The Week on the Breadboard: The Emperor of Tone

[cooder]

I want to ask everyone about their preferences w.r.t. the charge pump.
1. No charge pump. Run it on 9V or 18V. That's the schematic in post #13.
2. Optional charge pump. The charge pump can be installed or not. Or you can put a voltage switch on the board. If the charge pump is not installed, then you have option #1.
3. Split rails. That's the schematic in post #1. Charge pump is mandatory. Must run on 9V only.

I don't have a strong preference one way or the other. They all have advantages & disadvantages and none of them are show-stoppers. #1 is the minimalist solution. #2 is the most flexible, but also has the highest parts count. #3 removes one electrolytic cap from the audio path in each channel (C6 & C16).

If there's no real sound advantage to the split rail design I would vote for option 1, no charge pump.

 

[jimilee]

I would like to have the option of both, because options. I have no other good reason.

 

[joelorigo]

It’s interesting to finally find out what mike did to the bluesbreaker to get to the KOT.

 

[Chuck D. Bones]

The advantage of split rails is there's no Vref. Everything that connects to Vref in #1 or #2 connects to GND in #3. We don't need C6 or C16 to block DC, so they are removed. Theoretically, every component that the signal passes thru colors the tone whether we want it to or not. So it should sound better with those two caps removed. I doubt any of us would hear the difference.

 

[Chuck D. Bones]

Just FYA, this is what the power section looks like with a charge pump and a voltage switch. Ignore the ref des,

 

[kristopher]

Help me understand: what is the benefit of running the channels in parallel? Both channels do basically the same thing. Have you tried it?

I have not tried it. My friend wanted to know, I believe he wanted to be able to blend the two together.
I didn’t mean to distract from the Charge Pump talk.