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
If you think this thread is long in the tooth go over to the one on DIYAudio. It makes this one read like a short story.
You can get them pretty cheap, but if you're concerned about sound degradation Decware makes one for $119.

Thanks, Clio. I might just go ahead and get that Decware, as my wife likes to use the system to watch her Korean dramas :). The IC's look promising as well.

Also, are you suggesting that the Decware would not lead to any degradation or that it would tend to minimize it, given its quality? I don't know anything about how switchers work.

regards.
Banquo363
This warm up period with vinyl, it's probably cold/stiff cartridge suspension to start as they are made of rubber then it get's more malleable as it's used this could be the reason.

Cheers George
As for having my own Lightspeed Attenuator forum Tsciame, it would be nice, but I would have to maintain it, moderate it as well, and I'm flat out building them, it's nice when I have a break in orders to go down and have a surf at the beach come back refreshed and get stuck into it again. A smart man would sell it all off to someone in China, then one could surf all day, but then who said surfers were smart?

Cheers George
Banquo363,

Steve builds quality products at great prices. I'd be surprised if you could hear a difference using his input selector. He uses quality parts and backs it up with a 30 day trial (stock units, not custom orders).

I was pleasantly surprised with the interconnects. I've tried one of his phono stages in the past as well and would love to try his speakers some day. I'm not the best customer he has, far from it in fact, but if I call and talk to him he will spend whatever time he has to with me. Great person to deal with. Tell him what you're going to use the input selector for and he'll shoot straight with you.