I haven't heard this particular chip in a top flight implementation (I have an old Cambridge Audio amp which uses it but that implementation sucks). Its brother and sister chips with similar internal design sound wonderful when given a decent PSU. Suggest you uprate the PSU you have on those PCBs you're showing...
I agree that LM3886 sound sucks in comparison to the Philips chip family (I'm playing with TDA8566). I suspect there's a sound technical reason for this - PSRR at higher freqs on the Philips chips smokes the LM.
The TDA1514A integrated circuit is a hi-fi power amplifier for use as a building block in radio, tv and other audio applications. The high performance of the IC meets the requirements of digital sources (e.g. Compact Disc equipment). The circuit is totally protected, the two output transistors both having thermal and SOAR protection (see Fig.3). The circuit also has a mute function that can be arranged for a period after power-on with a delay time fixed by external components. The device is intended for symmetrical power supplies but an asymmetrical supply may also be used.
· High output power
· Low harmonic distortion
· Low intermodulation distortion
· Low offset voltage
· Good ripple rejection
· Mute/stand-by facilities
· Thermal protection
· Protected against electrostatic discharge
· No switch-on or switch-off clicks
· Very low thermal resistance
· Safe Operating Area (SOAR) protection.