Adding blend control to Big Muff

[akkar]

'Cause you quoted RG's http://www.geofex.com/Article_Folders/panner.pdf, where 1^st page op-amps are powered from dual (symmetrical) supply..
(not clearly shown but guessed from non-inverting inputs bias..)

Sorry I'm still confused... I have a single +9V power supply, 9V goes to TL074 Vcc pin, ground goes to - pin, 4.5V (from voltage divider) goes to uninverting input.

Now what should I connect to the central tap of the potentiometer? Ground or 4.5V?

[ElectricDruid]

http://www.geofex.com/Article_Folders/panner.pdf

Sorry if I resume this old thread... If I use for eg a TL074 for the inverters (creating a double power supply from the 9volts) should I connect the tap of the pot in the link to the 4.5V, instead of ground?

If you've got the standard Ground and +9V power with a 4.5V Vref then then pot wiper (and the other points marked with a little Ground triangle on the panner.pdf) goes to the 4.5V Vref.

As Antonis says, it's because the pdf shows things done with a full dual supply, whereas you're using a single supply with Vref.

[antonis]

If I use for eg a TL074 for the inverters (creating a double power supply from the 9volts)

What exactly does this mean..??

[akkar]

If I use for eg a TL074 for the inverters (creating a double power supply from the 9volts)

What exactly does this mean..??

9V -> voltage divider -> 4.5V

[akkar]

http://www.geofex.com/Article_Folders/panner.pdf

Sorry if I resume this old thread... If I use for eg a TL074 for the inverters (creating a double power supply from the 9volts) should I connect the tap of the pot in the link to the 4.5V, instead of ground?

If you've got the standard Ground and +9V power with a 4.5V Vref then then pot wiper (and the other points marked with a little Ground triangle on the panner.pdf) goes to the 4.5V Vref.

As Antonis says, it's because the pdf shows things done with a full dual supply, whereas you're using a single supply with Vref.

Thanks.

I wonder if it's better to take it use the volume pot of the Big Muff as an overhaul level pot (taking the distorted signal input to the blend before the pot) or not as a control for the distorted channel only (taking the distorted signal input to the blend after the pot)

[antonis]

I have a single +9V power supply, 9V goes to TL074 Vcc pin, ground goes to - pin, 4.5V (from voltage divider) goes to uninverting input.
Now what should I connect to the central tap of the potentiometer? Ground or 4.5V?

As long as:
1. non-inverting inputs are biased at 4.5V from respective voltage divider, and
2. +4.5V divider respective point is decoupled (via a cap to GND)

you're free to connect pot's wiper either to GND or +4.5V point..
(a decoupled bias point is considered AC ground..)

[antonis]

If I use for eg a TL074 for the inverters (creating a double power supply from the 9volts)

What exactly does this mean..??

9V -> voltage divider -> 4.5V

(you probably wanted to mean "half"..)