Saturday, October 31, 2015

Personalized Ultra-Class A (Class AA) Headphone Amplifier with Portable Design

Personalized Ultra-Class A (Class AA) Headphone Amplifier with Portable Design


Audiophiles had asked me, or whether the device or circuit determines the sound quality? In our experience, the answer is, circuit design, technology and debugging is more to decide sound, HIFI devices, op amp selection and personalized tone tuning is more to define Timbre. It is so-called HIFI to focus on quality, high-fidelity idea. The HI-END is integrated personalized tuning philosophy into the trend to the highest HIFI level.

There is a portable headphone amplifier that is designed according to the concepts as above. 

Portable Ultra-Class A (Class AA) Headphone Amplifier--Gray

Portable Ultra-Class A (Class AA) Headphone Amplifier -- Black


Personalized design, all aluminum casing, ultra-thin body. Circuit structure used a ultra-Class A (Class AA) circuit, because voltage amplifier stage of Class AA headphone amplifier is equivalent to a no-load state, no matter how the load followed by the headphone, it will not affect the voltage amplifier stage of work, which is common Amplifiers can not achieve that status. As results, it will make a very real interpretation of the music, space and very good positioning performance, and efforts to extend the sense of sound performance; it is just a little weird. In addition, we use HIFI grade components and process to make it, and bring a better listening experience.


It's PCBA inside


Selection aspect of the op amp, we used OP IC OPA2604 plus LM4562 match, we passed several tests comparing those match, we find that they can complement each other; If the preamp use OPA2604, and power stage use LM4562, we tested them with a 20KHz square wave, which output waveform distortion is very small. From the listening sensation, LM4562 relatively straightforward, OPA2604 more beautiful!


OP Amplifier used


Specifications


1.       Output power: 320mW (at 32 ohm)
2.        Headphone Impedance: 16 ~ 300 ohms
3.       Total Harmonic distortion: <0.0005%
4.       Frequency Response: 20Hz ~ 20Hz
5.       SNR :> 110dB
6.       Built-in rechargeable lithium battery 1200mAH
7.       Weight: 0.5kg
8.       Dimension (L * W * H): 100 mm * 61mm * 13mm
9.       Color: Black / Silver/Gray
10.       Accessories
    3.5mm audio cable x 1
    USB charging cable x 1

3 color selections

Appliccations by audiophiles













Wednesday, October 28, 2015

Bluetooth study tool---CSR8645 Rom Version Development Simulation Demo Board

Bluetooth study tool---CSR8645 Rom Version Development Simulation Demo Board (For study only)


Have you thought to develope yourself Bluetooth speaker? Maybe it is a crazy thinking, but if you have some basic Bluetooth program and hardware skills and love to DIY your things, or study this porpular and fantactic things, you can try it.Also, if you can solve that you will face problems of Bluetooth speaker development, you can try it from this CSR8645 Rom Version Development Simulation Demo Board.

Here is the board. It is fast, convenient, practical and essential tool for product developmentwith 4M FLASH for product developers . This board can be used to develop a Bluetooth headset, car handsfree, Bluetooth speakers, etc.



CSR8645 Rom Version Development Simulation Demo Board






Main features as below
1.     Provide 3W amplifier output can be directly connected to the speaker as a Bluetooth speaker using.
2.     Offers 3.5 headphone output interface, plug in headphones can be used directly as a Bluetooth headset.
3.     Provide 3.5AUX-IN port, support AUX-IN switching.
4.     MIC interface, can make and receive calls, and provides debugging Dual MIC noise cancellation.
5.     SPI debugging burning interface for easy developer debugging.
6.     Bluetooth PIN feet IO ports are reserved for development and debugging use.
7.     Buttons, eight IO ports with LED indication IO port operation.
8.     MFB provide power button and the power button to boot the boot in two ways.
9.     Three-color LED indication, LED status debugging easier.
10.  Using 4M FLASH, large space, easier debugging voice prompts.
11.  USB communication capabilities for debugging USB sound card functions.
12.  This development board backplane can be used for all other modules CSR.


