V2 Class A 12AU7 Tube Multi-Hybrid Headphone Amplifier

The V2 on it's own is outstanding, the sound is very colorful, smooth & rich. The better the cans, the better the sound as you would expect. I use a older set of Bose headphones for now. I will prolly upgrade to something better in time. They have served me well for years now their time is coming to an end, BUT..if you want it a more full stage as I wanted. I linked it up as a pre-amp to a Fiio A1 Amp, in turn powers Micca Club 3's which are my main monitor speakers for my computer sound system, I also have a set of old Sony 3" satellite monitors I re-fitted with RS75-4 3" Reference Full-Range Driver's from Dayton & a 10" Kicker Comp Sub pushed by a Lepai LP-168HA for it's sub output. The Fiio A1 amp sounds rather nice on it's own, but paired with this as a preamp music really shines...giving me the beautiful near field sound stage I was aiming for. I tried many different configurations but in the end, the set up I have now gives me what I was after. A headphones sound without the need for headphones. I honestly don't think it would sound as rich & pure without this as the preamp. I didn't feel the stock tube it comes with was giving me the sound I thought it should be, so I swapped it out for a JJ Electronics 12AU7 / ECC82 Preamp Tube. In doing so, after the tube burn in time, it has really come alive the way I was hoping it would. Classical guitar almost brings a tear to your eye as if it were being played in front of you. Simply amazing. Bass isn't overly punchy, just deep & solid. Mids are richly enhanced & the highs accurately sparkle. It's size/thickness is comparable to two iPod classics stacked on top of each other with the tube popping out of the top. RCA input is on the right side (Use the RCA input, it's sounds better as apposed to the----> ) & AUX 3.5mm input is in the front, center front is the volume dial (not an ON/OFF dial), to the left of that is the 1/4" headphone jack. The ON/Off Power switch & 12V 3.5A DC power plug-in are in the back. (I'm thinking on upping the juice output a bit by using a 12V 4.5A power supply although the supplied power brick seems to do just fine for now). Overall it's pretty straight forward. The "bells & whistles" are it's AMAZING sound quality & visual appeal, it's got serious "cool factor" going on with it's soft "Blue Purplish" glow that separates into blue & red... It's not too obnoxiously bright. A Blue LED under the Tube (that makes the tube glow blue) & a red LED behind that. The heat sinks stay pretty warm to the touch but it hasn't clipped due to an overheating issue. Although I haven't had a need to turn it ALL the way up either. 1/3rd to 1/2 way seems to be just fine paired with the Fiio A1 amp also turned up to 1/2 way for my listening needs. I almost got the step up version of this (BRAVO Audio V3 Tube Headphone Amplifier) which also has a physical EQ added to it. But I went for this one for it's size & simplistic nature. Music should sound good as it is. Besides how often these days do you come across a media source that doesn't have EQ settings of some sort?!

Few things can completely change the way you listen to music like a tube amplifier. Bravo Audio has created a small, yet powerful, and minimalistic headphone amplifier in the V2. Being an audiophile is considered a luxury hobby, with headphones easily reaching the 5 digit range, amplifiers going even higher, and the whole host of other "necessities" to be considered an audiophile being out of the price range of most average consumers, audophilia is left to the stupidly excessive. But what about those of us who love music with a passion and want to listen to music louder and crisper, but don't have an absurd amount of money to drop? In comes Bravo Audio V2 to the rescue! Sitting at a pretty price range of around $50, almost anyone with the slightest hint or desire to try out a tube amplifier should be looking towards the V2. It is small, easily fitting on my desk next to my laptop. It's open design is very modern, and while it was most likely done in an effort to alleviate overheating, looks very cool. The slight blue glow from the tube looks like something out of a sci-fi high tech movie, and people are stunned by it every time. Sound wise, it's simply outstanding. With more power running into your headphones, music comes alive. Instruments separate and you can hear different locations of instruments within the music. Bass is bigger, treble is cleaner, and the mids feather out the two much better to create an impressively more concise musical experience. While streaming music or playing MP3s is great, to really get every ounce of quality out of your amp, look to find and download lossless music. Specifically .flac I do not have a DAC just yet, but I still want the best quality I can get out of my laptop, so I use a 3.5mm to RCA input cable into the amp, which I feel fills out the sound much better than simply a 3.5mm to 3.5mm dual audio jack cable. There is a slight and constant hiss in the background, usually during pauses within the music, it completely disappears when nothing plays for a second or two, and is mostly inaudible during the music. I feel this is more of an issue with the sound card and signal transfer through that 3.5mm to RCA cable than it is as a result of the amplifier itself. Thus, I refuse to take away a star just yet, if I get the DAC and see that the hiss is still audible, then I might decide to drop it one star. Another very slight negative is the tube itself, it's cheap and so is the sound it produces. It's not terrible, and as I described earlier, it definitely does an amazing job of separating music and making it much cleaner, and for most will do just well. I expected the tube to not be the greatest from how low the price of the entire unit is. But if you just spent money on something as excessive as a tube amplifier just to listen to music, "just well" is not good enough. The tube amp is great, don't get me wrong, but when I switched the tube to the Genalex Gold Lion 12AU7 Tube, WOW! Simply eargasmtastic. Bottom Line: -------------------------------------- Don't have enough money for an amplifier that's more expensive? Buy this one and you definitely won't be disappointed!

