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
Yeah, I bought one from " buyincoins_au " and the charger never worked or if it did it didn't work for long. The battery itself works fine though. Been using it for a couple of months with a different plug I had lying about.
Yikes!!! Thanks for the info Pubul57. Mine works fine so far but will keep an eye on it while charging from now on.

Maybe there was a bad batch of chargers ...
for the same price, or less, (~$395 shipped), i would strongly recommend the diyparadise eva-2 ldr attenuator - this sucker actually improved my sound, (i use an active preamp), by enabling me to run the (already wery transparent) melos tube potentiometer in my highly modded ma333r wide open. the eva-2 is the real deal, imo... 3 remote-control inputs, remote wolume... and yes - ldr

http://diyparadise.com/shop/index.php?main_page=index&cPath=18
http://diyparadise.com/shop/images/P1012169.JPG

doug s.
At the DIY Audio LSA forum http://www.diyaudio.com/forums/analog-line-level/80194-lightspeed-attenuator-new-passive-preamp-391.html

the EVA is mentioned. Here are some comments from George. I've neve heard the EVA so can't comment one way or another. It would be nice to have multiple inputs and remote, but then it might not sound the same....

"And there's where your HF noise is comming from, a dirty switch mode power supply.
And from a high res photo of the guts I was sent by an anonymous sender, they don't use Silonex NSL32SR2S's, it's a far cheaper one so they can max out on profits, and to boot they have input and output mini relays in it, this is the exact reason for the Lightspeed Attenuator, "it's to get rid of all contacts between the source and poweramp" not add more contacts, no wonder it does not sound as good.
But it does look cute, with remote and digital readout, this will attract the naive customers.

Cheers George"
__________________
From a customer who has both the Lightspeed and Eva II

----- Original Message -----
From: Sirot Seta
To: George Stancheff
Sent: Thursday, December 23, 2010 4:32 PM
George,
The lightspeed is great and is "light" years ahead of diyparadise's EVA II.
It is much quieter and linearity is perfect.
BTW I wrote a review of a DAC and did mention the use of the Lightspeed, just FYI.
http://www.digitalaudioblog.com/2010/12/review-db-audio-labs-tranquility-dac.html
Regards,
S

Cheers George