Stereo_Electronics 0 Report post Posted March 22, 2014 Posting on behalf of staff and directors of team iFi. Micro iDSD: Urban Ultra-Fidelity The next iFi advanced skunkworks product is the micro iDSD. It is the bigger brother of the nano iDSD, a top-selling portable DAC in Japan and with a loyal Head-Fi following around the globe. The micro iDSD is expected to be on sale early June. This time, the launch of the micro iDSD will be somewhat different. At the design stage, we would like to involve you, the customer. YOU specify the features of the micro iDSD. We are all ears (no pun intended) Thanks to you, the customer, we now have a super accomplished range that spans 10 products and continues to grow. Along the way, your suggestions have really had an impact - such as the 2013 update of the Head-Fi #1 micro iCAN with gain selection. You have asked to be involved in the next major iFi project. Well, we hear you and we are very happy to respond. Whether you are an iFi customer or not, we would like to invite you all to the iFi design group. Micro iDSD, customer-driven Our proposal is simple. You tell us what you would like to see in the micro iDSD. The customer design input process available via ANY of the following channels: 1) The thread on Head-Fi (will be the focal point). 2) PM us via Head-Fi 3) Message us on our official Facebook page: www.facebook.com/iFiAudio 4) Email us: design@ifi-audio.com Over the course of the next few months, we shall collect all the data. There will be a constant flow of updates - Facebook, Twitter, Head-Fi. Along the way, we will happily answer any questions you may have. The pre-production version will be showcased at the upcoming Munich High-End Show on 15-18 May. Is there a catch? No, you do NOT pay/pre-order anything. We would just like you to get involved! Just like our parent company AMR, we have always taken the long-term position and that means building the best customer goodwill possible rather than raising a few dollars in the short-term. Mega “micro” thanks We just don't like the idea of receiving your input without giving something back. So for the top-10 contributors whose features are adopted, you will each receive the all-new micro iDSD. Above all, we value your design input as this is most precious to us. In advance, we would like to say big “thank you” to you all and looking forward to your design inputs. From the staff and directors of team iFi. Share this post Link to post Share on other sites
Stereo_Electronics 0 Report post Posted April 17, 2014 iDSD micro Crowd-Design. Phase 2: Open to everyone, 5 iPurifiers up for grabs! Click here to take participate iDSD micro Crowd-Design. Phase 2 Poll: What % of your listening is Desktop vs Portable? (click on ONE answer) The poll will close next Tuesday 22nd April. (you do have to be a Head-Fi member to vote). iFi Audio(UK) will put the names into a hat and the 5 out of the hat will receive an iPurifier (from their local dealer). The iPurifier placed at the USB port of the DAC, audibly improves sonics by filtering out grunge on the audio+power lines. More details on the iPurifier here: iFi-audio iPurifier See you there! Introduction The next iFi advanced skunkworks product is the micro iDSD. It is the bigger brother of the nano iDSD, a top-selling portable DAC in Japan and with a loyal Head-Fi following around the globe. The micro iDSD is expected to be on sale early July. This time, the launch of the micro iDSD will be somewhat different. We are all ears (no pun intended) Thanks to you, the customer, we now have a super accomplished range that spans 10 products and continues to grow. Along the way, your suggestions have really had an impact - such as the 2013 update of the Head-Fi #1 micro iCAN with gain selection. Whether you are an iFi customer or not, we would like to invite you all to the iFi design group. While the features competition has closed, the next phase is for us to announce the features and update you on how and what they do. Feature specs: 18th April iFi stockists: early July There will be a constant flow of updates - Facebook, Twitter, Head-Fi. Along the way, we will happily answer any questions you may have. The pre-production version will be showcased at the upcoming: - Headphone Festival 2014 Spring by FUJIYA-AVIC (10-11 May) AND - Munich High-End Show (15-18 May) Is there a catch? No, you do NOT pay/pre-order anything. We would just like you to get involved! Just like our parent company AMR, we have always taken the long-term position and that means building the best customer goodwill possible rather than raising a few dollars in the short-term. In advance, we would like to say big “thank you” to you all and looking forward to your involvement here. From the staff and directors of team iFi. Share this post Link to post Share on other sites
