8 best audio preamp circuits

Product description

Specification:

Item Type: Preamp board

Material: Synthetic cardboard

Chip Model: NE5532 78M12

Input Voltage: DC 12-30V / AC 9-20V

Architecture: Dual 5532 2.0 full tone + 0.1 bass

Frequency Range: Full tone 20-20KHz / bass 20-200Hz

Features: 2.0+0.1 Controllable volume, adjustable bass frequency and phase

Package List:

1 x Preamp Board

• Onboard bass frequency regulator potentiometer can make a relatively wide adjustment, so that subwoofer can be blend in the mid‑to‑treble harmoniously without a sense of violation
• Phase switch designs, both noninverting amplifier and see‑saw amplifier are compatible to use
• Dual 5532 2.0 full‑tone + 0.1 bass structure can control the volume of each channel of 2.0+0.1, adjustable bass frequency phase with powerful bass
• Both full frequency and bass output signals have independent interfaces, which is very convenient
• Support both DC 12‑30V and AC 9‑20V input voltage, powerful and practical

• ✅DIY YOUR SPEAKERS:Up2stream Pro V3 can add wireless/network streaming capabilities to your current speakers, home stereo or receiver. And it can be used as a USB DAC, which you can connect directly to your PC and stream PC audio digitally. Using our ACPWorkbench audio effects tool, you can precisely adjust TREBLE and BASS to customize the audio effect that you like
• ✅STABLE STREAMING AND HIGH SOUND QUALITY: Supports playback of lossless music files-MP3, APE, FLAC, WAV with Hi-Res audio.When streaming wirelessly, Bluetooth can reach up to 30 meters. With stream music over the network, Wifi can reach anywhere the signal covers. And free iOS and Android app: 4stream
• ✅Multiple Music Sources & Protocols: Supports Spotify, Tune in, iHeartRadio, XIMALAYA, QQ Music, TIDAL, Napaster, Qobuz, QQFM, Deezer etc. And airplay1, Qplay, DLNA, UPnP protocols. Also Other audio sources for local music, USB flash drive, NAS and line inputs.
• ✅Application: Advanced circuit design with built-in speaker protection circuitry, best suited for your home bookshelf/ceiling/desktop/speakers; recommended for home TV audio, computer audio system games, tower speakers and garden speakers. If you have high knowledge in the audio field, the small and compact design is also suitable for car audio system. You can enjoy high quality music everywhere!
• ✅Multiroom Control: Enables multiroom and multizone streaming through multiple devices connected on the same network and control with your phone.

User questions & answers

Question:	Does this support ultra hd on amazon music
Answer:	No, currently output is 44.1khz, 16bits CD quality. HD feature is hardware limitation and may add the MSRP. We will have higher spec to support that. Thanks
Question:	Does the infrared remote as well included in the package? i do see ir reciever sensor on the circuit board
Answer:	Sorry, it doesn't included now. You can buy from our official website arylic.com The IR sensor is on the right top of the picture. The black one.
Question:	Does it require the app to operate Bluetooth and 3.5mm port or is it only required to operate the nas/usb playback
Answer:	All control can be available inside app . for bluetooth ,due to we have a lot of input audio source ,you can use app or remote switching to bluetooth .After that ,you can use as normal bluetooth ,and system will remember last setting .For usb/nas it handled inside app .
Question:	Xiang X mentioned that you can set up a stereo pair but latency is lower than "20 ms". Is that 20 milliseconds or 20 microseconds
Answer:	Hi Microseconds. 0.02second

Product features

Wireless Stereo Receiver Board

TV sound, Online Music, Gaming Audio. All sounds of your home entertainment can be streamed wirelessly by Up2stream stereo receiver board. Compatible with your constant use phone, PC, and Tablet. Meet your needs and give you different music enjoyment.

Micro USB Sound Card

Up2stream V3 Series can work as an USB DAC, you can directly connect it to a PC and stream PC audio digitally.

