tyrian distortion: wrong capacitors?

[akis182]

Hi, i'm planning to get the Tyrian distorsion, but while reading the schematic it seems something strange in 1st gain staging section



selecting one route instead of the other, nothing seems to change (C6 and C7 are the same, so same hz are blocked/passed). in sanguine distortion, which is pretty the same in the first GS section, the caps are different




Am I wrong?
Thanks
Ak

 

[giovanni]

The problem is that the two switch positions in both schematics are equivalent. The cap values are irrelevant. My guess is that one of the positions actually disconnects the cap. @Robert can clear this out I’m sure.

 

[Robert]

selecting one route instead of the other, nothing seems to change (C6 and C7 are the same, so same hz are blocked/passed). in sanguine distortion, which is pretty the same in the first GS section, the caps are different

It's a three position switch. (and we're only seeing one half of it here)

Both capacitors are connected in parallel in the top and bottom position, but only one capacitor is connected when the switch is in the center position.

 

[giovanni]

It's a three position switch. (and we're only seeing one half of it here)

Both capacitors are connected in parallel in the top and bottom position, but only one capacitor is connected when the switch is in the center position.

Wait so top and bottom positions are identical? Or are you saying top gives one cap and bottom the other?

 

[jcpst]

Let’s expand the pic with the rest of the switch.

 

[Robert]

Wait so top and bottom positions are identical? Or are you saying top gives one cap and bottom the other?

In the Tyrian, yes. The capacitor values are different in the Malachite and Sanguine.

Keep in mind (like @jcpst pointed out above) the bottom and top positions are not the same in the stage that follows this one.

 

[giovanni]

Always look at the big picture...

 

[akis182]

Thanks guys. So, to undestand, how are they coupled? Which path is enabled while switching the 3 positions?

 

[Robert]

When the switch is up or down the signal flows through both capacitors in parallel. The equivalent capacitance is the sum of both capacitors.

When the switch is in the middle the signal only flows through the upper capacitor. The lower capacitor is out of circuit.

The gain/frequency response of the next stage is switched simultaneously with the other half of the DPDT.

 

[comradehoser]

Even in the original post, the switch routes the signal along different paths even if the cap values are the same (if I'm reading it correctly). Up feeds the signal back into the TL072 1.1 pin 1 (output), whereas down feeds the signal through some resistors and back into pin 2 the of IC 1.1.

Anyway, even if I am totally misunderstanding the schematic, I can testify that regardless of the cap values, the switch actually does something and markedly changes the sound.

It's like this: chonk chonk chonk/ChOnk ChOnK ChonK/***CHONK CHONK CHONK***

 

[akis182]

When the switch is up or down the signal flows through both capacitors in parallel. The equivalent capacitance is the sum of both capacitors.

When the switch is in the middle the signal only flows through the upper capacitor. The lower capacitor is out of circuit.

The gain/frequency response of the next stage is switched simultaneously with the other half of the DPDT.

So, correct me if I'm wrong:

• In position 1 (on, don't know if up or down), stage 1 has C6||C7 and stage 2 R15||R16
• In position 2 (off) stage 1 has C6 and stage 2 R16
• In position 3 (on, the other one), stage 1 has C6||C7 and stage 2 R14||R16.

Is it correct how dpdt works here?

Thank you again and again!

 

[Robert]

Up feeds the signal back into the TL072 1.1 pin 1 (output), whereas down feeds the signal through some resistors and back into pin 2 the of IC 1.1.

It's the same path regardless, we're just throwing an additional cap in parallel with C6 to increase the value.

It's drawn a little funny in the schematic, it's a bit more obvious if you redraw it like this (but exactly the same electrically):

 

[Feral Feline]

Even in the original post, the switch routes the signal along different paths even if the cap values are the same (if I'm reading it correctly). Up feeds the signal back into the TL072 1.1 pin 1 (output), whereas down feeds the signal through some resistors and back into pin 2 the of IC 1.1.
...

All roads lead to Rome.

They might be different paths, but they're all connected at the same points, so C6 & C7 in the OP's first circuit snippet are just as parallel as the SATURATION caps C3 & C4 in the Mutagen, for example...

STOCK:







SATURATION MUCKED WITH:




Well that was pretty fugly, try again:





That's why you'll see the exact same Rat/808/Muff/etc circuit with a differently drawn schematic ...



EDIT: DANG! Robert beat me to it and did it simpler, better and faster.