Note: an earlier version of this text was first published as «The DDDAC1794 is no (ordinary) DAC!» on Computeraudiophile.
Why the heck would anyone buy and build a DDDAC1794? This thing seems very much out of place in the arena USB and FireWire DACs out there, it costs a lot of money, and it requires an intimate relationshop with a soldering iron, too. However, I have been in the DIY world long enough to know that nothing beats a good DIY system.
I had many and very different DACs in the past. My beloved Stokes DIY Tube DAC was restricted to S/PDIF and red-book 44/16 audio. I plunged into computer audio with a not-so-great Headroom USB DAC. Then I hot rodded an Apogee Mini FireWire DAC with a hefty DIY power supply. I use an Audiolab M-DAC in our living-room system (and it tends to break from time to time). My main system had a Linnenberg UDC1. And I’ve listened to the Weiss and many other cost-a-lot stuff. However, while some of those DACs sound pretty good compared to others, they all screw up the music in the same way. And I don’t mean the painful “S” sounds and similar boorishness from crummy DACs. Even the «good» DACs take away the life, flesh and breath from the music, very much in contrast my trusted vinyl rig (Scheu platter and bearing, Teres motor, and Schröder arm). The Stokes Tube DAC and the Audiolab M-DAC both allow using different built-in digital filters with different characteristics. The different filters usually sound slightly different, and some sound «better» than others, but they never get rid of the artificial sound completely. But, maybe unfortunately, the filters cannot be turned off completely.
When I «stumbled» over Doede Douma’s description of his DDDAC1794 that does away with digital filters I knew I had to try a non-oversampling (NOS) DAC sooner or later. Why not just skip the digital oversampling/filter, if it affects the sound by inventing new sound data that never existed in the first place?
Doedes technical description and documentation is very comprehensive and makes a lot of sense. My only hesitation was that I didn’t want to start yet another DIY project that I’d never finish, because time is limited (there’s a family, work, and too many other hobbies). But Doede sells completely assembled and tested DACs modules, power supplies, and USB interfaces. He even gave me a copy of the files needed to order a very nice custom-made chassis for the DDDAC1794 at Schaeffer AG. And when I asked him about the specifics of the additional bits and pieces needed to build a complete DAC, he simply included these in the package. For example, when I asked about which power switch would fit in the chassis, Doede just put the switch in the package (three switches, to be precise. Just in case I’d break the first and loose the second one). All this allowed me to build the DDDAC1794 in no time. The only gripe was when the Schaeffer chassis was a wee to too small to fit the power-supply heat sinks, but there was an easy fix (just a little side note to illustrate how smooth building the DDDAC1794 was: before I found the DDDAC1794 on the net, I asked the local Bryston distributor if I could borrow one of their DACs to give it a try. They keep promising I could have one once they receive one. In the meantime, I am playing my music using the DDDAC1794).
How does it sound? Spectacular? Phantastic? Superb? Damn good? Fucking great? Yes, all of this. But that’s all secondary with the DDDAC1794. The really important thing is that the DDDAC1794 doesen’t sound like a DAC at all. It’s a bit like a vinyl rig on steroids, but without the pops, clicks, and rumble (and I don’t mean the old record player your dad had when he was a boy, but the freaky good 2013 stuff). The music and all the little details are just there in a very relaxed way. Ry Cooder is having a party in my house, Phil Collins’ (yes!) drumsticks are flying in front of me, Sophie Hunger has moved to my house (was close anyway), Willy DeVille has risen from the dead, no more doubts about No Doubt, Timber Timbre is timber timbered, Mark Knopfler is in Dire Straits, Marianne Faithfull finally confessed her love for Bruce Springsteen, Jeff’s Wine is as Lilac as it gets, Glen Hansard got a shave, Depeche Mode are Exit(er)ing, Lou Reed made me a Perfect Day, and Giant Sand and Marla Glen just called to be the next acts in my listening room. In short: I hear the music, not a DAC. In contrast to oversampling and digial filters, the NOS concept not only works, but also sounds good!
As a final and very important comment, I’d like to congratulate Doede not only for designing the DDDAC1794, but also for documenting everything in full detail. The deep insight into how the DDDAC1794 works provided a lot of confidence that convinced me to try Doede’s design and to buy his stuff. One can only guess why others don’t do that.
Update 11.3.2013: Doede sent me two Sowter 1298 transformers, which he designed as an alternative to the standard coupling capacitor in the analog out line. Apart from avoiding the coupling capacitor in the signal, the transformers also allow using the inverted output of the DAC chips, thus cancelling out even-order distortion. I immediately noticed the sound improvement with the transformers. The music sounded as if the musicians just got a pay increase! The transformers were expensive, but the money was well spent in my case.