NiHo

I’m sorry to hear about these problems. I run three separate Mac Mini based systems, all using Yosemite, without these issues. They are: • Late 2014 model. JRiver, output via HDMI to an Oppo for surround sound. Files on a disk connected via Thunderbolt. Controlled via wireless keyboard/trackpad. • 2012 model. A+, output via Usb to the Dac. Files on a disk connected by Thunderbolt. Controlled via screen sharing from my Macbook Pro. • 2010 model. A+, output via Usb to the Dac. Files on a disk connected by Firewire. Controlled via wireless keyboard/trackpad. In all of these cases my approach has been to ensure that different types of connections are used for the disk drives and the Dac.

Ted, Thanks for making this available. I played three of the files from an SD card directly in my Resonessence Invicta → Bryston PowerPac 300s → Wilson Benesch Discoveries. Comments are: • Grimm DSD 64: Impression of a slightly blurred sound. Sounds more like a recording than a live concert. • Horus DSD 64: Clearer than the Grimm, and gives the impression of being more dynamic. Could this be due to a lower noise floor? • Horus DSD 128: The attacks and generally the shape of the notes are better defined than at 64. Starting to sound more like a live concert. As the Invicta doesn’t play DSD 256 I didn’t bother downloading that version.

Thanks for sharing. The apparent simplicity of the machine shows great clarity of thought.

Musicophile, I have this in its SACD release which came out in 2003. I fully agree that this is Oscar at his very best, wonderful music. My version notes that it was digitally remastered by Angelka Rudloff at Emil Berliner Studios, Langenhagen. Do you know if this download is the same version, or a different version? The SACDs were released on six CDs, but contain the same 37 tracks as the download.

Am I the only one who finds it strange that there is a discussion about improving the soundstage, apparently without agreement about how it is perceived and hence what would be required to improve it. The book “Auditory Neuroscience” has a chapter on the neural basis of sound localization, which is well written and quite accessible. The comments below have been taken from that reference. As has been noted above by Fokus we have a duplex system of sound location, using both interaural level differences (ILDs) and interaural timing differences (ITDs). ITDs are higher in frequency than ILDs. The result is that we can hear changes in location of as little as one degree from a midline in front of head. Sensitivity to vertical changes or from behind the head is much lower. This implies timing differences at our ears of as little as 10 to 15 microseconds, or level differences of 0.5 to 0.8 db. The implication is that anything that changes the relative timing of the music by more than 10 microseconds risks distorting the sound localization. The above does not address determining sound source distance about which less is known. It is probably worth adding that differing aspects of hearing use differing parts of the brain. In particular the qualitative assessment of sound is performed separately from the localization aspect.

A couple of guides to speaker placement: Cardas Cardas Room Setup Guide The Audio Beat http://www.theaudiobeat.com/blog/speaker_placement.pdf

Part of the issue between differing power supplies may be with small fluctuations in the voltage level from various computer activities, which translate into audible differences. Resonessence changed their USB software in software release 5.0 for the Invicta. Evidently USB data is received in packets, which cause micro fluctuations in the computer’s voltage level, and this software change had the effect of smoothing the flow of data, hence minimizing those voltage fluctuations. This resulted in an improvement in sound quality, such that their listening panel could no longer differentiate between inputs via the USB or via the SD card built into the DAC. And that is consistent with my experience.

Spacey, Thanks for the response. Interesting how much change there has been with the enhanced hardware over what is by any standard an excellent product. Nigel

Spacey, I'd be interested if you can distinguish how much of the sound improvement is from the software upgrade to 5.0 and how much is due to the revised hardware. The software upgrade surprised me on my Invicta with its sound quality improvement. There is a meaningful improvement in both USB and with DSD, even when the later is played from a SD card. Thanks, Nigel

Piotr, This is interesting. I was surprised by the reverberation times shown in your blog. Can I assume that these are for the amphitheatre without an audience? How would they have changed if the theatre was full? Thanks, Nigel

My current set-up has been simplified to take advantage of the facilities of the Invicta. Sources may be either the SD card or a Mac Mini using either PM or A+. Obviously the SD card has the cleanest sound, but the Mac mini has a better user interface. Output is to a pair of Bryston PowerPac 300s (via balanced cables) and Wilson-Benesch Discoveries. All components are plugged into a Bryston Torus. The Invicta is an exceptionally very low distortion device (where distortion is broadly defined to cover compression, timing errors, noise as well as thd). Other components in the system will inevitably cause a deterioration in the sound quality. Hence my preference for fewer, but low distortion, components. All told I’m enjoying a wide variety of musical sources, but high quality recordings, such as the Channel Classics DSD issues, are easy to distinguish by their recording quality. Nigel