Stereo_Electronics 0 Report post Posted April 30, 2014 Updates from the Team iFI UK on the Mirco iDSD Designer's Diary (1) Hi all. It's been a tough few weeks, feasibility studies, trying to fit everything, like trying to pour two pints of Guinness into a single pint glass. It's 23.07 GMT and we've just tucked into a KFC party bucket. While we aren't having a party, we're having a ball pushing ahead with the micro iDSD. Here is pretty much the mechanical design, confirmed and in part with models built to confirm things fit. Much of the design matches what Roamling showed in the first few days, colour us impressed, we could not do much better. Starting with the front, this will mostly resemble the iCan nano in layout, with the 3D Holographic sound and X-Bass switches. The HP Jack will be 6.3mm. What you can only see on the next picture is that the Filter switch is a slider switch on the left hand side surface which will fit flush. On the back you see leftmost the SPDIF input/output. This will be very interesting, more another time. The two RCA line outputs are in the middle, then the USB input. We have built a mock-up and tested that even with modestly fat "high end" RCA connectors that just manages to fit. So, externally at least we can deliver a lot of what you all have asked for. More to come... Ciao, Thorsten Share this post Link to post Share on other sites
Stereo_Electronics 0 Report post Posted April 30, 2014 Updates from the Team iFI UK on the Mirco iDSD LATEST Specifications - micro iDSD... With new product development, things are never early, seldom on time and almost always late. Well, at iFi we really do pull out all the stops and despite Thorsten's jetting off to the Shanghai Show, his team today passed on the Specifications of the micro iDSD for us to upload. Without further ado, please see below. Note: Final specs may yet change such as the option of adjusting gain. Specifications - iDSD micro Input: USB 3.0 type B Socket compatible with iPhone,iPod, iPad and Android Devices USB-OTG camera kit or USB-OTG cable required SPDIF RCA (only PCM up to 192KHz), only active if SPDIF signal detected Outputs: SPDIF RCA (only PCM up to 192KHz), only active if USB detected Audio RCA, (variable 0 to 2V) 6.3mm Headphone socket PowerSource: USB Bus power / 3,300mAH Lithium Polymer battery Battery life: appx. 10 Hours USB playback (varies with headphone load and volume setting) Indicator Single Multicolour LED to indicate Signal and Sample Rates DAC: Dual-Core Bit Perfect DSD, PCM & DXD DAC by Burr Brown (2-DAC Chip; 4-Channel; 8-Signals) (2-DAC Chip; 4-Channel; 8-Signals, custom interleaving for maximum SNR) Audio Formats: 44.1/48/88.2/96/176.4/192/384KHz PCM 2.8/3.1/5.6/6.2MHz DSD DXD Filter: PCM: Bit-Perfect Processing and Minimum Phase/Standard digital filter selectable DSD: Extreme/Extended/Standard Range analogue filters selectable DXD: Bit-Perfect Processing, fixed analogue filter HP Volume Control: precision analogue volume control, < 2dB Tracking error HP section: Output Power: >400mW(32Ω) Output Voltage: >5V (>600Ω) HP Volume Control: precision analogue volume control, < 2dB Tracking error THD + N (line): <0.005% @ 0dBFS THD + N (HP): <0.005% @ 0dBFS SNR (Line): 117dB(A) @ 0dBFS SNR (HP): 111dB(A) @ 2V out Clock: Ultra low jitter Crystal Clock (rms jitter < 300 Femtoseconds) Audio Path passives: Tantalum Oxide Thin Film thin film surface mounted resistors TDK high stability C0G surface mounted capacitors Panasonic PolyPhenylene Sulfide stacked film surface mounted capacitors We hope you like this and we'll be adding more info in the days to come. Share this post Link to post Share on other sites
