Kalakshar US

The “Apple effect” can be as helpful as it is infuriating. A good technology can exist for years, and many won’t care until it gets the Cupertino seal of approval. To that end, a lot of people are starting to care about “high resolution” digital audio as the company launched its upgraded music service to the masses.

But as many were quick to point out, some of Apple’s own products don’t necessarily support the higher sample rate and bit-depths on offer. No worries, there’s a dongle for that. (And there are options for Android and the desktop, too.) 

As hinted, it’s not just Apple in on the hi-resolution game: Qobuz, Tidal and Deezer have been doing it for a while, and Spotify is planning on introducing its own version soon. The products in this guide will play nice with any of these services, aside from Tidal’s MQA, which is a little more specific (and we have options for that as well).

Why do I need new hardware to listen to music?

The short answer is, you don’t. You can play “hi-res” audio files on most phones and PCs, you just might not be getting the full experience. If your device’s audio interface tops out at 44.1 or 48kHz (which is fairly common and covers the vast majority of music online) then that’s the experience you’ll get. If you want to enjoy music at a higher sample rate and bit-depth (aka resolution), you’ll need an interface that supports it and wired headphones.

It’s worth pointing out that “lossless” and “hi-res” are related terms, but not the same thing and will vary from service to service. Apple uses ALAC encoding which is compressed, but without “loss” to the quality (unlike the ubiquitous .aac or .mp3 file formats). CDs were generally mastered to at least 16-bit / 44.1kHz which is the benchmark that Apple is using for its definition of lossless. In audio circles, a general consensus is that hi-res is anything with a sample rate above 44.1kHz. Increasingly, though, the term is being used for anything 96kHz and above.

This, of course, isn’t only about Apple’s new streaming formats. External DACs and audio interfaces are a great way to get the best sound and upgrade your listening experience generally. Especially if you want to get into the world of more exotic (read: pricey) headphones, as they often even require a DAC to provide enough clean signal to drive them. For audiophile headphones, a phone or laptop’s built-in sound chip often doesn’t have the oomph needed.

Okay, but can’t I just use the headphone adapter for my phone?

No. Well, yes, but see above. A Lightning or USB-C to 3.5mm headphone adapter often is an audio interface and most of the ones you’re buying for $7 (or that come free in the box) do not support hi-res audio beyond 48kHz / 24-bit. Android is a little more complicated, as some adapters are “passive” and really just connect you to the phone’s internal DAC like old school headphones. Others (active ones) have a DAC built-in and good luck finding out what your specific phone and the in-box adapter delivers. (Hint: connect it to a PC and see if it comes up as an audio interface. You might find some details there if it does).

What is a “DAC,” though?

A digital-to-analog converter takes the digital (D) music from your phone or computer and converts (C) it into analog (A) sound you can hear. All phones and PCs have them, but since handsets moved to USB-C, Lightning or Bluetooth for music, the task of converting that signal was generally outsourced to either your adapter or your wireless headphones.

DACs can be used with phones, laptops and desktops but tend to be much simpler than a regular external audio interface. One basic distinction is that DACs are usually for listening only whereas an audio interface might have ports to plug in microphones and instruments (but an external audio interface is also technically a DAC).

The benefit of DACs is that they tend to be lightweight, making them more suitable for mobile use, although it still gets a little tricky with the iPhone as you still might need to add another dongle to make it play nice with Lightning. Also, not all DACs support all the higher audio resolutions. Most DACs require external power or an onboard battery, though some can use the power from whatever you plug them into — in which case expect a hit to your battery life. Below are some of our picks for a variety of scenarios.

Best for Android users looking for a simple, affordable option: Ugreen USB-C to 3.5mm headphone adapter

Okay, you were expecting serious outboard gear and we start by showing you a basic adapter? Yes, because this one supports 96kHz audio (24-bit) and is about as straightforward as you can get. Simply plug into your USB-C device (or USB-A with an… adapter), connect your headphones and away you go. There are no buttons, no controls, nothing to charge.

While this dongle doesn’t support 192kHz, the move up to 96kHz is still firmly in the “hi-res” audio category, and its super low profile and ease of use make it a great option for those that want an audio quality bump without going full-bore external DAC.

Of course, this budget DAC is best suited to devices with a USB-C port such as the iPad Pro, MacBook or most Android phones. As noted earlier, it’s possible your Android already supports hi-res audio and a simple passive dongle is all you need, but given the price and quality of this one, at least you know what you’re getting, as the specific details of audio support for every Android phone out there are often hard to find.

