DDCs—what’s the deal?

So I stumbled across a YouTube video that referred to a Denafrips Gaia DDC.

I know nothing about DDCs, so did some cursory searching. Basically it’s to clean up digital signals from USB etc and then feed to the DAC.

Is something like this useful if using a DS DAC and using the one of the non-i2s inputs? Is this snake oil?

Or currently I use a Lumin T2 and Roon as my streamer; it connects to my NAS over Ethernet. If I added a DDC into the mix, would it help?

Lumin T2 is a streamer/DAC and unless you plan to use it as a streamer feeding anther DAC via USB output, I can’t imagine how Gaia will work for you.

Personally I consider a good DDC ~ indispensable in my system lately. I use a Gaia.

Mostly used as USB (eg Tidal) → I2S out (HDMI or RJ45) to DAC.

But also for example, AES from a CDT → I2S out (HDMI or RJ45) to DAC.

Or even SPDIF → I2S out (HDMI or RJ45) to DAC. T

Yeah that’s what I was thinking too.

Watch this excellent explanation. (I use an Iris to a DAC with great results.)

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BTW I have a Gaia in black finish available if you’re interested. TK

Thank you. Let me think about it. Currently the only place in my signal path that a DDC would need helpful is at the USB input to my exasound e38 multi ch DAC. But I don’t have it connected at the moment. (Too lazy.)

The first D/D converter was the dCS 972 about 25 years ago. It was designed for studio use as a general purpose sample rate converter. It was found (not by dCS themselves) to benefit sound quality by upsampling 16/44 CD into dCS’s 24/96 ringDAC, so it was released into the consumer market. dCS, Chord and Denafrips produce upsamplers (or DDCs). They all make proprietary DACs (FPGA and ladder types) using proprietary data transmission (2xAES/EBU, 2xBNC, I2S).

It seems to me the esoteric end of hifi, but the dCS systems seem to me to give the cleanest, most transparent digital sound one could hope for.

Another reason to get a DDC is to give you more digital inputs. I have a Denafrips GAIA with 2 streamers, Amazon Fire Stick (for music) and my TV connected. From there I connect to my DS DAC I2S input #2.

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No, perhaps it was the first for audio consumers, but heck digital computer workstations had had general purpose sample rate converters for years before that. (WaveFrame had a general purpose samplerate converter as an optional board in their AudioFrame box in the late '80s.)


Interesting. How does the Gaia effect the sound of the DAC?

I have not taken the time to compare the GAIA to my Matrix Audio X SPDIF-2 for how it improves the USB output of my Innuos Zenith Mk3. My main point was that with the GAIA I have 4 digital inputs that all get noise and jitter reduction and an I2S output to my DS DAC. BTW: I had to configure the GAIA I2S output to work with the DS DAC.

I do think that the GAIA offers an improvement (more air and better detail), but so far not as good as my DMP > I2S > DS DAC. I still have some USB and HDMI cables to try to see how close I can get my streaming output to the DMP before I start ripping my appox. 3500 music CDs to my NAS. I will likely try the upcoming PSA Air Lens streamer when it comes out. YMMV may vary depending on your equipment and cables used.

I heard about the Matrix SPDIF on this site, got one and every time I get a DAC, I try it with and without. Maybe it’s because i use a PC to stream but once again, the PC to Matrix and then to DAC is an improvement vs. without. Not sure if Gaia etc is just a more pricey version of a SPDIF but before I put more money into a device like a Matrix, I would consider a better DAC.

For instance if I add a M Scaler to my TT2, I don’t think I need the Matrix but will probably at least try it.

Be interesting to hear if folks (a lot on this forum used a matrix) moved “up” and got better results?

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Thanks Ted, I stand corrected. It was the first consumer unit. I assume it must have been a pretty conventional piece of studio hardware, given digital recording had already been used commercially for about 20 years. (I have a couple of Denon digital pressings from about 1975/6.) The story goes that the Japanese dCS dealer put it between his transport and dCS 24/96 DAC and reported positive outcomes back to dCS.

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I use a $65 Douk U2 Pro DDC to convert USB to I2S LVDS over HDMI TO GREAT EFFECT. The short of it is that the improvement in my system was not subtle. The effect it has on the signal can be heard through two DACs, a Topping Dx7Pro with SparkOS op-amps, and the GainCell. Better spatial detail, bass definition and overall clarity can be heard.

When I ran my Roon through HQPlayer in order to output DSD to the DAC, the sound I hear is pretty much complete. There’s no guessing about what’s being heard. My wife is in total disbelief as she’s been there for all the upgrades, tweaks and insanely long listening sessions. Take the DDC out of the chain and you lose a bit of the magic, that solidity in everything that is heard is lost, some detail is odd sounding, dense high frequency not as distinct, subtle details previously uncovered are now lost. Does it sound bad without it, HECK NO, but now it’s like the “magic” is gone. To my ears, that was the last party trick and I’m not sure how I improve on this – the source that is. I’m sure I can go a bit crazier on the pre-amp, and amp, but I no longer hear a reason to.

The signal chain:
Roon (WinPC) >> Rpi4 w/ PI2AES HAT (currently just being used for the power input) RopieeeXL (Roon, HQPlayer NAA) [iFi Power Elite 24v] >> AQ Forest USB cable >> iFi Purifier 3 >> Douk U2 Pro >> AQ Cinnamon HDMI .75m >> Topping Dx7Pro (SparkOS SS3602 op-amp x 4) >> AQ McKenzie XLR 1m >> PSAudio GainCell DAC >> AQ McKenzie XLR 1m >> PSAudio M700 >> AQ 14ga w/ AQ banana plugs >> Tekton Moab spiked on some anti vibration slider pucks…
PSAudio Powerplant P3

HQPlayer: SDM, Closed-Form-16M [1x & Nx], ASDM7EC 512fs+, DSD256

Yep, I’m a big fan - I have an Audio DG DI-20 in the digital chain. To me it just completes the clean up of the vicissitudes of using a computer as a digital source. Big sound stage, great separation, and musical - easy to listen to. One contributor on the forum described all this front end clean up as “digital gymnastics” - that made me smile, as I dont mind what its called if it works. Incidentally there is an Audio DG DI-20 thread on Head Fi - It was reading this that sealed my decision to pull the trigger - glad I did. Signal Chain
Mac mini > Ammara Luxe Upsamples to 176 KHz > PS Audio LAN Rover > Chord MScaler Upsamples to 352 kHz > Audio GG DI-20 > via I2S > DSD Senior > NVA M600 Power Amps > Meadowlark Kestrel Hot Rods

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Which input on the DDC does the M-Scaler feed?


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I use the co-ax input on the DI-20 - I use a BNC adaptor to take the s/pdif output from the MScaler - one of the criteria for my choice was that the input on the DI-20 should accept 352 KHz on the coax input - which it does - then with Sunlight on the DSD snr the I2S input also acccepts 352KHz.
Hope this helps

Yes, thank you.

I ordered the external power supply board touted on the DS hot rodding thread and plan to move away from the Bridge II Ethernet card eventually.

I am exploring options for kit necessary to get the Ethernet signal to the DS inputs.



This begs a question: I don’t think I have a C place for a a DDC in my streaming signal chain since my Lumin T2 endpoint gets the data over Ethernet from my NAS.

However, if instead of my NAS the Lumin got it through usb from a DAS connected to the Mac Roon core, then a DDC would help, correct?

And if I replace the Lumin with an AL (->i2->DSDAC) the situation stays the same? Although I’d have to do something about airplay.

(My software signal chain is a PST to DS DAC through i2s so there’s no need of a DDC there either.)