Here it is a very interesting DAC with the best chips available on the
market and with an incredibly good price!
The Armonia Hi-Fi projects are available in kit, as assembled boards or finished products.
The Armonia Hi-Fi is a division of the Italian company Albatron srl, their target is to propose a product line competitive worldwide.
Before beginning the production of this DAC, making many prototypes,
all the DAC chips currently available from the Crystal CS4390 to the latest
Burr-Brown PCM1704 have been analyzed.
The choice has been in favor of the PCM63, a bipolar implementation of the very good 20 bit Burr-Brown technology.
Special care has been put into the analog output stage and into the power supply.
This DAC is available with 3 option for the output stage: operational amplifier, direct output with a low order passive filter or output transformers.
The chips used in this project are:
I have tested this DAC and currently I listen at music with it (see photo below) together with the LL1636 1:20 Lundahl transformers and the DACT CT2 100K+100K stepper attenuator.
I consider the sound of this DAC a step beyond the Crystal CS4390, it is stronger, cleaner and closer to the 'analogue' signal.
About the output resistor connected to the output pin of the DAC chip for the Current/Voltage conversion I have found that the best soundstage is in the rage of 100-125 ohm (here use only first class resistors as the Caddock MK132).
To use the LL1636 skip any resistor and capacitor on DAC chip output R8,R11,C22,C37 and connect directly the primary of this transformer in the 1:20 configuration and on output connect a 100K MK132 Caddock resistor and a 100K+100K DACT stepper attenuator.
If you ear some noise connect the ground output of one channel to the ground of the DAC.
Click to see enlarge image!
To increase sonic performance I have also changed the original 2200uF 25V of the kit with 220uF 35V ELNA Cerafine capacitors and I have reduced the heatsink of the regulators LM317/LM337 to insert in horizontal position two 4700uF 6.3V on output of the regulators.
The price of the DAC board kit will all the parts escluding the power
supply transformers, the output transformers and the operational amp. output
stage is about 220$.
The power supply toridal trasformer show in the photo below is a normal 12V+12V 30watt.
Armonia Hi-Fi have also a no compromise product with the same structure, the "D/A Converter N°1" with 3 parallel DAC chips and a separate power supply per each channel.
please contact directly Armonia Hi-Fi to get more information about prices of the versions and Lundahl about the transformers.