13 best bravo tube amplifiers

Product description

Enjoy the pure, non-fatiguing sound of Class A amplification with the Bravo V2 headphone amplifier.

• Includes high-quality Shuguang 12AU7 tube
• Parallel 3.5mm and RCA stereo inputs
• Gain control with Japanese ALPS potentiometer

User questions & answers

Question:	Does this boost sound enough to use as the only amp to listen to records with headphones
Answer:	Short answer: no. Long answer: this amplifier expects about 1 Volt input for a full power output. A phonograph player only generates output in the .005 Volt sort of range. Also, the signal from a phonograph has to go through an RIAA filter to recover the low-frequency information. A record would not be able to wiggle a needle correctly to generate bass, and so RIAA equalization is applied during record pressing.
Question:	I mostly listen to music in digital format (MP3) and trying to decide between this amp and a USB headphone DAC...thoughts
Answer:	You're comparing Apples and Oranges. The Bravo is strictly a headphone amp. I use my Bravo with a Behringer UCA222. I chose the Behringer because it's a DAC (digital to analog converter) and an ADC (analog to digital converter). I use the Behringer to "rip" vinyl to FLAC files. Why bother with sonically compromised MP3 files when storage space is so cheap?
Question:	I don't know much about tube circuits. Do both headphone channels go through the tube at once and remain seperate channels? Or are they combined
Answer:	The answers about being two separate channels in the tube are correct. But there is an issue in the amp that needs a simple modification. Because of the way it was designed, there is an issue with balance and separation of channels. If you balance to one side or the other, there is still sound out of both left and right speakers or headphones. See the first post on this forum, just scroll down to the picture entitled 'Crosstalk improvement', which is the 6th picture, for details: http://rockgrotto.proboards.com/thread/5297/bravo-12au7-mods-appreciation-thread And be sure to get some different old stock tubes on "The Bay" from the 50's and or 60's. The RCA Clear Top is my favorite so far.
Question:	Stupid questiion of the year. How do you use this and what do you use it for
Answer:	Another more pedestrian use is if you have high quality, high impedance headphones and want to listen to a consumer-grade device (e.g. iPod). Standard headphones are around 32Ω impedance, while higher-end ones can be anywhere from 80Ω to north of 600Ω. The device will still drive the headphones, but the sound may be quiet or sound muffled. A headphone amp does what it says on the box, and amplifies the output -- which results in louder and clearer sound on high-impedance headphones.

• P1 is a Bluetooth vacuum & valve tube preamplifier and headphone amplifier. Headphone output is 160mW @32Ω and is suitable for 32~300Ω headphones and headsets.
• Classic 6J5 vacuum & valve tube can provide warm retro tube sound. It can be replaced by 6J1, 6J4, GE5654, 6AK5, 6Ж1n-EB.
• It supports Bluetooth/USB/RCA inputs from various devices like iPod, Phone, MP3, TV, Blu-ray players, Echo Dot, CD players, computer etc.
• Bluetooth 5.0 supports APT-X, APT-X LL lossless transmission. PC-USB supports 24bit 192KHz and is compatible with Windows/Mac/Linux system
• Treble & bass control can achieve different sound style. Bypass function can suspend the tone control circuit to achieve purer music experience.

User questions & answers

Question:	Can this pre-amp stay on for long periods of time without damaging the tubes? Or can the tubes be switched off & still pass through to my amp
Answer:	Tubes last around 5000 hours. They can be on all the time.
Question:	Can you run this amp with powered speakers
Answer:	Confirmed working fine with JBL Professional LSR310S Powered Subwoofer and JBL LSR305 powered monitors. Sound does seems a bit tinny, perhaps better tubes would help.
Question:	Is this a DAC as well as a preamp
Answer:	Description states a CM6642 dac. How it's wired up will make a difference, have one on order.
Question:	Can I send audio out from the rear usb port into a computer usb to make recordings on audacity
Answer:	No. the USB port is only for power and receiving data from the PC. It does not send data to the the PC at all.

Product features

Parameters

• Chip Architecture: CM6642+QCC3008+NE5532+classic 47
• PC-USB Input Sampling Frequency: 192K/24Bit
• THD: 0.01% , SNR: 103dB
• PC-USB System supported: XP/W7/W8/W10/MAC/Linux
• Bluetooth VER: 5.0
• Headphone matching impedance: 32-300Ω
• Headphone Max power output: 160mW 32Ω load
• Bass & Treble Range: ±6dB
• RCA output level: 2.3V
• Frequency Range: 20Hz-20kHz(±3dB)

Bluetooth / USB / RCA Inputs & Preamplifier & Headphone Amplifier

• Bluetooth vacuum & valve tube preamplifier and headphone amplifier
• Headphone output is 160mW @32Ω and is suitable for 32~300Ω headphones and headsets
• Support Bluetooth/USB/RCA inputs from various devices like iPod, Phone, MP3, TV, Blu-ray players, Echo Dot, CD players, computer etc
• Bluetooth 5.0 supports APT-X, APT-X LL lossless transmission
• PC-USB supports 24bit 192KHz and is compatible with Windows/Mac/Linux system

