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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
pubul57 OP
3,712 posts
 
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"
__________________
georgehifi's avatar
georgehifi
10,312 posts
 
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
brislander
1 posts
 
Congratulations George, the Lightspeed pre/attenuator is just magic.
When I was a little boy I had the opportunity to listen to a RCA horn record player (His Master’s Voice) and I was intrigued and fascinated to hear music from it. Many years later I had the opportunity to witness the launch of the CD when I was working for Philips (Chile). The sound quality was impressive compared to the records and the impact to the guests was so big that the audience got up applauding the music. Today I offer my applause to you; the difference in listening to CD’s throughout the Lightspeed and other preamps or just the volume control, reminds me of the experience I had of the difference between vinyl and CD.
Congratulations.
kclone's avatar
kclone
679 posts
 
Okay, dumb question. I have an Arte Form i-150 integrated amp with dual light speed attenuators in it. What does that mean? Is that different that what this thread is about or is it just a type of attenuator that can be put into any preamp or integrated?
georgehifi's avatar
georgehifi
10,312 posts
 
Kcloone,
I believe it does have some form of LDR controlled volume in the new version with lcd readout on the front. I did ask Norman the owner of Arte Forma Audio to remove all references to Lightspeed Attenuator which he kindly did, he now calls his ldr volume the Nature Audio Light Sensor Volume Module.
I have no idea if it is my old MkI version, easy for manufacturers and much cheaper to implement into an amp.
I don't think it's the far better sounding MkII version as this would not be a stable environment for it, as the heat inside would change up to 20c at times inside an amp, and the MkII Lightspeed would go in and out of calibration, it could not be listened to without changing balance calibration every 10 mins.

Cheers George
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