2. amps-preamps
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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
fiddler
581 posts
 
Teajay wrote, "I will also never directly reply to any of your statements that might include me in the future because it would be a waste of my time."

How about wasting everyone else's time? Ever think about that? But nooooooo - it's all about me!
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charles1dad's avatar
charles1dad
10,250 posts
 
Unsound,
I don`t believe Mr.Tsuda, Nelson Pass, Kevin Hayes(VAC) Israel Blume(coincident) just to name a few very accomplished designers of active linestages would come on a public forum and mock/dismiss someone else`s work.

There`s such a thing as decorum, class and restraint that would prevent them from such smug and arrogant behavior.
I`m sure these men believe in their ideas and products as much as george.

I don`t believe they would put down those who after auditioning their components and then decidimg to choose another brand,they would`nt blame the listener`s system or attribute it to an inability to hear(the epitome of patronizing attitude).

Following this thread for a while, my take is that for some the Lightspeed will be ideal and make them very content.
Those who have taken the time and effort to audition this component and then selected something more to their liking don`t need to be subjected to, well you just prefer distortion and colorations. Utter nonsense.
pubul57 OP
3,712 posts
 
Why is a preference for distortion and/or coloration utter nonsense? What is wrong with prefering it. Distortion is measureable, not a subjective gremlin, what if you also happen to like the the piece with more distortion? How many folks have loved CJ equipment over the years knowing full well it was colored, but in a very satisfying way.

What I do suspect is that the signal from the source output is closer to the signal coming from the LSA output than if the signal must go through an active linestage. One might differ on whether this is what we should want, or what we should prefer, but I think (not 100% sure) that this would be measurably the fact of the matter, measurably truer to the source (meaning the CD player output, not the live performance). If the active linestage alters the relationship between the two (source ouput/preamp output) it is inarguably a distortion (and not true or part of what is exist in the signal at the source output connection) -- which you might very well prefer.

Carver's Hologram generator sure did unflatten a soundstage, but it was no part the recording, it was an effect, an artifact created by altering the source signal and delivering something different to the amp. And it may be lovely, enjoyable, pleasant, wondeful, magical, mysterious, etc. - but whatever it is, I just don't see how it can be said to true to the source, true in a measureable and meaningful way - assuming what we measure is relevant.
clio09
3,355 posts
 
George,

You, I, and your tube gurus will just have to agree to disagree on this one. I think there could be more to this than we know and if so it may give you and some of the tube gurus the information needed to fully understand the circuit design. However, I'm not going to waste Masa Tsuda's time on this any longer given that he is not prone to be part of a public debate.

Suffice it to say as I have stated before I believe Masa Tsuda's specifications for output impedance and can verify that from my own personal use of the CF-080 the tube sockets hold the tube pins tightly and there is no reason for concern that they would fall out. The purpose of the roll bars is to protect the tubes from being banged up against something.

I consider both you and Masa very competent designers who have different approaches to achieving specified goals for your respective products. Each of you also have very different personalities. Like I said in a previous thread, what we probably have is a failure to communicate. It's obvious your personality rubs some people the wrong way. For me, that is not an issue, I can handle that. Others, well we know how they react. I agree that one in particular would like to see this thread go away and their behavior shows it. Enough said on that subject.

You have been very generous with sharing your ideas and helping people like me learn about a new product that has enhanced my system. Masa Tsuda has done that as well, and in the process become a friend. Like I also said before, if I ever get down under I would certainly enjoy quaffing a few beers with you.

Let's get this thread back on course and continue the discussion on the LSA. Also I'd like to discuss this Warpspeed if you are inclined. Seems like another interesting approach.
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