This review is actually a simple comparison of 4 different Headphone Amps. First, I want to be clear that I am not an audiophile, not even close. I just like to listen to music, any kind of music that I feels right. So, this review just what I personally think about these products, nothing professional. Here are the 4 headphone amps (the DAC I am using is Logitech 980-000910 Bluetooth Audio Adapter, it will cost $21.98 from Amazon. And I know this is probably not the DAC you want to buy, you may want something recommend from z review or one of the most popular brand Fiio. But honestly, when I compare to those DACs under 100 USD, I just cannot tell the differenc. And the good thing about Logitech is they are Bluetooth and easy to re-pair to other devices. As I said before, I am not even close to Audiophile, that’s why I can’t tell the difference) 1. Fulla 2 by Schiit: $99 plus $10 shipping, total $109. I know this is a DAC/AMP, and I know this is a solid-state Amp. But if you buy any of the Tube amp listed below, you probably will buy a DAC to pair with it, after you purchase DAC, the price will be very close. And all the tube amps I compared here are not real tube amp, they are all hybrid. That’s why I also listed Fulla 2 here. 2. SMSL T2 2X6J9 Vacuum Tube Headphone Amp: $59.90 from Amazon (Total with DAC $81.88) 3. Nobsound NS-08E Vacuum Tube Integrated Amp: $50 from Amazon (Total with DAC $71.98) 4. Bravo Audio V2 Class A 12AU7 Tube Multi-Hybrid Headphone Amp: $66.98 from Amazon (Total with DAC $88.96) So now you know all the price, seems like all tube amps are cheaper. But…….if you bought tube amps, I am sure sooner or later you want to try tube rolling, please consider that’s also your cost on amps. That’s why I said the price of Fulla 2 is close to other tube amps. Price is the first thing I consider; the second thing is the power to drive headphones. I don’t have a lot of headphones and this review is not about headphones, so please don’t ask me any question about headphones. The headphones I am using here are Sennheiser HD600, HD6XX from Massdrop, Sony MDRV6, Sony MDR7506, Beyerdynamic Custom One Pro Plus, Audio Technica ATH-AD900X, Beyerdynamic DT 880 Premium 600 OHM, Beyerdynamic DT-990-Pro-250 OHM, Bose QuietComfort 35, Fostex TH-X00 from Massdrop, Skullcandy Hesh 2 Bluetooth, Philips SHP 9500S, and Monster NTune. NO, I don’t have Beats from Dre headphone. If you really want to know why, please GOOGLE. Some are cheap, some cost a bit more, some very easy to drive, some needs more power. Let’s say the volume knob is from 7 o’clock all the way up to 5 o’clock. This way will be easier for me to show you how every amp provides the power on the volume. Yes, I know the headphone amp drive headphone is not just about volume but also how well it controls. But again, I am not audiophile, so I don’t care about the tech issue and I don’t want to see a lot of numbers calculating here. All I care is how the music sound and how loud it can be. All 4 amps with DAC give you a good sound, but tube amps are a little bit warmer. You won’t tell the difference unless you compare them side by side. When using any headphone is under 250 OHM, you will love any of these 4 amps. They all do a good job. You won’t go wrong on any of it. So, money wise, just buy the cheapest one you can find. Any 300 OHM headphone or above, you need to start choosing. If you use 600 OHM, you can forget about #2: SMSL T2 2X6J9 Vacuum Tube Headphone Amp. You can cross it out from the list, and that’s what I did, I don’t even bother to roll the tube. On 300 OHM headphone, Fulla 2, Nobsound NS-08E, and Bravo Audio V2 all give you enough volume makes you headache if you turn the volume all the way up (your ears won’t bleed, not that loud), and I only need to turn the knob to 12 o’clock. But not SMSL T2, I need to turn all the way to 4 o’clock. On 600 OHM headphone, Fulla 2 and Nobsound need to turn to 2 o’clock to my normal listening volume, from 2 to 3 only gains a little bit, and from 3 to 5, it won’t gain any more (you can turn the knob and play back forward, nothing going to change). Bravo Audio V2 only need to turn to 1 o’clock to reach the same volume, and from 1 to 4, it only gains a little bit. And when you turn to 5 o’clock on Bravo, it did gain volume more, but it starts