FPGA DACs

[duxservit]

Folks,

 

I’m interested in FPGA DACs specifically.  Does anyone have a list of FPGA DACs available today?

 

(I’m aware of only PS Audio and Chord).

 

Thanks in advance.

 

 

[sockpit]

Exogal.

[firedog]

Playback Designs

[Miska]

Holo Audio

dCS

 

 

[One and a half]

Dupe

 

[duxservit]

Wow, thanks folks,  didn't realize there were so many.

 

I'll compile this into a list on this thread.

 

 

[asdf1000]

Ayre? A combination of ESS chip and FPGA for Ayre's own filters?

 

[Fokus]

Tube Technology and Chord Electronics were the first to do this, in 2001.

 

Both were Rob Watts designs.

 

[Ron Scubadiver]

Chord is the best known FPGA DAC.  If your current DAC does a good job on DSD, and your computer is powerful, you could try HQPlayer to convert to DSD 256 or 512.

[Miska]

2 hours ago, Fokus said:

Tube Technology and Chord Electronics were the first to do this, in 2001.

 

I thought dCS was first...

https://www.dcsltd.co.uk/timeline/

 

[Fokus]

I thought the first RingDAC was made with discrete logic. My memory’s eye sees a large board full of chips.

 

But there could have been an FPGA in there, yes.

 

[Nordkapp]

Resonessence Labs.

[Ralf11]

I asked about this a while ago - it seems there are a lot because the fixed cost to do up an ASIC can't be met by the volume of most HiFi DAC sales

[Miska]

3 hours ago, Nordkapp said:

Resonessence Labs.

 

Those are just ordinary ESS Sabre based DACs...

[Miska]

4 hours ago, Fokus said:

I thought the first RingDAC was made with discrete logic. My memory’s eye sees a large board full of chips.

 

But there could have been an FPGA in there, yes.

 

They still have separate flip-flops to deal with the switching (for good reasons), but FPGA was/is driving the show.

 

[biosailor]

Aqua Acoustic Quality. They just released a new S3 board for the La Voce, FPGA controlled.

[skatbelt]

Metrum Acoustics uses FPGA in their R2R ladder converters.

[Norton]

1 hour ago, Miska said:

 

Those are just ordinary ESS Sabre based DACs...

 

I guess that depends on what is meant by a "FPGA DAC".  As I understand it, the Mirus uses both FPGA and 9028 chips.

 

To my ears, nothing ordinary about the  results though....

[Miska]

49 minutes ago, Norton said:

I guess that depends on what is meant by a "FPGA DAC".  As I understand it, the Mirus uses both FPGA and 9028 chips.

 

By that definition, then there are a lot of "FPGA DACs", because FPGA is commonly used for routing and interfacing digital signals. Like in the case you describe. Then for example all RME Audio gear can be counted in as well as numerous others. Soon it then becomes easier to list DACs that don't have FPGA.

 

[Nordkapp]

2 hours ago, Miska said:

 

Those are just ordinary ESS Sabre based DACs...

Yeah, and they have FPGA processors as well, 

[diecaster]

The OP should clarify, but I don't believe he wanted a list of DACs that included FPGA chips. I think he wanted a list of DACs that did not have traditional DAC chips and instead used one or more FPGA to handle the D to A conversion.

[Miska]

 

2 minutes ago, diecaster said:

The OP should clarify, but I don't believe he wanted a list of DACs that included FPGA chips. I think he wanted a list of DACs that did not have traditional DAC chips and instead used one or more FPGA to handle the D to A conversion.

 

That's how I understood it too... Especially based on the examples he gave...

 

Although I don't know why it would matter if it is FPGA or some other approach to avoid using COTS DAC chips. Just referring to for example my DSC1 as an example.

 

[asdf1000]

35 minutes ago, diecaster said:

instead used one or more FPGA to handle the D to A conversion.

 

Is it the FPGA itself that is converting D to A? In particular the A.

 

Is there a separate analogue output stage in Mojo or is that derived directly from the FPGA?

Absolutely. An FPGA is entirely digital and cannot have analogue outputs. This is done with discrete components (flip flops, resistors, capacitors and separate reference circuitry). Doing the analogue discretely has big benefits. In designing silicon DACs there are enormous problems - the clock has to be distributed, and this increases jitter, the substrate injects noise and distortion into the analogue parts, the reference circuitry can't have low enough impedance and is noisy, resistors are non-linear, capacitors are non-linear too. None of these problems apply with discrete DACs.

 

http://www.the-ear.net/how-to/rob-watts-chord-mojo-tech

[diecaster]

24 minutes ago, Em2016 said:

 

Is it the FPGA itself that is converting D to A? In particular the A.

 

Is there a separate analogue output stage in Mojo or is that derived directly from the FPGA?

Absolutely. An FPGA is entirely digital and cannot have analogue outputs. This is done with discrete components (flip flops, resistors, capacitors and separate reference circuitry). Doing the analogue discretely has big benefits. In designing silicon DACs there are enormous problems - the clock has to be distributed, and this increases jitter, the substrate injects noise and distortion into the analogue parts, the reference circuitry can't have low enough impedance and is noisy, resistors are non-linear, capacitors are non-linear too. None of these problems apply with discrete DACs.

 

http://www.the-ear.net/how-to/rob-watts-chord-mojo-tech

 

Okay, you are being unnecessarily pedantic.

[asdf1000]

10 minutes ago, diecaster said:

 

Okay, you are being unnecessarily pedantic.

 

Just sharing accurate info from a DAC designer, for learning (myself included) purposes.