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

Showing 14 responses by marqmike

marqmike
850 posts
 
This kind of shared info is greatly appreciated. I am getting a LSA, and I don't even know if it will work. But I use a passive now(Sumo Athena in passive mode with a Sumo Polaris amp, it has about half the gain than the active side but sounds better), so I am hoping it will. What I would like some of you with experience with the LSA to share and keep going with this thread, what is a good(excellent sounding) amp and cd player to use with the LSA specifically? When I get mine and use it I will give my thoughts. Thanks.
marqmike
850 posts
 
Thanks Pubul57 and Clio09. My amp has input impedence of 47 KOhms and input sensitivity of 1.27 Volts rms, my source has a output impedence of 120 ohms and output voltage of 2 Volts. It is close to what you and George S. recommend so it should work. If not it might be time for some newer items, mine is over 20yrs old. It sounds like this could be a great reviewers tool? Thanks for the input.
marqmike
850 posts
 
I have had my LSA for about 3 weeks. George is great to deal with by the way. However my LSA is even better to deal with. I hope it doesn't have any longeity issues it is that good. Many people will mention specs, design superiorities or faults, and other reasons to make excuses for their equipment. George does not. In fact George is not positive(he thinks he knows)even why it sounds so good compared to other passives-actives and whatever in the right system. I for one find that honesty refreshing. But the proof is in the sound or listening. In my system the sound becomes a lot more colorful steeped in more accuracy of the natural tones and timing of real music. As a play around guitar player and a 35 year audiophile I hear way more of the real tags of music in persnickity audiophile terms. Equipment I have used is Jeff Rowland Consumate, Audio Research LS1, Forte 40, Sumo Athena passive/active. I don't know what could be this good. Just some old timey input. Keep up the good info on this line.
marqmike
850 posts
 
I want to chime in. I deal with color in differnt aspects of my business. I don't know if anybody is familiar with the gray scale? Color is measured, but not perfectly, by three primary qualities. Shade, intensity, and depth. The varieties are infinite as far as our eyes are concerned. Musical sounds are very similar, endless varieties. I think where it went wrong for me was going to digital before it could start to produce the endless varieties of sound that analog can. To me digital is better but it is still struggling. Sound systems I have heard over the last +40 yrs, many giving hours of listening, some with good tone, seem to be to restricted to way fewer different sounds than what I like and can achive. For instance I play the guitar, and when I go look at a new guitar I can look at 2 guitars or more, the same guitar, same brand, same model, same person putting it together, same close time of build, same wood from the same batch of wood(same tree and place on tree), everything possible the same and they all always sound different, quite a bit different. Most audiophiles I know (but there are a few that can) cannot hear a difference between such very similar guitars let alone 2 different but similar styled ones. I like to hear what the musician does with his paticular guitar because he may have 10 guitars but he uses the one he is playing specifically for that sound he wamts to achive. That is lost on a lot of sound systems that I have listen to. The same is true of other musicians and their instruments. And I cannot hear the variety of tones in many sound systems that people love and say it sounds like music. I don't deny it is music to their ears, it sounds good and it is musical. But it short changes the colors of sound that I like to hear. That is where I hear the biggest difference between passives and actives. From my experience even though you do get pleasant 'natural type' sounds from tube equipment(not all but most) it sounds very similar with all its tones and the result is very few colors of sound to me. It does do other things that make listening pleasant such as space, air, adds a bit of continuity or flow a tiny bit like analog off a LP. Solid state has it plus' and minus'. I like the LSA because it gives more variety of color to the music being played. But I do respect everyone elses tastes for themselves. Hope this doesn't confuse anybody but actually helps.
marqmike
850 posts
 
