drilled a stainless steel tray that I use for parts, turned it upside-down and mounted the bracket on that.
I liked the basic circuit, so I tweaked it by removing a few unnecessary components and adjusting the values of a few others. On the breadboard, Q1 is on the right, Q2 in the middle, spare parts on the lower left. I gave the gain (HAIR) control more range and adjusted the bias on Q1 for maximum headroom. C1 & C2 determine how much bass gets thru. The values shown below produce a fairly tight bottom end. The toggle switch in BtR's circuit was subtle and I had only one favorite setting, so I removed it. I tweaked Q2 for a little more gain. The tone (SHAVE) network was retuned for a slight treble boost above noon. As usual, all component values are negotiable. You might think that the 1N4148/LED clipping diodes would produce asymmetric clipping. Turns out they don't because C4 blocks DC and causes their clipping thresholds to balance. With HAIR above 8 or so, we get some asymmetry because Q1 is driven to saturation. Good tones all across the control ranges and good volume clean-up too. The breadboard matches the schematic except for R11 & RLED.
Knobs: Black - MUFF; White - SHAVE; Red - HAIR
Check out my new breadboard set-up. I grew tired of buying crap breadboards from China. On some, the plastic part was warped. Many of the contacts were too loose to make reliable connections. I had ICs literally popping out of a couple of them. I found a good source
here in the US for the solderless boards. I drilled a stainless steel tray that I use for parts, turned it upside-down and mounted the bracket on that.
