In 2004, an audiophile client asked us to made a hifi preamplifier for his vinyl disc player. At that time, the vinyl players was somehow obsolete. One can found a power amplifier but no more with electromagnetic or ceramic cartridge input.
Therefore, we put our knowledge to work and come with a innovative ideea: a low noise preamplifier with dedicated integrated circuits.
The clue was to supply differential voltage to the preamplifier from a single voltage supply.
All the components was hand-picked for stereo balance and the preamplifier has both RCA and RIAA EQ curves and also, a rumble filter.
For that, we choose monolitic DC-DC converters at high frequency.
PAT (Project Allocated Time): 3 weeks.
The preamplifier still works on our client's HiFi corner.