Warm Tube Sound & Replaceable Vacuum Tube & LED Selector

• Classic 6J5 vacuum & valve tube
• Warm retro tube sound
• Can be replaced by 6J1, 6J1, 6J4, GE5654, 6AK5, 6Ж1n-EB
• Tube light selector (blue / orange)

Treble / Bass Control & Bypass Function

• Support treble and bass control
• Bypas function (tone control can be turned off to achieve purer music experience)
• Bluetooth / USB / RCA input selector

Product description

Product information:

• VU meter display input signal voltage
• Software Control Fan cooling system
• Pre Amp Tube Model: 12AU7or12AX7or12AX7x2
• Power Amplifier IC:1941/5198
• Output Impedance:4-8ohm
• Bluetooth:V2.1EDR
• Bluetooth Range: <10 meter/<33 foot range(Open Area)
• AC Power Input:110V 50Hz
• USB Support: WAV/MP3/WMA/APE/Flac
• RCA Input for TV/Laptop/MP3 player/Smart Phone Earphone Jack

• 100W Hybrid TUBE AMPLIFIER: 35W 4 ohm / Channel& 50W 8 ohm / Channel. Front Panel has independent Treble/ Bass/ Volume adjustment Knob. Supplied with a replaceable tubes.
• EXQUISITE MATERIALS: Power Amplifier used Aluminum and Metal casing which provided stronger protection. Metal cutting knob for more delicate control.
• Build-in 6H3N: Replaceble with 6N3/5670(6.3V), Old version Build-in 12AX7/12AT7/12AU7(Random&Replaceble 12V , PROTECTION COVER( Removable ) : The use of thickened steel wire meshed for the tube protection cover not only adds protection of the tubes, but also provides cooling performance and user safety.
• STEREO Input&Output: Super powerful extension, multiple audio sources. Connectable with CD player, DVD player, PC, Smartphone, TV by using RCA & AUX ,Bluetooth, U disk, Optical and Coaxial. Those connection allows you to enjoy the “Tube”Sound.
• PERFECT SERVICE: 1year warranty gives you a great shopping experience. If you encounter any problems, please contact our customer service team immediately.

User questions & answers

Question:	The appears to be 2 large capacitors - what are their temp rating and capacitance rating? What brand
Answer:	I've reverse engineered the circuit. The tubes are implemented as cathode followers post fade and feed the power amp inputs. The cathode follower implementation is a little strange in 2 ways: 1- Triodes are paralled but one plate is disconnected (pin 1) 2- Both channels are connected to B+ via a shared 220K resistor (haven't bench tested yet but CROSSTALK?!?!). Subwoofer outputs are on a separate path and not routed through the tubes.
Question:	Can i use this to power my front speakers and sub in a 5.1 through my avr that has pre-outs
Answer:	Hi Ryan J, Yes, the speaker system with 4 to 8 ohms will work with this AV Receiver. https://www.sony.com/electronics/support/res/manuals/4726/55cd375e0f9e7103f2b6baa747ed9072/47269061M.pdf (page 15 - Setting/Connecting Speakers) Regards, David
Question:	I read new stock due Oct will be sub controllable, the volume knob will control a subwoofer... has new stock arrived
Answer:	HI, Chris! Unfortunately, no. The Bluetooth feature of the receiver doesn't support connection of Bluetooth speakers. Regards, Erin
Question:	Are the tubes powering this amp, not just for show and is the sound warm when played
Answer:	Hi Allen W., The HDMI ports are actual HDMI inputs. You may refer to this link for more product information: https://docs.sony.com/release//SPECS/STRDH590_mksp.pdf ~Ralph

Product features

Removable Tube Cover

Easy Loose two cross bolt to remove the tube cover for tube upgrade or replacement. Strongly recommend do not take-off the cover if kids at home.

Full balance “Mirror” circuits design

Classic full balance PCB circuits, well engineered for Hi-fi user. High volume eclectic components provide stable performance and life-time.

Ring type transformer

110V/50Hz , 23.5V 2.5A Power Supply , ø95mm B2 Grey SSP( Straight Steel Plate) Transformer. Low disturbance, Stable power supply, Full sound pressure, Overheat cut-off design.

Fan cooling system

Low noise Start/Off Fan cooling system and metal casing provide good cooling performance for long time playing.

