Vref vs ground

[Locrian99]

Good morning,

I’ve been playing around on my breadboards with a blues breaker circuit. I’ve been referring to both the original blues breaker circuit and the parthenon schematic from the main site in doing this. One thing I noticed was the original a lot of the “traditional” ground points are going to vref (apx 4.65 volts in my setup) while on the Parthenon they are going to ground. Anyone know what in the circuit is making that different. The basic idea between the two looks pretty similar to me.

https://docs.pedalpcb.com/project/Parthenon-PedalPCB.pdf

https://docs.pedalpcb.com/project/BlueBreaker.pdf

Thanks

 

[spi]

The short answer is that Vref and GND both look like ground to AC signals, so either work.

There's probably a better-informed long answer though.

 

[Locrian99]

The short answer is that Vref and GND both look like ground to AC signals, so either work.

There's a probably a better-informed long answer though.

Yeah I gathered that was what was happening. I wonder if it’s interchangeable then. I guess when I get home I could just change all those points that are going to vref to go to ground and see what difference it makes. But more curious as to why. The wampler video on the circuit just says that’s the way this circuit is or something to that extent.

 

[iamjackslackof]

I'm curious about this too. I looked at a bunch of opamp + diode clipper circuits like the Timmy once and noticed some circuits would go to ground and some to VRef, and I never could figure out the rhyme or reason behind it. I'd forgotten AC sees VRef as ground, but I've never understood why exactly.

 

[spi]

It's because of the capacitor between the vref and ground--it blocks DC from going to ground but lets the AC right through.