Sound Check, how does it sound and what is best?

The big day is coming...

We have been looking forward to this day very very much.... After all testing and designing, there is always doubt, how the end result will be. On top, Bernd, Klaus and Reinhard were dying to get their own DDDAC1794 to play their high resolution music... So on a still very warm Sunday, early September, I drove up to Klaus's place for the big day :-) Anyone who thinks, this is one of those stiff listening sessions, is totally wrong. This group of Audio Lovers is just an enthusiast bunch of guys and we always have a lot of fun in between, we discuss tons of other stuff and always try to have a nice lunch as well. The rule is, the host cooks :-)

Of course we also wanted to do some listening tests and to bring some structure in this I prepared our test bullets:

• In general 192 / 96 / 44.1 formats
• 12Volt battery versus DDDAC power supply
• DDDAC 12V power supply versus Bernd's 1543 power supply
• WaveIO Powered by USB-bus or DDDAC 5V power supply
• DDDAC1794 against DDDAC1543 on 44.1kHz
• Sowter output Transformer versus Mundorf Gold-Silver-Oil output
• Parallel Decks: one versus four

Preparing for the tests I brought quite some equipment and on top we needed to be ready for some serious listening tests, comparing all the test bullets from above. We made sure that all connections were easy to switch and sound levels were comparable. Otherwise the loudest tends to win... It is so convenient that the listening room (well, more like an own house... actually it is...) is so large. It is easy to swap equipment, walk around and have a place to experiment.

Ready to test: Between the GOTO bass horns, the good old DDDAC1543, DDDAC1794 and power supplies and batteries. Of course a notebook with Foobar and WASAPI

The Gang :-) I am very grateful I have met this group of HIFI enthusiasts a few years ago . Thanks to their interest in the hobby and never lasting curiosity in new media and high drive to keep improving their equipment and sound experience, I have been motivated on my turn to further develop the DDDAC1543mk2 and as next step also design the DDDAC 1794 NOS DAC. Through this group, in regular distance, we have wider listening sessions with audio enthusiasts, from literally around the world. I already mentioned earlier the impressive sessions we had with Jean Hiraga and his friends for example

The Gang :-): Klaus has a very large and cosy listening room. Optimum conditions for a great audio session...

	Cheers! We were so lucky with the weather! Enabling us to have a nice BBQ lunch organized by Moni and Klaus. Also giving ample time to discuss all aspects we learned at the listening sessions and gave opportunity to reflect on all great experiences we made.
BBQ party! In between hard work, we needed to strengthen the inner body... Great hospitality from Klaus and his wife Moni!

You hear this? Seems what Reinhard is saying to Bernd. On the terrace we had sweet sounds from Neil Young's live concert complementing the great food. Both creating more appetite...
	Bernd and Reinhard: Concentrating on the great food or sound?

And for now.... the results of our sound check session....

In general 192 / 96 / 44.1 formats

We did this before of course, but we wanted to set the scene again. If you take 44.1 as a reference, and then you listen to the same track on 192kHz, you already get the feel in the very first few seconds... Suddenly you hear more cubic meters. You can hear more air, acoustic room around the instruments and artists. On top, the voices and instruments show enormous improvement on their purity. The texture or low level detail makes the sound come alive, becomes more realistic. Best you hear this with voices and piano. Percussion gets more dynamic, high hats sound really like brass instruments. In other words, if you have the ability to listen to 192kHz tracks rather than the 44.1kHz, your listening experience is so much sweeter :-) But what about the 88.2kHz (most SACD rips) or 96kHz than? Well, it just hangs in between... all effects are similar, just not so pronounced like the 192kHz. Still clearly better than 44.1. It sounds like SACD, what in fact it is in many cases ;-)

12Volt battery versus DDDAC power supply

Something I was kind of refusing to believe in the past. I always thought a Battery was the better way to go. Well compared to cheap 12V power supplies, this is true. But after Bernd came with his very straight forward discrete regulated power supply design, things have changed. In my personal DDDAC1794 there is a power supply version which is a bit faster and has some less complex circuitry than the original one from Bernd. Using this power supply it all sounds so much nicer compared to a battery. Clearly there is more dynamic sound. Bass is tighter and the sound stage is a more transparent. Is using a battery bad? not at all... It still is an easy and very practical solution. For long term and stationary use, the power supply is highly recommended though. The difference is dramatic, the whole sound gains much more in pressure, precision and volume, which not at all could be foreseen even with the biggest lorry batteries, which Klaus had in use for years...

