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
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Does anyone how where or how to buy this preamp. I have tried to contact the manufacturer using the email from their website, with the intention to purchase, but there has been no response.
[email protected]

This is the email I use to contact George. Between the Stereophile article and a few recent threads I'm sure his time has been a little more consumed than normal. Also, you might be going into a spam filter. Hopefully he'll see your note here.
Fiddler, I was glad to see your post, to help me rest assured that I was not loosing my mind or going deaf:) I thought it was pretty good too. The fact that compared with the Supratek, and that I have owned ARC, Lamm, CAT, Joule, and Dodd, makes me feel that this things is indeed a very, very good piece in the right system. I trust Anthony's ears, but it is good to hear thought from another person with a top flight tube preamp. I sold the Joule LA150 Signature Edition this week, which I loved, becuase I felt that in my system (single source)with passive-friendly and no-gain needed, the LS is able to give me SOTA sound, or at least something as good as I was getting from some of the better tubed active linestages I have used. I don't think the LS is a flavor of the month product, and as Tvad point out, it will sound the same for the next 20-years or more.

Zendent7, not sure when you sent the e-mail to George, but he is in Australia, so he might be sleeping:)
Does anyone how where or how to buy this preamp. I have tried to contact the manufacturer using the email from their website, with the intention to purchase, but there has been no response.