• Tube A5 is a Bluetooth vacuum tube pre-amplifier and headphone amplifier,Adopt the Dual run amplifier chip NE5532 power conversion module.Adopt TPA3116D2 Amplifier chip,Bluetooth 4.2 Support APTX low latency
• The tube headphone amplifier Adopt classical tube 6j4 design and optimize the route, can provide warm retro soft sound,tubes can be replaced by 6K4, 6J1, GE5654, 6AK5, 6ж1П, 6BC5, 403A/B, EF40, EF95 etc,. to enjoy HiFi sound of different styles
• 3.5mm headphone jack output for 16-64ohm headphones,Power Amplifier Output Power 50W+50W, best for outdoor/ bookshelf/ computer/ desktop /ceiling /floor standing speakers, can use iPod, Phone, MP3 players, TV, Echo Dot, CD players, or Streaming Media players as input
• With DC 19V Power Supply,treble & bass control can achieve different sound styles,With Remote control makes the operation more convenient, very suitable for home and desktop audio systems
• Reasonable circuit layout,Exquisite and unique appearance design,aluminum case solid touch,perfectly suited for your desktop or a other space in your home or office;Under normal circumstances, distortion is caused by the mismatch between the power of the amplifier and the speaker. Therefore, it can be reasonably matched according to the ratio of 1.2-1.5 to 1 between the power amplifier and the speaker

User questions & answers

Question:	Does this amp (or pre-amp) support active (or passive) speakers? the product description differs from the diagram
Answer:	You can directly connect bookshelf speakers into it. Unfortunately, I had to return my unit because sound was coming out distorted, so I was not able to learn more about this product.
Question:	Does amp come with dedicated power supply
Answer:	Yes, small power plug 110 volts
Question:	Can i stream via bluetooth spotify from my ipad to this preamp and listen to music with my headphones?? thanks for your help
Answer:	if you device with the bluetooth moudle signal transmission,then it can connect our tube a5.But If you ipad with bluetooth moudle,you can use it match connect our tube amplifier directly as the audio input,then connect your headphone,any other technical support,pls contact us.
Question:	Is there a version that works with a passive or powered subwoofer? Suggestions
Answer:	it can work with passive speaker,pls see our product description,thanks

Product features

Using classical Vacuum tube 6j4 design

Tubes can be replaced by 6J1, 6K4, GE5654, 6AK5, 6ж1П, 6BC5, 403A, EF40, EF95 and so on；

Both the appearance and the build quality are very powerful；

Tube A5 is very suitable for your home audio amplifier system

Headset /RCA Audio Output

This is Vacuum Tube amplifier;Cannot be used for record player;

Bluetooth & RCA Audio input selectable;

3.5mm headphone Output for 16-64ohm headphones/RCA Audio Output;

It is best for outdoor/ bookshelf/ computer/ desktop /ceiling /floor passive speakers

Bluetooth 4.2 Amplifier

Support apt-X and apt-X low latency；

Adopt TPA3116D2 Amplifier chip,Bluetooth 4.2 CSR64215 chip and HT97220 Chip；

Applicable to most Bluetooth devices:such as iPod, Phone, MP3 players, TV, Echo Dot etc.

• NS-08E is a Hi-Fi tube headphone amp. It can offer >=1100mW at 32Ω and can drive 18~600 ohm headphones & headsets.
• New version adopts 6J3 vacuum & valve tube, which has warmer tube sound and more replaceable tubes.
• Upgrade circuit can ensure lower background noise, more powerful bass and more brilliant treble.
• It can also be used as a stereo preamplifier for other amplifiers and active speakers. For better preamp function, we recommend NS-10P (ASIN: B07719G56B).
• CNC Aluminum shell with super mini size. Very solid workmanship. Prompt and courteous customer service.18-month warranty and life technical support. For any questions, please contact us on Amazon.

User questions & answers

Question:	What is the difference between a tube amp and a dac/amp combo
Answer:	Not from my knowledge no. There's just an input on the back of the cab. With other cabs it may be possible though.
Question:	Can the line/headphone out be connected to powered speaker
Answer:	Mine did *not* come with a speaker cable. Please note that an 'instrument' cable is needed rather than a regular guitar cable.
Question:	Would this work for the audio-technica ath-m50x headphones
Answer:	It comes w/ jumper cable from head to speaker. Then you’ll need a guitar cable to go from instrument to head unit. I would recommend you buy head unit separate and get a larger speaker than the 8”. It’s loud but doesn’t sound as good as a 10 or 12
Question:	Is this a true 100% tube driven amp? Most Nobsound amps use tubes for pre-amp and use transistor amplification, rendering the tubes useless
Answer:	The head yes but the cab no. It gets really loud but sounds pretty bad through 8” speaker. Buy the head separate and get a 12” cab

Product features

Powerful Drive & High Sound Quality

• NS-08E is a Hi-Fi tube headphone amp. It can offer >=1100mW at 32Ω and can drive 18~600 ohm headphones & headsets.
• Upgrade circuit can ensure lower background noise, more powerful bass and more brilliant treble.
• It can also be used as a stereo preamplifier for other amplifiers and active speakers. For better preamp function, we recommend NS-10P (ASIN: B07719G56B).

