DNA Sonett 2 vacuum tube headphone amplifier

The DNA Sonett 2 vacuum tube headphone amplifier builds on the musicality of the original Sonett while providing greater power and control into low and high impedance headphones. This is accomplished through the operation of dual 6H30 tubes in parallel single ended triode mode.

Drawing on experince gathered during the development of the Stratus, the Sonett 2 incorporates some similar components for greater "you are there" natural clarity, microdynamics, resolution, and soundstage layering. The Sonett 2 also provides both XLR balanced and 1/4" stereo unbalanced output with selectable output impedance for greater headphone compatibility.

My design philosophy is direct, elegant solutions without needless complexity. From my experience: The simpler - the better, using the purest components in a complementary manner.

Most modern headphones are very efficient, producing 95-100dB with just 1 milliwatt (1mW) of input power. This means they don't require significant power to play loudly. However, what they do need is very high quality amplification to allow you to hear all the fine nuances in your music collection.

Listening through the Sonett 2, you will also easily hear the differences in tonal balance, resolution, soundstaging, and overall sound presentation among individual headphone models.

Design features include:

• Purist class A single ended triode design featuring the 6H30 Supertube

• Transformer loaded output - custom made to DNA's specifications in the USA

• No coupling capacitors or cathode followers in the signal path

• 4-pin XLR and 1/4" stereo TRS outputs

• XLR and 1/4" TRS outputs provide the same power: 56mW into 300 ohms, 122mW into 100 ohms

• XLR outputs are selectable between unbalanced (single ended) and balanced headphone drive

• XLR outputs have 28 ohm output impedance

• 1/4" stereo TRS output has selectable gain attenuation between 0dB and -6dB for greater volume control range on higher sensitivity headphones

• 1/4" stereo TRS output on full gain, 0dB attenuation setting has selectable output impedance between 28 ohm (Low setting) and 120 ohm (IEC setting)

• 1/4" stereo TRS outut on -6dB gain attenuation setting has selectable output impedance between 11 ohm (Low setting) and 100 ohm (IEC setting)

Why offer selectable output impedance?
Some headphones are designed to be voltage driven (low amplifier output impedance); others are meant to be current driven (high amplifier output impedance). Depending on the headphone, how you drive them can affect their tonal balance. Many high-end headphones are designed and tuned around the IEC 61938 specification for 120 ohm amplifier output impedance, yet virtually no headphone amplifiers offer this standard output. Using the Sonett 2, you can now hear your headphones as their designers intended.

• Just the right amount of gain: 6dB (XLR and 0dB TRS setting); 0dB (-6dB TRS setting)
Many headphone amplifiers have too much gain, thereby restricting the useable range of the volume control to the bottom of the potentiometer where the dual sections are imbalanced, causing one channel to play louder than other. Through the Sonett 2, you'll have plenty of volume control range with proper channel balancing at any setting.

• Flat and extended frequency response with very low distortion

• Zero feedback or other error correction trickery
Triodes are naturally low distortion when operated into a high impedance load such as a transformer with proper specifications. They do not require feedback to attain low distortion.

• 5AR4 tube rectified and choke filtered high voltage power supply
The 5AR4 is an indirectly heated rectifier with natural slow-start function for prolonged 6H30 tube life.

• Point-to-point hand wired audio circuitry using carefully selected audio-grade components

• DC heated for black background - no noise

Available in 3 versions:
1) Standard 4-pin XLR balanced with 1/4" stereo unbalanced output
2) Balanced output using dual 3-pin XLR jacks with selectable output impedance
3) Balanced output using single 4-pin XLR jack with selectable output impedance

Input impedance: 25Kohms

Dimensions: 6.9" H x 13" x 9.5" D (17.5cm H x 33cm W x 24.1cm D) including tubes and connectors & controls.

Mains voltage: 100/110/120/220/230/240V factory configurable

DNA Sonett 2 headphone amplifiers are proudly made in the United States of America from the finest components available.

Price: $1300- with Alps volume potentiometer; $1400- with TKD volume potentiometer


Some comments about balanced headphone drive

I am frequently asked why an amplifier with balanced outputs does not include balanced inputs. This is because balanced inputs are not necessary to provide balanced headphone drive. Being a single ended amplifier, all it needs for input is a single ended (unbalanced) signal. The Sonett 2 operates single ended triode with transformer loading the plate of the 6H30 amplification tubes. The secondary windings on the output transformers are center tapped (and grounded for safety), thereby providing a true, differential, balanced output. Thus, you get balanced drive without the complexity from additional balanced input circuitry or input transformers. Again, the simpler - the better.


Listener comments:

"Last week I received package from Donald with this beautiful gear. It was #1 Sonett 2 :)
I have had DIY headphone amplifier till now (OTL, similar to Allan Kimmel's mu-follower) and I must say, that Sonett gave new life to my Sennheiser :) The amp has only 40 hours of work, but it sound clear and direct. Main thing that I noticed till now is that the amp is very detailed even at low volume.
Specially thanks to Santacore, who wrote about Sonett 2 prototype. It is indeed "easy recommendation"."

"The amplifier is everything that I expected. One can always use the standard descriptions such as clarity, smoothness, lack of distortion, etc., but my reaction is the difference between live and recorded music. When you here a piano or wind instruments live, the tone and timbre have a lot to do with the harmonics the instruments produce. With the Sonett and a high quality source, particularly SACDs, the harmonics seem to float and then dissipate. The fundamental tones predominate, but do not smear together to obliterate the secondary frequencies. The sound was reasonably clear and robust before, but it sounded recorded and reproduced. With the Sonett, I also hear notes from individual instruments in an orchestra that I could not detect or differentiate before. Overall, it's like live music versus good recorded sound with my previous amp (the Sonett is also 3x the weight, which told me something before even listening).

Played the first chamber music (Schumann Piano Quintet) and it was possibly even more impressive than the orchestral pieces because of the relative impact of the delineation of each of only 5 instruments."

"I'll say that it's the best headphone amp I've spent time with. It's not in the slightest bit tubey sounding—the S2 is fast, extended, dynamic and highly resolving, the way I like it. And it retains the lit-from-within quality of good tube circuits as well as the beguiling lucidity of transformer-coupled single-ended triode amps. It's also powerful sounding, driving the Senn HD800 and HD650 with unremitting control."

"I'm pretty thrilled with Sonett 2. I can't hear any character to it's sound that could be described as a flavor. It' strikes me as pure, transparent, and neutral, but not in the least boring or polite. It's colorful and rich. It has plenty of power and control with the phones I've tried it with. I can, as they say, hear things I've never heard before. It doesn't make me want to do something else after listening for 15 minutes. It makes the HD800 into the most revealing transducer I've heard—and, with the right attention to ancillaries, also makes it fun, something I wasn't sure was possible. It's not too big. I really like the way it looks, and that it's blue. And I can't think of another amp under $2K I'd rather listen to (though admittedly I haven't heard the EC Super 7). Thank you, Donald North, for the opportunity to live with your new amplifier for a while. It's terrific."

Read more listener comments at:

The DNA Sonett 2 is sold factory direct.

Contact us for information how to purchase
Tel: 1 310 869 6214
E-mail DNA


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