Sources / Amplification
For this section we’re using the Musician Aquarius as DAC and the HEDDPhone TWO was always connected in balanced mode unless mentioned differently. The difference between balanced and single ended in this headphone is marginal. In SE mode bass hits a bit harder, while in balanced mode you get more note extension and some more mid-air.
The HEDDPhone TWO has an impedance of 41 Ω together with a sensitivity of 89dB, so it will require amplification to perform at its best level. The original HEDDphone had 42Ω impedance and 87dB/mW sensitivity, so the TWO isn’t that different. In this section we’re testing the TWO’s synergy with a series of portable and desktop amplifiers and I have selected a mix of portable and desktop gear, both solid state as well as tube topology.
Portable
With the Chord Mojo2, the HEDDphone TWO has more forward vocals and a lighter weight overall. There really is only a lighter amount of body from bass to highs, and the tuning is neutrally balanced. Bass is tight and punchy, yet light, and the focus is on the mid bass. The delivery is musical and the overall timbre is very nice and it’s my favorite thing in this combo. The top end is exciting yet inoffensive, which is always a good thing. It’s an enjoyable and technically strong combo if you like neutrality and can live with the lighter weight and bass impact. All-in-all the combo is nice, but it isn’t for everyone and I do feel the TWO has better energy and performance with other units.
With the Woo Audio Tube Mini you immediately notice the fuller body and bass weight. The vocals still are more forward but the mid timbre and layering here are impressive. Bass here reaches down lower and bass has better impact and punch making things more exciting, yet less neutral. The mids perfectly connect to the bass weight wise, and that really works better for the TWO. The treble section here is also fuller sounding but it is softer to the ear. The delivery is musical, fast and there is nice extension and airiness. It’s a nice combo but the real magic for me is with the Hugo2.
The Chord Electronics HUGO2 strangely enough is a unit I hardly ever use anymore, but I remember that the original HEDDphone’s synergy with the Chord unit was quite good, so here we are. Of course this is in single-ended mode as we’re used to from Chord. What you get here is the technical excellence of Chord and the Mojo2, but then with extra weight and body as well as with improved depth, timbre and layering. This combo is not only technically performant, but it also is musically strong. The TWO here sounds full and exciting, while keeping a high technical level and a musical delivery. If I have to use the HEDDphone TWO with a portable device, this is the one for me. I really like this combo.
DAP
The Cayin N8ii has been around for a while now, but the more I use it and work with it for testing head- and earphones, the more I like it. With the HEDDphone 2, I prefer using the N8ii in its excellent Power Mode (P+) in Class AB. I actually both like the solid state as well as the tube mode with the TWO. In solid state mode you get excellent PRaT, wight a slightly lighter delivery. In tube mode you get a bit more warmth and the delivery is smoother. Both modes sound airy, spacious and have excellent depth and layering. To me the note extension and decay really stand out in this combo, together with the stereo imaging. The combo is musical, engaging and technically strong. If I have to use the TWO on the go with a DAP, the choice is easy.
The Astell&Kern AK SP3000 is the DAP I use most when listening to IEMs on the go. We all know it isn’t always the best source to use with full sized headphones without amplification, but sometimes it surprises. With the HEDDPhone TWO you get a technically strong combo with a more forward sound signature and lighter weight presence. You get excellent PRaT, good note extension and a very high resolution in a neutral and balanced signature. This probably is the technically strongest combo so far, but for me it is a little light in bass and body.
Conclusion Portable: While the HEDDPhone TWO does sound good with portable units like the HUGO2 and Cayin N8ii, it really performs better with desktop amplification. That said, if you have no other choice but to go portable the two above mentioned units is where I would start.
