Marshall MG30 effects and headphone out

[reliq]

I am designing my first amp, and investigating the mg30dfx schematic (just happens to be the amp i own), but I don't understand where the effects come from.

I think the 5K pots VR10 and VR9 control the effect selection and level, but don't know what actually makes the effects.

Also, what is CN1?

And why is the headphone out coming from the output of the 2050 and not from output of the preamp stage? I thought you shouldn't feed 30W to headphone speakers.

Here is the full schematic https://elektrotanya.com/marshall_mg-30dfx_sch.pdf/download.html

[DIY Bass]

CN1 is a connector.  I suspect (without being certain) that there is a separate effects board that is joined to the main board through CN1, which is why you can't work out where the effects are :-)

[PRR]

Welcome!

> why is the headphone out coming from the output of the 2050

It isn't. The drawing is badly drawn. Headphone drive comes from IC8B, a small opamp, through 330 Ohm resistors to each ear. The jack contacts are shown all wrong. The third connection breaks the ground return to the internal speaker when you plug-in headphones, muting the speaker. (I suspect it does not go dead-silent.)

And yes, there has to be a thingie plugged into CN1 to do the magic.

[reliq]

Thanks guys!

I knew something had to be wrong in that schematic!