distortion, and I don’t like how the music sound like that. On SMSL T2, the volume is like someone whisper to your ear even you turn all the way to max, and you need to push earcup real tight to hear what they try to say, maybe good for training your listening skills and how sensitive you are to the sound, but not very good for listen to music. So, if you want to use 600 OHM headphones and you don’t want to spend a lot money to buy a High-end amp, then please choose Bravo. Now, I am going to talk about how much heat these amps will generate. Because I already cross out SMSL T2, so I only talk about the other 3. (If you really want to know, it’s the same as Nobsound) Fulla 2, you can put your hand on it or just grab it. You will only feel a little bit warmer than your hand. Nobsound, you can pretend it’s not hot and leave your hand on the case for a while and keep telling yourself it’s not hot, it’s not hot, it’s not hot……….. Bravo, you can put your hand on the glass part and do the same thing as Nobsound. But I dare you to touch the heat sink, it can fry eggs!!!!!! Why we talk about the heat here, it’s a safety issue. I don’t think you want to leave Bravo on when you go to work or any other reason that you need to leave your house for more than 3 hours, it’s kind of like you forget to turn off your stove when you left your house (a very tiny stove). That means you need to power on and off every time you use it and before you leave. This is not a problem to me, but you might want to know. Then the headphone jack, Fulla 2 and bravo are both 1/4", Nobsound using 3.5mm. Personally, I like the 1/4 better. Then the input, Nobsound only has 3.5mm audio input, Bravo has both 3.5mm and RCA input, I didn’t try to plug them with different sources and start the music at the same time, I just assumed that it cannot, but you are welcome to try it and let me know how it works. Fulla 2 has 3.5mm at front and USB input on the back. I like the Fulla 2 better here, I can just connect to computer and use it. Then the external power, both Nobsound and Bravo are using external power charger. Of course, you can carry a generator with you and make it portable. but I will just use it at home. Fulla 2 just use your computer USB to power it. But if you turn the volume over 3 o’clock, you will need external power. You can use either cellphone mini usb charger at home or battery bank when goes out. Then function, Nobsound and Bravo are headphone amps only, there is no other output. Fulla 2 can use as pre-amp, DAC, and headphone amp. I use Fulla 2 connect to JBL LSR310S then LSR 305 and it works great, and from different connection on Fulla 2, you can use headphone and speakers at the same time but control the sound from computer not the knob on Fulla 2. (By the way, when you plug in headphone to Fulla 2, it will mute the speakers. But Schiit Jotunheim won’t, you have to power off your speakers or unplug the speaker cables, that’s Schiit company try to force you do some workout, not just sitting there the whole day, thank you Schiit, Jotunheim is really a nice piece of Schiit.) On tube rolling, Nobsound need a pair matching tubes, and sometimes it will cause some problem if you didn’t buy them right. Bravo just need one. I can tell you that I tried a lot of different tubes on both tube amps and honestly, I don’t feel a lot difference between tubes. I think stock tube works fine on both tube amps. If you really want to try different tubes, then I suggest Amperex on Nobsound. For Bravo, I suggest Baldwin>Sctron>RCA. Again, I really don’t think you need to spend the money on tubes. These are not real tube amps, so the sound changing is not that much when roll tubes. But…….. again……, I am not an audiophile, not even close, so………what can I say. Finally, I can tell you what I choose, but that’s only me. I keep Fulla 2 and Bravo. One for portable (Fulla 2 with computer, not cellphone, and I usually carry a battery bank with me, so I can just use that as power supply for Fulla 2, or I just plug into computer. Cellphone I use Fiio E12), Bravo in my dining room, so I won’t forget to turn off the stove when finish eating. For the price these 2 asked for, you really won’t go wrong on any of it. Personally, I like Fulla 2 better, but I just can’t say no to this cute but powerful Bravo.