Stereo_Electronics 0 Report post Posted May 7, 2014 Team iFi Designer's Diary Update Okay, we have been lying low but behind the scenes we have been really jammed out on the micro iDSD prototypes. One of these we expect to ship to Japan for the upcoming Headphone Festival 2014 Spring by FUJIYA-AVIC (10th-11th May) Then afterwards, another prototype will be at Munich High-End 2014 (15th-18th May) Here are 3 prototypes that we are running right now. Thorsten and his team have provided this update. They asked us to relay this on. Specifically, the parts quality is going to quite impressive. We can confirm: * Tantalum Oxide Thin Film thin film surface mounted resistors - these offer ultra-low noise/distortion * TDK high stability C0G surface mounted capacitors - the C0G dielectric closely approaches Teflon® (which is pretty ideal) * Panasonic PolyPhenylene Sulfide stacked film surface mounted capacitors – Panasonic has a justified and enviable reputation for great-sounding capacitors * 4-Layer Board using oxygen-free copper traces with gold-plating - pretty much the highest-quality but also a costly approach More Soon! Share this post Link to post Share on other sites
Stereo_Electronics 0 Report post Posted May 12, 2014 Micro iDSD updates from team iFi PSSST - don't tell R&D Guys We swiped this off the R&D dept. when they were away doing some weird and wonderful measurements on their Audio Precision and other fancy measurement machines. The machine for Japan is en route to the 2014 Spring Headphone Festival by FUJIYA-AVIC this weekend. This particular machine is going to Munich for the High-End Show next week. Yes, there is one more prototype that is going to another destination... More pics to follow....Standby! Share this post Link to post Share on other sites
Stereo_Electronics 0 Report post Posted May 14, 2014 “Meaty Monster” Attacks 2014 FUJIYA-AVIC HP Festival The following are translations from the Japan press gleaned over the weekend of the debut of the prototype of the micro iDSD. We had high hopes and as usual, iFi Japan surpassed them! We hope you enjoy reading about the Japanese head fiyers going ga ga over the “Meaty Monster” (just as new reboot of Godzilla movie is around the corner!) “The world premiere of” top wing was (company) Portable DAC of British iFI-Audio a “micro iDSD”. The DAC that is equipped with two a customized chip of Burr-Brown, for a wide range of hi-res file, the official announcement from the British iFI has not yet been done, but, PCM system to 384kHz/32bit you check the back of the product, and there is a description of DSD 256 (12.4MHz). By a built-in battery of 3200mAh further, “about twice the nano iDSD Do not be driven” ITmedia LifeStyle iFI-Audio was the world premiere at the festival headphone DAC built a prototype portable headphone amplifier “micro iDSD”. We are targeting the launch of the summer, price is undecided, “Do not go until Odai (100,000 yen)” It’s expected. As “(monster full of Miti Monster = contents) Meaty Monster”, British iFI-Audio has developed, DAC uses the “dual core 4 signal bar Brown DAC chip”. Corresponding not only PCM, also playback of DSD / DXD file. In addition to operating as a USB DAC, it has a coaxial digital input / output terminals, can be connected to the portable player with a digital output. With one system standard terminal, headphone output is also available analog audio output of the RCA. I have a built-in battery of 3,000 mAh so portable amplifier. DSD support 2.8MHz (DSD64) / 5.6MHz the (DSD128). Sing the officially supported at this time it’s up to 5.6MHz, except that there is also a character shows the DSD 11.2MHz corresponding “DSD256″ on the back, tried by preparing a 11.2MHz DSD file actually in this exhibition, reproduction that could be. But DSD256 little support, micro iDSD portables even seem capable of processing in hardware but also in the stationary machine. AV Watch Share this post Link to post Share on other sites
