Click pics to Enlarge. Note the Kondo-like Split-Level chassis with holes for cables to go through.
Review: Artemis Labs LA-1 Preamp, Part II
7119 vs 5687
LA-1, Part I
Artemis Labs, now long defunct, was headed by John Atwood, former Technical Editor of the much missed Vacuum Tube Valley publication of Charles Kittelson. Its first products in 2004 were this Preamp and the companion PH-1 Phonoamp. It was much later that I saw and heard them at the AV show in HK, though as usual, given show conditions, the sound did not register with me.
In HK, their products, though receiving wide praise, never sold well. I suspect that had something to do with the aesthetics. These products have the form of a bulky brick with a V(or U)-shaped trough in the top center, where the tubes are seated. The aluminum face plate looks rather Gothic to me. I actually don't quite like the look, but some reviewers seem to like it. Unusual shapes usually is not a good idea in the conservative world of audio consumerism. Second hand prices are low, even when I got it in 2010 (even lower now).
Construction This preamp is definitely not run of the mill, and is intriguingly constructed. There is a lot of technical information in the 2006 positive-feedback and belated 2010 dagogo reviews.
My interest in the LA-1 lies in its use of a single 5687 for amplification. The use of this tube in a preamp was initially developed by Kondo (I have yet to see one of these as he then moved away and used other tubes) and later much emulated in DIY circles. The split level construction of the LA-1 is also Kondo-like, but on a less luxurious level. Parts quality is superb. The coupling cap is Auricap (personally I harbor doubts about Teflon caps). The potentiometer is stepped Goldpoint and Chokes are used for Loading (somehow I was not able to get the front cover off but at the bottom there is a pic from the net). I popped open the back cover though and that overbuilt power supply is fit for an amp! BTW, see that black wire used for the signal (lower right corner)? It is Belden 8450, the solid core version of the 8451 that I use!
Ergonomics Excellent. Stepped volume can sometimes be trouble, but it is well designed here. I always get the exact volume I need. The two level knobs also come in handy in balancing the stage. And the Mono switch is a luxury.
Sound There is something very direct about the sound, and a presence that some of the reviewers had alluded to, but I find it difficult to exactly pin down the sound. What I find significant are:
- Simplicity Despite its realization, this is as simple as a preamp can be. Just a triode section capacitor coupled to the output, with very little feedback. One can hear this simplicity.
- Dynamics and Headroom There is definitely something outstanding about the headroom of this unit. It is never fazed. It is not ultra-dynamic in the usual sense. Its gain is modest at 13db. It doesn't immediately impress one as punchy as, say, a preamp based on the SRPP circuit. But the way it follows the dynamic is exceptional. No stress, no matter what. It is not reticent, it just gets out of the way. It is good with all manners of music.
- 5687 vs 7119 The 5687 was made famous by Kondo. Since then it has been used widely in DIY circuits, as well as in some mass products such as the iconic Audio Note (UK) Kit 1, which I used to own. It is a very good amp, and better than its then much more expensive commercial brethens Conqueror and Conquest. But still, I could not get over its trace of brightness. I rolled 5687 and 7119 but thought the 7119 sounded quite off. Fast forward to now. The LA-1 is completely different, and highly amenable to both tubes. The 5687 has a more airy sound, but the 7119 is definitely more corporeal sounding, and that is my preference.
- A Steal At current price, this is a steal. If your system is kind of laid back, this may not provide you with the jump factor you need. But, if your system is in ship shape, the Artemis can be a big surprise and make you re-evaluate what you think you know about dynamics.
Beefy Power Supply!
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Cool! I had a chance to hear this pre-amp very recently in the system of a local friend, albeit for a brief audition, as he was getting ready to sell it. I was impressed with the construction, I didn't know who was behind Artemis at the time, I wish I had paid more careful attention.
ReplyDeleteSome words on the design: the 5687 is choke-loaded on the plates; this offers better distortion, impedance and noise characteristics than a conventional resistor, and is probably to thank for the unstressed dynamic characteristic you mention. I didn't see which make 5687 you are using BTW, tungsol is the way to go.
I am not really a fan of stepped attenuators using thin-film resistors such as Goldpoint or Elma. I prefer the simple carbon pot. I am also very skeptical of Teflon/polypropylene capacitors. They have a very modern sound, which infers both good and bad.
There is 4dB of NFB applied to the 5687. I think this attributes to the lack of punch or jump factor you mention.
I agree this is a good line stage for the right price second hand. However I have to state I believe the 4P1L line stage by Radu Tarta in my last-last article is superior in every design aspect.
I have all makes of 5687 but in this pre I prefer the 7119. Using Holland Amperex right now. I also bought 2 polypropylene caps and may do a little surgery to see if it can be improved.
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