I've had the Bravo Audio V2 for only 3 days but I've found myself 'connected' to it most of the time that I am at home (no Netflix or Amazon Prime for the last 3 days!). The sound is great, I am impressed at the improvement I got for such a small investment. I am using an iPod touch connected using the Line-Out to RCA on the Bravo which is driving my 8 year old the Sennheiser HD590. As my Sennheiser HD590 are not as demanding as the newer HD600 (and above), with a rated Impedance of 120 ohms (Vs 300), I've always liked the sound straight out of my iPods and MacBookPro. Looking to see what is all the hype about headphone amps, and knowing my cans could handle a bit more power than an iPod I started looking. The idea of trying a hybrid amp was appealing to me as my musical taste goes from hard-rock to classical with jazz and blues to the mix and everything else in between including electronica. The Bravo V2 fitted the bill and at a price point I could experiment! The first thing I noticed was a fuller and more spacious sound and a beter soundstage. My cans gained new life! I also noticed that with the included tube (china-12au7) the sound was too bright (aggressive actually!). But It was no surprise as other reviewers claimed the same, so when i bought the Bravo I also bought 3 more tubes with it for experimentation: The Behringer 12AU7, the JJ Electronics 12AU7 and the Groove Tubes ST-12AU7 Preamp Tube Silver. It's really interesting to start rolling tubes and noticing the different nuances that they bring to the sound. First one I tried was the Behringer and the difference was staggering. The sound was now a lot smoother and more melodious. The vocal performances gained a new life without bringing the mids up overall. The aggressive treble was gone, but so was the bassy punch and although i really liked the Behringer, I usually prefer a darker sound and a bit more bass. The treble was also a bit too soft in some musical styles like hard-rock. After some more hours of listening to the Behringer, I swapped it with the JJ Electronics. The JJ enhanced the treble. It wasn't an issue anymore for Hard-rock! The bass was still smooth though (almost lacking) and now, the vocal performances were not as astonishing. One thing that i noticed too was the electronic interference from other devices (like my wireless router). I do not hear any interference at all with the other tubes... So on to the last tube: the Groove Tubes ST Silver. The bass is back! the sound is a bit more bright too, but not enough to cause fatigue even after multiple hours of listening to high volume music. Currently this is my default tube. It works very well with all musical styles although I feel it performs better for rock and electronica. (I need to do some more swapping, but my feeling is that the Behringer is my preference for classical and blues). Not knowing what to expect from this amp and knowing that it came with a vacuum valve I started with classical and blues which sounded really good and improved compared to just the iPod. But my biggest surprise was when I played Jambi from Tool. I could not believe my ears! The bass was immersive and the drums packed a punch all with a nice control to it. I kept listening amazed as I was moving to different bands (Foo Fighters, Evanescence, Rammstein, Muse, etc.). In sum, this amp has improved the sound on my Sennheiser HD590. To all musical styles too (although I may have to swap the tube for some :) ). I've also found that if you are willing to do some soldering, you can improve it even more with some simple mods. So far I don't feel that need, I may keep trying different tubes (maybe invest on a 1958 Mullard or Siemens and go vintage :) ) I am very pleased with it, specially for its cost! If you have a decent pair of cans and you want to go to the next level without breaking the bank (less than $75!), this is it. Look no more!

