Features:
The output of 4 groups of speakers can be divided into 4 zone switch control, each group of speakers can independently select A and B power amplifier output, and each group of speaker output can independently turn on and off the function.

Do you have 2 power amplifiers and 4 sets of speakers that need to be connected to each other?
Do you need 2 amplifiers and 4 sets of speakers to get stuck?
A powerful amplifier and audio switcher can solve these problems,
1. 2 power amplifiers push-button select switch input,4 sets of stereo speakers push-button select switch output (4 sets of speakers can be opened or closed independently)
2. Sets of stereo speakers can sound at the same time, you can also turn off one group of speakers or more groups of speakers individually, manually select the pushbutton switch
3. The maximum power of each channel is 300W
4. Signal input provides vacuum tube power amplifier signal no-load protection function
5. Manual selection of input and output switching, straight plug straight use, switching signal stability, between channels will not produce another dry close or noise
6. Compact design of solid metal shell, easy installation, the product does not need external power
7. Simple installation: input and output plug and play easy installation, you can enjoy different audio experience


Product Parameter:
1. Compatible with all types of power amplifiers and speakers
2. Input/output accepts heavy-duty speaker wire or speaker pin wire through the terminal port
3. Connect the power amplifier to amplifier A and B
4. Connect the loudspeaker to position 1-2-3-4 respectively
5. Turn on your power amplifier stereo device and the product requires no external power supply
6. Input: 2 sets of inputs (banana plug)
7. Output: 4 sets of output (banana plug)
8. Power: up to 300W
9. Metal material, fine steel housing, compact size suitable for any system
10. Channel Power: Each channel supports up to 300W of power
11. Frequency response: 10Hz-50KHz
12. Product size: length 240mm X width 105mm X height 55mm
13. Net weight :0.92 kg
14. Kit list: 1 x 2 input 4 output power amplifier switch distributor

Product description:
2 in 1 out or 1 in 2 out audio source signal selection, switcher, computer, speaker, audio source, switcher, RCA interface, lossless transmission
1. No need for power supply design, direct plug and direct use, no loss of input and output signals, switching transmission,
2. This product is mainly used to select a common output device for switching various stereo signal input. If there are two stereo signal sources (such as TV audio, MP3 player, CD player, video game, mobile phone, tablet, computer, record player), the device needs to output to the power amplifier or active speaker.
3. Two sets of stereo source switchers solve the complex line plugging operation. As long as the required input device signal source is uniformly connected to the switcher, it can be easily selected.
4. RCA interface design is used for product input and output standards, and the switch is designed with manual push-button switch of precise 2 positions.

Product parameters:
1. Power supply: no power supply, plug in and use directly
2. Material: All metal case design
3. Input and output impedance: 10 k ohms - 50 k ohms
4. Frequency response: 20-20 kHz
5. Distortion: Less than 0.002%
6. Insertion loss: Less than 0.01dB
7. Signal gain: 0dB
8. SNR S/N: More than 98dB
9. Input interface: Standard RCA interface
10. Output interface: Standard RCA interface
11. Number of input channels: 2 stereo input signal sources
12. Number of output channels: 1 channel stereo output
13. Control switch: Accurate selection of gear 2, manual switch
14. Net weight: 0.14kg
15. Gross weight after packaging: 0.16kg
16. Product size: Length 69mm x width 43mm x height 39mm
17. Package size: Length 83mm x width 73mm x height 51mm
18. Kit list: 2 in 1 out signal selection switcher x 1

Product description:
1. If you have a line level signal source (TV audio, MP3 player, video game machine, cell phone, tablet, computer, record player, etc.) to output to other devices at the same time (such as power amplifier and speakers or headphones), this product can solve the problem of one set of stereo input, which can allocate four sets of stereo, output independent four sets of volume adjustment function, with each channel output band + 20dB gain.
2. For a powerful signal amplifier distributor, you may need to run several long lines between the TV audio line and a receiver on the other side of the room, providing high gain through any line level signal source, allowing longer cable lines to run, or requiring "buffering" to solve low volume problem. You can use it to add signal amplifiers between the line level signal source and the power amplifier, and the RCA jack matches almost all other product interfaces.
3. This product can increase the sound quality of the control signal and reduce the bottom noise. With a large dynamic range, it will not produce a burst. The output volume is controlled by sensitivity adjustment knob, and DC 12V power supply is adopted to ensure full thrust.

