Power supply for mixer

[rodrigosalvati]

Hello,

I have a 12 channel mixer I am upgrading and would like to know if the power supply it has can be optimized. The psu is on the same board as the headphone amp, and I am trying to figure out what belongs to what.

Can anyone, with a photography, tell what kind of power supply this is?

If the voltage from the wall outlet is 230, and the ac transformer in the mixer is wired for 240, could that affect the mixers behavior? Its feeding the powersupply 15vac which then outputs +-12vdc to the circuit. Other british mixers from the same era I have read about seem to operate at a higher dc voltage, and thats why I am wondering if its something worth addressing.

Attached is a photo.

As always, thanks

 

[cbdb]

The 12v rails give you the max headroom (max output signal). Increasing the voltage will increase this, but you would have to make sure the higher V doesn't destroy any components.

What kind of mixer? Does it have +4dbm outputs or only -10dbm. If +4 you won't have much headroom (~10db).

 

[rodrigosalvati]

Its a studiomaster rsd 12 into 2 mixer. It has xlr outputs, I doubt that assures+4Dbu outputs though. Is the only way of knowing with a tone and meter or scope?

Would the lower ac voltage mean a lower voltage ?

 

[cbdb]

Yea a xlr dosnt always mean +4. Try to find a manual online or, For +4dbm, 0vu should give around 1.2volts output.

 

[rodrigosalvati]

I took out the original power supply and it has 8 rect. diodes, 2 larger filter capacitors, two 12 volt regulators, and 2 very pretty chewing gum looking capacitors (red, yellow, black, red. Would anyone know what these last ones do, if in paralel to the regulators? Can they be replaced by something worth investigating?

Have a feeling the mixer is -10 dbv, but will check when I reinstall the psu.

Thanks

 

[rodrigosalvati]

I have read that the smaller capacitors are mullard film capacitors.