Customize your Name

Support changing device WIFI SSID and bluetooth name by mobile app and save it forever.

More Extension

SPDIF out, ADC KEY for buttons use, 2 I/O for extension, such as volume knobs. Give you more creativity with DIY projects.

All Musics you like

Huge music resources supported like Spotify, Pandora, Amazon Music, Tidal, Deezer, Qobuz, Internet Radio, iheart Radio, Napster etc. Except online music, you also can play local music by NAS, USB storage where you have collected your favorite song for years.

Wireless Connectivity

Streaming your audio all the way by Wifi, Bluetooth 5.0, DLNA, UPnP, Airplay, Spotify Connect.

Streaming your Music Everywhere

No matter where you are in your house, you can always take out your phone to play a song for you or your family. Like play a Bedtime Story for your Children, a love song for your wife, easy and wirelessly.

Free iOS & Android App

Our App called “4stream” that is compatible to your iOS & Android system. All the features can be simply controlled by App. And you also can receive the notification for our regular online firmware update automatically in our App.

• ♪ HIGH QUALITY MATERIALS—The chassis of the preamplifier is made of a solid aluminum alloy material, and uses accurate and stable integrated circuits and high-quality components to eliminate low-frequency noise and ensure clear sound quality; The material of its PCB board is made of FR-4 insulation board and black immersion gold Craft, which has the characteristics of stable signal, high temperature resistance, long service life, and not easy to be oxidized.
• ♪ EXQUISITE APPEARANCE DESIGN—FX AUDIO pre-amplifier has a mini exquisite appearance and light weight, easy to carry around, its brushed texture surface and high-quality tube combine to appear more fashionable,elegant and Classical.
• ♪ SEPARATE CONTROL OF BASS&TREBLE—The vacuum tube preamplifier can independently adjust the bass and the specific proportion components in high-frequency sound to perfectly achieve HiFi effects. At the same time it can maximize the rendering of an atmosphere like being in a music performance to satisfy your experience of different sound styles in pursuit sound quality.
• ♪ RCA INPUT & OUTPUT—From RCA output ,the preamp can also be directly connected to the audio source and active multimedia audio equipment or indirectly connected to passive audio through the power amplifier(The item includes RCA cable).
• ♪ NOTE—The item just is a tube preamp, not a power amplifier or phono amplifier. Because it is a household circuit design, the home theater tube preamp can not be used in cars, turntables or passive speakers, nor can it directly work for headphones, speakers and can not be used as a phono amplifier.(Only suitable with 12V power cord).Package Include: 1 x tube preamp, 2 x 5654 tubes,1 x power supply, 1 x RCA cable,1 x user manual, 1 x security card/1 year warranty

Product features

In order to dedicated to serve audiophile and display our cultural concept of "enjoy music,enjoy life", FX AUDIO developed the mini electronic tube preamp.

FX AUDIO tube preamplifier is designed by using aluminum alloy shell, PCB board of black immersion gold craft and gold-plated interface, mainly to enhance the weak voltage signal from the audio source and control the sound quality to achieve the effect of beautifying the sound.

Adopt GE5654 Vacuum Tube Design

The audio preamplifier is designed with two GE5654 vacuum tube, which can simulate natural sound,that is soft and delicate, dynamic and pleasing, strong and powerful, and very penetrating. FX AUDIO Pre-amplifier is the best choice for the friends who have high pursue with the sound timbre. (The tube can also be replaced according to personal preference).

HiFi Sound Quality

The function of the audio quality control of the audio preamplifier is to control the frequency characteristics of the audio system to achieve high-fidelity sound quality, or to modify and beautify the sound according to the listener's preferences, but also to adjust the sound range to achieve balance Make the resolution of sound more natural and transparent.

Wide Compatibility

FX AUDIO tube preamplifier have a wide compatibility,which input can be connected to various audio source equipment, including mobile phones, computers, CD / DVD, etc. From RCA output ,the preamp can be connected the power amplifiers to use ,also can be connected directly to an active speaker.

