Amp/Preamp Asylum: REVIEW: Audio Note Kits L3 Signature Preamplifier (Tube) by Paul Folbrecht

Model:	Kits L3 Signature
Category:	Preamplifier (Tube)
Suggested Retail Price:	$2000
Description:	Kit line stage, 5687, transformer-coupled
Manufacturer URL:	Audio Note
Model Picture:	View

Review by Paul Folbrecht on April 27, 2009 at 19:52:09
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for the Kits L3 Signature

This is a review of the Audio Note Kits L3 Signature line stage. I built one recently - the latest version, complete with the choke-decoupling circuitry.

The Cut to the Chase:

It's quiet, dynamic, linear, neutral, smooth, with no bad habits.

The Long Version:

I've owned a lot of preamps. I mean - a lot. A short list:

Prima Luna
Cary
Supratek
Bottlehead
Shindo
Dodd
ModWright
Eastern Electric
Audio Sector
Sonic Euphoria
Placette

Let's start with a question: What should a preamp (let's simplify to 'line stage') *do*? There are pretty much two schools of thought on the matter, I think:

1) The preamp should control source selection and volume control and pass the (delicate) signal with the least possible modification (distortion) of any kind.

2) The preamp is the heart of an audio system and makes or breaks it. It 'shapes' the sound - and if it doesn't do it well, 'musically', it's useless.

The Audio Note line stage is the type of unit that excels by the definition given in (1) above. It is very quiet, very extended, has wonderfully tight bass, preserves correct timbre and harmonic structure, and gives great micro and macro dynamics.

But it doesn't really seem to 'shape' or *add* to the signal. If that's what you're looking for, for the cash, I do not think one can do much better.

[The Shindo [Monbrison] I owned would be an example of a unit excelling in category #2. It can hardly be doubted that it is, in fact, imparting *something* to the signal, as it definitely has a sort of homogenizing effect: but what a, I must say, wonderful something that is. If you want a piece of gear that makes everything sound very nice, yet does preserve timbre and especially PRaT extremely well, you probably cannot do much 'better' than looking at Shindo. However, I have heard none of the factory Audio Note preamps competing in its price bracket.]

Back to the Audio Note Kits L3 Signature. It has everything I want in a line stage at the moment, and is quality through-and-through in terms of parts & performance.

The build is quite simple. I had previously build the AN Kits DAC 2.1C Signature; the Line uses the same power supply board and line board. When I built the DAC, I opted for the hard-wired board; this is a board that surface-mounts components and looks like a PCB but it's not: you hard-wire component with leads & silver wire underneath. Well, when I ordered my L3, Brian had just introduced his new 'super PCBs' that use a very high-quality, thick silver trace, sounding as good as a hard-wired board. I opted for this, and of course it does cut the build time down quite a bit. It is a very fast built, being less complicated than the DAC.

One of the big theoretical questions I had with regard to the line stage concerned the transformer-coupling - was it worth it? Was it a detriment or a benefit? By the Laws of Audio Impedance Matching, I should not 'need' a transformer-coupled line stage, feeding as it would a Yamamoto A-08S with its 200K Zin, but, the fact is that the transformer-coupled preamp has bass tighter and more extension than the modified, cap-coupled, 6SN7 Bottlehead unit it replaced (a stellar performer, especially for the money, by the way).

Detractors of transformers, with their hundreds of feet of wire in the signal path, would accuse them of restricting bandwidth and obscuring detail. After listening to the L3, the former charge is especially laughable to me, and the latter also proves baseless in terms of this particular specimen: it is quite detailed and nuanced, among the best I've heard in that respect. (Like a good tubed unit, though, never analytical or rough-sounding.)

Thus, I must conclude that transformer-coupling - assuming the iron is up to the task - is superior to cap-coupling. (And these transformers are at the entry-level end of the Audio Note line. I hear tell that c-cores up the ante considerably.)

I'm going to move on to some comparisons now. For you, see, there's a big hole in the logic defining Preamp Rule #1 Above: Who knows what 'neutral' is? Who really has any idea what moving along the signal with no modification really means? Nobody, that's who; though we may be able to make a *positive* judgment of Preamp A doing something decidedly *non-neutral*, we can really only define true neutrality in relative terms. Right?

In addition to being a good bit quieter than the modified Bottlehead 6SN7 pre, the Audio Note is quicker, more dynamic, more detailed, and what I would call more neutral-sounding - though others might call it 'leaner'. (6SN7s are known for 'tone', whatever the source of it may be.) It's what you might call a more 'modern' sound - it sure isn't 'tubey' in anything but the good sense, meaning that there's no [transistor] glare, no hardness, and instrument timbres are full and correct.

Compared to the Dodd Audio Battery Preamp I had not long ago, I think the AN unit is a little fleshier and little more dynamic. Whether or not it's as quiet I'd only be able to determine with direct A-Bing; I can say that the noise floor of the L3 is at least very near to the lowest I've experienced. (I run high-efficiency speakers and am made pretty readily aware of any noise in the electronics chain.)

In relation to the Monbrison, which is, let's face it, a piece of 'audio art' voiced with a specific presentation in mind, I feel pretty confident saying that the Audio Note is closer to True Neutral. Whether it's as faithful to true timbre, and as nuanced in the musical sense, without being analytical - that's a tougher question. I suspect not *quite*. However, we are comparing apples & oranges here, the Monbrison being a full four times as expensive, although it is also a full-function phono preamp.

Though my Monbrison was indeed a wonderful piece of musical machinery, I do not miss it. It had a very special perspective which I enjoyed very much, but, for now at least, I'd rather be a bit closer to 'neutral'.

Product Weakness:	I'd say none
Product Strengths:	See review please

Associated Equipment for this Review:

Amplifier: Yamamoto A-08S
Preamplifier (or None if Integrated): Audio Note Kits L3
Sources (CDP/Turntable): Audio Note Kits 2.1C DAC, Acoustic Solid TT
Speakers: Supravox 215-2000 on OB, Audio Note AN/E
Cables/Interconnects: Various
Music Used (Genre/Selections): Acoustic jazz, modern jazz, rock
Room Size (LxWxH): 25 x 25 x 15
Time Period/Length of Audition: 2 weeks
Other (Power Conditioner etc.): Exact Power
Type of Audition/Review: Product Owner

Amplifier:	Yamamoto A-08S
Preamplifier (or None if Integrated):	Audio Note Kits L3
Sources (CDP/Turntable):	Audio Note Kits 2.1C DAC, Acoustic Solid TT
Speakers:	Supravox 215-2000 on OB, Audio Note AN/E
Cables/Interconnects:	Various
Music Used (Genre/Selections):	Acoustic jazz, modern jazz, rock
Room Size (LxWxH):	25 x 25 x 15
Time Period/Length of Audition:	2 weeks
Other (Power Conditioner etc.):	Exact Power
Type of Audition/Review:	Product Owner