Product parameters:
1. Input impedance: 100K Ohm
2. Input level: +14 dBV
3. Output impedance: 47 Ohm per output channel
4. Frequency response: 20 Hz-20K Hz
5. SNR: Less than 107dB
6. Total harmonic distortion: Above 0.02%
7. Intermodulation distortion: Above 0.01%
8. I/O interface: Stereo RCA
9. Power supply: DC-12V
10. Net weight: 0.31 kg
11. Product weight after packaging: 0.46kg
12. Product size: length 109 mm x width 79mm x height 38 mm
13. Package size: length 185mm x width 135mm x height 65mm

Kit list:

1. 1 in-4 out-front Stereo Signal Amplifier Allocator x 1
2. DC-12V Power Adapter (gauge American) wire length: 100cm

Product description:
1. Are you stuck with a set of power amplifier signals that need to be assigned to several speakers? Now this distribution panel can solve the problem of allocating one set of stereo inputs to four sets of speakers at the same time.
2. Number of speakers: we recommend you to use no more than 4 sets of speakers
3. Support power handling: rated power of each channel with amplifier up to 300W
4. Speaker wires: 2 or 4 wires, 16 AWG to 14 AWG
5. Easy to install: The input and output connectors can be wired, and the partition can be set. Compact design - Simple and compact design

Product parameters:
1. Material: Metal
2. Input: 1 set of input (banana plug)
3. Output: 4 sets of output (banana plug)
4. Power: Support 300W (The product requires no external power supply and is easy to install)
5. Net weight: 0.51 kg
6. Product weight after packaging: 0.56kg
7. Product size: length 245mm x width 65mm x height 51mm
8. Package size: length 250mm x width 73mm x height 60mm
9. Kit list: 1 in and 4 out Amplifier x 1

Product description:
Do you have trouble connecting two power amplifiers to four sets of speakers? Do you need a power amplifier to make all four speakers sound at the same time?
A powerful power amplifier with a sound switcher can solve the above problems.
1. Touch-tone switching input for 2 power amplifiers, touch-tone selective switching output for 4 stereo speakers (4 sets of speakers can be turned on or off independently)
2. Four sets of stereo speakers can sound at the same time, or one or more sets of speakers can be turned off separately, manually selecting a push-button switch
3. Maximum support power per channel is 300W
4. Signal input provides no-load protection function of vacuum tube power amplifier signal
5. Provide output earphone monitoring function, 6.5mm interface, earphone output with volume adjustment function
6. The input and output are manually selected for switching, and directly plugged in for direct use. The switching signal is stable, and there will be no additional dryness or noise between channels
7. Compact design, strong metal case, easy installation, no external power supply

Product parameters:
1. Compatible with all types of power amplifiers and speakers.
2. The input/output receives heavy speaker wire or speaker pin wire through the terminal port.
3. Connect the power amplifier to the position of amplifier A or Amplifier B.
4. Connect the loudspeakers to the 1-2-3-4 loudspeaker respectively.
5. Turn on your power amplifier stereo, the product does not require external power.
6. Earphone listening interface: 6.5mm
7. Input: 2 sets of input (banana plug)
8. Output: 4 sets of output (banana plug)
9. Power: Support 300W
10. Metallic material, stainless steel case, compact size suitable for any system.
11. Channel power: Each channel supports up to 300W.
12. Frequency response: 10Hz - 50KHz.
13. Net weight: 0.86 kg
14. Product weight after packaging: 0.98 kg
15. Product size: Length 240mm x width 113mm x height 55mm
16. Package size: Length 260mm x width 185mm x height 65mm high
17. Kit list: 2 in 4 out power amplifier x 1

Product presentation:
1. Sound adjustment: support high/medium/bass EQ adjustment, high/medium/bass can enhance +15dB and attenuation -15dB adjustment, support left and right channel balance adjustment, suitable for some need to adjust the tone of equipment, using compact and thin desktop mini design, compact size, compatible with any equipment
2. Three sets of stereo mixed input: 3.5mm+6.5mm+RCA
3. Provides three sets of stereo output simultaneously: RCA+RCA+3.5mm
4. Independent Toner Audio Control: With independent audio source channel high/middle/bass control attenuations -15dB and +15dB gain, the sound adjustment design allows you to adjust the audio independently to listen to the experience and control the output volume independently
5. Simple installation: input and output plug and play easy installation, you can enjoy different audio experience
6. USB 5V power supply, suitable for different applications

