Tuba - Vacuum Tube Headphone Amplifier
The Tuba is a world-class vacuum tube headphone amplifier designed to operate with either low impedance (Grado) or high impedance (Sennheiser) headphones. The power stage is a single-ended, zero-feedback, parafeed EL84 triode into an impedance matching transformer, offering very low distortion and huge signal headroom. An internal switching power supply creates a stable high voltage for tubes after a 30 second warm up delay. The amplifier is conveniently turned on and off by pressing the volume knob inwards. Sonics are warm, organic, punchy, and extremely non-fatiguing. Fantastic with IEMs.
- 50k ohm input impedance
- 5/35 ohm output impedance (LO/HI)
- 10Hz to 150kHz bandwidth (-3dB)
- 350mW output power @ 32 ohms
- 7Vrms output voltage (HI)
- 6dB gain (HI)
- 3.5Vrms input sensitivity
- 0.25% distortion @ 0dBV 400Hz
- EL84 x 2
- 6 x 10 x 3.5 inches
- 7 pounds
- 15Vdc @ 1.35A
- 120V/240V operation
- Includes power supply & tubes
Scope photos show plate voltage on tube swings 170Vpp before onset of soft-clipping; square wave output at 10kHz into 33 ohms.
- George Dobrescu, Audiophile-Heaven
- Herb Reichert, Stereophile
- MI, head-fi.org
- Matty, Headfonia
- Bob Levi, Positive Feedback
- Trav Wilson, Headphonesty
- AA, headphones.com
- "The Tuba-Grado combination generated a tidy, naturally detailed, highly musical sound that I found 100% enjoyable. Midrange tone was exemplary." - Herb Reichert
- "Tuba rewards the listener with a rich, luxurious tone but will still happily go toe-to-toe with all but the most high-end of amplifiers in terms of resolution and musical insight." - Matty
- "I utilized 14 pairs of headphones with the Tuba, and not one misbehaved ... My Audeze LCD-X and LCD24 headphones, which were way too revealing for an amp like this — so I thought — were absolutely lovely ... The Tuba is way better than its price tag would indicate, built by a master designer, and tweaked to over-perform ... The overall performance was consistently excellent with strong colorful imaging and distortion-free power." - Bob Levi
- "As expected, the Tuba is a very well-mannered and non-fatiguing amp to listen to ... Throughout my time with the Tuba, I found it to be very laid back and non-aggressive. It’s an easy amp to like and to listen to for extended periods ... Sure enough, the Tuba sounds great with very sensitive in-ear monitors (IEMs) like the KZ ZS10 Pro. It has a very low noise floor and doesn’t add any unwanted hiss to playback, something I can’t say about most of the other desktop amps that I use ... I can happily report that the Grado SR325 has never sounded better with any other amplifier I’ve tried. The laid-back sound of the amp paired with the brighter Grado signature is a terrific combo. It made me remember why I fell in love with the Grado house sound the first time ... The Tuba is a unique product. It really doesn’t remind me of anything else currently available. The combination of tube warmth, polite sound, highly-efficient headphone compatibility, and crossfeed will make it ideal for some, but not for all. It certainly brings something different to the table for someone who currently owns an OTL tube amplifier." - Trav Wilson
- "It really is an amazing amp. Totally unlike any amps I’ve used. It’s very quickly become the one I reach for most."
- "The Tuba and the Stellia is an amazing pairing. The Stellia sounds wider and warmer, while still being very detailed. I would absolutely recommend the Tuba if you have the Stellia. I swapped tubes and had it on low gain."
- "I have listened to it all weekend. Compared to what I currently use there is a very clear improvement, which I would summarize as a feeling of purity in the sound (transparency, no noise, and absence of distortions). It is extremely pleasant, detailed but non aggressive (as it should be). I am really impressed."
- "I just wanted to let you know my TUBA arrived safe and sound this morning. Even out of the box it sounds wonderful. It's accurate, musical and overall very pleasing. I can't wait for it to fully break in and see what time will reveal."
- "I truly would like to convey full gratitude to the work you have put forth to make a piece of art. The Tuba has surpassed my expectations. I have found several tubes that fit my subjective tastes and I thank you. This has paired amazingly with my ZMF Verite Closed LTD in Leopardwood being sourced with an iFi iDSD Micro BL."
- "I recently received my Tuba headphone amp. I must say - so far I'm really impressed. I feel like my hifiman headphones have really come to life. I'm thoroughly happy with my purchase."
- "The Tuba arrived today and it was packed extremely well ... not a single blemish on the unit. I did a few hours of listening and this has brought my HD650 back to life ... like a perfect match. Now I am going to let these tubes burn in a tad longer. So far, listening to the HD650 on the Tuba has been an awesome experience. Thank you again for the awesome product and great customer service. :-)"
- "I've never had a tube amp before, but listening to it was jaw-dropping. Pairs extremely well with an Aeolus. Never heard an amp that sounds this good. You weren't kidding about world-class. Gave me chills. Well worth the wait!"
- "My favorite paring of all the headphones I used were the Focal Clears in the LO output, with the Clears tonal balance and clarity it matches the Tuba's output absolutely wonderful. Close to audio perfection here with a $649 amp. The combination could be described with all those glowing adjectives, but the one that sticks out is the 'clarity' of the combination of the two, but the Tuba's 'sound' makes the Clears shine ... like a light saber and I am talking about a tube amp! This amp compared to other tube amps removes another layer of the 'veil' that stands in the way of us and a real live performance. The most admirable trait of the Tuba is its clarity and its wonderful ability to help articulate all that's in a recording. This clarity comes from a very quiet tube amp, when listening you don't hear anything form the amp, just the music good or bad."
- "I think that the Tuba will appeal to those who've invested in expensive IEMs; they may use them with a portable device on the go, however, desire better amplification for these IEMs for home listening. With many IEMs costing $1000 or more, the Tuba can take advantage of the growing IEM market and is a bargain, given its build quality, performance and 10 year transferable warranty!"
- "You have designed and built a wonderful amplifier and the price is so reasonable! I am amazed by its ability to reproduce the harmonic qualities of the range of musical instruments, mainly acoustical. I listen primarily to classical and I have to say, pianos, which are very difficult to record, sound really good and different from each other (NY Steinways, sound different than Hamburg Steinways and Fazoli's are monumental)."
- "I just received the Tuba and am listening to it as I type. You have created yet another winner with this amp. Dead silent background with great musicality and detail retrieval, yet completely non fatiguing."