Stereo_Electronics 0 Report post Posted May 28, 2014 Micro iDSD updates from team iFi The Final Countdown (for the micro iDSD) Apologies in advance. We are truly sorry…some not so great product development news concerning the micro iDSD. We were just unable to produce the micro iDSD with the same features as the beta unit shown in Tokyo and Munich. Call it fate, it just wasn’t to be. So here is the truth, the whole truth and nothing but the truth… The production micro iDSD is going to annihilate the beta micro iDSD!!! The production micro iDSD is going to make the beta micro iDSD look like yesteryear technology! For sure, each and every single feature will allow you to squeeze so much sonic performance out of the cigarillo-sized micro iDSD that you not stop listening to music with the micro iDSD. You will just not stop grinning from ear to ear (no pun intended). Today, looking at the final prototype of the micro iDSD, we still cannot believe how “feature-rich and sonically-stonking” the micro iDSD is going to be. We are buzzed! Are you ready? We sure are! Please click on this link: iDSD micro Crowd-Design. We're sorry. SNAFU with the beta micro iDSD. - Page 38 Share this post Link to post Share on other sites
Stereo_Electronics 0 Report post Posted May 31, 2014 Micro iDSD updates from team iFi - Crowd-Design Super Duper Features 1.1. - The Dual-Core Burr-Brown DACs Background Due to cost constraints surrounding an extra DAC chipset and added parts count, few DACs at any price feature more than 1 chipset. But the micro iDSD features x2, hence Dual-Core. Technical Explanation Doubling the DAC results in 3dB lower in noise floor and better channel separation. In layman terms, together with other power supply improvements and advanced channel interleaving, the noise floor of the iDSD micro has been halved. All of this = stellar sonic performance. How this benefits the listener Better inner resolution, better tonality. More meatier sound, hence codename "Meaty Monster." It really does give a hefty and weight to all genres of music. The only apt analogy is that compared with other DACs, what you here is sometimes only the bones, but the micro iDSD puts flesh and meat to the bones. This should not be confused with more bass. As every instrument throughout the dynamic range has greater gravitas. Click on the link and see the first of our the Super Duper features and the next clue to Outta This World feature #3! iDSD micro Crowd-Design. Super Duper 1.2: Different Strokes for Different Folks (re: Digital Filters) - Page 40 Share this post Link to post Share on other sites
Stereo_Electronics 0 Report post Posted June 4, 2014 Micro iDSD updates from team iFi - Crowd-Design iDSD micro Crowd-Design. Super Duper 1.2: Different Strokes for Different Folks. (Filters for different formats) Background Ringing (in electronics): "artefacts" that appear as spurious signals ("rings") near sharp transitions (transients) in a signal. Visually, they appear as "rings" near edges; audibly, they appear as "echos" near transients BEFORE the transient = Pre-Ringing AFTER the transient = Post-Ringing. "Ringing" arises in recordings and DAC chipsets. There is a wealth of information on the Net. Technical Explanation In the micro iDSD, when playing back PCM and DSD it has the following filters that reduce/eliminate such types of ringing: DSD: Extreme/Extended/Standard filters PCM: Bit-Prefect/Minimum-Phase/Standard filters DXD: Bit-Perfect Further, from our point of view, measurements and listening are not necessarily identical. Generally, we recommend "Standard" for measurements (such as when hooked-up to test equipment) and the other filters for listening. But always try them out, on-the-fly. Filters will be discussed more in-depth in a future Software Team's Notes. How this benefits the listener Audio is ultimately subjective. Hence we always try offer customer options to adjust the sound to suit what they like and the headphones speakers of choice. The different filters come with our recommendations under each format but there is no such thing as "best" and we leave the customer to make the "last mile" selection. Where applicable, we recommend trying Bit-Perfect first: for listening, at AMR/iFi this is what we use most. iDSD micro Crowd-Design. Super-Duper feature 1.3. Intelligent SPDIF voted #1 by you (page 43) - Page 42 Share this post Link to post Share on other sites