Product Parameter:
1. Input channel: 3-way stereo input 3.5mm+6.5mm+RCA interface
2. Output channel: 3.5mm/RCA interface
3. Input impedance: 100K Ohm
4. Output gain: High, medium and low -15dB and +15dB
5. Frequency response: 20Hz-20KHz
6. Signal to noise ratio: More than 107dB
7. Total Harmonic Distortion: Less than 0.08%
8. Intermodulation distortion: Less than 0.01%
9. Power supply: USB 5V
10. Net weight: 0.38kg
11. Gross weight after packing: 0.53kg
12. Product size: Length 130 mm X width 77 mm X height 38 mm
13. Packing size: Length 200mm X width 185mm X height 55mm

Kit list:
1. Front Stereo Phoner High/Middle/Bass Adjuster x 1
2. USB power cord, length 120CM x 1
3. USB power adapter US standard x 1

Product presentation:
1. Support power is 200 watts: 1 and 2 power amplifiers with 1 pair of speaker selector switches, ideal for home theater sound systems, power of 200 watts per channel, suitable for 4–16-ohm impedance speakers, with a compact thin desktop design, compatible with any home theater setting.
2. AMPC Amplifier Control: The two-channel speaker switcher controls the stereo connection between two amplifiers and a set of speakers, or the combination connection switch selection, input/output through the screw-type connector terminals, which accept 14AWG speaker wire.
3. Independent audio control: With independent audio source channel volume control. The button design allows you to individually select each amplifier to customize your home listening experience, and the volume switch controls the volume adjustment of the output speakers.
4. Simple installation: The enjoyment of quality audio performance requires connecting the left and right channel outputs of the amplifier to the left/right and 1/2 amplifier inputs with 1 on 2 speakers on a mini dual channel controller.
5. Overload protection: Equipped with a front panel control switch consisting of volume control knob and amplifier switch.Provide high quality audio and overload safety protection circuits and long-term reliability.

Product Parameter：
1. 2 input 1 output amplifier speaker selector switcher
2. Convenient audio control accommodates 2 amplifiers with 1 pair of speakers.
3. Home theater stereo amplifier system support, independent audio source channel volume control
4. Input/output: screw type connector terminal, compact desktop/desktop mini design
5. Front panel button control center, the product needs no power supplyBuilt-in electronic overload protection circuit
6. Power processing: 200 watts per audio/speaker channel
7. Speaker selector type: 2 soundtracks
8. Speaker cable support: 14 wire gauge (14 AWG)
9. Support impedance: 4-16 ohms
10. Frequency response: 20Hz-20kHz
11. Net Weight: 1.06 kg
12. Packed weight: 1.21 kg
13. Product size: Length 160mm x Width103mm x Height 55mm
14. Package size: Length 260mm x Width 185mm x Height 65mm
15. Kit list: 2 input 1 output amplifier speaker switcher output with volume adjustment function x 1

Product description：
1. External power amplifier rear passive speakers left and right sound channel double knob independent volume adjustment control box
2. Each channel supports 150 watts of processing power
3. Independent control of stereo channel (Left track and right track)
4. Volume control knob, clean, smooth volume adjustment can be achieved.
5. Input/output：Use screw type connector terminals
6. Simple for operating, after the left and right sound channel of the amplifier is connected respectively in volume control box, the output of the left and right sound box realizes volume to adjust the volume size of the left and right sound box respectively.
7. Desktop type power amplifier output passive speaker volume control box, it can easily control the volume of the sound channel of the passive sound box, easy for installation, just plug it in and use it.
8. There is a separate volume knob switch, metal construction, brief outward and Compact Size.

