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DAC tour

Tour list now: (please advise if I left anyone out or if you are no longer interested)
Achim - currently in transit to him
Jonne
Johncee
Crimsondonkey
bencat
 
IsoDAC arrived and is playing now.

First impression very positive. Will post more in a few days.

Thanks, John and 00fiete!
 
Ciunas Audio said:
Tour list now: (please advise if I left anyone out or if you are no longer interested)
Achim - currently in transit to him
Jonne
Johncee
Crimsondonkey
bencat
Click to expand...

It suits me very well now to be after Achim since I'm likely to be away most of next week.
 
@Achim, thanks for confirming its arrival - look forward to your further impressions - please shout if you have any questions

@jonee, thanks, so when would b best to receive it?
 
Ciunas Audio said:
@Achim
@jonee, thanks, so when would b best to receive it?
Click to expand...

I'll be here to receive it from 11th Sept. on. (I'm 'jonne' btw, not 'jonee'. Lot of Johns here!)
I see your summer sale is 'about to end'. Any chance you can hold the sale prices until the tour is over in case I'm tempted?

John
 
jonne said:
I'll be here to receive it from 11th Sept. on. (I'm 'jonne' btw, not 'jonee'. Lot of Johns here!)
I see your summer sale is 'about to end'. Any chance you can hold the sale prices until the tour is over in case I'm tempted?

John
Click to expand...
Yes, summer is over & the 25% discount will end in a week or so
Sure, Jonne (sorry for the typo) I'll hold the 25% discount for tour participants until tour is over
 
So, here's my report after two days of listening.

I have been round the block DAC-wise, with costly investments into these, in order of their appearance in my system:

Audiolab M-DAC
Chord Hugo
Oppo 105D heavily modded, modding cost north of 1500 dollars
DIY Soekris R2R DAC

Every step was a step up in quality. With the Soekris so far being deemed the crown of DAC technology. With every step I felt there was an improvement. Especially the Soekris brought stability into the sound, lacking the nervosity that most other DACs were plagued with. Chord Hugo was a step in this direction as well, the modded Oppo with Sabre DAC coming head to head with the Hugo.

Now the seemingly pedestrian IsoDAC, with another Delta-Sigma-DAC chip at it's heart, even an off the shelf chip with output stage included - how should that thing be able to compete? No fancy filter choices, no casing built like a tank to keep out unwanted electromagnetic interference, no audiophile parts or tubes inside for "natural sound".

Well, I cannot tell you what's inside the box - but I can tell you that finally, after obviously having been running round in circles ever since I put vinyl playback on the back burner, finally yesterday I could listen to music again like I could in the old days...

For me the IsoDAC has all the qualities of analog playback. Tranquility and definition I would name as the most important ones. Easiness in hearing what's happening in the recorded event, in the space, in the instrumental lines, in the heads and mouths of the artist. This definition, at least in my system, now finally extends the apparition of the music far beyond the speakers, creating more of a 3D experience. Space between parts is increased, it's simply much more there.

The funny thing is that of course during the last years I had this impression several times, with the other DACs as well. It's the work of our perception mechanisms that recreates what's played on our systems. So in the right mood, with the right material this experience will emerge. But then we tire of doing so much of the work ourselves when listening, and we get the need to upgrade the audio system...

The direct comparison between the IsoDAC and my other DACs clearly shows their shortcomings which I had not imagined being there to such extend. IsoDAC gives you a very similar experience to a well setup turntable with a very good MC cartridge (my reference is an AT-OC9) on a very good phono preamp.

So I ordered one from John today.

Will send my sample on to Jonne at the end of the week.

Thanks and congratulations, John K!
 
Thanks Achim
You describe well what I too feel are the qualities of the ISO-DAC
As you said, what our playback systems are doing is creating an illusion of a soundscape (either natural or one created by a recording engineer).
This illusion relies on the our auditory system finding enough of a match between the reproduced soundscape & our inbuilt model or rules for how such sound objects would be heard in the physical world. The better this match, the better the illusion & more natural the illusion. If we knew all the criteria that we need to match we would be able to work towards the best illusion but we don't know this (yet) so this explains how some systems get some things right & other systems get other things right - none get everything right - including mine. When I introduced the Ciunas DAC I thought it was as good as I could make it but then I discovered that USB isolation & USB signal cleansing improved on this - so the ISO range.

