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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
catastrofe
90 posts
 
I've been following this discussion with much interest, and I feel inclined to chime in. . .

There have been several comments about the goal of our systems (preamps here specifically) being to sound like the live event. Bill just commented above about hearing Van Morrison live, and feeling that the LSA doesn't provide that experience.

I submit that the role of our systems is to reproduce the recording, not the live event. If the recording doesn't contain the appropriate information or is of poor quality, then by default, if it reproduces the sound of the live event it's coloring the sound. If I happen to like that sound, that's okay but I'm not fooling myself into thinking it's an accurate reproduction of the recording. The question then becomes, "what does the recording actually sound like?".

I think the suggestion is that the LSA provides the best answer to that question, all things being equal.

JMHO
pubul57 OP
3,712 posts
 
I must say that when I come home after listening to a live jazz concert, natural acoustic, unamplified, I realize that if I had a $1,000,000 system, with a perfect room, and and 24/96 digital recordings, it would still never sound like real instruments in a real venue - in some ways it might even sound better, or be more pleasurable at home, but it never really feels like the real thing to me - but that is OK with me, I'm not going to find Coltrane or Mingus at the club down the road either.
clio09
3,370 posts
 
Catastrofe and Pubul57 hit it.

I don't care how hard you try, even if you put considerable investment ($$$$$) and built a custom dedicated room you would not get anywhere near true live sound. You stand a much better chance of getting the true essence of the recording, or at best something that meets your listening preferences and is pleasing. There's nothing wrong with that either. I've been in some really nice listening rooms too, but the replication of live sound (even on a live recording) is not what I hear. Great sound yes, live sound no.

Personally, if you want to replicate live sound go build/buy a studio, club, or music venue and book live performers. If you're going to do it then do it right.
grannyring's avatar
grannyring
6,614 posts
 
Thanks all for the great thread of life here. Van the Man has the same hefty and full bodied voice on all of his last CD's recorded over the past 20 years or so. I simply don't get that or the 3D stage of the recording or live performance with the LSA as much as the Dude. But the Dude is that 1% that may in fact do it better! Ha!

Really, I do think my system is a best/great match for the LSA. My speakers are so very hard to drive with an impedence curve from a low of 2 ohms all the way up to 35 ohms in the bass. It is hard on my OTL amp! Fact is I need more power.

I would welcome the opportunity to bring my Dude over one of your home's with a great LSA matching system and do the A/B. I am most interested in your take away from that experience.

Ok, any takers? I live in Southern ,MN.
grannyring's avatar
grannyring
6,614 posts
 
I do want my system to sound like the natural sound of an instrument or voice un-amplified electronically. A piano for example is the most difficult to get right. That is where I really miss the weight and scale on the LSA as well as large Orchestral works. Even Van the Man and other live events can and do sound great at the right venue. The PA comment does not always define the sound of live music as we know.

I hope to bring my 40 pound active, looks like an amplifier active, to someone's LSA friendly and smokin system soon.
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