Hello everyone. I hope I did not sound condecending on my last post. I just wanted to share my view. Everybody here has shared theirs in a positive way, and no doubt helped others that read them. Personally I hear a big difference between actives and passives. What I mean by big, it is big to me. It's when I sit down and spend some time with other equipment accesing it. It is not always right off the bat I notice I don't like its overall presentation as well. I have had a few passives and actives(mind you not over $4,000.00 though, so not super high end but some good ones. That being said all my passives have been very sensitive to everything I do around it. That is both good and not so good. It is good in the sound it results in but in can be a challenge to get there. But when you do it is like the important nuances of sound going from a newspaper color to a high quality magazine color. When I say sensitive I mean everything in the chain. That includes speakers and might be why Grannyring hasn't met his preconceived expectations with the LSA. Yes power on the back side of speaker can help some but in my experience(I don't mean super sensitive) the more sensitive the better, there is a point where insensitivity can negate benefits of a passive in my experience. I no there is no same absolute standard of neutrality for everyone but in my experience if a source does not sound good behind a passive something down the chain is changing the signal to sound better. Source as is cables and amp all are very important when evaluating a passive. Clio09 said it way back when. He said something like you really have to build your system around the passive. But to me that is a really good place to start. Enjoy your music.
marqmike
850 posts
 
Hey, hey , hey guys. I personally like the LSA to anything I have ever heard, which you can see most of that is on my previous posts. I have experience with real musicians in real space and real time. And from that perspective I find on most non-musician friends and others systems there is to much concern with the 3d thing and spacial ques, it is out of proportion to what I find in real space. And I feel it effects the tonal response of the whole recording and the timber of the instruments and voices. I say sure you can hear a fly land on the back wall of the auditorium but that is not what I listen to a recording for. But the truth is we all live on our own worlds when it comes to music and its reproduction. And that is fine and good.
marqmike
850 posts
 
Agears I hope I did not say mine was better than yours. Even musicians don't agree on sound. But that it is my perspective. I haven't even speculated in this thread as to the reason why, I think I know the simple answer, it is the 'why' in every other situation that causes something to be closest to the original. Anyway I thought my perspective would help someone looking at this thread or LSA for a view. I appreciate others view. We can learn something if we contribute. So George, Pub, Clio09, Atmasphere, Fiddler, Tvad, Grannyring and others thank you for some good information.
marqmike
850 posts
 
I have happily had a Lightspeed for a year now but I would like to have the ability to control both channels independently. It was just mentioned they weren't backward compatible. I was wondering if it would be as good as a dual control Lightspeed to use another regular Lightspeed with mine and just one in and out per attenuator for each channel. Why I ask is I see some regular ones for sale here from time to time. Thanks.
marqmike
850 posts
 
Thanks you George
marqmike
850 posts
 
Thanks Lacee. I am glad George recommended this PS and that you and Banquo263 have used it. So now hearing about its positive effect it is on my list to get as soon as I get my new innerconnect, Amadi Maddie Sign., in my system and broken in. Thanks again.
marqmike
850 posts
 
It is nice to hear ones having success with a passive. I think it takes time and patience to adapt it to a system. This might be quite contrary to what one might think but I think I have found that the more neutral and clean sounding cables are(or I should say what I consider a neural and clean cable because I don't pretend to be a cable expert), the more warmth and fullness in a recording comes out(I am supposing that only if it is on the recording because the LSA doesn't add anything right?). At least that is kind of contrary to what I thought. When I say neutral I don't mean lean or edgier or brighter, I mean what I perceive as a cleaner signal. In fact is seams like the cleaner the signal (less distortion?) you have from source to speakers the better the passive's strengths show. I guess I am saying when a signal doesn't get as muddied up? Just my take but I thought I would share, it may help someone else.
marqmike
850 posts
 
Thanks for the heads up on that Vyokong. Give us some more impressions after you have had them a couple of months. Thanks again.
marqmike
850 posts
 
Thanks Vyokyong
At times I use a Burson ab 160 with my LSA. It is a buffer that is exceptionally organic sounding. I wanted to say tube like but organic/natural sounding is more correct. They are not made anymore but sometimes available used. Now I may change out my internals. Thanks again
marqmike
850 posts
 
Thanks Grannyring on the power supply. I will get one.
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