ALO Audio Continental V5 Portable Tube Amp Review

ALO Audio is an Oregon-based audio company who have quietly taken over the audiophile scene with their portable headphone amplifiers, interconnects and cables. Also a redistributor of notable headphones from Audeze, Sennheiser, and Beyerdynamic, they are no strangers to the music scene. With their workshop situated in Portland, the team claim to be music fans first and craftsmen second. As such, there is a heavy emphasis placed on personal audio with each of ALO’s products breaking the boundaries of the subjective listening experience.

ALO has a wonderful boutique collection of portable amplifiers, and I was fortunate enough to try out their recent release: The Continental V5. Coming in at $799, the V5 represents another well-regarded collaboration between renowned engineer Vinnie Rossie of Red Wine Audio and ALO Audio. Unlike the transportable Continental Dual Mono, the Continental V5 is a more portable offering with a single dual triode amp which runs in stereo. Like its older brother, however, the V5 offers a tube-rolling experience combined with hybrid technology which exploits the best of the vacuum tube and solid state hybrid worlds.

Packaging

The V5 appears in a sleek and low-profile black box with a slide out featuring a picture of the amp covering it. Once this slide-out insert is removed, the ALO Audio inner box can be removed by pulling a green ribbon to reveal the V5 amp resting into a foam cut-out below. Accompanying accessories include a carrying pouch, charger, USB adapter, elastic cables and a manual. One thing that was removed from the original Continental Dual Mono’s accessory line-up was the Green Line cable (worth $150 of its own). This would have been a nice touch to add, however,  ALO audio has decided to make this amp more affordable.

Design

Much like many of ALO’s creation, the Continental V5 is visually stunning with its CNC machined aluminum enclosure which comes in a solid black or silver color. ALO has done well to avoid the gorilla glass window, which although looked fantastic on the previous Continental dual mono amp, would have looked awkward with this single triode amp topology. Also featured are machined ventilated holes which despite looking industrial, promise to keep the temperature of the device to a minimum. Overall, I am extremely impressed with this company’s design language throughout its amp use. It is clean and retro-looking, yet incredibly sturdy and premium to the touch – a job well-done.

Build & Features

Dimensionally, the ALO Continental V5 is a relatively small device with a 92mm x 59mm x 20mm size. This coupled with its modest weight enables listeners to use this as a portable device with room for stackability.

Front

The front panel of the ALO Continental houses the 3.5 mm stereo headphone output on the far right. Next to this, is the well-machined gain switch which features high and low settings. The line-out is immediately next to this and the potentiometer is finally on the far left of the device. The potentiometer has moderate levels of grip and is more aesthetically pleasing than the original Rx’s indented design.

Back

On the rear end of the Continental Dual mono, there is a single micro USB charging port. Much welcomed is the ability to charge this device from the wall or your laptop device which the previous Continental Dual Mono amp was not able to do. The form factor for charging the V5 is also less heavy than the CDM which is another beneficial advantage where portability is concerned. 

Internals & Power Supply

Behind the aluminum chassis of the ALO Continental V5, is a hybrid design which features a Class A input stage with a dual triode 300ma JAN Philips 6111 NOS (new old stock) fed into a SS Class AB design output stage.

The Continental V5 receives a clean 16V power supply (+/- 8 V) and projects 325 mW per channel which is said to be more powerful than the Continental Dual Mono in both balanced and unbalanced modes. This, coupled, with the low noise floor makes it a stellar companion for both portable and serious high-end headphones alike.  

Owing to the single tube use, the amp runs relatively cool compared to the CDM. Battery life also extends as a result of this with a decent 8 – 9 hour playback time.

Blue LED

The V5 has a built-in temporary muted-output during turn-on (20 seconds) during which a blue LED will light up. The purpose behind this was to get the tubes working at thermal equilibrium to get the best sound (although in practice, sound did get even better following an hour use). Once the 20 seconds are up, the blue LED turns off and the user is able to use the V5 as instructed.

Sound quality

Tonality (w/ Stock 6111 tubes)
On first impressions, the Continental V5 runs with a quiet background with no channel imbalances at low or moderate volumes. Noise does increase slightly with sensitive IEMs, however, this is not intolerable. With larger headphones and less sensitive IEMS, the background noise floor is remarkably clean despite the amp’s large output power.

The sound signature of the Continental V5 can best be described as neutral with some added harmonic distortions from the tube design. The result is a smooth yet fast sound which really does get the best out of the hybrid technology. The V5 is not a typical tube amplifier which presents a compellingly rich and euphonic signature. Instead, the sound is more orientated towards the solid-state sound with some of the added smoothness and richness of the stock 6111 tube.