• ❶ This tube preamplifier Using classical tube 6j1 design and optimize the route,Match amplifier home audio and home theater amplifiers to use,Let you enjoy the imagination music(Note:Cannot be used on a record player and phonographs)
• ❷ Tube can be replaced design,soft voice.Adopt the Dual run amplifier chip NE5532P power conversion module
• ❸ The power circuit is completely separate from the audio circuit ,in order to Minimize interference,Treble and bass knob design allows you to adjust the sound according to your preferences
• ❹ With DC12V power supply(Can't beyond 12V),Reasonable circuit layout,Exquisite and unique appearance design,aluminum shell solid touch,perfectly suit for your desktop or a small space in your home or office
• ❺ This tube preamp Can match digital power amplifier,Analog power amplifier,Active speakers.It doesn't connect the speaker direct

User questions & answers

Question:	How much gain does this preamplifier have? Thanks
Answer:	A preamplifier's purpose is to enable a user to play a turntable through an amplifier (or receiver) that either does not have a phono input, meaning a left an right RCA jack (and many newer amplifiers do not have phono input in rear of unit), or if you want to use two turntables with the amplifier and the amplifier only has one phono input. Thus there is no "gain." Only regular amplifiers have a "gain." It is NOT a waste of money if there is no phono input for the turntable. It is actually NECESSARY in such case.
Question:	I think i have mc tt. it has line level out but missing riaa eq. is this what i need to get bass back into the music and tone down the harsh treble
Answer:	You asked the right question about equalization(and level matching) because m/m requires one circuit ,and m/c requires another. Your existing gear determines what you need .You must verify your cartridge type,picking m/m is a lazy fall back. Yes a m/m circuit will often carry a m/c signal but at a poor sound quality pass through,reduced signal, reduced response. Many dubious preamp sellers use a single fits all cheap m/m circuit claiming it covers both because of that. Then like myself you will find your $450 Audiotechnica MkIII suddenly SOUNDS LIKE CRUD. That said if you have m/m already your set,and thats fine then your matched up. When you get good with test equipment you can seee a difference when a pre amp has both dedicated circuits instead of scamming m/c users.
Question:	Will this substitute the main amp device on a Panasonic console if I just want to hear the turn table and nothing else
Answer:	No it's a pre amp for stereo that doesn't have a phono input. It's not a stand alone amplifier.
Question:	when connecting a turntable to a phono preamp/preamplifier dodoes one connect the rca jacks from the turntable to the output or the input on the pream
Answer:	The signal path is 1# energy out of the turntable (record player) 2# into the preamp (preamp's in) 3# out of preamp -preamp's out- into receiver ,amplifier, or etc the device your going into.

Product features

Specification

RCA line output: 0.9vrms

Signal to noise ratio: 98db

Distortion: 0.3%

Audio inputs/Audio output:Gold-plated RCA

Bass adjustment range: ± 10db

Treble adjustment range: ± 6db

Frequency response: 20Hz-20KHz

Power supply: DC12V / 1A

Size:95 * 119 * 31mm (3.75*4.6* 1.22inch)

Weight: 0.35Kg/ 0.77Lb

Accessories: 12V/1.0A power adapter + manual user(As picture shown)

Delicate appearance design , Stable quality control , Perfect sound performance

Operation Steps

1 Make sure the VOL turn to the minimum

2 Install the tube into the base of the tube according to the direction (the tube is not left or right, check whether the pin is deformed before installing the tube, and the deformation can be corrected by hand)

3 Connect the sound source that needs to be used

4 Connect the external post equipment to the audio source output interface

5 Connect the DC12 power supply(DC power cann’t beyond 12V)

6 Turn on the power switch

7 Rotate the knob clockwise to select the desired volume

Operation Principle

1. Please do not open the shell without permission. Improper operation may cause the danger of electric shock.

2. Please use the power supply of the regular manufacturer, otherwise it will damage the machine.

3. Please do not use the machine in a high temperature and humidity environment.

4. Please don’t replace the tube when the power on, otherwise the tube & machine will be demaged.

5. Please don’t use the non-matched tube, otherwise the tube & machine will be demaged.

Can this machine be connected to a phonograph/record player?

