Preamp for SMPS powered class D

matherp

Member
2009-10-26 11:52 am
Hi all

I've got a Sure TK2050 amp powered by a Meanwell 32V supply and now want to add a PGA2310 based volume control and input selection circuitry.

My thinking is that I need to create a virtual ground for the preamp at the same potential as the TK2050 loudspeaker terminals (15.7V measured from the power supply negative terminal). So I'm thinking of using a BUF634 fed by a potential divider with a trimmer at the centre to split the SMPS rails at exactly this point. I would then use a LM317/LM337 combo to create say +/- 12V centred at 15.7V to power an OPA2134 as a buffer and then the PGA2310 which will feed the power amp.

Does this make sense as an approach?

Best regards

Peter