Pocket HiFi Audio

https://forum.lowyat.net/topic/3653567 Do you know what is this? Headphone amplifier

Headphone amplifiers are simply miniature power amps designed specifically to drive tiny speakers inside headphones. A headphone system can deliver sound quality comparable to an audiophile-worthy home stereo system, for a fraction of the cost. Headphone version HiFi system, instead using the HiFi Speaker system. Mobile and desktop HiFi system.

Why do I need headphone amplifier? Computer, tablet, smartphone, iPod, MP3/MP4 Player Don't Headphone amplifier Only use single audio microchip/IC (Audio CODEC/HUB) all in 1 no power to do all the job including both input microphone and output headphone/speaker amplification. In hardware, audio codec refers to a single device that encodes analog audio as digital signals and decodes digital back into analog. In other words, it contains both an Analog-to-digital converter (ADC) and Digital-to-analog converter (DAC) running off the same clock. This is used in sound cards that support both audio in and out, for instance. Very simple, to listen your favorite music properly I mean with headphone amplifier module/gadget that involving certain cost, the proper recording equipment setup also need certain cost. To be fair at both end, production company and end user.

Plug in headphone amplifier using 3.5mm to 3.5mm analog audio cable what will happen? If music source from smartphone or computer/Mac headphone out jack this will be double amplification or double amp, you will listen the gain of loudness but not the sound quality in term of clarity and detail. Just double laying of the original output plus the external amp like Fiio E06 will cause confusing blur, muddy and congested sound. Amplifier ether build inside the music player or must be from a line level out clean line out output, if 30 pin iPod or Sony Walkman can use a LOD (Line Out Dock) cable. Mostly the HiFi music player has and additional special line out jack or through setting to do hardware internal amplifier bypass, beside the headphone jack.

Some with USB Digital Signal input Something like musician interface same DAC but without music instrument and Microphone input This is the correct method for a basic setup for smartphone or computer/Mac user. Of course this the connection cable are a USB digital audio cable instead the 3.5mm to 3.5mm analog audio cable. Digital signal are being transfer out so the audio signal conversion processing are by a better external DAC the real thing instead the original build audio microchip/IC (Audio CODEC/HUB) bypass it directly right after DSP digital signal processing by smartphone or computer/Mac's CPU . This is an audiophile version of Soundcard no surround 5.1/7.2 DTS Dolby, no Microphone input/ unlike the gamer/multimedia version. Nothing can be play, nope see below: Only 2.0 Stereo mostly above CD quality, studio mastering quality MP3 not the right thing it sure can be playback by DAC but too much data being deleted. Basic starting from PCM, (CD quality) 44.1kHz/16 bit to 96kHz/24 bit or 192kHz/24 bit Some high end able to decode PCM 384kHz/ 32 bit And there a niche another totally different from PCM (CD quality) studio mastering format develop by Sony call DSD 1 bit only music used to produce Super Audio CD or SACD. This can be archive by using this method name PDM Pulse Density Modulation, relaying density to produce sound shaping instead PCM Pulse Code Modulation using more bit 16 or 24 to make audio bit depth or staircase step. DSD 64 mean 64 time more sampling rate than CD 44.1kHz x 64 = 2.8MHz / 1 bit or 2800kHz / 1bit. Also there are DSD 128

• 1-bit audio is simple to understand in concept. There are no samples, there are no words, there is no code. Instead there is a continuous streaming “train” of single identical bits that are either on or off. The more bits that are on, the higher the eventual output voltage becomes. The more bits that are off, the lower the eventual output voltage. We refer to this type of scheme as Pulse Density Modulation because when you have a greater number of on bits it appears as more densely populated. Here’s a picture that will help you visualize a 1-bit system.
• An alternate conversion process developed by Sony and Philips called Direct Stream Digital or DSD. The Super Audio CD (SACD) is based on DSD and unlike pulse code modulation (PCM) technology used commonly in pro audio applications and normal CD recordings, DSD technology is based on a one-bit ‘sigma-delta’ converter that produces a stream of pulses. The amplitude of the analog waveform is represented by the density of pulses, and is called Pulse Density Modulation. The resulting digital bit stream is encoded at enormous 2,822,400 samples per second! (2.8224MHz) The speed of the bits is 64 times the sample rate of a CD and some DSD schemes run at 128 times faster than a CD.
• Here’s the interesting part of this: if you take a DSD stream and run it through a simple analog lowpass filter to smooth out the on/off transitions, you get music! This is amazing considering that if you do the same with PCM you get only noise.
• DSD is a lot closer to analog than PCM ever thought to be. •DSD or Direct Stream Digital is a one bit recording format. DSF and DFF are 'kinds' of audio files that are delivered as downloads or read by software for playback.
• DSF has the ability to hold metadata and DFF doesn't, however, some players only read DFF files.
• In PCM recording, DSF and DFF would be similar to having .wav and .aiff files which are both PCM

DAC what is that thing? DAC is needed to convert the digital signal (.mp3/.WAV/.flac/.ape/.alac) to analog to drive an earphone or loudspeaker amplifier in order to produce sound (analog air pressure waves)

• An analog signal can be used to measure changes in some physical phenomena such as light, sound, pressure, or temperature.
• For instance, an analog microphone can convert sound waves into an analog signal.
• Even in digital devices, there is typically some analog component that is used to take in information from the external world, which will then get translated into digital form (using an analog-to-digital converter).

A music portable machine/device has build in headphone amplifier, seriously A basic player like Fiio X1 HiFi music player or HiFi version of iPod. Totally different thing from smartphone and MP3 player these don't have headphone amplifier, inside HiFi music player as know as Digital Audio Player DAP contain Headphone amplifier and DAC Digital Analog Converter. Anyway MP3/MP4 player, iPod and Smartphone/Tablet able to listen to music but sound 2D normal comparable to SD standard definition TV or VCD disk , HiFi music comparable to HD high definition TV FHD/4K or Blu Ray disk.

Does earphone/IEM need amplifier? Yes, amplifier beside providing raw power, clean power and also toning/colour change to enhance and smooth the IEM sound signature/character. Audiophile never use the sound equalizer because it sound fake/unnatural/digital.