A: At present, this does not support the signal input of the phonograph/record player. Because the amplitude of the output signal of the phonograph/recorder is very small, it is necessary to increase the phono amplifier.

Can I replace the tube upgrade?

A: Yes, at present, we have tested and matched 6K4/6J4/GE5654/6AK5/6*1n, which can be directly replaced.

Why do I not play the sound source after I plug in the input cable, and the speaker will have a loud beep?

A: When the unshielded signal line is used, the interference signal will enter the amplifier for amplification. If you hate this sound, you are advised to replace the shielded signal line or unplug the signal line.

Product description

Squeeze every inch of detail from your record collection with our highest quality moving magnet and moving coil phono stage, with integrated headphone amp; the Duo Phono Preamplifier.



MAX POWER CONSUMPTION



10W



CARTRIDGE SUPPORT



Moving Magnet | Moving Coil



GAIN @ 1KHZ



MM: 39dB | MC: 60dB



NOMINAL OUTPUT



300mV



SENSITIVITY FOR NOMINAL OUTPUT



MM: 3.35mV | MC: 305uV



EQUIVALENT INPUT NOISE (A-WEIGHTED)



MM: ~0.09uV | MC: ~0.08uV



RIAA CURVE ACCURACY



+/- 0.3dB 30Hz-50Hz



SIGNAL TO NOISE RATIO GROUNDED INPUTS REF. 1V OUTPUT (20HZ-20KHZ BW)



MM: >90dB | MC: >70dB



THD+N 1KHZ (20-20KHZ BW)



MM: <0.0025% | MC: <0.20%



INPUT IMPEDANCE



MM: 47k Ohms | MC: 100 Ohms



INPUT CAPACITANCE



100pF



OVERLOAD MARGIN



>30dB



CROSSTALK @ 10KHZ



MM: >85dB | MC: 75dB



DIMENSIONS (H X W X D)



48 x 215 x 159 mm (1.9 x 8.5 x 6.2")



WEIGHT



0.95kg (2.1lbs)

• ✓ DESIGNED FOR VINYL – Cambridge Audio’s Alva Duo was designed to give you a superb sonic experience from your favorite record collection using its state-of-the-art switch mode power supply and a new surface mounted circuit board.
• ✓ ATTENTION TO DETAIL – The Alva Duo's switch mode power supply and surface mount technology delivers short signal paths and a faster response with precision and lower background noise so you don't hear a hum over the vinyl's low-level signals.
• ✓ SUBSONIC FILTER & BALANCE CONTROL – The Alva Duo will even work if your vinyls are a little worse for wear. The subsonic filter and balance control eliminate low frequency rumbles from imperfections in your vinyl for an accurate soundstage.
• ✓ HEADPHONE AMPLIFIER – Cambridge added a unique 6.35mm headphone jack directly into the phono stage so you can listen in private. The integrated headphone output also means no need to turn on your amplifier just to power your headphones.
• ✓ TECH SPECS - MAX POWER CONSUMPTION 10W, CARTRIDGE SUPPORT Moving Magnet | Moving Coil, GAIN @ 1KHZ MM: 39dB | MC: 60dB, NOMINAL OUTPUT 300mV, SENSITIVITY FOR NOMINAL OUTPUT MM: 3.35mV | MC: 305uV, DIMENSIONS 1.9" x 8.5" x 6.2", WEIGHT 2.1lbs

