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
fiddler
581 posts
 
George,

If they don't get that explanation, they ain't gonna get it.

Lots of folks may prefer an active preamp, me included at times. But your explanation above is about as simple as it can get.
knghifi
1,668 posts
 

Georgelofi,
What comes after the source can only be corrupted by more electronics, it cannot fix a "bad" cdp dac or cd. It can only add corruptions, colourations, distortions and euphonics.
There is no magic preamp that can add bits or remove distortions from a cd or re-design a bad output stage in a cdp or dac, you can however falsely add colourations, euphonics, and tonally change things, but this is not "being true to the source".
I believe if you have a source that needs this sort of treatment, you need to get a better one, and one you like, without having to bandaid fix it.

Every component has a sonic signature. It's not bad or good but just a sonic signature. By the time signal reaches the preamp, it has sonic signature of the source and IC. The signal still needs to pass through the amp, ic, speaker cable, speakers, PC .... and will get altered and altered again. In a sound system, you are hearing a combination of 10+ sonic signatures, not just the source and interconnect.

Let's try this, apple juice is the taste all the chefs want you to experience. Once it's mixed with 9 different juices, you are tasting a combination of all the juices. Use water for LSA and is added after the apple juice, apple taste is preserved until you add the 8 different juices. At the end, the taste is the combination of all the juices. Now if the 9 juices have the properties of water, NEUTRAL, then apple will be prominent. I guess this is the reason everybody claims their product is neutral.

It appears my view is more at the system level than yours.


01-03-11: Pubul57
Which Shiraz?
2buckchuck.

Wine is like audio. Price does not equate taste. I have 2 friends that own liquor stores, even with discounts I was spending too much $$ on wine over the years. I was reluctant at first but after I tasted 2buckchuck, I sold ... ok I won't list them :-):-) This is what I drink most of time at home. Doesn't taste like an cheap wine but actually best many more expensive ones.
pubul57 OP
3,712 posts
 
If you like the grape, you'll like the wine 98% of time, no matter what the $$$.
clio09
3,346 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.
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