Sunday, June 3, 2007

DAC part improvements

A good sounding DAC requires:

  • low jitter

  • clean, low noise power supply for analog part (and for clock)


Audio Note digital board (signature version) is my DAC board base. It is really well good designed, but still not perfect. Audio Note completely ignores the jitter issue. I take low jitter as important component of DAC design - reclocking must be done just before DAC. This is the thing I will have to do on my own.
Secondly, I will investigate analog voltage regulator design for the DAC chip analog voltage supply - this has to be clean as possible. AN board does not use classic LM317/TL471 regulators (they are good, but not good enough), but LF351/pass transistor/LED combination. I hope it does its work good or I will provide it myself.
I also consider using battery power supply (SLA/VRLA) as they provide low-noise DC (yet to be measured under load).

I also have to provide low-noise DC voltages of 6.3V and 230V for the 6DJ8 tubes.
Any suggestions?

Matej

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