6J3 Vacuum & Valve Tube

• New version adopts 6J3 vacuum & valve tube, which has warmer tube sound and more replaceable tubes.
• Full List of Replacement Tubes: 6J1, 6ж1П, 6AK5, 6BC5, 403A/B, 5654, EF40, EF95, CV850, 6J2, 6ж2П, 6AS6, CV2522, EF11/732, CV4011, 6J3, 6ж3П, EF96, CV848, 6BC6, 6AG5, 6J4, 6ж4, 6136, 6BX6, 6AC7, EF94, 6AU6, 6J5, 6ж5П, EF80, CV2521, 6F36, 6AH6, 6AN5, 6K4, 6K5, 6K4П, 6BA6, 6DA6, EF89/93, 5749

Mini Size & Solid Shell

• CNC Aluminum shell with super mini size. Very solid workmanship.

Product Details

• Output power: ≥1100 mW (32 ohm)
• Headphone Adapter Impedance: 18-600 ohm
• Total harmonic distortion: <0.005%
• SNR: ≥110 dB
• Frequency Response: 20 Hz - 30 kHz
• Size: 111*69*32 mm / 4.37*2.72*1.26 in (Height: 73 mm with vacuum tube installed)
• Net Weight: 185 g / 0.41 lb
• Power supply: Input voltage: AC 100-240V 50/60 Hz; Output voltage: DC 6V 2000Ma

Notice:

• Please turn on the amplifier for about 15 seconds before you connect the audio source and put on the headset.
• We recommend using 24~600Ω headphones, while armature earphones and headphones that have low resistance and high sensitivity are not suitable.
• As there will be tube Microphone effect, please keep the amplifier steady while using it.
• For noise issue, please keep it away from devices like routers, mobile phones or something that may interfere in the audio signal.
• If there are no interference, please remove all input and listen to see if the noise still exists.

Product description

Why us?

The Nobsound NS-02E designed by Douk Audio Studio is a powerful Hi-Fi headphone amp. It has an anodized aluminum chassis with a replacable vacuum tube shining blue illumination on the top. The Nobsound NS-02E can provide soft and warm sound while maintaining its exceptional clarity. Most importantly, the affordable price makes both Hi-Fi freshmen and Hi-Fi veterans can enjoy it. And that's exactly one of our targets.

The Nobsound NS-02E can be paired with your preamp, smart phone, computer, iPod, stereo system, and other audio device as well as your favorite headphones. It can easily power high-performance headphones including the HD 580, HD 600, K 701, K 702, Q 701, DT880, T70, T90, SR225, SR325, RS1e. It will also be a good match for active speaker systems.

The Nobsound NS-02E can also be used as a tube pre-amplifier. You can connect it with any types of power amplifier to upgrade the musicality and dynamic of the original system.

What's more, its high playability can provide more pleasures for you. The default tube is 6N3, which can be easily replaced with various types of tube as below:

• United States: 6A8Q, 2C51, 5670, 5185, 6385, 6185, WE396
• Europe: ECC 42
• Soviet Union: 6H3N, 6H3II
• Germany: ECF82
• Czech Republic: 6CC42

Definitly, you will always find a place for it in your stereo system.

Specifications:

• Tube: 6N3
• Output power: ≥1100 mW (32 ohm)
• Adapter Headphone Impedance: 18-600 ohm
• Total harmonic distortion: <0.005%
• SNR: ≥110 dB
• Frequency Response: 20 Hz – 30 kHz
• Size: 90 * 90 * 39 mm (L * W * H; 3.54 x 3.54 x 1.54 inches) /H: 80 mm with tube and feet
• Net weight: 165g
• Colors Available: Black, Silver
• Input and Output Audio Jacks: 3.5 mm

Package include:

• 1× NS-02E amp
• 1× power supply

• The Nobsound NS-02E can provide soft and warm sound while maintaining its exceptional clarity.
• The default tube is 6N3, which can be easily replaced with 6A8Q, 2C51, 5670, 5185, 6385, 6185, WE396, ECC 42, 6H3N, 6H3II, ECF82, 6CC42.
• The Nobsound NS-02E can be paired with your preamp, smart phone, computer, iPod, stereo system, and other audio device as well as your favorite headphones.
• The Nobsound NS-02E can also be used as a tube pre-amplifier.
• The affordable price makes both Hi-Fi freshmen and Hi-Fi veterans can enjoy it.

User questions & answers

Question:	How many amps does the 6v power supply push? What are the ratings
Answer:	2A
Question:	Will changing the standard 6N3 tube to one of the other tubes listed in the description change the quilty of sound
Answer:	It can change the character of the sound yes depending on the tube you switch to.
Question:	Hi: this product says 'diy' in the description. is it a kit, or do you basically just need to put the tube in and plug in the power supply? tia
Answer:	im not sure why it says diy.. it came complete in box. All you have to do is plug it in to the power adapter and its ready to go.
Question:	I have a solid state amp and want to add a tube amp to the mix. Is it possible
Answer:	If you have a line level out on your SSA then yes.