The downside is that this adapter won’t do much to help drive higher impedance headphones, so it’s less suited to audiophiles who really need more power to drive their favorite cans. I used this on both an Android phone and an iMac and it worked just fine, although with Apple computers you need to head to the Audio/MIDI settings first to make sure you’re getting the highest quality available.

Best for streamlined desktop use with high-end headphones: Apogee Groove

Apogee gear is usually found in the studio. The Groove takes the company’s decades of audio experience and squeezes it into a highly portable DAC that’s perfect for those who want a lightweight option for their desktop or laptop. We’re stepping up the sound quality here with support for 192 kHz (24-bit), which will cover everything from Apple’s new lossless service.

Connecting your iPhone to the Groove is a little more complicated. It works just fine, but you’ll need something like the Apple Camera kit, as it needs external power. In short, it gets a bit “dongly” but it works if you want something for your desktop first, that can do double duty on iPhone. Android support is a little hit and miss, though you would still need a way to feed it power while in use.

Once you’re set up, just plug in your headphones and you’re away. The rubberized base of the Groove stops it from shifting around on your desk, and the large buttons make controlling volume a breeze, with LED feedback to show you volume levels.

Audio sounds dynamic, with a generous bump in gain over whatever you’re plugging it into likely offers. The frequency response is flat meaning you get out exactly what you put in audio-wise, making this a great choice if the connectivity (and price) matches your specific use case.

Best for power and portability: AudioQuest Dragonfly Cobalt

Bar the Ugreen dongle, the Dragonfly is easily the smallest, most portable device on this list. And better yet, it almost certainly works with your phone, PC or laptop and won’t require a dedicated power supply (despite the lack of a built-in battery). You’ll still need an adapter for phones (USB-A to Lightning or USB-A to USB-C for Android) but otherwise, it’s plug and play. There’s no volume control, just one 3.5mm headphone jack and a color-changing LED (to tell you what sample rate the track you’re listening to is using).

At $300, it’s a pricey proposition, but the cable spaghetti of some devices or the sheer heft of others, means the Dragonfly’s small footprint and rugged simplicity make it refreshingly discreet and simple. AudioQuest also offers two cheaper models, starting at $100 that are likely more than good enough for most people.

Don’t let the Dragonfly’s size and lack of controls fool you, the Cobalt throws out some serious, high quality sound. According to AudioQuest, the maximum resolution has been intentionally limited to 96kHz for the “optimal” experience, and that’s plenty enough to cover what you’ll get from most music services.

The output from the in-built headphone amp will make your phone’s audio feel positively wimpy by comparison, and the powerful internal sound processing chip delivers crystal clear audio with a wide soundstage across a range of genres and formats.

One extra trick up the Dragonfly’s sleeve is native support for Master Quality Authenticated (MQA) files. This is the preferred format of Tidal, so if that’s your service of choice, the Dragonfly is ideal.

Best for super high resolution: Fiio Q3

Fiio has been a popular name in the portable DAC scene for a while now, and for good reason. The products deliver solid audio quality, support all manner of resolutions and are compatible with a wide range of devices. The Q3 is bigger than the previous options on this list (it’s about 1cm shorter than an iPhone 4), but remains fully portable. There are even some goofy silicone bands so you can strap it to your phone, rather than have a flappy, heavy appendage.

For users on the go, the Q3’s built-in battery (good for about eight hours) means you won’t need to drain the power on whatever you’re plugging it into. It also means mobile users won’t need a dreaded second cable. Throw in support for three different size headphone jacks (sadly, ¼-inch isn’t one of them) and you have a DAC that will serve you souped-up sounds wherever you are and whatever you’re listening to.

There isn’t a display, which you might expect for something this size, but there is an LED that changes color when you’re listening to something higher than 48kHz, so you can tell which tracks in your streaming service’s library really are higher-res. The dedicated volume control doubles as a power knob and there’s also a “bass boost” switch just like the good old days. On top of the USB-C input, there’s also the option for analog audio sources via the 3.5mm port.

Even if you’re not listening to high sample rate music, the Q3 sounds fantastic. The difference in volume, punch and dynamic range that comes through in songs that sounded flat and dense when listening directly through a phone or laptop was remarkable. Throw in support for all the hertz and bit-depths that you’ll likely ever need and what’s not to like? Especially as the Q3 comes in cheaper than some of the less capable options in this guide (the slight extra heft will be a key factor here).

Best for high resolution / fans of Tidal: iFi Hip Dac

If this were a spec race, it’d be a photo finish between Fiio’s Q3 and iFi’s Hip Dac. Like the Q3, the Hip Dac blows right past support for 192kHz right up to 384kHz. It also offers balanced output via 4.4mm headphones which is rare to find on consumer headphones, but some higher-end cans offer it for those who want to eliminate any potential interference. There’s also an internal battery, bass boost and a very similar form-factor to the Q3.