User questions & answers

Question:	Where is the Input located on this? I only see output
Answer:	Mine appears to be coated aluminum...
Question:	Will this system increase the volume of my phono
Answer:	I have not used a wireless sub of any kind with this unit, but I would be surprised if this worked with a BT sub. The BT on this unit as far as I have read will pair with a device as an “input” to the receiver for audio but will not transmit to an external device. I would not count on using it this way.
Question:	Can the amp wake up from standby when it receives a signal
Answer:	Yes I am driving elac unifi ub5 with this. Kept it on 8ohm but can be switched to 4 ohms if you don’t want to live adventurously
Question:	Does the volume control the output of the line levels, as well as the headphone
Answer:	I just purchased this receiver. N803 and YES, hooked up my EQ. Here is how. 1st depends on how many INPUTS you have on your EQ. Mine has 6. Plug in devices you have into INPUTS you have on back of EQ. Phono, Tape, Tuner, Aux, etc. Device name is only to help you remember what is hocked up. where. You could plug in CD player into Tuner INPUT. It's just a memory thing. Now your OUTPUT on the EQ, hook to the back of your RECEIVER IN LINE 2 OR 3. NOT 1. You need an OUTPUT. This would be like adding a reel to reel to tape to. But you don't have to. [1 doesn't have an output.] I hooked up to [Line2] on receiver. Turn dial on receiver to [Line 2]. Control your devices you want to listen to on EQ, not the receiver. Receiver will always be [Line 2]. this set up allows you, if your EQ has memory to program each device, save the settings from one device to another. Change settings by a push of a button. You get double the punch. EQ plus the base and treble on Receiver. No sub-woffer needed. Good luck, have fun. I am

• ✅WIFI & BLUETOOTH STEREO PREAMPLIFIER: Add wireless/network streaming capability to your current speakers, home stereo or amplifier. And S10 can be used as a USB DAC, which you can connect directly to your PC and stream PC audio digitally. Using our ACPWorkbench audio effects tool, you can precisely adjust TREBLE and BASS to customize the audio effect that you like
• ✅STABLE STREAMING AND HIGH SOUND QUALITY: Supports playback of lossless music files-MP3, APE, FLAC, WAV with Hi-Res audio.When streaming wirelessly, Bluetooth can reach up to 30 meters. With stream music over the network, Wifi can reach anywhere the signal covers. And free iOS and Android app: 4stream
• ✅Multiple Music Sources & Protocols: Supports Spotify, Tune in, iHeartRadio, XIMALAYA, QQ Music, TIDAL, Napaster, Qobuz, QQFM, Deezer etc. And airplay1, Qplay, DLNA, UPnP protocols. Also Other audio sources for local music, USB flash drive, NAS and line inputs.
• ✅Application: Advanced circuit design with built-in speaker protection circuitry, best suited for your home bookshelf/ceiling/desktop/speakers; recommended for home TV audio, computer audio system games, tower speakers and garden speakers. If you have high knowledge in the audio field, the small and compact design is also suitable for car audio system. You can enjoy high quality music everywhere!
• ✅Multiroom Control: Enables multiroom and multizone streaming through multiple devices connected on the same network and control with your phone.

User questions & answers

Question:	There is no AirPlay
Answer:	It support Airplay 1. For multiroom features. You can control with our Free App"4 stream"
Question:	After purchase this does not have pandora as in the description. how can i add an app to this device? i need pandora
Answer:	First you download the 4stream mobile app. Then in the app you can sign in to the music services that you want including Pandora. Once signed in to Pandora or another music service you are ready to play music.
Question:	The device does not broadcast wifi hotspot for setup. How are you supposed to set this thing up for wifi? I tried the hard reset already many times
Answer:	You need to set your modem to act on 2.4 GHz for setup or use the LAN connection. After that your modem should auto select the frequency, but for setup it has to be 2.4. Wiring direct to the modem is easier (if you have a spare cable).
Question:	Do the apps run on this device, or is this just a connector from your phone to your speakers/stereo
Answer:	We have free iOS& Android APP "4stream" And we also available on some third party app that support DLNA, UPNP protocols.