Product description

Input: Gold Plated Unbalanced (RCA) Jacks Output: 1/4" Gold Plated Stereo Headphone out Tube Options: 6JI standard Frequency Response: 10HZ ~ 50KHz (minus3 dB) THD plus N: 0.2 percent: 1Vrms @ 1000Hz 0.6 percent: 3Vrms @ 1000Hz 1.0 percent: 5Vrms @ 1000Hz Signal to Noise: 92dB Suitable Headphone Impedance: 8 ~ 600 ohms Input Impedance: 50K ohms Power Output: 150mW @ 300 ohms 300mW @ 120 ohms 800mW @ 32 ohms User variable gain settings: 6.5x or 3.25x Power Consumption: 15VA Measurements: Metric: 180mm (L) by 97mm (W) by 100mm (H) English: 7.08 inches (L) by 3.81 inches (W) by 3.93 inches (H) Weight: 1.5 kg or 3.3 lbs. Available in Black Available in either 120VAC or 220VAC

• Little Dot I+ 6JI standard is a hybrid transistor-vacuum tube headphone amplifier
• Little Dot I+ 6JI standard offers versatility and incredible sound quality in a tiny footprint

User questions & answers

Question:	Hi, Anyone tube roll with the Little Dot MK2? Siemens 6AK5W & Soviet 6N6P were stated as a great combo. Any Combo's please state them. Thanks Steve
Answer:	Yes, I have that exact combo. I purchased little dot mkii from amazon on 04/07/14 and the Siemens 6ak5w (blue tint) + Soviet 6h6n combo from ebay same day. The factory chinese tubes do provide that "girl in a red dress in a smokey room experience" that being said a colored sound but very enjoyable. With the Siemens/Soviet combo it is more even and flat sounding with more dynamics and bass. I have HD650, DT880 600ohm, Q701, AH-D2000, SR325is, SR60i, K550, HD280pro, HD518, ATH-M50, Triple Fi 10 and more. with the higher ohm models coming "alive" with little dot mkii and the lower ohm models coming "alive" with my solid state Schiit Asgard1 . That being said Fiio E9 OK great starter. Schiit Asgard1 a big step over the Fiio E9 and the little dot mkii with stock tubes almost as good as Asgard and with Siemens/Soviet tube a step above the Asgard as far as sound quality Bass Mids Highs and Soundstage. HD650 300ohm and DT880 600Ohm sound awesome and now my DT880's are dare I say Bass heavy which thay are not with other said amps. Using Asus Xonar ST as DAC with 3 LME49860 op-amps using RCA pre-out's connecting with high quality shielded RCA Monster Cable and not the built-in headphone amp.(muddles the sound) RCA's bypass internal amp. Total package is HEAVEN after a hard day being able to sit down and relax to music is the best medicine for the mind/body/soul.
Question:	Does this MK II model come with circuit revision 2.0 (or higher)? Am i able to run 6H30 power tubes without changing the resistor on the board
Answer:	I purchased mine 04/07/14 from amazon and mine is v2.0 with 5watt 180ohm white ceramic resistors in place. Which means yes you can use 6h30 power tubes. easy to look at motherboard and find two rectangle white resistors next to the bigger tubes on the end of board opposite the side with the gain switch's next to three large black 330uf capacitators (rca plug-in end) Look at motherboard writing where it say's "Little Dot MKii" it will state v1.0 or v2.0 with only 2.0 having larger resistors to accept the 6h30 = 6h30pi = 6h30p-dr power tubes. As per little dot website "6h30 type tubes will provide a more dynamic and impactful sound" G00gle "little dot mkii 6h30"
Question:	What different tube types can you use to tube roll
Answer:	I would use the following tubes: Soviet 6N6P Gold Grid power tubes that will give you at least a 6 DB gain improvement and the Siemens Blue Glass 6AK5W driver tubes. These tubes sell on Ebay as a matched set for $65 including shipping. This was the best set I came across after days of research. I also bought a pair of Sylvania NOS 6AK5W driver tubes for $20 to mix and match the driver tubes. For this Little Dot MK 2 being a entry level all tube headphone amp these are a great choice in tubes since your spending less than $100 in additional tubes.The Blue Glass Siemens 6AK5W's will give you a great flat but extended bass response that's noticeable before they are even burnt in. The Sylvania version will give you a better sound for Classical music with a more airy type of sound.I stuck with the Soviet 6N6P Gold Grid power tubes as they were highly recommended. The Siemens Blue Glass were also such a improvement that I have just kept them in since I compared them with the Sylvania from 1945.So it's really up to what type of music you listen to. I like mostly classic 70's rock and some modern stuff by Sarah McL. and groups like Maroon 5. But I still listen to Led Zepplin, The Doors, Supertramp, and of course Pink Floyd's classics. I like all sorts of music including some classical, but classic 70's rock is still my favorite and I have been buying new virgin vinyl of all the latest re-mastered recordings and loving it with this Little Dot MK2 with these new NOS(New Old Stock ) tubes. So figure you spend a total of $260 on the amp and the NOS tubes which will really make a huge difference.So this entry level all tube headphone amp becomes more of a above average unit with the added tubes. Also separate the power plug from the RCAs being used and you can really minimize any hum produced. I have read a lot of complaints about hum from this amp. I personally have only heard it on a few recordings and it's also very possible it was the source(The recording ) and not the amp causing the hum.Hope this helped you out. You can find the tubes on Ebay for a fair price with a 14 day return policy as well. The yare also shipped within the United States, so no long wait time for your new tubes. Rock on :)
Question:	Supposedly there is a gain control switch. Where is it and how does it work
Answer:	Don't confuse yourself with using the jumpers at all. That's for "Tube Rolling" that's a whole different thing. To adjust the gain you carefully tune the unit over (Pull the tubes if you feel safer) I left mine in and made sure it didn't tilt at all. Unscrew the four bottom plate mounting screws. You will see two dip switches that are little red boxes with white slider switches that are very small. You set them the same on both sides since each switch is for one channel. The manual shows the settings very clearly and it's very easy to switch(Dip Switch Setting using the tip of a pen or a paper clip)Settings are as follows: A: off-off gives a gain of 10DB B: on-off gain of 7 DB C: off-on gain of 5 DB (My choice for 50 OHM headphones) and D:on-on for a gain of 3 DB (This is for headphones between 32 and 50 OHMs)Easy peasy! Enjoy :)