Product parameters：
1. Power processing: Each audio/speaker channel 150 watts
2. Support soundtrack: Stereo left and right channels
3. Support impedance: 4-16ohm
4. Speaker cable support: 14 wire gauge（14 AWG）
5. Support interface: Input/Output, using screw type connector terminals
6. Volume adjustment: Left and right sound channel independent volume size adjustment
7. Net Weight: 0.7 kg
8. Packed weight: 0.8kg
9. Product size: Length 150mm x Width 68mm x Height 55mm
10. Package size: Length 185mm x Width 135mm x Height 65mm
11. Kit list: Passive loudspeaker volume control box x 1

Product presentation：
Do you have 4 power amplifiers and 2 sets of speakers that need to be connected to each other?
Do you need four amplifiers and two sets of speakers to get stuck?
A powerful amplifier and audio switcher can solve these problems,
1. 4 power amplifiers push-button select switch input,2 sets of stereo speakers push-button select switch output (2 sets of speakers can be opened or closed independently)
2. sets of stereo speakers can sound at the same time, you can also turn off one group of speakers or more groups of speakers individually, manually select the pushbutton switch
3. The power of each channel is 300W
4. Signal input provides vacuum tube power amplifier signal no-load protection function
5. manual selection of input and output switching, straight plug straight use, switching signal stability, between channels will not produce another dry close or noise
6. Compact design of solid metal shell, easy installation, the product does not need external power
7. simple installation: input and output plug and play easy installation, you can enjoy different audio experience

Product Parameter：
1. Compatible with all types of power amplifiers and speakers
2. Input/output accepts heavy-duty speaker wire or speaker pin wire through the terminal port
3. Connect the power amplifier to amplifier 1-2-3-4
4. Connect the loudspeaker to position A and B respectively
5. Turn on your power amplifier stereo device and the product requires no external power supply
6. Input: 4 sets of inputs (banana plug)
7. Output: 2 sets of output (banana plug)
8. Power: Up to 300W
9. Metal material, fine steel housing, compact size suitable for any system
10. Channel Power: Each channel supports up to 300W of power
11. Frequency response: 10Hz-50KHz
12. Net weight: 0.93 kg
13. Packed weight: 1.09 kg
14. Product size: Length 240mm x width 105mm x height 55mm
15. Packing size: Length 260mm x width 185mm x height 65mm
16. Kit list：4 input 2 output power amplifier and sound switcher loudspeaker switch distributor x 1

Product Presentation：
Do you have 4 power amplifiers and 2 sets of speakers that need to be connected to each other? Do you need four amplifiers and two sets of speakers to get stuck?
A powerful amplifier and audio switcher can solve these problems,
1. 4 power amplifiers push-button select switch input,2 sets of stereo speakers push-button select switch output (2 sets of speakers can be opened or closed independently)
2. sets of stereo speakers can sound at the same time, you can also turn off one group of speakers or more groups of speakers individually, manually select the pushbutton switch
3. The maximum power of each channel is 300W
4. Signal input provides vacuum tube power amplifier signal no-load protection function
5. manual selection of input and output switching, straight plug straight use, switching signal stability, between channels will not produce another dry close or noise
6. Compact design of solid metal shell, easy installation, the product does not need external power
7. Simple installation: Input and output plug and play easy installation, you can enjoy different audio experience

Product Parameter：
1. Compatible with all types of power amplifiers and speakers
2. Input/output accepts heavy-duty speaker wire or speaker pin wire through the terminal port
3. Connect the power amplifier to amplifier 1-2-3-4
4. Connect the loudspeaker to position A and B respectively
5. Turn on your power amplifier stereo device and the product requires no external power supply
6. Input:4 sets of inputs (banana plug)
7. Output: 2 sets of output (banana plug)
8. Power: Up to 300W
9. Metal material, fine steel housing, compact size suitable for any system
10. Channel Power: Each channel supports up to 300W of power
11. Frequency response: 10Hz-50KHz
12. Net weight: 0.93 kg
13. Packed weight: 1.09 kg
14. Product size: length 240mm x width 105mm x height 55mm
15. Packing size: length260mm x width 185mm x height 65mm
16. Kit list：4 input 2 output power amplifier and sound switcher loudspeaker switch distributor x 1