Low-frequency notes sound well-balanced, extend low and have a good sense of linearity. Compared to the PlusSound Cloud Nine amp, the Continental V5 has a more decisive bottom-end performance which is tactile, smooth and retains quite a bit of detail. However, compared to the Continental Dual Mono, the V5 loses out on a bit of detail with less sub-bass presence. Overall, the bass notes are well-done and capture a good sense of decay without ever being bloated or woolly.

Midrange frequencies are excellent with the Continental V5. Again, the hybrid nature of the amp really works well to define mids which are not only well-spaced and layered but also present with a good amount of detail and richness. Though not as rich and tube-sounding as the Continental Dual Mono, the V5 is a sound which is more of a mix between ALO’s CDM and RX amp. The soundstage is not the best. But, for the price, it is simply great. A perhaps unfair comparison to the desktop Schiit Mjolnir 2 sees that the latter renders a more holographic and 3D presentation of sound while the former delivers a more linear albeit spacious presentation of sound. In terms of harshness, the CDM does well to tame sibilance and is never grainy sounding; qualities of a well-designed amp set-up.

Higher frequencies sound slightly cleaner than ALO’s Continental Dual Mono owing to a more forward treble section. This is perhaps the most noticeable difference between the CDM and the V5, where the latter has adopted a more solid-state sound and the former, a more tube laid back presentation. With the V5, ALO Audio have captured a good timbre as tracks do not sound artificially bright or unnaturally subdued but maintain a lively and engaging sound.

Pairings

HE1000 V2
The Continental V5 and HiFiMAN’s HE1000 V2 pair incredibly well. I was surprised to see how the little device could sustain the amount of power it does to drive the HE1000s to levels that the CDM never could.

The overall sound signature benefits from a lively and engaging midsection which sounds rich and fast. The slightly forward treble also increases the fast sense of space as well as the clarity that the HE1000 benefits from. All the while, a dead black background is presented in avoidance of low noise floors and other distortions.

Campfire Audio Vega
Unlike full-sized headphone set-ups, there is some hiss to contend with. Although this is not immediately distracting when tracks are playing, this combination is another well-done pairing with the Continental V5s. The overall sound signature becomes more spacious with an engagingly fast and smooth mid-section and evened out the bass. Compared to the DAC/Amp of the Q1PR, however, the V5 falls short in extreme details but does well to contend with other amps within its price range.

Tube-rolling
Another way to enhance the sound is the ability to tube-roll. The V5s, like the CDM, were made for this kind of customization where users have the ability to roll in different tubes after purchasing them on ALO’s store front or other tube suppliers. The instructions for doing so can be found on ALO’s Head-Fi thread. However, the company could have released an instructional video like the Continental Dual Mono so that users do not get confused. The manual should also have highlighted how to roll tubes which would have allowed better accessibility to this feature for the general user. In terms of tube selection, ALO Audio is recommending a 400ma Raytheon 6832 tube as a solid upgrade to the 6111 Philips stock tube.

Comparisons

In comparison to the PlusSound Cloud Nine amp, the Continental V5 has better levels of detailing, separation and midsection presence. While the Cloud Nine has good levels of detail, the softened upper midrange and lower treble frequencies fall short of the more engaging and decisive Continental V5. Like the CDM, the V5 has better immersion than PlusSound’s mid-fi offering.

Compared to the Schiit Mjolnir 2, the Continental V5 has a more linear sound with less sub-bass presence. Although the former is a desktop amp, the V5 does well to compete in driving hi-end devices. With that said, however, the holographic and sonic projection of sound in width AND depth allow the former to be a bit more immersive. The Continental V5 also has great tonality with an engaging midsection and treble. 

Conclusion

Overall, ALO’s Continental V5 represents an extremely well-performing device with the ability to complement and even replace some hi-end desktop set-ups. It is detailed and fast with good richness in the midsection resulting in a lively and engaging sound presentation. Vinnie of Red Wine Audio set out to create a smaller device with more power, cooler running, better portability and a more defined battery charging status than the CDM. On that front, the Continental V5 has certainly succeeded and redefines a new slice of the market for those looking for hi-end quality for a fraction of the price of the original Continental Dual Mono. With that said, $799 is not the cheapest price for portable amps but ALO audio certainly promises outstanding build quality with a sound to match. The beautifully defined aluminum edges, well-designed topology, and quality potentiometer all contribute to the premium feel and inherent durability than the V5 offers. Do I think this is consequently worthy of a place in any audiophile’s inventory? Most certainly.

Unless otherwise indicated, this is a preview article for the featured product. A formal review may or may not follow in the future.