Why Connect Output Clipping Diodes To Vref?

[Paul Marossy]

I was looking at the Boss DS-1 schematic and noticed there are what appears to be clipping diodes on the output right before the tone control which are connected to the Vref supply. What is the purpose of that? Can you do this in other pedal designs? I don't recall seeing that before on a schematic, so that's why I am asking the question.

I have a design I'm goofing around with that has a Vref supply which I'm considering trying clipping diodes to ground on the output, but I have never really liked that sound. But seeing this arrangement on the DS-1 schematic has me wondering if that might be worth a try if it doesn't sound too bad.

[Mike Burgundy]

The diodes are inserted in a bit of the circuit sitting at Vref DC. Connecting them to ground would turn one fully ON, one fully off all the time. Doing it like this is is the same as diodes to ground with a dual supply.

[Paul Marossy]

The diodes are inserted in a bit of the circuit sitting at Vref DC. Connecting them to ground would turn one fully ON, one fully off all the time. Doing it like this is is the same as diodes to ground with a dual supply.

So in other words, if you have an opamp on a 9V supply and a Vref supply then clipping diodes on the output should be connected to Vref and not directly to ground? What happens if you connect them directly to ground?

It seems like the Vref scheme would do a more mild clipping and the one connected directly to ground would sound much nastier. Or am I perceiving that incorrectly?

[KMG]

Problem not with opamp & diodes but with the following bypass circuit. Whole bypass circuit (except fet gates) is  DC coupled to Vref.

[Paul Marossy]

Problem not with opamp & diodes but with the following bypass circuit. Whole bypass circuit (except fet gates) is  DC coupled to Vref.

Oh, OK now I get it!