For anyone interested in either of these two it might come down to a single feature. Be that the highest sample rate it can support (Q3 wins) or its ability to decode Tidal’s MQA files (in which case, you want the Hip Dac).

The sound out of this thing takes on the Q3 blow for blow and even the same knurled volume control is here. But let’s be honest, the fact it looks like (and was named after) a hip flask is clearly also a major selling point. Though it’s worth mentioning the Hip Dac takes a female USB cable, supplied in the box. But this does mean you’ll need to use the Camera Kit to get into the iPhone, whereas the Q3 works with one single provided cable.

Regardless, it’s another robust option that will more than cover most bases for most people. As with the Q3, the internal battery means you won’t need to feed it power while in use (estimated eight hours) and connecting it to your phone or computer is the same; as long as you can pipe a USB cable into it, you’re good to go.

Best for desktop warriors: Focusrite Scarlett 2i2

Only looking for a desktop DAC? Then a good old fashioned audio interface might be the best choice for you. Focusrite’s Scarlett series has near-legendary status at this point and an eye-wateringly high review ratio on Amazon for a good reason: It does what it does very very well.

Most current laptops and desktops can probably handle at least 96kHz audio, but with the Scarlett you can be sure you are getting the full 192kHz when available and the dedicated audio processors and headphone amps will do a much better job of it.

The main benefit here is the general upgrade you will be giving to your PC. Not only will your listening experience be enhanced, but you’ll be able to plug in microphones and instruments if streaming or recording are your thing, all in one device and all for about the same price as some of the more mobile-oriented devices on this list.

This article originally appeared on Engadget at https://www.engadget.com/the-best-dac-for-lossless-high-resolution-music-iphone-android-160056147.html?src=rss 

Ever year, more than a million people in North America suffer some form of spinal cord injury (SCI), with an annual cost of more than $7 billion to treat and rehabilitate those patients. The medical community has made incredible gains toward mitigating, if not reversing, the effects of paralysis in the last quarter-century including advances in pharmacology, stem cell technologies, neuromodulation, and external prosthetics. Electrical stimulation of the spinal cord has already shown especially promising results in helping spinal injury patients rehabilitate, improving not just extremity function but spasticity, bladder and blood pressure control as well. Now, in a study published in Nature Tuesday, SCI therapy startup Onward Medical, announced that it has helped improve a formerly-paraplegic man’s walking gait through the use of an implanted brain computer interface (BCI) and novel “digital bridge” that spans the gap where the spine was severed.

We’ve been zapping paraplegic patients’ spines with low-voltage jolts as part of their physical rehabilitation for years in a process known as Functional Electrical Stimulation (FES). Electrodes are placed directly over the nerves they’re intended to incite – externally bypassing their own disrupted neural pathways – and, when activated, cause the nerves underneath to fire and their muscles contract. Researchers have used this method to restore hand and arm motion in some patients, the ability to stand and walk in others and, for a lucky few, exosuits! The resulting limb motions however were decidedly ungraceful, resulting in ponderous arm movements and walking gaits that more resembled shuffles.

Onward’s earlier research into epidural electrical stimulation showed that it was effective at targeting nerves in the lower back that could be used to trigger leg muscles. But the therapy at that time was hampered by the need for wearable motion sensors, and by, “the participants … limited ability to adapt leg movements to changing terrain and volitional demands.“ Onward addressed that issue in Tuesday’s study by incorporating a “digital bridge” to monitor the brain’s command impulses and deliver them, wirelessly and in real-time, to a stimulation pack implanted in the patient’s lower back.

Clinicians have employed these systems for the better part of a decade to assist in improving upper extremity control and function following SCI – Onward’s own ARC EX system is designed to do just that – though this study was the first to apply the same theories to the lower extremities.

Onward’s patient was a 38-year-old man who had suffered an “incomplete cervical (C5/C6) spinal cord injury” a decade before and who had undergone a five-month neurorehabilitation program with “targeted epidural electrical stimulation of the spinal cord” in 2017. “This program enabled him to regain the ability to step with the help of a front-wheel walker,” the research team noted in the Nature study. “Despite continued use of the stimulation at home, for approximately three years, he had reached a neurological recovery plateau.”

In addition to the EX, Onward Medical has also developed an internally mounted electrostimulation therapy, the ARC IM. Per the company, it is”purpose-built for placement along the spinal cord to stimulate the dorsal roots,” to help improve SCI patients’ blood pressure regulation. The system used in Tuesday’s study used the ARC IM as a base and married it to a WIMAGINE brain computer interface.