• Military grade 6N3 electronic tubes and carefully tuned circuits.Powerful drive circuit up to 600mW at 64Ω .
• Fully balanced headphone amplifier,including balanced input interface.
• Hi-End volume control NJW1195 produced by JRC Japan.
• Use relay for mute control.Humanized operation with memory function.
• Aluminum CNC,very fine workmanship.

User questions & answers

Question:	What is the voltage and amperage of the included power supply
Answer:	12 volts DC @ 1.67 amps.
Question:	I have a dragonfly red, would this amp be a good match? also have xlr balanced sennheiser hd600 cable out
Answer:	I don't have the dragonfly red, which has the ESS 9016 DAC chip but feed mine with the SMSL SU8 which has the ESS ES9038Q2M DAC and it pairs very nicely with it. My guess is that it would be slightly warmer and less clinical than the built in headphone amp chip on the dragonfly red, but I'm only guessing. The SU8 and the Loxjie sound very nice with Tidal and Qobuz although you may have an edge with the dragonfly red with Tidal since it has MQA decoding which the SU8 does not. I have the HD 6xx's and the HD 58x running balanced and they both pair very nicely with the Loxjie. I imagine the HD600's will pair well too.
Question:	Could this amp power 300 ohm headphones
Answer:	Yes,P20 can power 300 ohm headphone.
Question:	Is it safe to use a higher quality 12v rated power supply, but rated at 3 amps instead of the stock
Answer:	While someone more knowledgeable has answered the question already, I would like to correct one thing they said... The LOXJIE P20 does indeed have a on/off button... press the volume knob in for 3 seconds to power off the amp.

• This Class A single-ended vacuum tube amplifier adopts hand welding to ensure the true reality of the sound quality (with headphone amp function ASIN: B076CC92BX).
• This amplifier adopts transformer parallel output to reduce its internal resistance by half and achieve doubled improvement on its power.
• Using antimagnetic transformer covers to shield current interference and achieve much lower static noise.
• Its sound output is full of analog style. The bass part is deep and powerful and the vocal part is sweet and intoxicating.
• It has a classic and graceful appearance. The VU meters and vacuum tubes makes it more elegant and attractive.

User questions & answers

Question:	input sensitivity
Answer:	How loud it will get greatly depends on your speaker sensitivity. If you are using very efficient speakers it will fill a medium size room with sound. My speakers have a sensitivity of 99 db and it will fill the medium size living and dining room with plenty enough sound for my liking. If you are talking about a large gathering of people in a large area I am not sure this amplifier will fit your needs.
Question:	Can the VU meters sensitivity be adjusted to deflect (jump) more for aesthetic reasons
Answer:	Is this the one with point to point wiring and the tube cage?---------YES. point to point wiring and come with the tube cage.
Question:	w? Seems light. Is that enough to power a large speaker or is this amp for powered speakers only
Answer:	Most turntables will need an additional pre-amplifier to boost their signal before plugging them into the Reisong A10. However, if you happen to own the Audio Technica AT-LP60, which contains it's own inboard phono pre-amplifier, you won't need a separate phono pre-amp.
Question:	How loud can it get? Is it adequate for just bedroom listening or can it be used for a party
Answer:	Can i replace 6n2j tubes with 12ax7/ecc83 tubes? ----YES. But you please pay attention to adjusting the electronic pin position when you replace them.

Product features

Parameters

• Output power: 6.8W * 2
• Frequency response: 20Hz-20KHz
• Input impedance: 100K ohms
• Output impedance: 4/8Ω
• SNR: 90db
• Input Sensitivity: 500mv-2000mv
• Harmonic distortion: 1% (1KHz)
• Tube: 5U4C * 1 + 6H8C * 2 + 6P1 * 4
• Operating voltage: 110V

Retro Classic Vacuum Tube

• 5U4C * 1 + 6H8C * 2 + 6P1 * 4
• Vacuum tubes can offer warm retro analog sound unlike normal digital sound.

