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. Analog crossfeed circuit can be added special by request.
- 50k ohm input impedance
- 5/35 ohm output impedance (LO/HI)
- 10Hz to 150kHz bandwidth (-3dB)
- 350mW output power @ 32 ohms
- 7Vrms output voltage
- 5dB gain
- 0.25% distortion @ 0dBV 400Hz
- 6 x 10 x 3.5 inches
- 7 pounds
- 15Vdc @ 1.35A
- EL84 x 2
- Includes power supply & tubes
- Free shipping!
Scope photo shows plate voltage on tube swings 170Vpp before onset of soft-clipping.
- Matty, Headfonia
- Bob Levi, Positive Feedback
- Trav Wilson, Headphonesty
- "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
- "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."