The main comparisons I will be making are between the Hagerman Tuba Amplifier and Feliks Echo, which is pretty much the most direct competitor from the whole world. I will also add Aune S6 PRO, given the price points of both, and also Chord Mojo, which comes pretty close in terms of pricing, being about 500 USD on amazon, with another over 100 USD to pay for shipping to Romania, which ends up costing almost the same as Tuba.
Hagerman Tuba vs Feliks Echo (650 USD vs 500 USD) – Echo has more functionality, and it also has better overall aesthetics, but also a heavier build that takes more space than Tuba. The volume wheel is better on Echo, and it feels like it was built with more attention to details, But Tuba makes up for the slightly less interesting build by having an even sweeter, more colorful, vivid and punchy sound. Indeed, this is especially when using it from the Low Gain output, which sounds cleaner, but it really sounds more controlled and cleaner, especially if you have a headphone that matches well with a more analogue-sounding amplifier.
Hagerman Tuba vs Aune S6 PRO (650 USD vs 650 USD) – S6 Pro has far more functionality and serves considerably more purpose, because it has a DAC inside too, but the sound is very digital in direct comparison to the Tuba, S6 PRO has a pretty edgy, digital-ish sounding treble, with some glare, where Tuba has a far more convincing soundstage, cleaner overall sound, it also has a more musical, analogue-like presentation. The driving power is also considerably higher from Tuba, and although it doesn’t have an XLR output, it will do just fine for hard-to-drive headphones be it planars or high-impedance dynamics, where S6 PRO will work much better than Tuba for IEMs and low-impedance headphones.
Hagerman Tuba vs Chord Mojo (650 USD vs 500 USD) – Mojo is a unique case, where it is a portable DAC/AMP, and I’m mainly adding it to the comparison list because the price is quite close to that of the Tuba, especially when you factor in taxes and shipping. The first thing I noticed about the devices was that Mojo has no noise, like Tuba, but despite it having a slightly soft and liquid sound, Tuba comes off as considerably sweeter, more colorful, wider, and quite a bit more punchy with hard-to drive headphones. Mojo is more serious, and has a less playful tone, but a more controlled sound with IEMs and easy to drive, low impedance headphones.
You should keep in mind that the Tuba is mainly designed to work well with very high impedance headphones, and it was not designed to sound good with low impedance cans. This means that it is most probably going to sound distorted and have a pretty odd overall sound if paired with something that is less than ideal, and I seriously recommend using it more with Headphones rather than IEMs. Best pairing has been with high impedance cans like Beyerdynamic Amiron, Sennheiser HD660S and HIFIMAN Arya, for example. The main DACs I have been using throughout the review are Aune S6 PRO, Chord Mojo, Mytek Brooklyn DAC+, M2Tech Young MK III, Topping E30, and even Pro-Ject Pre Box S2 Digital. All of them work really well as DACs, and Tuba prefers a natural sounding DAC, and the more detailed the DAC, the better the entire sound is. The main pairings I have experimented a lot with have been the one with Grado SR80e, Sennheiser HD660S, and Beyerdynamic Amiron.
Pro-Ject S2 Pre Box Digital + Hagerman Tuba + Grado SR80e (420 USD + 650 USD + 100 USD) – Grado SR 80 e has a slightly strong treble, but Tuba actually helps with that, as it has a softer presentation, with excellent overall dynamic. This works well with SR 80e, and although I mention a slight hum in the background, with SR80e it is not audible at normal listening levels, of ~60-70 dB, and even though they have a very low impedance, compared to most of the headphones I tried the Tuba with, they still sound excellen. The soundstage has a nice width and a holographic presentation.
Mytek Brooklyn DAC+ + Hagerman Tuba + Beyerdynamic Amiron (2000 USD + 650 USD + 700 USD) – Tuba has enough driving power for it, and since Amiron was quite hard to drive, this is a huge compliment for Tuba. The sound is actually nice, because both the Brooklyn DAC+ and the Tuba are natural-sounding, and they make Amiron much more musical, and given their already good technical performance, Amiran sounds really clean and crisp out of the Tuba.
M2Tech Young MK III + Hagerman Tuba + Sennheiser HD 660 S (1600 USD + 650 USD + 500 USD) – Hd 660S always has been a bit too narrow in the stage, and a wide-sounding pairing like the Young MK III and Tuba makes it much wider, and more holographic. The treble is also fairly well-extended, and especially if you’re a fan of crispy sounds, you’ll love this one pairing.
