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 13 responses by b_limo

I'm curious about that too. I'm using two matched pairs of blue jeans interconnects that sounded like poo between my dac and classe pre amp, and between my classe pre amp and classe amp. For dome reason, they sound fantastic with the lightspeed. I can't wait if it will sound better using some analysis plus or signal cables :-)
I just recieved my lightspeed this morning. First off, George does great business. He e-mailed me back three or four times a day in the beginning in order to answer any and all of my questions. Second, he over delivers on his promises. I was expecting it would take 5 to 7 weeks for me to recieve my lightspeed and it took about three weeks.

Now, for the sound. Talk about transparent and detailed! My system had some grunge, a little bit of mid range mud I guess you could say. Well it's all gone; all of it. My sound is so clear and transparent that if I had to stop here with the upgrades, I'd finally be satisfied. Everything from here (power cords, isolation footers for my components, more room treatments, analysis plus interconnects), it's all icing on the cake. I have finally got the sound I was after.

This "pre amp" is worth it's weight in gold. Don't buy one, buy two and give one to a friend. I'm serious, they're that good.

Thanks again, George!
:-)
Just wanted to say that I'm still happy with my Lightspeed Attenuator. I plan on never getting rid of mine, and in fact, I'll probably buy another one when I build a second rig.

Thanks again George, you're a trooper to still be active in this thread as I'm sure you've answered every question 3 times! If you quit, I'm sure no one would blame you and I'm sure you'd still be selling Lightspeed Attenuators, as they kind of sell themselves.

Incredible product, ridiculously low priced for what you get!
How is my battery pack comparing to these wal warts? I went with the battery pack because I thought it was better...

I'd prefer not to go to the teradak simply because the battery pack looks cleaner and I don't have to buy another powercord and I only have 2 components plugged into my ps audio quintet in different banks.

If the teradack is going to be an improvement over the battery pack, well of course I'll buy it, but it seems like you guys are comparing the teradack to the worst power supply (smp is the worst one, right?) and not the linear one. I read some comparisons between the linear power supply vs. the battery pack, and the battery pack supposedly sounded better...
Off Topic but I wanted to say I switched from a Classe CA-150 amp to a Prima Luna Prologue 5 lastnight and the lightspeed works great on both. No problem whatsoever with using the lightspeed with the Prima Luna; it sounds great! I secretly thank George everytime I fire up my rig. His piece is one of about four that changed my rig from mid-fi to hi-fi.
My bad Banquo, didn't see the link, didn'tknow you looked into it at all, let alone actually digging around a bit. I apologize. I'll check the link, but like I said, I'll probablyend up just buying the terradak to back up my battery pack and will report back.

George, two questions: does the lightspeed ever need to be recalibrated? It seems like my volume control may be adjusting in larger increments than before...

Question 2: is it okay to dress it up a bit? I was thinking about a small wooden case or having it professionally painted.
Thanks George.

What about painting the exterior chasis of the lightspeed with automotive paint? Yes, no?
George,

Another quick question: would the lightspeed attenuator work well with a prima luna prologue five tube amp?

Input impedance 100 kohm
input sensitivity 600 mv (the man. site said 600mv on one page, 775mv on another...)

Thanks in advance, George!
Thanks Clio!

Well put Lacee. I'm no skeptic when it comes to upgraded power supplies or power cords; they've all made improvents in my system, so I don't know why I'm skeptical over an upgraded power supply for the lightspeed (maybe because someone (George?) said that rubbing two sticks together is enought to power the lightspeed, lol. I'll be getting a teradak next month to compare to the battery pack I'm currently using.

Now if there was a way to harness all the damn static electricity in my house, I could power all my equipment for free...
Milpai, I was wondering if you were going to be able to pick up on the ringing that George was talking about. Guess its a good thing that you can't!

Soundgyy, good to see another happy Lightspeed owner. I had to sell mine but will have to buy another one when I have the funds available. It's the only pre amp I've had in my system that removes ALL of that slight haze or fog that is present with any other preamp I've tried. Another thanks for your thoughts on the wavetouch speakers; if they didn't look like pinocchio I'd consider them, but I can't get past that "happyto see me" look.

Milpai, I'd be interested in you comparing a Lightspeed to your tvc...
Hmmm, Interesting. I'm a believer in upgraded power cords, power supplies and outlets but I can't see how this could make the lightspeed sound better.

Correct me if I'm wrong, George, but the light in your Lightspeed Attenuator is really only controlling volume, right? I don't see how there could be "dirty" light....

I'm confused, but if Banquo continues to hear a difference I'll give it a try also.
Lacee and Banquo,
Come on guys, if you won't tell us, or find out, whether you were using an smp wall wart or linear, maybe you could tell us the brand and model number so we can look it up??

It's funny that I'm on the other side of the upgraded power supply debate on this one, because I upgrade all of my power supplies and power cords, but I just don't see how this teradak would be an upgrade over the battery pack. It just seems logical to me that if it's a linear power supply, and your power supply isn't introducing noise into your system, then you would'nt gain anything here.

George states "A 300mA wall wart will power 6 x Lightspeeds. So it's not a question of power, thicker wires or getting more current to the Lightspeed. ".

I have been thinking about buying a wall wart to back up my battery for those times when I forget to shut off my battery pack, now I'll get a terra dak and compare it to my battery pack. I must say though, I don't like the idea of buying another upgraded power cord for the terra dak but whatever.
This thread has had 18 million views... that is nuts.

I had a lightspeed years ago.  Should have never sold it.  They are the best preamp for the $ no doubt.  It really does just get out of the way of the signal.  You do need proper gain matching but if you have that, a good dac and a good amp, the lightspeed is just awesome.