Product features

Wireless Mini Controllo multiroom Stereo Preamplifier

With S10 preamplifier Integrated, You can stream your audio wirelessly to your speakers by Wifi, Bluetooth 5.0, Airplay, DLNA & UPnP. And no matter where you are in your house, you can always take out your phone to play a song for you or your family. Like play a Bedtime Story for your Children, a love song for your wife, easy and wirelessly.

No Distance Limitation

Wifi Streaming is more stable than Bluetooth that you can play the music everywhere in your house as long as your wifi signal is covered.

No Compression

Wifi streaming also has an advantage of streaming audio without compression, while Bluetooth streaming will compress the audio quality.

Hi-Res Audio

S10 Preamp support up to 24bit,192khz decoding which means you can stream with High Resolution audio wirelessly. Enjoy your high quality

All Music you like

Huge music resources supported like Spotify, Amazon Music, Tidal, Deezer, Qobuz, Internet Radio, iheart Radio, Napster etc. Other than online music, you also can play local music by NAS, USB storage where you have collected your favorite song for years.

Wireless Connectivity

Streaming your audio all the way by Wifi, Bluetooth 5.0, DLNA, UPnP, Airplay, Spotify Connect.

Streaming your Music Everywhere

No matter where you are in your house, you can always take out your phone to play a song for youryou or your family. Like play a Bedtime Story for your Children, a love song for your wife, easy and wirelessly.

Free iOS & Android App

Our App called “4stream” that is compatible to your iOS & Android system. All the features can be simply controlled by App. And you also can receive the notification for our regular online firmware update automatically in our App.

• ✅STABLE STREAMING AND HIGH SOUND QUALITY: Supports playback of lossless music files-MP3, APE, FLAC, WAV with Hi-Res audio.When streaming wirelessly, Bluetooth can reach up to 30 meters. With stream music over the network, Wifi can reach anywhere the signal covers. And free iOS and Android app: 4stream
• ✅Multiple Music Sources & Protocols: Supports Spotify, Tune in, iHeartRadio, XIMALAYA, QQ Music, TIDAL, Napaster, Qobuz, QQFM, Deezer etc. And airplay1, Qplay, DLNA, UPnP protocols. Also Other audio sources for local music, USB flash drive, NAS and line inputs.
• ✅Application: Advanced circuit design with built-in speaker protection circuitry, best suited for your home bookshelf/celiing/desktop/speakers; recommended for home TV audio, computer audio system games, tower speakers and garden speakers. If you have high knowledge in the audio field, the small and compact design is also suitable for car audio system. You can enjoy high quality music everywhere!
• ✅Multiroom Control: Enables multiroom and multizone streaming through multiple devices connected on the same network and control with your phone.

User questions & answers

Question:	Does the package include case and remote
Answer:	No. this contains main board*1+7 pin cable*1+4 pin cable*1+2 pin plug cable*1+ Wifi Antenna*1+Manual*1 You can find the remote and case here: https://www.arylic.com/collections/accessory
Question:	how many devise can install at same home in same network ? to play up 20 zones same music
Answer:	Actually no limitation, it is based on your configuration and strength of your wifi router. By your settings, I recommend you can connect by Lan for stable connection. Thanks
Question:	I just received your product and set it up and it fails to update. Stops at 36 percent and a voice says update failed. How do i solve this
Answer:	This issues usually can be solved by try more times. I advice you can remove the device and phone more closer your router where have stronger wifi signal. If not succeed, you can send a mail to our official mail: info+{at}+arylic.com We have tech support to help you.
Question:	Does it support eq settings like the up2stream preamp board
Answer:	Yes supported

Product features

Product Description

TV sound, Online Music, Gaming Audio. All sounds of your home entertainment can be streamed wirelessly by Up2stream audio receiver board. Compatible with your latest control device constant use phone, PC, and Tablet. Meet your needs and give you different music enjoyment.