One thing I've always thought is that improvements in the source are a different type of change to the sound versus changing speakers - the ISO-DAC changes more fundamental aspects of the sound than frequency amplitude changes.

Btw, thanks for the order, Achim :)
 
I may add one or two things.

About frequency spectrum vs. "other aspects". We may safely assume that across the audible range all DACs will measure the same, flat within few tenths of dB.

But then this measurement is not done with music but with continuous or averaged test signals that have no informational dynamic content. Frequency sweeps or noise have no informational cues.

These cues we have to be able to extract when listening. They are hidden or apparent in the sequence of amplitudes the DAC creates from the data stream. This sequence has to be spaced in time correctly, and its amplitude changes have to be of the correct amount.

I think John managed to improve the timing as well as the amplitude correctness by reducing interference from things like USB noise and noise on the voltage reference. Those noises always overlay on the musical information and therefore mess up timing and amplitude correctness. And this blurs the informational content.

I went extra miles to set up the ISO-DAC and its hub so that I could parallely connect the Soekris and the Oppo and so switch DAC in Roon very quickly for A-B comparisons. In the end what really was needed to understand what was going on, was a whole day of listening to just the ISO-DAC, and then switching back.

You first need to unlearn the sound of what you are used to. Because some of the errors you well have learned to equate with qualities, like a sharpening effect in Photoshop that adds seeming clarity by outlining pixels that are not originally there.
 
Hi Jonne,

posting in parallel ;-)

My speakers are a German product myro "a priori". Their developer is a stickler for transient perfection. Chassis used are Accuton ceramic drivers, driven by a very complex crossover that controls the drivers resonances and creates the perfect response. Nonetheless, the midwoofer runs without lowpass, and the tweeter with 6dB highpass only. The speakers are as exact as a Stax headphone, I am not kidding.

And with the ISO-DAC, they completely disappear! When with the other DACs I heard a bit too much here and a bit too little there, and thought that the speakers were the culprits - no, they tell you everything about the system in front. Which brings me back to frequency - the ISO-DAC has indeed remarkable bass and treble extension without any overprovision or glare.

My current amplification is a German transistor pre, stst Agmen II with very high bandwidth and "zero distortion", going into a DIY class D power amp.

So behind the DAC there is no stage that hides or beautifies anything.
 
jonne said:
@Achim
Would you tell us a bit about your system? What you are using to feed the DAC, which amp and speakers?
John
Click to expand...
Like the cobbler whose children have no shoes, my system is in constant flux.
I use various laptops running Windows & Foobar
Amplifiers switch between a Naksa or NAD C390DD
Speakers are DIY using fullrange Jordan JX92S drivers

When I want a quick test, I use headphones directly connected to the analogue outs of the DAC as the initial test for possible improvements when I'm testing some changes

I also participate in a local active audio group & we routinely have meetings at which various DIY devices are audtioned - heavily moddified PCs running on batteries & using WTFPlay (Linux based playback software), various high quality amplifiers (including DIY ones) various speakers but the mainstays are ESL electrostatics. And various DACs are compared including Soekris. You might find our forum of interest - I'm not sure it's allowed to post links to other forums but you know how to contact me

So all my devices get a good audition over time on a variety of systems in different houses.
 
Achim said:
I may add one or two things.

About frequency spectrum vs. "other aspects". We may safely assume that across the audible range all DACs will measure the same, flat within few tenths of dB.

But then this measurement is not done with music but with continuous or averaged test signals that have no informational dynamic content. Frequency sweeps or noise have no informational cues.

These cues we have to be able to extract when listening. They are hidden or apparent in the sequence of amplitudes the DAC creates from the data stream. This sequence has to be spaced in time correctly, and its amplitude changes have to be of the correct amount.

