Review: oBravo Ra C Cu – Top of the line

It’s brother, the CL Trio is tube powered and it makes the Ra C Cu sound more like the Solaris, though it’s not as smooth. It’s somewhere between the Duet and the Solaris, and that means it’s an excellent clear sounding combo as well. Great bass, with good speed, tightness and layering. Rich, smoother mids with good spaciousness and energetic, clear treble. Another good setup.

Another CL amp I keep going back to is the little Picollo: it’s musical, warmer sounding and it has a smoother delivery. The end result is a sound between that of the faster Duet and the more romantic Trio. It’s a little warmer and darker sounding nut not too much, though it doesn’t have the clarity of the previous described CL amps.  It’s like a little Duet with a softer character of the Trio, but the Ra C Cu really loves it. This brand seems to be made for the oBravo C Cu.

It probably won’t be easy to buy one of these units but as they sound so good with the Ra C Cu, I just had to mention them in this report. I’m sure you can still find them on the 2nd hand market.

The battery powered PlusSound Cloud Nine is old as well but when we reviewed it we said it could do everything. This one is still being sold though, and the Ra combo also sounds excellent. You get a warmer, smoother, romantic sound but it retains good clarity and precision. The sound stage is wider than it is deep however and you don’t get that immersive sound feeling you get from the Solaris and V281. But then again, you don’t get that from the CypherLabs amps either. The sound is more in your head and it’s less spacious with shorter decay. It’s still excellent sounding though with good detail, clarity and prat. Also recommended.

oBravo Ra C Cu

oBravo Ra C Cu

Seeing all my fav portable amps up to now were doing it, I expected the Meier Audio Quickstep to do the exact same. It’s also 9V powered like the CloudNine is but it has a much more neutral presentation. The mids and treble here are very good but the bass is behaving a bit particular, for some reason it’s a bit bigger in body and not the tightest, and it doesn’t really match with the neutrally presented mids and treble. So this combo isn’t as good as the other ones for. It would have been nice but the bass really doesn’t sound as it should. It’s still very acceptable but once you’ve heard how it can sound…

DAC/AMP Combos

For this category I chose the Chord electronics Mojo and Hugo 2, as they probably the world’s most popular ones. Then there’s the RHA L1 as it’s really powerful and finally we have the DragonFly Red.

With the Chord Mojo, the Ra sounds pretty good though there’s a focus on the upper mids and treble section. You get a very nice, balanced sound with lighter, yet tight and fast bass. The mids are very clean and dynamic and treble is rich and energetic. It isn’t the most spacious and layered Ra C Cu and the sound stage isn’t the widest or deepest, but it shows the typical Mojo characteristics. It’s a pretty nice combo, but not the best.

With its big brother the Hugo 2, you get a fuller sounding Ra and with the right filter and cross feed you get a really good sounding Ra, with better layering, a deeper and wider sound stage and more emotion. Bass has more impact, the mids sound more natural and treble is more energetic, detailed and extended. A really nice combo, but not as smooth, rich are wowing than the V281 or Solaris.

The RHA DACAMP L1 also does a really nice job with the oBravo. It’s a very powerful unit and it seems to like the Ra C Cu. Full bodied bass and mids, very dynamic sound. Bass has good impact, mids are rich and natural and treble extended and crispy. I in general find the L1 to make a lot of gear sound too aggressive but the power hungry Ra, just loves it. It’s a really nice combo, comparable to the Hugo 2 level, but just below.

The super popular AudioQuest DragonFly RED isn’t the ideal source for the Ra. That aggressive effect I mentioned with the L1 is present here and it just doesn’t make listening to the Ra really enjoyable.


For the DAPs, I selected three TOTL units: the SP1000, the WM1Z and the L6. Next to those I selected four really popular DAPs: the X7ii, the N5ii, the DX150 and the R3. Like I mentioned before, the Ra C Cu doesn’t really perform well when driven directly from a DAP, though there are some surprises.

The Astell&Kern SP1000 is my favorite DAP when it comes to BA drivers but with this oBravo it in single ended mode simply doesn’t sound good at all. Bass sounds underpowered and bloated, mids are ok but the treble is really soft as well. If you know how the Ra can and should sound, then you’ll be disappointed with this setup. In balanced configuration bass is a lot more how it should be but it’s still not good enough for my ears. The mids and treble section however are pretty amusing but you just feel something is missing. It’s not bad but Ra C Cu is capable of more.

The iBasso DX150 only arrived last week so it’s still getting warmed up. I have to say the iBasso sound in general is quite nice but I’m not a fan of the UI at all. The DX150 has daily hung up on me and it’s so slow. The combo in single ended mode with the Ra isn’t to write home about either with a muffled flat sound without any treble and flat loose bass. Sorry but it’s not good at all. In balanced mode you get a better balanced and more energetic sound where bass is more in control and where treble is pleasing, the mids are a bit more behind however. It’s an acceptable quality but I again long for an amp.

The L6 is the TOTL DAP from Luxury&Precision. We’re always raving about its sound quality so my hopes were high and I was very pleased to hear a quite excellent Ra C Cu in Single Ended mode. The only thing I want more here is some extra treble to keep it more exciting, but the bass and mid-section actually is pretty nice. In balanced mode the Ra comes alive however and you get a more balanced sound where treble plays a better role. Good bass, excellent layering, rich deep mids and extended treble. It’s an excellent combo, but it’s not at the same level as when externally amped.

The Fiio X7ii in balanced mode really sounds good with the oBravo and that pleasantly surprised me. Great clarity, tight bass, rich mids, good speed, nice decay, sweet sound stage. Really, an excellent combo if you ask me. And one of the few that really makes Ra sound really good. In SE mode you get a slower and smoother sound but it’s a very pleasing one as well. It’s missing something in the mids and the vocals aren’t as natural but it’s acceptable. The balanced output is the one to go for here.

The Cayin N5ii in balanced config doesn’t sound quite as good as the Fiio and it’s not the first time we say that, then again there’s quite a price difference between them as well. Taking into account the level of the N5ii, Ra sound pleasing, balanced, very clear and energetic. My ears are happy. The really good news is that it even in SE mode also sounds darn good, just not as refined as in balanced mode, but certainly good. Nice!

With the Sony WM1Z, the Ra C Cu in Single Ended mode sounds darker but very rich in detail. The bass however is on the lighter side while the treble is more present. That however changes when switching to the balanced output, and you get a more coherent sound with a high level of detail and good depth. It’s still on the darker side but layering is excellent and the musicality factor is very high. This can be an excellent pairing depending on what it is you like.

On the LAST PAGE you’ll find even more combos, a comparison and the conclusion

3.8/5 - (44 votes)

Lieven is living in Europe and he's the leader of the gang. He's running Headfonia as a side project next to his full time day job in Digital Marketing & Consultancy. He's a big fan of tube amps and custom inear monitors and has published hundreds of product reviews over the years.


  • Reply May 16, 2018

    Dave Hutchinson

    I guess a couple of good comparisons might have been the Audeze LCD-i4 or the Shure KSE-1500?
    Of course, they aren’t the same price but they are TOTL IEMs and with the law of diminishing returns it would be a very interesting comparison.

  • Reply June 18, 2018

    Guy Lamaar

    If you look at the price delta between the Ra-C-Cu and the “standard” Ra-C, that’s some pretty expensive copper. I think I’ll wait until oBravo release the -Pt or -Au variants; hopefully, they’ll be priced a little more realistically …

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