About the product
1. A high-performance portable mini size front-end signal amplifying switcher and sound quality processor,
2. Built-in high-performance power processor and signal amplifier
3. For circuit design, Texas Instruments(TI) NE5532 dual operation amplifying chip in top quality acts as the front-end amplifier.
4. NE5532P is tailored for the high-performance audio system, which features ultralow harmonic distortion, low noise, high gain bandwidth or other.
5. Dual FET input widens the dynamic range for NE5532, and sound signal amplification and bipolar operational amplifier.
6. NE5532 audio enhancement technology can correct and recover any signal loss and phase deviation of audio signal system for any reason, reproducing sound and indulging the audiences in the spot effects of enhanced high-low sound, somewhat ideal positioning, definition and brightness.
7. With the audio enhancement circuit, audio system will brighten sound, bring you closer to depth, slenderness and definition, fine treble, penetrating middle and strong and natural bass, placing the audiences on spot.
8. Sound signal amplifying switcher, mainly used to switch various multi-channel signal inputs, such as computer, cellphone, tablet, game console, TV set, TV box, MP3.
9. Additionally with output equipment of signal source or other signal inputs, used for amplifying switch
10. The front-end output adopts 3.5mm interface, the back-end output adopts RCA interface. 11. 11. Simultaneous output of balance circuit architecture is enabled in front-end and back-end, output can be connected to the headphone, stereo, amplifier or any other equipment, used as sound signal amplifying switcher for four-channel signal input and two-channel signal output.
12. With a wide range of application, readily used in any signal input equipment, or used as the front-end signal amplifier, power supply adopts bleeding technology, uses the high-precision potentiometer for balance adjusting, and the positive and negative voltage balance is ultrahigh.
13. Additionally with the tailored high-capacity filter capacitor, ensuring the clean power supply.

Main Features
1. Four-channel switch circuit (3.5 headphone base and gilt RCA base) replaces input signal with no need to unplug, just turn the panel option switch.
2. High-precision power bleeder circuit ensures the stability of circuit and reduces DC shift of output.
3. Advanced input and output connecting base ensures the smoothness and durability of signal channel.
4. NE5532, well-tailored for the high-performance audio system in best signal amplification, acts as front-end amplification.
5. Original potentiometer made in Taiwan, with small sound loss, high balance, good hand feel and durability.
6. Aluminum alloy housing has a high density of wiredrawing in oxidation treatment, good-looking and noble with screen, but with no color-shading as paint spraying.
7. Standard input interface: 4 x 3.5mm (with four-channel signal input switch)
8. Standard output interface: 3.5mm headphone base and RCA red-white audio base (with simultaneous output)

Package Contents
- 1 x A926 Four-In Two-Out Signal Amplifying Switcher
- 1 x 100-240V Power Adapter (DC12V, US Standard, 100cm power cord)
- 4 x 3.5mm Audio Cable (Length: 100cm)

1. Rated voltage: 12-18V
2. Rated power: 40W
3. Resolution: 47K
4. Distortion: 0.01%
5. Size: 14.00 x 11.50 x 4.00 cm; material: metal.
6. SNR: >=80dB
7. Amplifier type: AV amplifier
8. Rated response: 20Hz-20KHz

About The Product
1. LINEPAUDIO A967 Passive PreAmp Active Speak Volume Two-Channel Controller is small and compact, applicable to use with active speaker or PostAmp, supports full-balanced or single-ended signal I/O, equipped with a switch for easily switching I/O signal.
2. Infinitely picky about the sound quality, infinitely tolerant on music. Passive PreAmp Volume Controller makes the desktop simple.
3. Small size but great wisdom, LINEPAUDIO A967 is tiny but with a complete set of common interfaces, supports full-balanced audio signal regulation and single-ended audio signal regulation, and switches I/O signal.
4. Suitable for the decoder and speaker without volume regulation, with the balanced I/O, RCA I/O architecture and switch function enabled. Its PreAmp will not cause a loss of signal source. In general, the audio source signals out of the decoder reproduces the original signals. The large dynamic range will not cause a quality loss, but keep the original signal source intact.
5. The preferred choice of active speaker, more and more music fans are not satisfied with the sound quality performance of common multimedia speakers, but rather select professional active monitor speakers. But such speakers generally don't have a volume regulation knob, but have to use with PreAmp. Most active monitor headphones are used for the desktop near-field listening, but a common HiFi PreAmp is large and occupies a large area. Moreover, most are concerned about whether the timbre of PreAmp matches the speaker or not, whether the sound effect is ideal or not.
6. But from now on, LINEPAUDIO A967 Two-Channel Volume Controller perfectly addresses the above two concerns, LINEPAUDIO A967 is small and compact, the internal circuit architecture design will not cause a loss of sound quality, the internal power amplifier of active speaker is enough to drive the speaker, so that you can hear the most genuine timbre and quality of the speaker, free from the need of choosing a suitable PreAmp.