Hand Welding & Better Sound Quality

• Totally hand welding can decrease sound losses and ensure better sound quality.
• Its transformers adopt parallel output design, which achieve only half resistance. It has doubled power and still keeps the features of>

Luxury Components & Multiple-Paint Transformer Shield

• This amp adopts 150µV 450V Hi-Fi level BC Components high voltage capacitors.
• Multiple-paint transformer shield can avoid current interference, which can get lower background noise.
• Sound quality is more natural and warmer.

Gold-Plated Pure Copper Terminals

• Adopts gold-plated pure copper terminals.
• Speaker out binding posts can accept banana plugs and bare speaker wires.
• Both 4Ω and 8Ω speakers can connect to the 8Ω and 0Ω posts of this amplifier.

• Home Hi-Fi integrated amplifier, 50W RMSx2 (4 ohms, 20 Hz - 20 kHz, 0.04% THD), Adopt High-quality TPA3116D2 chip, exclusively designed for the customers who pursue HiFi sound
• Bluetooth Receiver, range: about 40 ft-- Adopt CSR64215 Bluetooth 4.2 core Supports the aptX Low Latency codec to virtually eliminate audio-visual lag making an ideal choice for watching TV/ movies. For best results, use with aptX Low Latency supporting speakers
• Adopt 2pcs 6J4 tubes, It could make sound soft, thick, sweet and transparent, tubes can be replaced by 6K4, 6J1, GE5654, 6AK5, 6ж1П, 6BC5, 403A/B, EF40, EF95 and so on
• Advanced circuitry design, built-in speakers protection circuit, solid aluminum chassis for long time use, small size, good looks, simple functionality, and excellent sound quality
• 【Power amp + Headphone amp】 Power amplifier is easy to connect to your audio system with no software to install or settings to change. Headphone amp supports most headphones of high impedance 16-300Ω, Perfectly suited for your High impedance headphone

User questions & answers

Question:	Can the power supply take 220v? i ordered the unit from amazon us but we use 220v here. does the power supply detect the voltage
Answer:	Not sure, I believe it depends on your outlet. 110-220v three prong standard outlet.
Question:	Hi I can't get no sound out of mines I put them on 40 watt speakers speakers work fine I even tried 20 watt speakers anybody else have that problem
Answer:	Make sure your speakers are 4-8 Ohms. These are 50 watts 4 Ohms and 30 watts 8 Ohms per speaker.
Question:	Is it good for movie watching
Answer:	I would recommend buying an actual home theater amplifier for watching movies, but if you are using this little amplifier for desktop monitors then it is perfect for movies
Question:	does this have a built in DAC
Answer:	This model doesn't built in DAC. If you want a Stereo Audio Amplifier built in DAC, you could check this one as following: https://www.amazon.com/dp/B07XLLLSFS Hope it help.

Product features

2 Channel Mini Hi-Fi Class D Integrated Amp for Home Passive Speakers 50W + 50W

Home Hi-Fi integrated amplifier, 50W RMSx2 (4 ohms, 20 Hz - 20 kHz, 0.04% THD), Adopt High-quality TPA3116D2 chip, exclusively designed for the customers who pursue HiFi sound

Bluetooth Receiver, range: about 40 ft-- Adopt CSR64215 Bluetooth 4.2 core Supports the aptX Low Latency codec to virtually eliminate audio-visual lag making an ideal choice for watching TV/ movies. For best results, use with aptX Low Latency supporting speakers

Adopt 2pcs 6J4 tubes, It could make sound soft, thick, sweet and transparent, tubes can be replaced by 6K4, 6J1, GE5654, 6AK5, 6ж1П, 6BC5, 403A/B, EF40, EF95 and so on

Advanced circuitry design, built-in speakers protection circuit, solid aluminum chassis for long time use, small size, good looks, simple functionality, and excellent sound quality

Power amp + Headphone amp

Power amplifier is easy to connect to your audio system with no software to install or settings to change. Headphone amp supports most headphones of high impedance 16-300Ω, Perfectly suited for your High impedance headphone

Package Content:

1 x Bluetooth Audio Amplifier

2 x 6J4 tube

8 x Speaker Banana Plugs

1 x 24V/4A Power supply

1 x AC power cord

1 x User's Manual

• Notice: ① Preamplifier needs to work with amplifiers or active devices; ② Not PHONO preamp and can't be used for record players
• Excellent sound performance; No background noise; Warm and soft tube sound; Sound quality enhancement; Pure tube preamplifier; Suitable for all amplifiers and music types
• With independent treble, bass and volume control; Vacuum tubes can be replaced by various models
• Mini size and exquisite appearance; CNC aluminum shell and front panel; Blue tube light; Mellow and solid touch feeling