DDDAC 12V power supply versus Bernd's 1543 power supply

Well this was VERY close and hard to tell. We actually had different opinions, so it might be hearing or taste. My conclusion was much more that the new DDDAC power supply, which is a derivate of the BIG one for the DDDAC1543, is a success after all. Sounds as good (is a fair statement) and relatively easy to build (even for reasonable budget)

WaveIO Powered by USB-bus or DDDAC 5V power supply

Now exactly the same power supply, but as a 5 Volt version is compared with BUS power (on the WaveIO Board easy to select by a jumper - or switch instead) I tried this before earlier and used a simple 5 Volt supply based on a LM317 5Volt supply. I could hardly hear any difference. With the DDDAC (Bernd) Version, this is a different cup of tea :-) Almost similar experience as with the Battery versus the power supply, more dynamic, more transparent, clearer voices (less curtain effect). And you get this double up! No wonder we declared for the rest of the listening sessions, that we use only the power supplies for supplying DAC and USB boards

DDDAC1794 against DDDAC1543 on 44.1kHz

Battle of the Giants! We listened a bit longer and to more tracks for this comparison and one thought comes to mind after a short while. Regardless how good 192kHz material is, good old CD red book can sound awesome as well. This is definitively NOT a dead duck now. Good to know, as I still have quite some CD material (understatement ;-) Back to 1543 versus 1794... Well, hard to say what is really BETTER... both are great and do sound a bit different. Like eating steak or fish? Both can be great but they have their own user experience so to speak. I think it can be summarized as follows. Both deliver a transparent and detailed spatial sound. On top of that, the DDDAC1543 is forceful and direct, where the 1794 tends to be more precise and detailed, but still is very dynamic and direct as well. I believe the direct sound has strongly to do with the NOS aspect. No digital filter is just throwing the music on your plate just as it is. Good recording sounds beautiful, where bad recordings are immediately uncovered as one... Conclusion is an almost tie, where the 1794 gets may be a few points more. Still the 1543, specially for the fans of a forceful sound stays a great DAC for Red Book!!

Sowter output Transformer versus Mundorf Gold-Silver-Oil output

Actually the Sowter was meant mainly to help on a 4x times higher output, so at home, where I lack some gain in the whole music reproduction chain, I would be able to play some low level recordings and still reach a decent sound level. At Klaus place this is no need at all, but nevertheless I wanted to know if using a transformer was deteriorating the sound much. I was expecting less tight bass and loss of detail. WHAT a BIG misconception! Total surprise..... This (specially made for me) transformer is a BULLS EYE... I don't know why, may be it is the fact it uses both DACs in the PCM1794 in balanced mode? Probably yes, but also, it can have to do with the simple fact, that the output impedance is so low over the whole audio range. This is definitively not the case with a capacitor at the lower frequencies. The transformer delivers such a stable, and solid sound, we were pretty much perplexed. Not miles away from the Mundorfs, but very much worth it. Well, that is quite a statement... the transformers are actually pretty expensive compared to the whole DAC it self, so probably more for someone who likes the extra tickle and or more gain. Man I am so glad they sound so good, as now I have the gain I needed and actually better sound rather than having a compromise.... Important notice, they need minimum 4 DAC decks for decent low frequency response !

Parallel Decks: one versus four

Well, a lot of talk about paralleling DAC chips, so we were quite keen to have a direct comparison. Therefore I had an extra DAC set with me containing only one deck, but still have the same Mundorf output capacitors. Listening from one deck to four decks gave the expected improvement on additional low level detail and purity of sound, which we also know from jitter improving activities in other DAC equipment or CD players. As a total surprise, we did not expect this, the whole sound stage got more sound pressure. Hard to describe this, but we were all in agreement that this describes it best. More push, more direct, more powerful. Specially the horns from Klaus made this very clear! The good thing is, that this was a somewhat different improvement of what you get from the better power supplies or output capacitor. It is an improvement from a totally different perspective. Proof for that, so to speak, is the fact, that when you switch back to battery mode, the other aspects (as described) were less good, but the "parallel" effect stayed the same.

conclusions?

Very simple conclusion, we all agreed! Sound wise the DDDAC1794 NOS is the best we ever heard overall. The HD music is awesome and all the design tricks, like No Digital Filter (NOS mode) and the extended voltage for the analog side of the DAC chips, really paid off. If you invest a bit more in more DAC Module Decks, two great power supplies and analog output options (Mundorf Silver-Gold-Oil or the Sowters), you are in audio heaven :-) I am sure this DAC will have another very long life in my audio chain (and I am sure I can speak for Klaus, Reinhard and Bernd as well....) The picture below shows the DDDAC1794 NOS in my audio rack ...

Keep reading ...... the story continuous with the listening session with Triodedick ( Dick )