Value and Conclusion
The value of the Tuba is not as good as that of Feliks Echo, as Tuba lacks some essential features, like having a line out, to be used as a preamplifier for a large speaker setup, but it has good build quality, when paired with the right cans, it does an outstanding job, and it has a good amount of clarity, punch, and although it only uses two very common tubes, it manages to sound really good. The value is fair, and I am looking forward to more interesting Amplifiers that have more features, but sometimes having one that does one job, but which does that job really well, can be good enough.
The build is great, although the volume wheel is a bit wiggly, and there is no preamp output, it does the one thing it is made to do, really well. That is being a headphone amplifier, especially not an OTL one as it has output transoformers, which is how it manages to have 5 OHMs of output impedance. It is made to drive hard-to-drive or high-impedance headphones, and for that role, Tuba is pretty darn great. Not for IEMs, but for the full size and full package experience.
The sound is sweet, musical, analogue-like, and has good extension both in the treble, and in the bass, is dynamic, vivid and colorful, without ever being aggressive. You may actually say that it lacks some of the edge that the solid state counterparts have, but to its defense, it has such a beautiful overall presentation, you may be inclined to pardon the detriments in the technical area, when you start it and start enjoying it.
At the end of this review, if you’re looking for a high-quality Headphone Amplifier, with a slightly soft, but sweet sound, which can drive hard-to-drive and high-impedance cans, Hagerman Tuba should make a great companion, especially if you always felt like Analogue sounded better than Digital, and if you want to hear some of that romantic sound of the past in the present.
You can always get the Tuba Amplifier from here: https://hagerman-audio-labs.myshopify.com/products/tuba-vacuum-tube-headphone-amplifier
Full Playlist used for this review
While we listened to considerably more songs than those named in this playlist, those are excellent for identifying certain aspects of the sound, like PRaT, Texturization, Detail, Resolution, Dynamics, Impact, and overall tonality. We recommend trying most of the songs from this playlist, especially if you’re searching for new most, most of them being rather catchy.
Bats – Gamma Ray Burst: Second Date
Eskimo Callboy – Frances
Incubus – Summer Romance
Electric Six – Dager! High Voltage
Kishida Cult – High School Of The Dead
Dimmu Borgir – Dimmu Borgir
Breaking Benjamin – I Will Not Bow
Thousand Foot Krutch – The Flame In All Of Us
Gorillaz – Feel Good Inc.
Infected Mushroom – Song Pong
Attack Attack – Kissed A Girl
Doctor P – Bulletproof
Maximum The Hormone – Rock n Roll Chainsaw
Rob Zombie – Werewolf, Baby!
Escape The Fate – Gorgeous Nightmare
SOAD – Chop Suey
Ken Ashcorp – Absolute Territory
Machinae Supremacy – Need For Steve
Ozzy Osbourne – I Don’t Wanna Stop
Crow’sclaw – Loudness War
Eminem – Rap God
Stromae – Humain À L’eau
Sonata Arctica – My Selene
Justin Timberlake – Sexy Back
Metallica – Fuel
Veil Of Maya – Unbreakable
Masa Works – Golden Japang
REOL – Luvoratorrrrry
Dope – Addiction
Korn – Word Up!
Papa Roach – … To be Loved
Fever The Ghost – Source
Fall Out Boy – Immortals
Green Day – Know The Enemy
Mindless Self Indulgence – London Bridge
A static Lullaby – Toxic
Royal Republic – Addictive
Astronautalis – The River, The Woods
We Came As Romans – My Love
Skillet – What I Believe
Man With A Mission – Smells Like Teen Spirit
Yasuda Rei – Mirror
Mojo Juju – Must Be Desire
Falling Up – Falling In Love
Manafest – Retro Love
Rodrigo Y Grabriela – Paris
Zomboy – Lights Out
Muse – Resistance
T.A.T.U & Rammstein – Mosaku
Grey Daze – Anything, Anything
Katy Perry – Who Am I Living For
Maroon 5 – Lucky Strike
Machinae Supremacy – Killer Instinct
Pendulum – Propane Nightmares
Sirenia – Lithium And A Lover
Saving Abel – Addicted
Hollywood Undead – Levitate
The Offspring – Special Delivery
Escape The Fate – Smooth
Samsara Blues Experiment – One With The Universe
Dope – Rebel Yell
Crazy Town – Butterfly
Silverstein – My Heroine
Memphis May Fire – Not Over Yet