The Onward team had to first install the BCI inside the patient’s skull. Technically, it was a pair of 64-lead electrode implants, each mounted in a 50-milimenter circular-shaped titanium case that sits flush with the skull. The WIMAGINE “is less invasive than other options while offering sufficient resolution to drive walking,” Dave Marver, OnwardMedical CEO, told Engadget via email. “It also has five-year data that demonstrates stability in the clarity of signals produced.”

Two external antennas sit on the scalp, the first providing power to the implants via inductive coupling, the second to shunt the signal to a portable base station for decoding and processing. The processed signal is then beamed wirelessly to the ACTIVA RC implantable pulse generator sitting atop the patient’s lumbar region where 16 more implanted electrodes shock the appropriate nerve clusters to move their legs. Together they form a Brain Spine Interface (BSI) system, per Onward.

The entire setup is designed to be used independently by the patient. The assistive walker houses all the BSI bits and pieces while a tactile feedback interface helps them correctly position the headset and calibrate the predictive algorithm.

In order to get the BCI and pulse generator to work together seamlessly, Onward leveraged a “Aksenova/Markov-switching multilinear algorithm that linked ECoG signals to the control of epidural electrical stimulation parameters,” which seems so obvious in hindsight. Basically, this algorithm predicts two things: the probability that the patient intends to move a specific joint based on the signals it’s monitoring, and both the amplitude and direction of that presumed intended movement. Those predictions are then dumped into an analog controller which translates them into code commands that are, in turn, cycled to the pulse generator every 300 milliseconds. In all, the latency between the patient thinking, “I should walk over there,” and the system decoding those thoughts is just 1.1 seconds.

Calibrating the system to the patient proved an equally quick process. The patient had figured out how to properly “activate” the muscles in their hips to generate enough torque to swing their legs within the first two minutes of trying — and did it with 97 percent accuracy. Over the course of the rehabilitation, the patient managed to achieve control over the movements of each joint in their leg (hip, knee and ankle) with an average accuracy (in that the BSI did what the patient intended) of around 75 percent.

“After only 5 min of calibration, the BSI supported continuous control over the activity of hip flexor muscles,” the team continued, “which enabled the participant to achieve a fivefold increase in muscle activity compared to attempts without the BSI” Unfortunately, those gains were wiped away as soon as the BCI was turned off, instantly losing the ability to step, they explained. “Walking resumed as soon as the BSI was turned back on.”

It wasn’t just that the patient was able to graduate from walking with a front-wheeled frame walker to crutches thanks to this procedure – their walking gait improved significantly as well. “Compared to stimulation alone, the BSI enabled walking with gait features that were markedly closer to those quantified in healthy individuals,” the Onward team wrote. The patient was even able to use the system to cross unpaved terrain while on their crutches, a feat that still routinely proves hazardous for many bipedal robots.

In all, the patient underwent 40 rehab sessions with the BCI – a mix of standard physio-rehab along with BCI-enabled balance, walking and movement exercises. The patient saw moderate gains in their sensory (light touch) scores but a whopping 10-point increase in their WISCI II scores. WISCI II is the Walking Index for Spinal Cord Injury, a 21-point scale measuring a patient’s ambulatory capacity ranging from 20, “can move zero assistance,” down to 0, “bed ridden.“ Onward’s patient went from a 6 to a 16 with the help of this therapy.

“As the participant had previously reached a plateau of recovery after intensive rehabilitation using spinal cord stimulation alone, it is reasonable to assume that the BSI triggered a reorganization of neuronal pathways that was responsible for the additional neurological recovery,” the Onward team wrote. “These results suggest that establishing a continuous link between the brain and spinal cord promotes the reorganization of residual neuronal pathways that link these two regions under normal physiological.”

While the results are promising, much work has yet to be done. The Onward team argues that future iterations will require “miniaturization of the base station, computing unit and unnoticeable antennas,” faster data throughputs, “versatile stimulation parameters, direct wireless control from the wearable computing unit,” and “single low-power integrated circuit embedding a neuromorphic processor with self-calibration capability that autonomously translates cortical activity into updates of stimulation programs.”

Despite the daunting technical challenges, “the BCI system described in Tuesday’s Nature publication may reach the market in five to seven years,” Marvel predicted. ”It is possible and realistic that a BCI-augmented spinal cord stimulation therapy will be on the market by the end of the decade.”

This article originally appeared on Engadget at https://www.engadget.com/swiss-researchers-help-a-spinal-injury-patient-to-walk-more-naturally-using-a-wireless-bci-151542965.html?src=rss