Saturday, December 19, 2015

Enjoy DIY 300B Tube Anplifier PCBA Kit With Free Testing

Enjoy DIY 300B Tube Anplifier PCBA Kit With Free Testing


A lot of HIFI audiophiles like to do DIY 300B tube amplifier with scaffold-soldering way previously, but that is a great engineering and too much wiring, reliability and performance may be affected, also its appearance does not look good. Now, there are well-made PCBA instead of scaffolding soldering, the problems above will be completely resolved, and it is not difficulties since then. Because the PCBA board is free testing, and its manufacturing difficulties is equal to assemble a LM1875 amplifier. 

You can use this kit to build your 300B tube amplifier.Framework of the 300B tube amplifier kit adopts 6SN7 plus 300 B single-ended outputs. And this 300B PCB material is 2.0 thick double copper immersions gold. Output transformers are made of high-grade silicon steel plate Z11, and used imported electronic vacuum tubes.




Wednesday, December 2, 2015

3-bands MW / SW Tube Radio with Little 7 Tubes Nostalgia Style

 3-bands MW / SW Tube Radio with Little 7 Tubes Nostalgia Style

In our memories, tube radio was the product of the last century. But from then on, transistors had replaced those tubes, and digital had replaced analogy accordingly, however still some people like tube radio, like its taste, and more like its nostalgia style...

This is a pure tube 3-band radio, it can receive a medium wave and two band shortwave signal. Tube radio is built in 4-inch small speakers, which can meet listening need for 15 square rooms. If you connect an external 6-8 inch full-range speaker, then there will be a leap in sound volume. It has MW / 3-band frequency range: MW: 535-1605 KHZ, Shortwave 1: 2.3-7 MHZ, Shortwave 2: 6-18 MHZ

WVT-RSX02(4L)
Little 7 Tubes  3-bands MW / SW Tube Radio

WVT-RSX02
Inside View


WV-RSD02


WVT-RSX02(ZL)


WV-RSD02(I7L)


If you want to get better listening effect, you will set up a longer antenna that length is about 5 ~ 10m or more and leave it outdoor, this is common sense for tube radio's fans. We set up the antenna as below and get better effect.

1. Outdoor antenna is connected to the fifth floor, which is a about 10 meters aluminum wire with plastic cover for drying clothes, and connected with an ordinary wire led to the second floor studio listening, there is no ground wire.
a) During daytime and it can receive 5 MW stations, in the evening receive more than 10 one. Good listening experience.
b) Short-wave 1: 2.3-7MHZ. receives 2-3 stations in daytime, receives more than 10 stations in evening, the effect can still listen.
c) Short-wave 2: 6-18MHZ. receives more than 10 stations in daytime, receives more than 30 stations in evening, good listening experience.
2. If indoor antenna with ordinary wire 2 meters, listening effect is general.

In order to ensure that the tube radio is original taste and flavor, the old components is used on the unit, most of them came from new inventory of 70-80's of the last century, power transformers is DB -50-300 inventory produced in the 1980s, and output transformer is model CB-3.5W-80, they are produced by Shanghai radio No 27 factory all. And Double variable capacitors, wire wound resistors 4W100Ω, fuse holder is disassemble (but tested and performance is intact), its appearance looks like a little rust; after all they are decades of inventory. Dial has not improved, and this depends on you and the buyer's hands capability.

Main Specifications

1. Equipped with seven tubes: 6A7PJ, 6K3PJ, 6N9PJ, 6H6PJ, 6P6PJ, 6Z5PJ, 6E2M
2. Bass / tremble control
3. Built-in Radio / Phono (CD player) switch
4. Built-in a switch jack between radio speaker and outside speaker.
5. Aluminum chassis Dimensions (L * D * H) 340mm X 200mm X 190mm.
6. Working voltage: 220V / 50Hz

 





Sunday, November 29, 2015

A tool to improve sound of HIFI Speaker-- Shock Spike & Mat Kit DIY

A tool to improve sound of HIFI Speaker-- Shock Spike & Mat Kit DIY

It is very simple that working principle of shock spikes, that is by reducing contact area to increases the pressure of speakers or amplifier device, thereby restrain vibration generated by the end of the jump instant, stable to direct wave. And absorb, attenuate the shock given by the equipment itself, block external shock given.

In order to achieve these two points, materials of shock absorbers nail must be three characteristics, high-quality, high hardness, high shock attenuation rate.

Although quality steel has the characteristics of high quality, high hardness, it is lack of high attenuation. In this regard, we put material with high attenuation characteristics to combine with the steel to obtain this "three high" characteristics. After a series of material screening, we finalize the selection of quality SUS304 stainless steel and graphite polymer combinations. Through debugging proportion for materials used, we finally completed this spikes.

The sound character of nails is very thick density, while maintaining the sense of low frequency, which greatly improves line and solid feeling of high-frequency, and expand the ends of frequency response widely, three-bands is equalized, has excellent control in large dynamic, and open sound field as if the music has injected vitality, flew alive! This upgrade is definitely more important than the change of signal cable or power one.