Stereo_Electronics 0 Report post Posted June 9, 2014 Software Team Notes: Real-Time like Jack Bauer! We use an advanced 32bit ARM (given US$ with TI, nice to £s back in the UK) core microprocessor (similar to an Intel Pentium in computing power) that has multiple high-precision 12bit ADCs. They are there to monitor the voltages in real-time in the micro iDSD, just like the voltage sensors built into a BMW. So we are sure all the voltages are spot on, as designed. Together with the 12bit DAC (yes, even the microprocessor has a DAC built-in, and no, we are not using it for audio decoding), we can adjust the supply voltages to the most appropriate values (very precisely to 0.0008V if we wish). We will refer to this later as OTW feature #2 and #3 would not have been possible without this infrastructure. Hence this is why we published this software note today ahead of announcing OTW #3 this week. Further, this advanced ARM core microprocessor has Ultra-Low power consumption, less than 5mA when running and ~2uA when sleep. So what is the benefit? The micro iDSD gets a longer playing time which no-one will be unhappy to discover. cont'd: iDSD micro Crowd-Design. Measurements Matter (Not!) Hearing a fly fart at 20 feet (page 45) - Page 43 Share this post Link to post Share on other sites
Stereo_Electronics 0 Report post Posted June 9, 2014 iDSD micro Crowd-Design. Super-Duper feature 1.3. Intelligent SPDIF voted #1 by you! This was by far, the most popular choice on this Crowd-Design thread and while we knew SPDIF output was popular, we did not really place much importance on SPDIF input. So a big thanks to you all for this one. The Intelligent SPDIF port: The coaxial port on the micro iDSD enables: SPDIF transmission via: - Coaxial In/Out - Optical In (via supplied adapter) Background Nowadays, cable set top boxes, Network Streamers, TV Boxes, DVD/Blue-ray players etc, all usually come with (co-ax/optical) SPDIF connectivity. Sometimes the customer would like to have USB > SPDIF conversion (with digital output) or SPDIF input (with analogue output). Explanation Normally, the iDSD Micro expects optical or coaxial SPDIF in, but when USB PCM (up to 192KHz) is sent through the USB port, it automatically switches the coax to put out an SPDIF signal. If no USB Stream is playing, it will automatically switch to SPDIF (it will first look for coaxial signal, if that is not present then an optical signal, if that is not present it will go into power-save mode.) As soon as a USB Stream plays again, the SPDIF port becomes a Coax SPDIF Out (no optical output). It is "bi-directional" and uses Global Master Timing/Zero Jitter for the receiver part and re-clocking / driver. It will not perform at the level of the iLINK but it is pretty flexible and more than capable of high-quality SPDIF duties. How this benefits the listener In practice one might connect the SPDIF connector as input from an external SPDIF source (in this case to power the iDSD, no USB source is needed, a 5V Charger will do). The source may be a streamer, DVD Player or some such component. One may even connect USB and SPDIF together, just remember that playing USB overrides SPDIF. There is no risk of damaging either the iDSD or SPDIF source when the SPDIF input becomes temporarily, an output. Alternatively one may use the SPDIF output to drive another (PCM) DAC. In this case there will be no SPDIF signal when there is no USB stream and the iDSD just goes to sleep after a minute or so. Nice flexibility, multi-options. We hope you like it and of course enjoy it! cont'd: iDSD micro Crowd-Design. Technical Notes 3: Going to the nth degree (page 47) - Page 43 Share this post Link to post Share on other sites
Stereo_Electronics 0 Report post Posted June 10, 2014 Femto Clocks – Picky about Phase Noise Background All Femto clocks are good, very good in fact. They exhibit jitter levels lower than most clock crystals which leads to better sonics. An oft quoted benchmark for accuracy is Femtoseconds (Fs) / parts per million. Back in 2008, before the word “Femto Clock” became all the rage, AMR developed a special type of clock in DP-777 as part of the “Global Master Timing” (GMT) and “Jitter less” technologies (why special? See below, because not all Femto clocks are the same). We called it the GMT Clock platform (which is comprised of specialised hardware+software) as it is not just buying a “clock in a can” and job done. Having worked with all sorts of clocks, including discrete, Rubidium, Superclocks and not the least Femto clocks over the years, we know them quite well. All Femto Clocks exhibit excellent low phase-noise (measured jitter within the clock). However, as