Overall: I've owned the Bravo Audio V2 since 2014 and it was my first headphone amp with a tube. I was happy at first, but didn't know any better. As of 2021 there are many other entry-level amps on the market. I barely recommend the V2, but only for those who tolerate danger and like to tinker. The Loxjie P20 ($99 in 2021) is a far better amp, has more features, is more neutral, and is more refined. Strengths: * This amp was early to the market and is therefore well established online. You can find plenty of info on its use, characteristics, tube options, and potential modifications. * It is ridiculously loud and powerful (but see negatives below). * The choice of tube does impact the tone. People new to tubes might learn about them at the lowest cost. For tube buyers, look at the shape and mass of the internal metal parts of the tube. The factory tube and other "short plate" 12AU7 tubes have little mass, tend to be brighter, and deliver less bass. "Long plate" 12AU7s have more mass, deliver more bass, and (IMO) produce a more balanced tone. Don't dwell on the brand for this cheap amp, as specimens vary and wear over time. One can easily find vintage 12AU7s for $10 to $20, and it will not benefit from more expensive tubes. Do not waste money on rare or exotic tubes for this guy. Negatives: * Electric shock hazard: The open build may look great, but beware of shocks and shorts. I shocked my hand several times, and almost killed a cell phone when it shorted (hand touch) while connected as the audio source. Any open build is a dangerous design. * Vulnerable to electrical interference. If you hear hissing, noise, or clicks move it away from your cell phone and other equipment before blaming the tube. A metal case would help, and perhaps a tin-foil hat too. ;-) * Light weight: This is a small device that can be accidentally pulled off a desk or shelf by the headphone cable. When using it regularly, I wrapped either the power or headphone cable around a post to prevent sudden moves. * Absurdly high gain (part 1): The volume knob is way too loud way too fast. When connected to an average notebook, tablet, or phone set at maximum volume, the useful range with Sennheiser HD600 headphones is from 7:00 o'clock to 11:00 o'clock. When connected to a standard 2 volt DAC, the useful range is from 7:00 o'clock to 9:00 o'clock. * Absurdly high gain (part 2): The volume during playback tends to suddenly jump from soft to loud passages. This follows from the high gain magnifying each and every variation. As such, this amp is always cartoonish, never nuanced, never refined. In sum, this amp taught me about the rough impact of tube design and how they can affect tone. It's an easy entry point, but I wouldn't personally buy it in 2021.

Okay, so this is my first headphone amp. I wouldn't call myself an audiophile, but an audio admirer. I just like cool stuff, and a tube headphone amp clearly falls in that category. I have been using the SHP9500 for the past couple of years, currently waiting for the HD6xx to come in december. Wanted a tube amp to power those badboys, so went ahead and bought this after doing tons of research. I've only been using this for 5 hours, so here is an initial impressions review. I will update later on. I was excited to try this out, curving my expectations (glad I did). I was expecting a little coloration. Not something to make everything sound sparkling clear, or to make it so that I could here the sound guy eating chips as a guitarist is playing through a guitar solo. No. I wanted something... more than what I had. Something to make the sound fuller. Not sure what to expect with this little guy. I know that I am happy though. The tube amp sparkles up the mids a little bit with a tiny TINY bit of tube distortion. It butters up the low end quite nicely. As of right now the highs can sound more distorted than I would like, but I am expected that to fade with some more break in. And it isn't noticeble on well mastered tracks. But if you are listening to low res audio from a bad youtube video, it can hurt. Listening to rush and classic rock through this baby is freaking amazing. It makes it more lively. The soundstage does increase ever so slightly. Oh, I have my SHP9500 running at great volumes at 9'o clock. Plenty of power to spare. Not worried about the HD6xx when the come in. On a very happy note, my bravo came with a Genalex Gold Lion Ecc82 tube. The tube was already installed and packaged nicely (either they changed what tube it came with or I am just lucky). This tube is highly rated as one of the better 12ax7 tubes out there. You can find them for 40 bucks on amazon. So holy crap, if you take out the 40 bucks, the headphone amp costed 26 dollars. AWESOME! can't wait for this thing to break in some more and to discover more music. The design is cool looking to me too. and it doesn't get crazy hot to me. Just don't be dumb and grab the heatsinks. Just watch where your hands are when messing with open electronics. TLDR; Smooths sound like butter, while giving tube distortion and liveliness. soundstage SLIGHTLY increases Plenty of power to drive demanding headphones. Comes with a gold lion ecc82 tube now? worth every penny for you audio lovers

Update: *Please see my original review for anyone who wants a review if you are willing to keep your cellphone away from the amp itself* I just can’t stand the constant buzzing that happens with this tube amp when other electronics are nearby to cause interference. I have this amp on my desk in my office setup.... with my computer, and it is just annoying that some things (mostly my cell phone and router?) are causing the amp to output a loud buzz to my headphones. This amp could be so good, but I can’t use it unless I remove every single electronic that is not my amp and headphones. How am I supposed to get music through the amp?! I am just super disappointed with this thing over the years. Changing my rating to a 1/5 because it is ultimately unusable for me. Good luck! Original: Decent amp for the price. I would definitely recommend upgrading the tube from the stock original. It powers my Beyerdynamic DT 990 PRO (250 Ohm) headphones pretty well. I have it connected to a cheap, Fosi Audio DAC-Q5. Some advice if you own this amp or plan on buying one (I wish I knew about this a long time ago....): make sure it is 5+ feet away from any router, cellphone, etc. You will get a very annoying white noise, humming, buzzing, static, etc. from the signals they give off. Only other complaints I have are that it gets pretty hot after being on for a bit. I also am not a fan of the RCA cables needing to be put in the side of the amp instead of the back.

