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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
grannyring's avatar
grannyring
6,526 posts
 
Ok, please don’t yell at me Fiddler. Please read George’s post below. Seems pretty clear he is saying it is the most accurate means to hearing recorded music. He implies this on his LSA vs all other attempts at a preamp. He has said this same thing in several other posts here. I have no problem with him thinking this or saying it, I just don’t agree and want to voice my opinion.

“the Lightspeed Attenuator (LSA) as you guys have nick named it, is the closest you will get to playing music that's truest to the source (cdp, phono ect), and the truest way to hear the way the recording engineers wanted you to hear how they have recorded the music.

12-31-10: Georgelofi
You are right guys the Lightspeed Attenuator (LSA) as you guys have nick named it, is the closest you will get to playing music that's truest to the source (cdp, phono ect), and the truest way to hear the way the recording engineers wanted you to hear how they have recorded the music.
As it adds nothing and subtracts nothing, like I say it is like you have plugged the (cdp or phono ect) directly into the poweramps input, no preamps at all in the signal path, yet still maintain control over the level (volume).
I accept that for some listeners it's preferable to have the added ambience, echo (if you have microphonic tubes). Also the tonal changes, because all active components have their own signature, even different brand potentiometers (Alps, Bournes, Penny&Giles ect)) sound different, compared to a direct (source to poweramp connection) gives, maybe to their ears this is preferable.
But the Lightspeed Attenuator is all about listening to the source nothing added nothing subtracted warts and all.
kevinzoe
167 posts
 
. . . now that that school yard bickering is finished ;) let's get back to the topic of the Lightspeed and its performance . . .

I took posession of my Lightspeed last week and have only about 5hours on it thus far. Last night I was listening to Bobby McFerrin's latest CD which is a spectacular vocal potpori of harmonies, complex arrangements and some rather interesting African tribal chants and rythmns. I got goose bumps listening to it and for the first time those goose bumps migrated down my body to my legs - wow, what a sonic affect and physical sensation.

Now considering that I am using an old Sony 5 disc carosel CD player and that my room treatments were in disaray due to some current reno's I'm doing, I would hazard to guess that these sub-optimal conditions that didn't exist when I used to use my Audio Aero Capitole MKII SE CD/Pre speak volumes to the excellent quality of the Lightspeed.

Of course you could argue that with so many different variables that it's next to impossible to isolate the sonic goose bumps to the Lightspeed alone, and of course you'd be correct. However, I'm pretty sure the Sony's sonic quality isn't as good as the Capitole so what I heard was an improvement, plain and simple.

Congrats George!

Kevin
clio09
3,360 posts
 
Ok, please don’t yell at me Fiddler. Please read George’s post below. Seems pretty clear he is saying it is the most accurate means to hearing recorded music. He implies this on his LSA vs all other attempts at a preamp. He has said this same thing in several other posts here. I have no problem with him thinking this or saying it, I just don’t agree and want to voice my opinion.
Grannyring

I don't have any problem with people disagreeing or voicing their opinion as long as they are not shilling (which you are not) and are open to respectful rebuttal, as you have been. Nor do I take issue with George's strong comments regarding his design. As I said previously I like his conviction.

I don't see any examples of him selling though (and I didn't interpret your comments to indicate he is). That's kind of where I'm puzzled.
pubul57 OP
3,712 posts
 
I guess we will not, nor can we. resolve the issues of what is best, and if the LSA is better than Product X, Y, or Z, and the try to deal with the issue of what "better" means and in what context. Maybe if the Subject were: Lightspeed Attenuator - Worth a Try...." we would be closer on the subject. BUt. I think we all understand that how good we think the LSA versus other great line stages will depend on the amp it is used with and other factors, and the kind of sound we like, which we are perfectly entitled to, and isn't worth arguing about, that is fruitless and can turn personal which would be ridiculous.

Perhaps the issue of active versus passive, and when one approach would be preferable is a more interesting technical subject - for example Ralph Karsten seems to often that the real issues is controlling the preamps ability to control the interconnect, and even then I think he admits it is more of an issue if you have the need to run long interconnects. On the other hand, he makes very good linestages and is never going to say you don't need an active linestage, I would not expect that of him. In fact, I think his amps do benefit from an active linestage with some gain.

These discussion are interesting for folks that love the hobby and gear. For my non-audiophile brother who just wants to listen to music, I would tell him to get the LSA/RM10 combo for less than $2,500, a speaker that can be driven by 35 watts, and feel comfortable that I gave him very good advice in building an excellent, affordable system.
clio09
3,360 posts
 
For my non-audiophile brother who just wants to listen to music, I would tell him to get the LSA/RM10 combo for less than $2,500, a speaker that can be driven by 35 watts, and feel comfortable that I gave him very good advice in building an excellent, affordable system.

Without a source he isn't going to be able to listen to his system;)
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