Micro USB Sound Card

Up2stream V3 Series can work as an USB DAC, you can directly connect it to a PC and stream PC audio digitally.

Customize your Name

Support changing device WIFI SSID and bluetooth name by mobile app and save it forever.

Bluetooth 5.0

Now you can Stream your audio all the way by Wifi, Bluetooth 5.0, DLNA, UPnP, Airplay, Spotify Connect with Up2stream Mini V3.

All Musics you like

Huge music resources supported like Spotify,Amazon Music, Tidal, Deezer, Qobuz, Internet Radio, iheart Radio, Napster etc. Except online music, you also can play local music by NAS, USB storage where you have collected your favorite song for years.

DIY Rookie Friendly

If you are a DIY rookie and don't understand complicated ports. Don't worry! On our receiver, the ports we use are common ports and simple to use, our app is user friendly as well. Using our remote control is another convenient option for your streaming music needs.

Streaming your Music Everywhere

No matter where you are in your house, you can always take out your phone to play a song for you or your family. Like play a Bedtime Story for your Children, a love song for your wife, easy and wirelessly.

Free iOS & Android App

Our App called “4stream” that is compatible to your iOS & Android system. All the features can be simply controlled by App. And you also can receive the notification for our regular online firmware update automatically in our App.

• AUX / Bluetooth Audio input Manual switch mode,Use DC12V/1.5A power supply(Do not use a power supply exceeding 12V)
• This is Bluetooth 5.0 tube preamp,With Bass and treble,Sound great,Satisfies your need for more sound quality! Great Warm Smooth Sounding! Let you enjoy sweet and warm sound quality
• Using the classical tube 6j1 design for easy replacement,soft voice.Adopt the Dual run amplifier chip NE5532P power conversion module
• All aluminum alloy shell,heavy gold PCB,Build quality is surprisingly solid,Nice touch!The power circuit is completely separate from the audio circuit, Minimizing interference for clear sound
• NOTE:This is a preamplifier,not a power amplifier or phono preamp, can't be used for turntables.(More technical support and help,pls ask me:www.amazon.com/hz/help/contact/A3BG62S1F23IH5# .Or leave any of your instant messaging account and I'll contact you!)

User questions & answers

Question:	If this bluetooth preamplifier is connected to a bluetooth amplifier, which one should be paired to the music source, the amp or preamp
Answer:	15 to 20ft
Question:	What means amplifier preamp for home theater system in the description
Answer:	I bought it for my 6 year old and it’s the perfect size. For a 10 and 12 year old the cart is too small.
Question:	what's the difference between the $49 one and this $59 one? thanks
Answer:	I contacted the company by email with problem with washer that held on peddle they sent me another bike
Question:	What Bluetooth codecs does this unit support
Answer:	12” x 24” x 36” +\- not heavy.

Product features

Function indicator

6J1 Vacuum Tube Preamplifier

With Bluetooth 5.0 & AUX switch selection;With Treble and Bass tone control,

Short Circuit Protection;Overload Protection;Overheat Protection;AIYIMA Tube T2 will give you a different acoustic enjoyment with dynamic, sweet tube sound enjoyment!

Using original 6J1 Tube Bile

Tested and matched Pair (2 tubes) of low-noise 7-Pin Vacuum Tubes,Classical Tube 6J1 Buffer Design,Higher Durability and Life.The 6J1 electronic tube can be replaced with:

6K4, 6J4, GE5654, 6*1n, 6AK5, according to different sound styles.The board layout is reasonable, beautiful, and the current is small The exterior design is delicate and beautiful!

AUX/QCC Bluetooth 5.0 Audio input Selection

Bluetooth Connection:Turn on our Tube-T2,Manually Toggle to Bluetooth mode,disconnect the AUX audio input,search for our Bluetooth "AIYIMA-T2" to connect.

Please make sure the Bluetooth antenna is installed correctly(Without obstacles such as walls)