Features
1. Input/Output impedance: 10Kohms - 50Kohms.
2. Two-channel I/O switch, RCA and Balanced XRL I/O.
3. Input: RCA / Balanced XLR (switch).
4. Output: RCA / Balanced XLR (switch).

About The Product
1. LINEPAUDIO A966 is a high-quality eight-channel high-power headphone amplifier which perfectly drives various high-impedance pro monitor headphones, provides the performer with quality monitor sound quality, and enables the performer to get immersed in the show and fully present his own musical work. This product not only provides the function of headphone amplifier, in order to be more user-friendly, it has a built-in intercom function at the studio-level. When the sound engineer wants to communicate with the performer in a different room, just insert the microphone (intercom microphone) to easily issue to the performer various working instructions, what the engineer jus said will be transmitted to eight headphones.
2. It provides eight sets of stereo channel outputs to improve the sound quality control and amplification and the background noise is small, with a wide dynamic range without sonic boom, the output sound volume of each channel is controlled by sensitivity adjustment knob, each channel can drive 16ohms-600ohms headphone, lossless in the quality without distortion. The product also provides an independent 6.5mm stereo associated input port, which can be easily connected to other devices in the studio; furthermore, it provides one-channel microphone intercom function input function, allowing for an easy intercom in the internal channel.
3. The circuit has OP + BUG architecture and uses AC12V transformer power supply to ensure a strong drive.
4. The 16ohms-600ohms high-impedance headphone can be driven through the volume regulation knob, with full sound, calm bass, clear high frequency, without any signal sonic boom. It is a headphone distributer as well as a headphone amplifier, which can easily drive the 16ohms-600ohms headphone. It has extensive applications, including band rehearsal /studio recording/ home entertainment/music enjoyment/comparison of business headphone distribution.

Features
1. 4x 6.35mm Stereo headphone output port (optionally connected to the headphone of any impedance).
2. 4x 3.5mm Stereo headphone output port (optionally connected to the headphone of any impedance).
3. TS 6.35mm L and R input port (optionally connected to the signal sound sources such as computer sound card or mixing console).
4. TRS 6.35mm Stereo input port (optionally connected to the intercom such as microphone).
5. 4 Independent channels stereo volume output control knob.
6. Input impedance: 100KOhm.
7. Max. input level: +14dBV.
8. Output impedance: 47 Ohm at each output channel .
9. Power source: AC12V.
10. Frequency response: 20Hz - 20KHz.
11. SNR: > 107dB.
12. THD: < 0.08%.
13. IMD: < 0.01%.
14. Input port: Stereo 1/4 TRS plug, L and R channel, 1/4 TS plug.
15. Output port: 4x 6.35mm Stereo 1/4 headphone jack + 4x 3.5mm Stereo 1/8 headphone jack.

About The Product
1. LINEPAUDIO A962 fancier-level HiFi Vacuum Tube Power Headphone Amplifier PreAmp, made of Beijing classic quality 6J9-J vacuum tube, USB-PC supported ASIO sound effect software will give out more professional, full, open-stage, soft and smooth sound, especially applicable to voice, string music, light music, and classical music, the performance of different frequency points is so perfect! Fine at high frequency, strong at low frequency! Easily drive 16??-600 ?? headphone of any class, quiet background without any current background noise! Two sets of audio signal inputs, one is USB signal input (USB-PC), USB cable is connected to PC, plug and play without a drive, directly used as an upscale USB external sound card. The USB port can be also connected to any model of Android mobile phones with OTG function. The other is 3.5mm interface audio signal input and you can connect it to mobile phone, CD, lossless music player or other audio source devices. In case of simultaneous inputs of USB signal and 3.5mm interface signal, 3.5mm interface signal input is preferred.
2. LINEPAUDIO A962 has three sets of audio signals, simultaneously output to meet the interface of different devices (RCA/3.5mm/6.35mm), the output end will deliver to you a real HiFi experience, whether connected to your upscale headphone or speaker, or used as a timbre adjustable PreAmp to connect your digital power amplifier, multimedia speaker or various stereo devices, what a real PreAmp. Of course, if you want to try the timbre style of different tube amplifiers, this product can fully meet your requirement, compatible with E180F, 6688 and other tube models, you may exchange at will.
3. Many music fanciers are concerned about the background noise of vacuum tube headphone amplifier, but this product frees you from this concern, its performance in controlling background noise is extraordinary, the background is quiet after several tests and optimizations of the circuit design, without any current background noise, you will hear the purest, most natural, and most nostalgic sound. As to the testing of the current background noise: as it is known to all, the current background noise comes from two sources, one is the vacuum tube headphone amplifier, the other is the audio source or the audio cable (the audio cable makes it more likely to generate background noise), the correct procedure of testing the headphone amplifier is to disconnect the audio input cable, with power on, if the background of the headphone amplifier is quiet, it indicates that the headphone amplifier has a very high SNR. If unquiet, or this seriously affects you from listening music, it indicates that the headphone amplifier has a very low SNR.
4. Notes: An electronic interference device near the desktop may also affect the SNR. For example, if the vacuum tube power amplifier is placed near a wireless router or device, it may be interfered to some extent. Enclosed by an aluminum shell, miniaturized but exquisite, the front, rear panel is precisely processed by CNC machining center, you will get a terrific handle, the ultra-small volume will not occupy your desktop space too much. More than a multi-functional upscale high-fidelity USB sound card vacuum tube headphone amplifier, it is also a beautiful desktop ornament. All letters on the machine panels are printed using expensive laser carving and will never fade off.