HIFI Speaker Shock Spike & Mat Kit


HIFI Speaker Shock Spike & Mat 



3M Sticker


Two diameter




Thursday, November 26, 2015

2 x 25W HIFI Bluetooth digital power amplifier with Bluetooth 4.0 CSR8635 Placying CD Level Music



Have you looked for a Bluetooth Amplifier without cable connection? You may only use wirelessBluetooth connection through your Bluetooth enabled devices, this one will be a better choice.

Specially, it built in CSR8635 Bluetooth module, that adopt Bluetoth 4.0 technology. And you can enjoy CD level music once connected with you smart phone and play lossless traces, like as WAV, FLAC, AFAC, APE format music...

As a desktop amplifier, output power of this HIFI Bluetooth 4.0 digital amplifier is  2 * 25W stereo with whole aluminum enclosure, matte oxidation process; Adopted customized advance air core inductors to improve the LC filter of digital amplifier, which is the most important aspects for digital amplifier, Adopted 3300uf BC-048 filter capacitor as a reservoir with internal shun in order to meet the power needs bursting to solve problem of partial handsome voice for switching power supply;

Also it built in speaker protection and power-delay circuit, so there was no impact sound switch and protect your valuable speakers; 












Specifications of this HIFI Bluetooth digital power amplifier as below.
  1. Signal input: Bluetooth 4.0 + EDR; RCA line input
  2. Work type of amplifier: Class D
  3. Working efficiency: about 88%
  4. Quiescent current: 50mA
  5. Rated output power: 2 * 25W
  6. Frequency response: 20Hz to 20KHz
  7. THD: 0.09% (@ 1W)
  8. Output impedance: 4 / 8Ω
  9. Working voltage: DC9V to DC15V


More details, please find http://www.aliexpress.com/store/product/Free-Shipping-HIFI-Bluetooth-digital-power-amplifier-PAM2021-2-x-25W-Bluetooth-2-1-EDR-RCA/725205_1314318116.html

Monday, November 23, 2015

An Elegant Desktop Audio Based on LM1875 and PCM2706 (HIFI Amp + labyrinth HIFI speakers Cabinet)

An Elegant Desktop Audio Based on LM1875 and PCM2706 (HIFI Amp + labyrinth HIFI speakers Cabinet)


What is your expected desktop audio? Maybe you could say that it is an HIFI entry level at least, here you are, it might be suitable for if you want to look for an elegant desktop amplifier that based on LM1875 and PCM2706 which can decode the music from your computer or notebook,also include a pair of HIFI speakers which adopt two full-range speaker unit with labyrinth structure.


The Amplifier with DAC function, which is made of LM1875 and DAC used PCM2706, its panel is made of expensive rosewood, and using popular environmentally friendly water-based varnish with manual painted. The color of speaker cabinet is same as its amp panel.



WHFA-K1875DAC

WHFA-K1875DAC(1l)


Rosewood Panel


WHFA-K1875DAC(Al)

Back view of the amplifier


WHFA-K1875DAC(Bl)

WHFA-K1875DAC(A1l)

Rosewood panel

WHFA-K1875DAC(2l)

WHFA-K1875DAC(sp1l)

WHFA-K1875DAC(sp2l)

 Full-range speakers with labyrinth structure


WHFA-K1875DAC(inl)

Product specifications

HIFI Amplifier DAC

  1. Input ports: Mini-USB and RCA x 2
  2. DAC: PCM2706
  3. Amp IC: LM1875
  4. Rated output power:  2 x 10 W
  5. Frequency response: 20Hz-20Khz
  6. Total Distortion: 0.015% (@ 1 kHz 10W)
  7. Output impedance: 4 or 8 Ohm
  8. Signal to Noise Ratio: 105 Db
  9. Amp Size (L*W*H): 130 mm * 110 mm * 40mm
  10. Colors: Black
  11. Gross Weight: 1 kg (Including power adapter)
  12. Accessories
  USB cable x 1
  RCA cable x 1
  Power adapter (Input: 110-220v, Output: DC 24V/2.5A) X 1
 Speaker connection cable x 2

HIFI 2 Inches Full Rang Labyrinth Structure Speaker

1. Outer power: 2 X 10W
2. Impedance: 4 ohms
3. Speaker unit: 2-inch full-range neodymium speaker unit
4. Sensitivity: 84dB
5. Cabinet material: Wooden
6. Interface Type: RCA inputs
7. Weight: 1.6KG / pair
8. Dimension: 165mm X 72mm X 126mm


Package

WHFA-K1875DAC(Packagel)

WHFA-K1875DAC(P2l)

Packing list


WHFA-K1875DAC(P1l)

Applications


WHFA-K1875DAC(a4l)

WHFA-K1875DAC(a2l)

WHFA-K1875DAC(a3l)



WHFA-K1875DAC(a6l)