2. amps-preamps
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Lightspeed Attenuator - Best Preamp Ever?

The question is a bit rhetorical. No preamp is the best ever, and much depends on system context. I am starting this thread beacuase there is a lot of info on this preamp in a Music First Audio Passive...thread, an Slagle AVC Modules...thread and wanted to be sure that information on this amazing product did not get lost in those threads.

I suspect that many folks may give this preamp a try at $450, direct from Australia, so I thought it would be good for current owners and future owners to have a place to describe their experience with this preamp.

It is a passive preamp that uses light LEDs, rather than mechanical contacts, to alter resistance and thereby attenuation of the source signal. It has been extremely hot in the DIY community, since the maker of this preamp provided gernerously provided information on how to make one. The trick is that while there are few parts, getting it done right, the matching of the parts is time consuming and tricky, and to boot, most of use would solder our fingers together if we tried. At $450, don't bother. It is cased in a small chassis that is fully shielded alloy, it gets it's RF sink earth via the interconnects. Vibration doesn't come into it as there is nothing to get vibrated as it's passive, even the active led's are immune as they are gas element, no filaments. The feet I attach are soft silicon/sorbethane compound anyway just in case.

This is not audio jewelry with bling, but solidly made and there is little room (if any) for audionervosa or tweaking.

So is this the best preamp ever? It might be if you have a single source (though you could use a switch box), your source is 2v or higher, your IC from pre-amp to amp is less than 2m to keep capaitance low, your amp is 5kohm input or higher (most any tube amp), and your amp is relatively sensitive (1v input sensitivity or lower v would be just right). In other words, within a passive friendly system (you do have to give this some thought), this is the finest passive preamp I have ever heard, and I have has many ranging form resistor-based to TVCs and AVCs.

In my system, with my equipment, I think it is the best I have heard passive or active, but I lean towards prefering preamp neutrality and transparency, without loosing musicality, dynamics, or the handling of low bass and highs.

If you own one, what are your impressions versus anything you have heard?

Is it the best ever? I suspect for some it may be, and to say that for a $450 product makes it stupidgood.
pubul57
pubul57 OP
3,712 posts
 
Oh, and Miguel, beautiful system!
teajay
1,691 posts
 
I just got through reading Sam's Space in the October issue of Stereophile and have to give the old boy for nailing why this thread really says the same thing over and over again and gets no were really at all.

Tellig has really changed his position that the best preamp in no preamp at all. Remember, he gave great praise to the LSA, yet comes to the conclusion that it ultimately leaves something out of the music that only an active preamp can provide in most systems.

Now, Paul would call this either a pleasant added distortion or it just is some euphonic change that gets in the way of the "pure signal", yet when I asked him way he uses some of the most "colored" IC's and speaker wires to muck up this "pure signal" coming from the LSA in his system he never did answer that question. This total thread, besides being a free advertisement/promotion of George's product, is techno-babble going over and over why the purity of the LSA or passives in general is objectively the only way to reach the truth of the music, and any active preamp just an out dated expensive waste of years gone by.

I totally accept that many passives including the LSA offer great performance for the price, but to say that they are on the same sonic level as world class reference active linestages for some factual/objective scientific reasons is just a realization regarding what is personal taste and system synergy in different systems for different people.

So, Sam just flipped from no preamp is the best preamp to why many music listeners would still invest their money in an excellent active linestage really shows why this thread is really a discussion that is a closed circle of logic developed by true believers regarding the LSA and passives in general. Take a look at Tellig's piece and tell me what you think.
unsound
7,329 posts
 
And if you've read Sam for any length of time, you'll know that in the next issue there's a good chance he'll change his mind again.:-)
pubul57 OP
3,712 posts
 
True. An endgame to opinion is an endgame to the reviewing game (Tellig has to move on or he will have nothing to write about).

As to coloration, I think all all recorded playback is significantly different from live - simply changing microphones making enormous differences in the recorded sound signature. My ICs (Cardas GR) just happen to be what is used in the design of my speakers, so however colored they might be (accepted for the sake of argument), the speakers are voiced with that in mind.

I just find the LSA to be minimally intrusive in the overall system - whereas the various active tube line stages I have owned made their presence in the chain more obvious - the CAT Ultimate perhaps the most neutral, least flavored of all (and $7000 when I bought it)

All threads, all opinions and comments, are nothing compared with listening. I hope one thing this thread accomplishes is that it makes some folks try a passive (TVC/AVC/Resistor/LSA) and see how it works for them. Are they as good as world-class, $20,000 active line stages? For some folks, getting something that can compete for $1000 or less is reason enough to go passive, and if passive works for them, than the LSA is likely to be a very good option, and if you need a bit more connection flexibility, the BENT TAP-x with autoformers.

As some will note, and Arthur Salvatore now concludes, for some folks an active line stage is absolutely necessary for their systems to perform their best and they should stick to actives, but there are systems in which passives will offer SOTA sound at a fraction of the cost (for volume control).
clio09
3,355 posts
 
Your many reviews on here aren't free advertising? The comments you make in them aren't a reflection of personal taste and/or results you are hearing from system synergy?

Maybe in his old age Sam has had a change of heart and prefers the distortions an active linestage adds to his listening experience. He's certainly allowed to change his mind like any of us. Heck even Arthur Salvatore changed his mind and raves about the new Coincident linestage.

Maybe instead of referencing all the techno-babble here you can help Sam out and give us a technical explanation on how an active linestage fills the void in the music created by the LSA, or other passives for that matter.
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