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First, I’d like to thank the folks at Bravo Audio for providing samples of the S1 and V3 to review.
Bravo Audio is no stranger to me. One of the first amplifier reviews I wrote on this site was of their V2 hybrid tube amplifier. It was my first tube amplifier and one that I liked for the time. It was inexpensive and scaled nicely with nicer tubes. The V3 was around back then, and always intrigued me, boasting a hardware EQ feature built in. The S1, however, is a new product and the first solid state desktop amplifier on offer from Bravo Audio.
Design and Build Quality
The Bravo Audio V3 and S1 share a similar and attractive (if you’re into that sort of thing) design aesthetic, with clear acrylic top and bottom plates and with fully exposed circuitry, capacitors, inputs, outputs and large black and silver MOSFETs. They’re not sleek and sophisticated in the same way the iFi iCAN is but they’re not without their charms.
Though the open air design is certainly eye catching, especially with the super bright LEDs, it loses points in terms of practicality. The S1 and V3 rely entirely on passive cooling for those exposed MOSFETs and they get extremely hot. and can easily burn you, so you have to be careful when touching the amp and especially when turning the amp off, since the power switch is located around back, between two of those MOSFETs.
But this, of course, isn’t a design flaw, rather a “feature” of Class A amplification. If it’s on, there’s always some current running through it which generates heat. But, for the record, I will say that the S1 and V3 get much, much hotter than any other Class A amplifiers I’ve used, like iFi’s iCAN amp.
The open design also makes the amps susceptible to EMI (electromagnetic interference) which can result in audible distortion finding its way into the signal path.
The S1 is identical in terms of overall build quality, featuring that distinctive open air design and exposed MOSFETs that get just as hot as those on the V3. So, once again, be careful of them. The biggest difference between the two is that the S1 only has a 3.5mm input, compared to the V3’s RCA and 3.5mm inputs. Both feature a 6.3mm headphone output and both come with gold-plated 3.5mm to 6.3mm adapters.
Sound Quality
S1
The solid-state S1 is a slight departure from the amplifier designs that Bravo Audio has become known for but there are more similarities than differences between this new amp and the V3 and V2 hybrid tube amplifiers I’ve heard. Like the tube rolling enthusiasts often do in the quest for that perfect sound, op-amp rolling is also a common practice in solid state amplifiers with socketed op-amps like the popular CMoy portable amplifiers. I had a couple of chips on hand from my op-amp rolling days and eventually settled on using an Analog Devices AD8620 chip on a Brown-Dog adapter for use in the S1.
The S1 comes with a Texas Instruments TL072 op amp preinstalled, a nice enough sounding chip in its own right and one that delivers a smooth sound with a hint of grain that was subtle enough to not be distracting on its own. All told, I found it to be a solid chip in the S1 but one that could be improved on.
Its sound is not the most transparent but is smooth and enjoyable with a pleasant warmth and good overall resolution. It doesn’t have the resolving capabilities of more expensive amplifiers but then again, especially when I take its price into consideration, I wouldn’t expect it to.
Due to the freely swappable socketed op-amp chip and hobbyist design, it almost seems like the S1 is a cMoy on steroids and in some ways, it is. But it’s a cleaner and much more powerful amp than any cMoy I’ve ever used.
V3
The V3 is Bravo Audio’s other tube amplifier, slotting in alongside their V1, V2 and Ocean amplifiers, but arguably the more exotic of Bravo Audio’s designs with its built in 3-band hardware equalizer.
The sound is, for the most part, warm and a tad thick. Tube amps aren’t known for window-like transparency, rather their warmth and richness and the V3’s sound is pretty much exactly what you’d expect. The sound with the stock tube is a bit grainy and edgy to my ears and I eventually upgraded to a higher end vintage GE tube which sounds more rich and involving. So, like the S1, the V3’s sound is customizable to some degree.
The most unique feature of the V3 is the built in three-band equalizer, the first I’ve ever seen on an amplifier, and a fairly well implemented one at that. Though I’m not a big user of EQ, I did find myself using it a bit more than I thought I would, adding a bit of bass to the HD 600 and a bit more midrange to the HE-400 at times. The effect isn’t quite as cleanly implemented as I’d like (and there’s no way to simply bypass it entirely unless you’re keen to break out the soldering iron and mod away) but it works well enough that I never found it to be a nuisance.
So the V3 is a solid little tube amp. It’s a great start for anyone looking to dabble in tube amps and playing around with various tubes and seeing what kind of sound they deliver.
Conclusion
All told, both the Bravo S1 and V3 are good little amplifiers for the money. Both offer more than enough power for most headphones and both can be upgraded for slightly better, cleaner sound with fairly inexpensive parts. I have some qualms about their open air designs, given their susceptibility to EMI and those extremely hot MOSFETs but those are fairly minor annoyances, all things considered.
The Bravo Audio S1 can be found for about $65 or so from a number of online retailers including Bravo Audio themselves and Parts-Express while the Bravo Audio V3 can be found for about $80 or so from a slightly wider range of retailers and at those prices, I’d say both are good deals, especially for someone looking to experiment with tube sound or op-amp rolling.
So the Bravo S1 and V3 are good, solid headphone amplifiers that, while rough around the edges (and hot to the touch), are good enough to get the job done on a budget. The warmth and richness of the V3 is a fine introduction to tube sound and the S1 is great for people who like to play around with their amplifiers.