User questions & answers

Question:	I connect my pc to amplifier - the audio output of pc is weak - could it boost it (aoudio aut of pc)much more
Answer:	I don’t have a meter, so I can’t tell you that. However this amp was a vast improvement from the starter Vox amp that I had before. I’m sure if I spent more to buy a set of stacks that would be even better. It never ends.
Question:	Will this improve sound to the AUX port in car stereos
Answer:	There is a slight hiss in these amps, I own the guitar and bass. It's very minimal and does not seem to hiss when its playing, it has to do with the nutube neon light tubes in the amp, it's really cool stuff if you look into it and really creates great tube tone, but hussy when it's just sitting, if you invest in a noise gate pedal, I'd it would help quite a bit
Question:	Does the bass function really work
Answer:	It is not waterproof,, I do have it installed in my 185 searay,,, under my dash and tucked away clear from water,,,, it sounds amazing!! But it is not waterproof....
Question:	What kind of rca cable would i use for the “in” since both ends only have one jack
Answer:	It comes with every thing you need

Product features

Nobsound NS-10P Mini Vacuum Tube Preamp HiFi Audio Pre-Amplifier Tone Control

Parameters:

• Power supply: Input -- AC 100~240V; 50/60Hz (universal) & Output -- DC 6V 2000Ma
• Voltage amplification: 1.5 ~ 2.0 times
• Audio input / output: standard 3.5mm
• Power interface: 6V -- 5.5 * 2.5
• SNR: ≥ 110dB
• Frequency response: 20Hz ~ 30 KHz
• Dimensions: 105 * 69 * 32 (65mm height with tubes)
• Net weight: 205g

Packing List:

• 1 * NS-10P tube preamp
• 2 * 6J1 tubes
• 1 * 6V / 2000mA power supply

Using Instructions:

• Phone / Player / MP3 / CD / DAC / Computer Audio source→ 3.5mm / RCA audio cable → NS-10P preamp → 3.5mm / RCA audio cable → Amplifier / Headphone amplifier / Active speakers

• 12AU7 vacuum tube MOSFET Class A amplifier without any OP amp or IC; Pure warm and sweet tube sound
• Unlike acrylic shell, PCB shell is more expensive and solid and has fine anti-interference and shielding
• Input: 3.5mm (phone/MP3/palyer) & RCA (CD player/computer); Output: 3.5mm&6.5mm headphone port & RCA
• RCA LINE OUT: Can be used as a preamaplifier for other amplifiers or active speakers
• 12AU7 vacuum tube: can be replaced by 12 series and 6 series tubes (with a switch to select)

User questions & answers

Question:	Can I connect this to a denon receiver to get the tube sound
Answer:	While I cannot speak specifically to your situation with a Denon receiver, I can tell you that I I'm happily using the Little Bear as a stage between my turntable preamp and amplified speakers to add the warmth of a tube stage.
Question:	Can this also be used for a pre amp for phonograph
Answer:	Hi, I haven't tried it but usually you need a different type of amp to amplify the signal since the phonographs voltage is so low. I bought this one and it works well with mine. https://www.amazon.com/gp/product/B00025742A/ref=oh_aui_search_asin_title?ie=UTF8&psc=1 . Hope that helps. You would need both amps if you want to use your headphones with your phonograph. Good luck!

Product features

Nobsound Little Bear P10

Front

Back

Inside 1

Inside 2

Product description

Notice:

Input signal overload may cause distortion and noise. When this happens, please turn down the volume of the audio source until no noise and then adjust proper volume through the amp itself.



Parameters:

Audio input: 1*3.5mm Jack

Audio output: 2*3.5mm headphone jack(one for 12-40Ω headphone and one for 40-200Ω headphone)

Power supply: DC 12V@2A(5.5/2.2mm)

Tube model: Beijing FU32

Op amp: NE5532

Color: black

Dimensions: (L)86 mm *(W)86 mm *(H)43 mm(Excluding the tube)

Net weight: 320g



Packing List:

1*Headphone Amplifier

1*Power Supply

1*FU32 Tube



Noise may be resulted from:

1. Low-quality audio cables, poor audio source can cause the static noise.

2. The tubes not are plugged well on the tube sockets or the two red wires are not inserted to FU32 tube.

3. Devices like routers, mobile phones will also interfere in the audio signal and may cause static noise.

• Not only as a headphone amplifier, compatible with wide impedance range(12-200Ω), but also as a preamp for your other power amplifier, convenient and efficient to improve sound quality.
• 1*3.5 mm stereo jack input, can be connected to computer, CD, mobile phone and lossless player. 2*3.5 mm output can also be connected to digital amplifiers and active multimedia audio devices.
• Default Beijing FU32 vacuum tube, can be upgraded to GU-32/832; Default NE5532 op amp, can be upgraded to OPA2604, JRC4558, OPA2132, OP275 and so on for enjoying different tones.
• Mini size with attractive appearance, compact design makes it suitable for desktop audio system.
• Prompt and courteous customer service.1 year warranty and life technical support.