Saturday, October 24, 2015

Speaker driver’s construction and related function

Speaker driver’s construction and related function


In any sound system, ultimate quality depends on the speakers. The best recording, encoded on the most advanced storage device and played by a HIFI speaker and amplifier, will sound awful if the system is connected with poor speakers.
A system's speaker is the component that takes the electronic signal stored on things like CDs, DVDs or digtial media such as your smartphone, tablet, music players, and turns it back into actual sound that we can hear.
A speaker is essentially the final translation machine -- the reverse of the microphone. It takes the electrical signal and translates it back into physical vibrations to create sound waves. When everything is working as it should, the speaker produces nearly the same vibrations that the microphone originally recorded and encoded on a tape, CD, LP, etc.
4 inches full range speaker driver unit


Now, let us take a look those components or parts of speaker. A typical speaker driver includ a metal basket, diaphragm (or cone), voice coil, spider, permanent magnet, ans also include dust cap, terminal,top plate, pole piece.

  •     The cone, usually made of paper, plastic or metal, is attached on the wide end to the suspension.
  •     The suspension, or surround, is a rim of flexible material that allows the cone to move, and is attached to the driver's metal frame, called the basket.
  •     The narrow end of the cone is connected to the voice coil.
  •     The coil is attached to the basket by the spider, a ring of flexible material. The spider holds the coil in position, but allows it to move freely back and forth.
  •     The dust cap covers the voice coil opening and sperker internal.
  •     The terminal with positive and negative is soldered wires where electronic signal come from.
  •     The top plate and pole piece to fix permanent magnet

 
Speaker driver's construction, the photo come from network, only for demostration there.Thank you for the original author

There are key parts for making sound

Diaphragm


A driver produces sound waves by rapidly vibrating a flexible cone, or diaphragm. Some drivers have a dome instead of a cone. A dome is just a diaphragm that extends out instead of tapering in.

Voice Coil


When the electrical current flowing through the voice coil changes direction, the coil's polar orientation reverses.The voice coil is a basic electromagnet. An electromagnet is a coil of wire, usually wrapped around a piece of magnetic metal, such as iron. Running electrical current through the wire creates a magnetic field around the coil, magnetizing the metal it is wrapped around. The field acts just like the magnetic field around a permanent magnet: It has a polar orientation -- a "north" end and and a "south" end -- and it is attracted to iron objects. But unlike a permanent magnet, in an electromagnet you can alter the orientation of the poles. If you reverse the flow of the current, the north and south ends of the electromagnet switch.
This is exactly what a stereo signal does -- it constantly reverses the flow of electricity. If you've ever hooked up a stereo system, then you know that there are two output wires for each speaker -- typically a black one and a red one.
Essentially, the amplifier is constantly switching the electrical signal, fluctuating between a positive charge and a negative charge on the red wire. Since electrons always flow in the same direction between positively charged particles and negatively charged particles, the current going through the speaker moves one way and then reverses and flows the other way. This alternating current causes the polar orientation of the electromagnet to reverse itself many times a second.

Magnets

When the electrical current flowing through the voice coil changes direction, the coil's polar orientation reverses. This changes the magnetic forces between the voice coil and the permanent magnet, moving the coil and attached diaphragm or cone back and forth.
So how does the fluctuation make the speaker coil move back and forth? The electromagnet is positioned in a constant magnetic field created by a permanent magnet. These two magnets -- the electromagnet and the permanent magnet -- interact with each other as any two magnets do. The positive end of the electromagnet is attracted to the negative pole of the permanent magnetic field, and the negative pole of the electromagnet is repelled by the permanent magnet's negative pole. When the electromagnet's polar orientation switches, so does the direction of repulsion and attraction. In this way, the alternating current constantly reverses the magnetic forces between the voice coil and the permanent magnet. This pushes the coil back and forth rapidly, like a piston.
When the coil moves, it pushes and pulls on the speaker cone. This vibrates the air in front of the speaker, creating sound waves. The electrical audio signal can also be interpreted as a wave. The frequency and amplitude of this wave, which represents the original sound wave, dictates the rate and distance that the voice coil moves. This, in turn, determines the frequency and amplitude of the sound waves produced by the diaphragm.

Different driver sizes are better suited for certain frequency ranges. For this reason, loudspeaker units typically divide a wide frequency range among multiple drivers.