Features
1. 2 sets of signal inputs (USB-PC and 3.5mm input), 3.5mm input is preferred.
2. 3 sets of stereo signal outputs: 3.5mm / 6.35mm / RCA simultaneous signal outputs, allowing you to connect different device interfaces.
3. USB: PC Supported ASIO sound effect software (ASIO drive to be installed)
4. Input power: >=1100mW (32ohms).
5. Matched headphone impedance: 16ohms-600ohms.
6. Frequency response: 20 kHz - 30kHz.
7. Support sampling rate: 16Bit - 32k Bit, 44.1kHz, 48kHz.

About The Product
Are you still using common headset to chat and sing on computer? Are you still directly inserting the microphone to sing on computer? Are you still having a headache for a good sound card? Are you still bothered by having no good singing device, although you are born with a good voice? The product adopts the top reverb chip, perfectly supports double chorus, independent control and user-friendly feature, manually regulates the voice volume, designs the universal RCA jack without drive, the aluminum alloy CNC shell has better shielding performance. The product integrates 6 features, with the most professional Karaoke device system:
1. The first powerful function: Professional reverb: an ordinary sound card has no reverb effect, and it goes without saying that the song directly from a microphone without reverb is unpleasant to hear.
2. The second powerful function: Pure KTV effects: The product not only has the reverb effect, but also has the real damping tone, so that your singing tone at home is as perfect as that in KTV.
3. The third powerful function: Audio amplification function: With A937 product, you can passionately sing at conference, stage and home.
4. The fourth powerful function: Connect musical instrument: With musical accompaniment, you can record and sing while playing guitar, oh year! It is absolutely a pleasure!
5. The fifth powerful function: Shield current interference: When a common microphone or headset or other device is directly inserted to the computer, a big current sound can be heard, with the unique product design and unique power shielded line, this function can filter out very pure sound, and the sound effect is comparable to the real concert.
6. The sixth powerful function: Independent control function: You can independently control the accompaniment volume and let you sing with ease.
A933 is a multi-functional analog sound console, more than merely a microphone effector, it is also a preamplifier system, Karaoke or reverberator, and the powerful hardware special reverb effect not only plays the music on computer or other audio player, but also allows you to hear the perfect combination of your voice and music like a professional singer. In addition, the product also enables mixing, reverb, delay, reverb volume regulation and other functions of professional sound console. In this way, you can easily become the DJ of yourself, make independent control, mellow bass, exercise your affection and understanding to music to the fullest, without delay, without noise, the sound will be clean and transparent, or mellow and charming! The unique middle and high-end microphone optimized design which is popular in the market will perfectly fulfill your degree of professionalism.