I think John managed to improve the timing as well as the amplitude correctness by reducing interference from things like USB noise and noise on the voltage reference. Those noises always overlay on the musical information and therefore mess up timing and amplitude correctness. And this blurs the informational content.

I went extra miles to set up the ISO-DAC and its hub so that I could parallely connect the Soekris and the Oppo and so switch DAC in Roon very quickly for A-B comparisons. In the end what really was needed to understand what was going on, was a whole day of listening to just the ISO-DAC, and then switching back.

You first need to unlearn the sound of what you are used to. Because some of the errors you well have learned to equate with qualities, like a sharpening effect in Photoshop that adds seeming clarity by outlining pixels that are not originally there.
Click to expand...
I agree completely, Achim & have been pushing for using test signals more suited to how a DAC is exercised when playing music - a dynamic signal with continuous amplitude & frequency variations. Sine wave testing is just so far removed from this.

A case in point - the J-test was created by Dunn & Hawksford to specifically exercise a suspected problem with SPDIF receiver chips - inter symbol interference (ISI). Up to the creation of that specific test ISI was suspected but could not be shown in measurements. Therefore according to a number of members here, it didn't exist.

Focusing on amplitude & frequency as the two measures of quality ignores the more salient aspects of how auditory perception works (the bits we currently know). It's a pattern matching machine which has stored patterns & rules from its exposure to sounds in the real world & how they behave. So for instance we recognise instruments & judge their timbre by the sound envelope which is not a simple thing - it consists of many parts which can last for a few seconds - attack, sustain, decay & release - each of these stages is internally composed of fine modulations in amplitude & frequency - what's called temporal fine structure (TFS) in the research. Auditory research is investigating the importance that auditory processing attaches to these different aspects - sound envelopes Vs TFS & their relationship.

The sound envelope is just one example of what needs to be correctly reproduced by our replay systems in order to achieve a sense of realism. That means that the relationship between TFS & sound envelope has to be correctly maintained over the duration needed (some seconds). As you say, this requires a stability in the power delivery system so that heavy bass current demands does not affect delicate transient signal reproduction. It also requires an elimination of the sources of noise which fluctuate

Thanks again for your post - it's right on point with what I'm trying to achieve in my devices
 
Hi,

I'd like a listen too, currently using an SoTM sms200 NAA into a Beresford Caiman SEG DAC via Promitheus TVC into a Primaluna Dialogue Premium HP power amp, it would be interesting to hear if the ISO-DAC made a difference.

Can I be added to the list please.

Thanks,

Mike.
 
Sure mike
Tour list now: (please advise if I left anyone out or if you are no longer interested)
Achim - currently with him
Jonne
Johncee
Crimsondonkey
bencat
mikeyb
 
John - I would love to have a go with the ISO-DAC please, assuming it works with a Sonore MicroRendu up front.
Have you or any of your users tried the ISO-DAC with the MicroRendu?

Thanks
Sam
 
Yes, Sam, it works fine with microRendu
One such user "The music it reproduce are just amazing! I can't find proper words to describe how nice the music it plays are. I am deeply moved. The music emerges in dark and silent background with clean deep bass and crystal clear treble. Vocals are so realistic and beautiful."

Another say "I'm really pleased , I have to say I wasn't sure because the Ciunas sounded so good before and I wasn't convinced it could be improved. But it definitely sounds even better now
There's an added musicality especially with older cds. It feels like I have just put a remastered copy on . There's more separation more depth , almost like you're at an intimate live performance.
Also listening at low volume levels (the past hour now that the kids have gone to bed) is much more enjoyable than I have ever experienced before."

Tour list now: (please advise if I left anyone out or if you are no longer interested)
Achim - currently with him
Jonne
Johncee
Crimsondonkey
bencat
mikeyb
SamS
 
jamwat added back to the tour

Tour list now: (please advise if I left anyone out or if you are no longer interested)
Achim - currently with him
Jonne
Johncee
Crimsondonkey
bencat
mikeyb
SamS
jamwat
 
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