There are more HIFI speaker driver units that cover most of the kinds on the market. More details, please find 

http://www.aliexpress.com/store/group/HIFI-Speaker-Unit/725205_256208811.html



Saturday, October 17, 2015

A Key of Bluetooth Speaker or Bluetooth Amplifier --- Bluetooth module

A Key of Bluetooth Speaker or Bluetooth Amplifier --- Bluetooth module 


Bluetooth speakers or bluetooth amplifiers have become more and more popular now as wireless signal transmission. You could see them  every year at CES. At same time, bluetooth Technology had been improved from 1.0 version to 4.1 one now, it is can achieve CD level music for the bluetooth 4.0 version, and it is used hifi audio.You will not connect those signal input cable, only set up bluetooth connection between your bluetooth devices like as iPhone or android smartphone, tablet.Then, you can play stream music form your local disk or internel through WIFI, of course, you should install a music play, if it support to play lossless format such as WAV, APE, FLAC, APAC, it absolutely achieve CD quality. 

But do you know how it is used in PCB?  normally, it is soldered as a module where the bluetooth ic and other op ic will be soldered there, also the program will be burned on ROM inside previously.manufacturer purchase it from module supplier, which is customized by the supplier, for example display name on the host, prompt, volume..., and so on.We also provide those customizations. There is more stable and quality module that is made of CSR8645, which support apxt decoding.The moudles had been used in a lot of bluetooth speakers or amplifiers, like as FATMAN mini tube bluetooth amplifiers and other Bluetooth speakers by UK.Especially, the original manufacturer of bluetooth ic provide us strong support from PCB designing.


 It is better to start weaving your fishing nets than merely coveting fish at the water, right? If you want to  develop your high quality Bluetooth speaker or amplifier or modify your current audio system to ass wireless connection function, it will be a better choice.





This CSR8645 Rom Module Functions:
  1. Bluetooth version 4.0 plus EDR standard specification.
  2. Radio power: Class 2.
  3. Support A2DP 1.2, AVRCP 1.4, HFP1.6(including WBS and Msbc), HSP1.2.,etc protocols.
  4. Adopt CSR voice enhancing technology of latest sixth version CVC to realize noise reduction and echo cancellation.
  5. Support multipoint connection (connection to 2 phone for voice and music)
  6. Support CSR Secure Simple Pairing, Proximity Pairing and CSR Proximity connection.
  7. Support user to define muliti-language voice prompt function.
  8. Support voice dialing / rejection calling.
  9. Support SBC, MP3, AAC, APT-X music format.
            10. Support output port: PIO / UART/SPI/AIO/SPK/MIC/USB.
            11. Built-in 16 bits stereo decoder, S/N of digital to analog convert is up to 95Db.
            12. Built-in DC DC conversion power management.
            13. Integrated Li-ion battery charging function, charging current is up to 400mA maximum.
            14. Smaller SMT package: 26.5mm*13mm*2.2mm.
            15. RoHS compliance.

 More details, please find http://www.aliexpress.com/store/product/CSR8645-ROM-Bluetooth-Module-Bluetooth-4-0-Mulitport-Output-Support-APT-X-Decoding-DIY-RoHS-Compliance/725205_1276174862.html

Or use this one with key board.

http://www.aliexpress.com/store/product/CSR8645-ROM-Bluetooth-Module-Bluetooth4-0-Mulitiport-Output-Support-APT-X-Decoding-With-Key-Board-DIY/725205_1644152718.html

Tuesday, October 13, 2015

Beauty Guitar Playing and Singing

Beauty Guitar Playing and Singing



Beauty Guitar Playing and singing..., the song only belongs to the heaven,it is hardly heard on the earth. The vedio from youtube, great guitar playing and sing the song!





Perhaps you like guitar playing and singing, there is no problem when you play and sing as practice by yourself.But, if you open a small guitao concert,you might need a guitar amplifier speaker to amply your sining and guitar’s accompany,then show your as you like.

There are some guitar amplifier speaker for different output power, you can select them according to your needs.

http://www.aliexpress.com/store/group/Guitar-Amplifier-Speaker/725205_256242019.html





Monday, October 12, 2015

Simple way to improve sound quality of your amplifier or HIFI speakers

Simple way to improve sound quality of your amplifier or HIFI speakers

Many audiophile spend a lot of money to desire improving the sould quality of their audio system like as amplifier or HIFI speakers.But they don't find a shortcut sometimes.If we can make sure the signal transmission isn't lossless through connetion cable, we will get twice the result with the half effort, of course, it based on the other components that work well at least.