Features
1. Support reverb, mix, echo, delay and other Karaoke special effects.
2. Use external power supply, universal power supply DC12V.
3. Support pure recording or mixing, alternatively used for independent PC or family recording connection device.
4. Support a variety of sound cards (PC integrated sound card, external independent USB sound card).
5. Support two sets of microphone input (6.3mm TRS), enable the simultaneous double singing function.
6. Support a set of output (headphone or speaker).
7. Support high-quality microphone amplifier, support multimedia microphone, dynamic microphone, self-powered capacitor microphone.
8. Support TS or TRS input.
9. Two sets of control knobs, one for microphone volume, and the other for reverb volume.
10. A set of Music in RAC stereo jacks, a set of Music out RCA stereo jacks, a set of video I/O RCA jacks.
11. Audio I/O: RCA stereo jack.
12. Power supply: Universal power supply DC 12V.

Package List
1 x A933 Mini Karaoke sound console.
1 x 3.5mm plug to 3.5mm plug (length: 150cm).
2 x 3.5mm bus to RCA (length: 50cm).
1 x 100-240V power adapter (DC 12V), American Standard, power cord length: 100cm.

1. Rated voltage: 12-18V
2. Rated power: 40W
3. Resolution: 47K
4. Distortion: 0.4%
5. Size: 15.30 x 10.00 x 3.50 cm; material: metal.
6. SNR: >=80dB
7. Amplifier type: HIFI amplifier

B015 – Front Stereo Signal Amplifier Booster Headphones Speaker Amplifier Headset Dual-Audio Source
Product description:
You have a line level signal source (TV audio, MP3 player, Video game, mobile phone, tablet, computer, record player), but desire louder sound or bigger volume?
A powerful signal amplifier receiver or volume control, you may need a long line connecting TV audio and the receiver on the other side of the room to provide high gain through any line level signal source, allowing longer cable operation or requiring “buffer” to amplify the lower volume. You may use it between the line level signal source and power amplifier as a signal amplifier, 3.5mm + RCA port matches almost all product interfaces.
The product improves the sound amplification and reduces ground noise by controlling the signal, and it has large dynamic range without produce cracking. It controls output volume through a sensitive volume knob, the output of the headphone interface can drive 16Ω-600Ω headsets, and uses AC9V transformer for power supply to ensure full power.
Product parameters:
Input impedance: 100K Ohm
Maximum input level: +14 dBV
Output impedance: 47 Ohm of each output channel
Frequency response: 20 Hz – 20K Hz
Signal to noise ratio: > 107dB
Total harmonic distortion: < 0.08%
Intermodulation distortion: < 0.01%
Input port: stereo 3.5mm socket and RCA port
Output port: stereo 3.5mm port and RCA port
Power supply: AC9V
Net weight: 0.51 kg
Gross weight with packaging: 0.61 kg
Product size: length 109 mm X width 79 mm X height 39 mm
Packaging size: length 185mm X width 135mm X height 65mm
Kit list:
1 X stereo signal preamplifier booster dual-audio source headphone amplifier
1 X AC9V power adapter (AWG) line length 100cm

B016 – 6 Input 1 Output Audio Signal Source Selection Switcher, Output Volume Adjustment Control RCA Port
Product description:
6-channel stereo audio signal selection switcher with output volume adjustment function,
The product adopts passive design, direct insertion, and has lossless switched transmission of input and output signals,
The product is mainly used to select and switch among a variety of stereo signal input and output through a common set of equipment, that is, a variety of stereo signal sources of devices, such as TV audio, MP3 player, CD player, video game, mobile phone, tablet, computer, record player, need to be output on the amplifier or on active speakers,
The 6-channel audio signal selection switcher solves complicated line plug in and plug out, which uniformly connects device input signal sources to the switcher for easily selection.
The product uses standard RCA port design for input and output, and uses precise 6-level manual switch design for the switcher, with independent stereo volume adjustment control.
Product parameters:
Power supply: passive design, direct insertion
Material: all-metal case
Input and output impedance: 10KΩ - 50KΩ
Frequency response: 20 – 20kHz
Distortion: <0.002%
Insertion loss: <0.01dB
Signal gain: 0dB
Signal to noise ratio S/N: >98dB
Input port: standard RCA port
Output port: standard RCA port
Number of input channels: 6-channel stereo input signal sources
Number of output channels: 1-channel stereo output
Control switch: 6-level precise manual selection switch
Switching channel: 6 channels
Net weight: 0.25 kg
Gross weight with packaging: 0.35 kg
Product size: length 113 mm X width 50 mm X height 38mm
Packaging size: length 185mm X width 135mm X height 65mm
Kit list:
1 X 6 input 1 output stereo audio signal selection switcher, output volume adjustment RCA port