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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
b_limo's avatar
b_limo
2,285 posts
 
I just recieved my lightspeed this morning. First off, George does great business. He e-mailed me back three or four times a day in the beginning in order to answer any and all of my questions. Second, he over delivers on his promises. I was expecting it would take 5 to 7 weeks for me to recieve my lightspeed and it took about three weeks.

Now, for the sound. Talk about transparent and detailed! My system had some grunge, a little bit of mid range mud I guess you could say. Well it's all gone; all of it. My sound is so clear and transparent that if I had to stop here with the upgrades, I'd finally be satisfied. Everything from here (power cords, isolation footers for my components, more room treatments, analysis plus interconnects), it's all icing on the cake. I have finally got the sound I was after.

This "pre amp" is worth it's weight in gold. Don't buy one, buy two and give one to a friend. I'm serious, they're that good.

Thanks again, George!
:-)
tradeontheweb
43 posts
 
Yep, another "normal" comment from a first time Lightspeed Owner !

Mine's coming up to it's 7th year of use now. Still haven't found aything to beat it for a single input Attenuator, when correctly implemented.

Cheers

Scott
lacee
811 posts
 
I use two short pairs(1.5 Mtr) of Heimdal from my source to the Lightspeed and from it to the power amps.

I was running a longer pair of Art Audio IC from the source.

I think I like 2 matched pairs.

I'm curious about future IC upgrades.

So what's the latest rave interconnect for the Lightspeed?

Two pairs of the same or mix and match?
b_limo's avatar
b_limo
2,285 posts
 
I'm curious about that too. I'm using two matched pairs of blue jeans interconnects that sounded like poo between my dac and classe pre amp, and between my classe pre amp and classe amp. For dome reason, they sound fantastic with the lightspeed. I can't wait if it will sound better using some analysis plus or signal cables :-)
georgehifi's avatar
georgehifi
10,312 posts
 
Hi B_limo (Bruce) , thanks for the very concise and accurate review of your new Lightspeed.
As for interconnects with it, it is always good to use good quality low capacitance ones from the output to the poweramp, as is the same for tube preamps, <100pf (picofarad capacitance) per foot is fine.(which most hi-end cables are).
Manufactures should be able to answer this, or have it printed in the specs on the packaging.
The input interconnects from the source can be whatever good ones you have handy and like the sound of.
As for the brand/construction this is more system dependent, I for my system prefer copper, some may like silver, which to me is always a tad brighter.

Cheers George
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