 The simple method is to use high quality connection wire or cable into your amplifier, HIFI speakers such as OCC cable.There is an OCC cable, which is made of 22AWG OCC frozen crystal copper with PE coat, pure sound extremely transparent nature really.Suitable for used as headphone cable, connection cable in amplifier.

We may use it as audio connection wire in amplifier, use it to make speaker cable, use it to make power cord...








Comparisons between OFC and OCC under High-power microscope, we can see the construction of this OCC Frozen Signal Crystal Copper 7N (99.99995%) wire.




Its specifications as blow

  1. 7N (99.99995%) single-crystal copper OCC Frozen copper wire
  2. Conductor: 0.06 mm * 25 pcs
  3. Outer diameter: 1.45mm
  4. Insulator: PE coat



Saturday, October 10, 2015

IWISTAO Tube Preamplifier with Matisse Fantasy Line Stage GE 5670W for Your Upgrading Car Audio

It is a Tube Preamplifier with Matisse Fantasy Line Stage GE 5670W, and its power supply is DC 12V, you may use it to update your car audio system from the DC12V.

The main feature of Matisse Fantasy Line Stage is sweet mellow sounds, calm and powerful low-frequency sound field is very open, like a sense of the scene, and here it goes without saying! Since tube preamp birth, it is well known as its design concept for distinguished from commonplace, pure and transparent sound quality to really spotless, and become a world-class reference.

The circuits adopt British famous circuit of Matisse Fantasy Line Stage, and with 12VDC power supply (Recommanded Power supply: DC12V / 1A ). The HIFI Tube Pre-Amplifier is made of HIFI imported components like as United States AB resistance, which can bring a sense of warm and soft vocals, Philips filter capacitor charging and discharging more reliable, Germany ERO coupling capacitor to that make the sound more balance, ALPS potentiometer sound good but also durable, gold-plated contacts Cinch make the connection more reliable and greatly reduce transmission of resistance signals.







Also there is vedio to paly music and it is taken by iPhone 5S.





Tuesday, October 6, 2015

What is an Operational Amplifier?---OpAmps Tutorial Vedio

What is an Operational Amplifier?---OpAmps Tutorial Vedio


Operationl Amplifier, especially OP IC had been used in Power Amplifer as preamplifier or other functions. 

There is a excellent OP IC with metal seal, this is LME49720,which is ultra-low distortion rate; it is a professional audio op amp that is able to achieve total harmonic distortion and noise performance under 0.00003% or less in the world's only, and pursued and loved by many audiophiles around the world.

LME49720HA is one of the most top HIFI op amps IC in the world, low noise, high slew rate, wide operating voltage range and output current, etc., high overall performance is unprecedented, and can easily meet the most demanding audio application requirements. Ideal for professional and high-end audio system, it can be widely used in high fidelity buffer amplifier, high-fidelity active filters, high-fidelity headphone amplifier, high-fidelity phono equalizer amplifier, high-quality audio amplifier, high-fidelity preamplifier, high-fidelity multimedia, high-performance professional audio, high-fidelity balanced network, high-performance line drives, high-performance line receiver, mixer, etc. with the division.

LME49720HA is National Semiconductor's new generation of "op-amp of the Emperor", LM4562HA upgrade, sounds beautiful noble, comprehensive and balanced, clean sound at the end, natural, high analytical, dynamic large, low dive deep, IF full, people sound sweet and moist, high frequency transparent, delicate soft, contagious.

Specifications
Operating voltage: ± 2.5V ~ ± 17.0V
Harmonic distortion: 0.00003%
Noise Density: 2.7nV / √ ^ Hz
Conversion Rate: 20V / μs

But,do you know know-how of Operatial Amplifier. If you want to know more, please find the vedio below.




Also, there is a Closs A Headphone Amplifier and it is a preamplifier with OP IC LME49720HA, its sound is great.

http://www.aliexpress.com/store/product/Headphone-Amplifier-Discrete-Component-Pure-HIFI-Class-A-Amp-Lehmann-Upgraded-Version-Plastic-sealing-LM47910/725205_1931445868.html

WDAC-02A(INl)
Metal seal LM47910

WDAC-02A(IN4l)
Headphone Amplifier with OP LM47910 WDAC-02A(IN2l)

WDAC-02A(IN3l)


WDAC-02A(IN5l)