Desktop Solid State
I recently have been using the Hifiman Prelude amplifier a lot, both as headphone amp as well as in my speaker system. The Prelude is a musical, fuller and warmer sounding amplifier and it is great when combined with high precision DACs such as the R2R Aquarius. I prefer using the HEDDphone TWO here in balanced mode and in low gain, as I find the vocals to sound too shouty with high gain. With the Prelude I really get the feeling the HEDDphone TWO is finally performing at its best possible level. You get a lovely sound stage width and depth, with excellent extension and layering. The presentation is airy, spacious, layered and the stereo imaging and 3-dimensionality are impressive. You also have excellent speed, a slightly smooth mid delivery and an exciting and engaging top end that doesn’t offend. Bass is punchy, full and engaging. The mids are weighty and technically strong and the highs are exciting and energetic. If there is one thing I would change in this combo, it would be pulling the vocals back a little as it can be more fatiguing in long listening sessions. All-in-all an excellent synergy and great combo.
The Ferrum OOR with the Hypsos power supply still is a very popular combo, and rightfully so. With the TWO that translates in a very airy and spacious delivery, which is technically strong but also lighter in weight and impact. The technical level is high here but it’s lighter in body though it has a soft delivery which is easy in the ear. That said, there is more body than say with the Mojo and SP3000. The vocals here sound more forward as well but they have more softness to them making them easy on the ear. The top end in this combo is rather normal, easy going and very friendly to the ear. For some of you it might even sound a bit too soft. The OOR and TWO combo is nice, especially if technical excellence, a natural amount of weight, softness in the delivery and musicality are your things.
The SAEQ PDA-1b is a more neutrally tuned amplifier with good weight, that is tuned specifically to make your music sound like when you’re listening to it live. With the HEDD TWO that means you get a very spacious and airy rendering, but in the most natural way. The SAEQ has a neutral tuning but it carries good weight from to bottom. The SAEQ is a transparent amplifier, so you can really hear the excellent technical level of the TWO here. The PDA-1b’s delivery is musically smooth and that combined with the high precision, makes it a top level amplifier for the TWO. Natural, engaging, musical, refined. Those are the key words, so what’s not to like. This is my personal favorite solid state desktop source so far.
Desktop Tube
Switching to tube amps, there are 3 amps I really want to try the TWO on. First of all the Feliks Audio Envy. The Envy has a fuller sounding character and brings a high technical level with tube smoothness to the party. With the Envy, the TWO sounds musical, technically strong, easy to the ears and soft in the delivery. The amount of weight is good, but not like with the Prelude to give an example. Same goes for the bass impact, it has a nice punch and impact. Both bass and body are present higher than neutral, but not too much. The Sound staging here is exemplary, giving you an impressive stereo image and depth. This combo is a pure joy to the ear, though it isn’t the most refined. If you yearn for tube flavour yet want the best possible technical level, the Auris Audio Headonia is the amplifier to look at.
The Headonia isn’t the fullest sounding amplifier and that is audible here, but it do is extremely refined, extended and precise. The overall timbre of the Headonia, is one of the best on the market and it does its magic with the TWO as well. It’s not that this combo is bass or weight shy, it’s just not as much present as with the ENVY. Combine the Headonia’s high technical level with tube smoothness, and you get a very good and super enjoyable HEDDPhone TWO. This is a very high-end setup and if the TWO has your preferred tuning, it’s an easy end game setup. I could listen to this all day long and every day of the week.
If you want to hear power, the Auris Audio Nirvana also is an option and it makes the TWO sound full, musical but a lit less smooth sounding in the delivery. I absolutely love the amount of body, bass impact, mid timbre, staging and stereo imaging in this combo. The vocals also sound very realistic and it’s here where the tube warmth really does its magic. It’s not as technically refined as the ENVY, but the Nirvana makes up for it with energy, rhythm, excitement and top end energy/extension. I really like this setup myself.
Conclusion Portable: Not everyone has the option to try the HEDDphone TWO on a dozen of headphone amps, so if you’re asking me which two I would recommend, I would say the PDA-1b as a solid state amp and the Headonia as tube amp. You can’t go wrong with either.
The part on sound continues on the fourth page. Click here or use the jumps below.
Page 1: HEDD Audio, AMT, HEDDphone 1 and TWO, Features, Specifications
Page 2: Box, Accessories, Price, Design, Build quality, Comfort, Sound Intro, Sound General
Page 3: Sound Synergy
Page 4: Sound Comparisons, Conclusion, Summary