The good news is that out of the box the V2 worked and drove my low impedance SONY MDR7506MDR and Grado SR125 as well as my high impedance Sennheiser HD580 and HD600. It has more than enough volume with all head phones. The mid and high frequencies are harsh using the supplied 24 Volt switching supply. This supply went dead after about a week but it was too much trouble to return it. I built a regulated 24 Volt linear supply and this cleaned up the V2’s harshness. Low frequency response is good but a little muddy in the low to mid–bass region. The heat sinks, especially those on the MosFet’s run very hot – too hot to keep your finger on for more than a second so be careful of this one. The bad news is that out of the box I think the V2 isn’t ready for prime time but if you are an electronics experimenter, have some decent test equipment and have experience modifying equipment the V2 is a great little platform to work on. With some minor component additions/changes, trace cutting/wire re-routing and sheet metal work on the heat sinks the V2 can be literally transformed into a very sweet sounding head phone amplifier worthy of the description “Audiophile Quality”. Brief Technical Description The V2 is a two stage “hybrid” design. Stage one is a 12AU7 dual triode tube with ½ of the tube used for each channel. The 12AU7 is set up to up to run in grounded cathode mode with a grid resistor used to bias into Class A operation. Gain of this stage is about 10. The tube is run in what is called “starvation mode” because of the low 24 Volt supply. Normal supply operation would be in access of 100 Volts. Bravo chose a 24 Volt supply most likely because of the low cost, easy availability and elimination of the liability of using a high voltage. Unfortunately 12AU7 tube manufacturers data sheets are not very helpful for this low voltage operation so Bravo must have done a lot of their own tube characterization before going with the 12AU7. Actually their choice of the 12AU7 compared to other tubes commonly used in high performance audio amplifiers of this type was a good one for a number of reasons I won’t go into here for brevity. The plate of the 12AU7 is DC coupled to the Gate of the MosFet output driver stage. The Mosfet is set up as a Source follower with a gain of just under one. The Mosfets operate Class A with around 160 mA of Source current – the reason the undersized heat sinks get so hot. The Source is then coupled to the output through a 1,000 uFd capacitor. The largest problem with the V2 design is the DC coupling between stages. Any variation in tube DC currents or voltages directly affects the MosFet operating point and tube filament voltage. This is true because there is an LM317 in the Source circuit which along with Gate voltage sets the Source current and filament voltage level. So any variation in tube characteristics or operating point directly affects the MosFet and any change in MosFet operating point directly affects tube operation. So “tube rollers” proceed with caution since changing tube types is not straight forward at all. Even dropping in another 12AU7 can have a negative impact on all DC operating points and sound quality. I spent a lot of lab time getting the V2 circuit to work well and got a good education on tube “starvation mode” in the process. Changing interstage DC coupling to capacitor coupling enabled me to optimize the operating point of each stage with no interaction. This modification along with other changes transformed the V2 into a very credible little head phone driver. I’m very happy with the end result. As I said earlier, the Bravo Audio V2 is a great little platform on which to build a very nice sounding head phone amplifier.