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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
georgehifi's avatar
georgehifi
10,312 posts
 
So is the Beryllium(Be) used in Focals/JM Labs and other speaker manufacturers that use Focals top tweeters.
So is Yamaha NS1000, NS1000X and NS2000, tweeters and midrange units.

So is NOS and OS tubes that have Nickle(Ni) inside them.

And so is the lead(Pb) based solder hiend manufactures still perfer to use.

I can go on and on, at least the Silonex LED/LDR package that the Lightspeed Attenuator uses, are hermetically sealed within a tough hard acid resistant plastic case, I don't think anyone is about to open up a Lightspeed Attenuator put one in their mouth and crunch down on it like a boiled lolly. It's not "Cadmium Gas" it's Cadmium Suplhide (CDs) solid.

http://en.wikipedia.org/wiki/Photoresistor

http://en.wikipedia.org/wiki/Cadmium_sulfide

Cheers George
erwann
6 posts
 
This is vintage EU mind control: identify genuine existential problems, say the girth of bananas, to justify a metastatic bureaucracy, whose days, judging by the latest EU Parliament elections, are numbered.
erwann
6 posts
 
Graham Slee's 2006 interview with TNT (http://www.tnt-audio.com/edcorner/july06.html) offers an eye-opening overview of the stark implications of RoHS for small to medium businesses, best summed up by his assessment that "all this legislation has a soul destroying effect on the designer who tries so incredibly hard to share his/her talents with the music lover, only to be shunned by what would seem to be ruthless dictators." Amen!!!
lacee
811 posts
 
I now use the fixed output on my Steelhead,bypassing the volume control of the manley.

This has further improved my enjoyment of the LSA.

Using the LSA with the Esoteric cd player into my amps was very revealing, and my old way of running the Manley with variable output(vol at full on the Manley)to retain the mono function,left me preferring the cd sound.

Not so anymore.
The manley is now just a phono stage, and a better one than I thought it was.

The LSA's transparency is quite apparent on vinyl as well as CD/sacd.
georgehifi's avatar
georgehifi
10,312 posts
 
That's great to hear Lacee, echoing many of my customers are reporting back to me and say that with the Lightspeed Attenuator as the preamp it's the best they have ever heard their vinyl/phono sound.

I did a bit of searching and found your Steelhead, has a great low 150ohms output impedance. With the Clearaudio Talisman Gold V2 you are using, where is the Lightspeed's volume control when listening to medium loud volume.

Cheers George
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