their origins lay in being part of SONET (Synchronous optical networking - Wikipedia, the free encyclopedia), the popular SONET targeted “Femto-clock” is less desirable as its best phase-noise performance is concentrated in the > 12KHz region (read: at the very top and way above the audible band, so benefits audio less). As an example, this link highlights the use of Femtoclock technology in the telecommunications sector where they are spec'd for: Clock Frequency Accuracy within Femtocells for timing and location | System | Technology The ubiquitous Femto (SONET) Clock This is an Optical Comm system (aka SONET - which is a Subset). We added the blue line to highlight the -70dBr region so that when referenced to the AP2 chart in the next section of the micro iDSD, it is more of an “apple to apple” comparison. The spike at 50KHz is the "signal" As you can see, for quite a few KHz around this region, phase noise is low, this is what matters in this application. However, the area around the green arrow is the most crucial human audible range of 20Hz > 20kHz where phase noise performance is less impressive in the region of -100dB to -70dB. Explanation Therefore, the key for AMR was to design a new system, the “GMT” clock platform which not only exhibits the lowest phase-noise in the crucial audible band, but offers precision (< 0.004ppm tolerance) adjustability with literally millions of possible frequencies (as per the DP-777 "GMT" Technical Paper). The GMT Clock system designed into the micro iDSD measures <280 Fs, comparable to many Femto-Clocks (because it was designed to give low jitter). From the AP2 graph of the micro iDSD below, you can see that jitter in 9kHz > 15 kHz is very good, the micro iDSD noise floor goes all the way down to -150dB which is virtually across the board.with no spikes. AMR/iFi GMT Clock Platform How this benefits the user Consistent, across the board negligible jitter means timing is supreme, with just the right amount of attack/decay and of course, tonal accuracy. We are really pleased with the very low jitter performance of the micro iDSD in the most crucial audible range – in fact, we would not mind if customers pit it against significantly more expensive DACs. We hope you found this interesting as it sheds some light on the particular attention we have paid to parts performance and custom design in the micro iDSD (actually, we took it from the DP-777!). Addendum: What about Rubidium Clocks? Below is a chart of several types of rubidium clocks. What they all exhibit is many sharp spikes in phase noise. Even though they measure well, some down to -150dB, when they spike, noise levels jump up to -70dB to -90dB. This is far from ideal which is why we have not used such clocks, neither in iFi nor AMR products. It all boils down to paying close attention to the specific clock/s used and its performance in the audible range. cont'd iDSD micro Crowd-Design. Technical Notes 3: Going to the nth degree (page 47) - Page 44 Share this post Link to post Share on other sites
Stereo_Electronics 0 Report post Posted June 11, 2014 Thorsten and gang have been a little quiet of late. We gave them a nudge and here is something they asked us to share with you. Measurements Matter (Not!) Part I of III – Hearing a fly fart at 20 feet Noise. Signal-to-Noise Ratio (SNR) Our team has just spent some time running the complete and working prototype (after redesigning the PSU and that little hiccup with the J-Fet switching) of the iDSD micro through the Audio Precision 2. The test bench. The micro iDSD has actually turned in a more than respectable performance. I hasten to add that up to now there is little proven link between audio measurement results and subjectively perceived sound quality. Most standardised measurements originated in advertising and were standardised to avoid excessive misuse (but not completely eradicated :tongue_smile:). Many a designer who relies on measurements only, finds himself bothered, bewildered and thoroughly confused when many a listener prefers a better sounding product that measured distinctly poorer than his own. That said, as some have already asked about measurements and it has never hurt to have respectable measured results, as long as the subjective listening results are also great Well, here goes, the iDSD