Mola-Mola New DAC Prototype

Mola-Mola's Bruno Putzeys says that he wants to leapfrog the idea of incremental DAC design and create a product that puts us a decade down the road in one jump. To that end, he was showing off a prototype design that he has working, but not fit into a product yet. He adds that it should be ready in about a year.

The soft spoken Putzeys, from the Netherlands, was stationed in Philip O'Hanlon's On a Higher Note suite atop the Mirage hotel, and handed me a brochure and pointed out some details. "Some things can't be done with off the shelf chips. Today's best DAC chip claims no better than 22 bits worth of dynamic range. Mola-Mola's DAC is designed from the ground up using circuits and digital algorithms developed in-house."

Putzeys said the new design is equivalent to 8xDSD and then suggested those who want to know more check his blog.

Regadude's picture

[Abusive content deleted by John Atkinson. Consider this your first warning, Regadude.]

Jason Victor Serinus's picture

Bruno Putzeys is deeply respected in the international DIY community for the quality of his designs and the depth of his thinking, and drew a huge crowd to his talk at Burning Amp. The notion of building a DAC without relying on an off-the-shelf DAC chip is not only valid, but one that dCS has embraced for years.

John Atkinson's picture

The very first digital filter I experienced, back in the late 1970s, actually operated in the analog domain, with an array of bucket-brigade devices. The array of shift registers that can be seen on the top board in Bruno's hands works the same way. With each coefficient effectively identical, this behaves as what is called a "top hat" filter.

John Atkinson

Editor, Stereophile

MLgrado's picture

John, you mention that the first 'digital' filter operated in the analog domain. Which raises the question, are these types of filters we are discussing analog or digital? Seems to be they are 'hybrids'. Or something like that.

MLgrado's picture

You will find variants of this kind of filter in a lot of places. Consider Burr Brown. The FIR filter used to convert DSD to analog is an 8 bit delay line, but rather than having equally weighted switches/coefficients, they are unequal.

Signalyst, the company behind 'HQPlayer', has plans for an Open source 'DIY' DSD DAC. It is a 32 bit delay chain via shift registers into equally weighted switches.

I have yet to confirm it, but I believe Lampizator uses some sort of this 'moving average' FIR filter in its DSD DACs. They advertise the first stage of filtering as 'solid state digital'. I am assuming this is shift registers and resistors. I could very well be wrong, though.

I do find Bruno's implementation to be fascinating, though, if simply for the fact it uses extremely high speed PWM. Can't wait for a final product!!