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
Postscript- I hadn't realized that the original thread starter had passed away recently, because I only caught this thread when folks were searching each other out in the last few posts. My condolences to all friends and family.
Best,
Bill Hart
George: Ok. I will contact you from a computer that does not have comcast as its provider.
Purchased a Lightspeed from George due to what I read in this thread and others. I adhered to all the caveats with respect to input impedance,input sensitivity and interconnect length.

Now , time to report.WOW............an ear opener,took sometime for my auditory senses to settle down with all the extra information. The sound stage didnt get bigger but became more transparent as if a veil has been taken off.Imaging was precise and rock solid. The dynamics was all there as my feet were tapping away with the music.The bass was very controlled and powerful and the highs were as smooth as silk.My ESS AMT 6 speakers are now shinning like a true diva.

All I can say is thank you George for a fantastic product and more importantly sharing his knowledge with the audio community.
Seshkir hi, thanks you for your encouragement and for the great review.
And most of all thank you for your second order/purchase of another Lightspeed Attenuator for your father.
You now know how true to the source the Lightspeed is, nothing added, nothing taken away, just what the source is giving.

Cheers George