2. amps-preamps
  3. 1276356977

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
 
If you like the grape, you'll like the wine 98% of time, no matter what the $$$.
clio09
3,360 posts
 
Maybe true to the source should be more about the least coloration added to something that's been colored from the beginning. By that I mean we need to take into account what the recording engineer adds to the mix before it gets stamped as a disc or a piece of vinyl and can be played on our sources. Lets even go further, the instruments played by the musicians add color to a recording whether by composition (ex. wood) or effects(ex. tube guitar amps or feedback).

From a recording perspective, not all recordings are made live in the studio or venue. Although I enjoy those types of recordings best. Many times the musicians that play on a recording are not even in the studio at the same time when their parts are recorded. Then take into account all the equipment and cables used, as well as mixing/EQ.

Knghifi's point is valid, everything contributes to the sound we hear. It's a system after all, and for me the system should offer the least coloration possible. I've told many of my firends that the reason I prefer passive preamps is that our systems already have more than enough gain, why add more to the mix. Seems Nelson Pass said pretty much the same thing in an excerpt from one of his designs philosophies that I quoted in a previous post. If I can eliminate one source of coloration from the mix I figure I've taken a step in the right direction (for me anyway).

knghifi
1,668 posts
 
Clio09, I see you point. Removing one sonic signature will improve the overall accuracy of the orig source ... one less to muck it up. For me, when dealing with so many sonic signatures in a system, removing one is not very significant to the overall result. Finding the correct combination is more important.
jdec
123 posts
 
>> Maybe true to the source should be more about the least coloration added to something that's been colored from the beginning.
...
If I can eliminate one source of coloration from the mix I figure I've taken a step in the right direction (for me anyway).
<< Clio09

You get it.
pubul57 OP
3,712 posts
 
"If I can eliminate one source of coloration from the mix I figure I've taken a step in the right direction (for me anyway)."

I think that is why things like soundstaging seem to change more than usual from recording to recording with the LSA - it is putting less of a imprint that carries through for every recording. The question becomes does the recording have depth, width, and localization cues - when it does, the LSA sounds like that, when it doesn't the LSA shows that too. The more neutral the system, the greater variation of these types of attributes from recording to recording. I think this was Ken Stevens' (CAT)notion of a preamp having the color of water, for him you should never be able to tell what preamp is in the chain, there should not be a sonic sameness between recordings that the footprint of the preamps sonic signature. No right or wrong here, I think, just a chosen approach to building a system, one that appeals to my sense of things.
More to discover