I've finally finished my Bottlehead Smack (am I the first?), so it's time to see how it fits with my existing sound system. I will be updating this post as I go through my different headphones and amplifiers.
***Remember, these are only opinions and observations made with my ears. Your result will vary.***
Amplifiers
Bottlehead Smack SET
Hagerman Castanet SET
Cavalli Audio EHHA rev.A Hybrid
Bottlehead Speedball Crack OTL
Headphones
Audez'e LCD-2
Grado HF-2
Sennheiser HD-600
Source
256 kbps VBR AAC recordings of original vinyl records, from my laptop using a AMB Labs Gamma 2 DAC
Music
RUSH - Tom Sawyer
MEKONG DELTA - Dances of Death
HARMONIUM - Depuis l'automne
CHARLES MINGUS - Better Git It in Your Soul
Compared to Hagerman Castanet
The Castanet is my second amplifier and my first SET. It was my main amplifier for a long time, until I got into Planar headphones, when the EHHA supplanted it. Its sound is warm and euphonic, with an emphasis on bass, and with a great soundstage. It loses the beat when music gets fast and complex, like in Thrash Metal (Mekong Delta)
Grado HF-2
The first thing that strikes me is how silent the Smack is: the Grado are so sensitive that I can clearly hear the power supply of the Castanet when no music is playing. With Rush, both amplifiers are close, with the Castanet having more weight and the Smack having more air. Both have good soundstage (for a Grado) and the instruments come clear, with a slight edge to the Smack. Harmonium was always great on the Castanet, very emotional and the reproduction of the darkness between the sounds. It still holds on to that last part, thanks to its warmer sound, but the added air of the Smack really gives an added brilliance to the single pinched cords and greater power to the crescendo. On Charles Mingus, the Castanet gives more presence to the bass, but sacrifices instrument separation. Since Mingus was a bassist, I would have preferred more weight from the Smack, but the better reproduction wins in the end.
The Castanet always loses it on Mekong Delta (which is one of the reasons I always pick that track), and today was no exception. The Smack, however, gave a much superior instrument separation and was able to follow the complex passages, which I found remarkable for a SET (though I must say I only ever had the Castanet as a SET).
Audez'e LCD-2
It always makes me sad to use the LCD-2 with my Castanet, since it reminds me why I stopped using it. On all tracks this combination sounds slow, muffled and lifeless. The impulses (when the drums are hit) are especially dull. The Smack does a much better job here, though not as good as it did with the Grado. Comparing it with the EHHA will be a much better indication of how it plays with orthodynamic headphones.
Sennheiser HD-600
For the rock tracks, it's petty similar to the Grado HF-2: better air, better separation and better dynamism (drum impacts) from the Smack. The Smack also does a good job on the Mekong Delta track: the guitars are crunchy, the drums are dynamic and the instruments are well separated. In comparison, the Castanet makes the whole too smooth and loses the energy of the track.
Then I got to Charles Mingus. Wow! All instruments are well separated, it's easy to pinpoint the directions of the instruments in the soundstage and the cymbals and brass instruments sound alive! The added air really brings out this jazz track. The Castanet sounds dark and the separation is not as good, though the soundstage is still wide enough. As I type this, I am listening to Blues and Roots, and I must say I am impressed at how life-like it sounds.
Overall
No matter how much I like my Castanet, it's not contest: the Smack is the better amplifier. With dynamic headphones, the Smack has great air, dynamism, instrument separation and soundstage. It does a fantastic job at jazz, which was the strongest point of the Castanet in my previous amp shootouts. It is also fast enough to handle Thrash metal, which the Castanet can't. I think we clearly see the advantage here of custom iron against off-the-shelves Hammonds.
Compared to Cavalli Audio EHHA rev.A
This hybrid amplifier is my main amplifier. I built it when I realized I needed a more powerful amplifier for my orthodynamic headhones. It is very fast, balanced and gives a newar perfect reproduction of the music, but it lacks a bit on soundstage and warmth, where the SET higher and more harmonic distortion help.
Grado HF-2
It's really an age-old debate: transistors vs tubes, technical perfection vs subjective enjoyment. The EHHA comes out with better instrument separation and better extension on both sides, but the Smack does better on a few other points: soundstage and volume changes in the music are more apparent. The Smack really plays Harmonium well, and keeps the emotion, while the EHHA is too cold and analytical for it. Mekong Delta is better reproduced on the EHHA, but the volume changes in it are brought up by the Smack, giving it a more life-like presentation. I've always preferred my Grados on SET, because of that increased soundstage, and the Smack is no exception. This is, of course, highly subjective.
Audez'e LCD-2
This was closer than I thought it would be, but it seems the EHHA survives the challenger. On Charles Mingus and especially Harmonium, the warmth of the Smack and the better representation of volume differences give a more emotional representation of the music, which is very pleasant. On the other hand, on Rush and Mekong Delta, the Smack starts to lose it on fast and complex passages, and the drums and guitars lose their edges. To be fair to the Smack, it is still a very respectable performance: I was writing the same thing last year, when comparing the Castanet against the EHHA, but it was with the Grado, not with an orthodynamic headphone!
Sennheiser HD-600
Now that's a tough one. The EHHA is clearer, faster and has better extension, but the difference is slight. The Smack does have better soundstage (but the Sennheiser is not starved for it like the Grado) and more warm. I feel it is better on Mingus and Harmonium, while the EHHA is better on Rush and Mekong Delta. I must also say that the Smack manages to do a very good job on Mekong Delta, a fast and complex track, which is no small feat for an all-tube amplifier.
Overall
The Smack gives a very good fight against the EHHA, and I am quite happy with the both of them. For dynamic headphones, it's all about what you prefer: clarity vs soundstage, extension vs warmth, transistors vs tubes (yeah, I know the EHHA has tubes, but it's still a very SS-like sound). If you have an orthodynamic, I still prefer an hybrid or SS amplifier for the higher current, but the Smack still manages a decent performance here, and the EHHA is no slouch.
Compared to Bottlehead Speedball Crack
The bargain amplifier and my only OTL. I found it has a bright sound, but it is quite capable when handling complex music. I only pair it with my Sennheisers, because of their higher impedance and their darker sound, which balances the amp's characteristics to my ears.
Sennheiser HD-600
Once again, I have to give it to the Smack. There's better extension, especially in the bass, better separation of the instruments and it is slightly more capable of handling complex music. The Smack was more capable when handling Mekong Delta, which surprised me, and really did a fantastic job with Charles Mingus. Frankly, as was the case with the Castanet, I believe it's an improvement on all the line.
Conclusion
The Bottlehead Smack is a clear winner from the Doc. This amplifier has the SET magic, soundstage and warmth, yet still manages to have great resolution, speed and extension. It is quite capable of handling varied musical genres, with very different headphones (you can't get much further apart then Grado and Sennheiser!) and is even capable of doing a decent job on current-starved orthodynamic headphones. If you use mainly dynamic headphones and want some of that tube musicality, the Smack is a great choice.