Resonessence Invicta I’ve now changed my Dac to the Invicta. This note gives some background as to why I chose the Invicta and my initial impressions. As background my listening is classical music and jazz. The rest of the system consists of Wilson-Benesch Discoveries, Bryston PowerPac 300s and an AudioZone Pre T1 (a passive, transformer based pre-amp). All interconnects are balanced. Some of my listening has been direct to the amps, bypassing the pre-amp. Music is on a dedicated, headless Mac Mini, played back using Pure Music (my preference) or Audirvana Plus. As I’ve listened to other Dacs prior to this acquisition, I’ve generally been disappointed. As these are systems set up in a store, it isn’t always possible to identify why they don’t work for me. It could be how they are set up or it could be the components. Having said which there is a tendency for Dacs to have a similar sound, particularly if they use the same chipset. The differences tend to be around their limitations/ engineering choices made in the implementation. The Invicta appealed to me as: • The manufacturer is keeping it up-to-date by regularly upgrading the software; • The reviews feature some common themes around the quality of the bass, which implies to me that it has a well engineered power supply and op-amp; • It is a compact design, which will fit into my stereo cabinet without a problem. Anyway I’m not a fan of large, somewhat empty cases; • The price is reasonable. My first reaction was a Wow! The clarity of the notes, their leading edges and trailing edges are clearly defined, is like being at a concert in a hall with good acoustics and having a good seat. Tonal balance is as close to a live concert as I’ve heard from my system; background noise is inaudible; imaging is very precise. Initially I thought that there was some inconsistency, but then I realized that one speaker needed to be very slightly moved to stabilize the image! Dynamics are excellent. It should also be noted that it has no trouble driving my passive transformer based pre-amp via the balanced cables; not all components can do this. I’m still experimenting with the different filters. However, the Resonessence filters are an improvement over the standard ESS filters. It is very difficult to describe the impact they have on the sound, but it is easy to recognize the effect of differing filters when you hear them. Listening to one track from Carol Kidd, which I’ve listened to many times, it was coming across as boring. Switching to the apodizing filter returned it to its normal vigor. Indeed the apodizing filter has become my default filter. The SD card player has been somewhat of a revelation. The sound quality is better than either PM or A+ and its simple to use. I’ll stay with them for he bulk of my listening as the music indexing is better via iTunes and anyway my library is too large to fit onto one card; but critical listening will now be via computerless computer audio! The ability to pay DSD files is great. If the recording was made in DSD, then it’s the best way to replay them. The Dac comes with a USB cable, which I’ve used for all listening to date, and I see no reason to change. All listening to date has been either via USB or the SD card reader. Initial experiments with an after market power cable revealed minimal difference; indeed the difference seems to be related more to the isolation transformer (Bryston Torus), than the cable per se. I suspect that it is simply that a fatter cable enables the Dac to access the stored power from the transformer more effectively and hence marginally improves the bass. Its the first time in my experience that using the Lessloss cables hasn’t resulted in a meaningful improvement in the sound quality. One of my surprises was that I’m enjoying some of the music that I’d stopped playing and rediscovering why I bought it. Its early days with my learning how to get the most out of this Dac. But it is a great Dac, and I’m thoroughly enjoying listening to music through it.

Robbby, As somebody based in Ontario, I should respond. I use the Bryston BIT 15 for my stereo, with all components plugged into it. This is actually made by Piltron (who are located in Toronto) for Bryston. The main component is a large toroidal transformer and consequently it weighs 50 pounds. It provides protection as well as stores energy, which helps with sustained bass notes. My amps are Bryston PowerPac 300s (ie 300 watts each). It helps with reducing the mains borne noise but doesn't eliminate it. There has been no degradation in the sound quality; quite the opposite. How much improvement you will hear depends upon the power supply in the amps and how much noise is picked-up between the unit and the amplifier from computer networks, etc.; I don't know your amps so cannot comment. I have a second unit for my home theater set-up. Nigel

This is a good article from Stereophile that explains the issue with solid state amplifiers and complex speaker loads.http://www.stereophile.com/reference/707heavy The general advice is not to use underpowered amplifiers as the speakers' tweeters risk damage. You were concerned about the bass; it will be reduced in both quantity and quality. My personal experience was that the amplifiers went into thermal overload and shut down. Nigel

The easiest way of connecting a Mac Mini to a Dac is using an optical input (also known as Toslink). Your Dac almost certainly has this input option, and optical cables are cheap and readily available. Alternatively you can acquire a device to reformat the digital signal from USB to RCA (which is known as S/PDIF) [hiface2"]http://www.m2tech.biz/hiface2.html[/url], although there are lots of other similar devices. You will also need connecting cables with most of these devices.