micro measured performance data. Please keep all these caveats in mind. The executive summary of the test results reads: Line Out Level: 2.15V SNR: 117dB A-weighted 111dB unweighted Line THD+N: < 0.003% (@0dBFS) HP THD+N: < 0.008% HP (@0dBFS and 0.5W/16Ohm simulated headphone load) Jitter: below AP System 2 measurement limit The signal-noise ratio may seem "only very good" but what must be remembered is that we are running the line out at 2V (nominal, industry-standard) level and as usual, the analogue stage is the noise limit, not the DAC. We could have boosted the SNR figure to make it look really sexy by choosing to set a higher line out level: - for example setting the line out level to 4.25V would have produced a 6dB increase in SNR 117dB un-weighted and 123dB A-weighted*, which reads great but in the real world, this would have resulted in much less usable volume control range for anything we are driving. Even as it stands we are only 3dB (0.5 Bit) off a 20 Bit equivalent SNR**. * The use of “A-weighting” is a long standing standard for dynamic range and SNR measurements in Digital Converters (ADC/DAC). All Datasheets nowadays quote the “A-weighted” number. Thus for consistency we always include A-weighted and unweighted SNR/DNR. ** This is the true measure of any DAC’s or ADC’s resolution, also called ENOB (Equivalent Number Of Bit’s), for example a certain DAC that is promoted as “32 Bit/384KHz” actually shows a SNR of 100dB which is actually 16.5 Bit ENOB, despite all that 32 Bit stuff, so in analogue terms it has around halve the bits claimed… For anyone who likes pretty graphs, we have oodles, this is the first of several select ones with short comments: Graph 01 - iDSD micro White Noise Line 100k 1X 2X 4X 8X This shows the frequency response of the iDSD micro using noise loading with different sample rates 48K (orange), 96K (red), 192K (purple) and 384k (blue) plus the system noise floor at 384kHz. - As the sample rate goes up we can see that the filtering of high frequencies is relaxed and by the time we are at 192kHz and above the filtering is very gentle, maximising time-domain (impulse) response fidelity. - We could show a square wave, but it would look essentially perfect, so little point. - The slight trade-off price is a little higher leakage of the ultrasonic images of the (noise) signal, however as most of it is 120dB down on full scale this is not very worrisome. I remember a professional recording engineer once describe -120dB as “Fly farts at 20 feet”… cont'd iDSD micro Crowd-Design. Super Duper 1.5: Direct/Pre-Amp and switches and pots (page 49) - Page 45 Share this post Link to post Share on other sites
Stereo_Electronics 0 Report post Posted June 15, 2014 Crowd-Design Super Duper Feature 1.6: Kylie and 3D Holographic There are TWO 3D Holographic features in the upcoming micro iDSD: i. 3D for Headphones (as from iCAN) - via 6.3mm ii. 3D for Speakers (as from iTUBE) - via RCAs It is actually quite interesting the history behind these two separate technologies. Super Duper Feature 1.6 3D Holographic for Headphones(i)/Speakers(ii) Section i: Background to 3D Holographic for Headphones Recordings are by and large, made for speakers. By definition, when listening on headphones, you get the "Kylie sensation." [YOUTUBE]IFx3WX4DES0[/YOUTUBE] Put politely, this really irks the human brain as it is not "normal." Explanation Human hearing needs a "mix" of left and right. Not purely left in left and right in right. There are numerous solutions available such as JRMC that use Digital Signal Processing (DSP). There are two drawbacks: 1. The signal is no longer Bit-Perfect. 2. Simple crossfeed does not fully address what the human hearing is missing. How 3D for Headphones benefits the listener Solution: The iFi solution for some time has been 3D Holographic for Headphones. This is an Analogue Signal Processing circuit (ASP) that retains the integrity of the audio signal getting the sound back out of the head + gives the sense forward spaciousness. More akin to this. More reading here: http://ifi-audio.com/wp-content/uploads/data/3DHolographic.pdf Further details here. We hope you like it: iDSD micro Crowd-Design. The Meaty Monster is Power Mad! (part i and ii) - page 52 - Page 49 Share this post Link to post Share on other sites
