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.

Showing 24 responses by fiddler

I love my Lightspeed, but it is not in my system for one simple reason. My Supratek Chardonnay is equal to the Lightspeed in all regards; transparency, slam, finesse, soundstage, etc., but my Chardonnay is not stock. It has a DACT attenuator and VCaps, both of which added much greater transparency. I also use WE 350B's that take the Chardonnay to another level, IMHO.

The only thing the Lightspeed can't do that my Supratek can is to add the 3 dimensionality and warmth of tubes. That speaks volumes considering the Lightspeed costs only 500 bucks. But regardless of price, the Lightspeed is phenomenal.

give it at least a week. It will open up more.

Question. Are you listening to the LSA with new RCA IC's?

Your experience mirrors mine. If you look back in this thread, I originally posted that my Supratek bettered the LSA in my system during my initial trial period, which as I recall, was a rather short audition. I later gave the LSA another chance after reading how many mega-dollar preamps had fallen to the LSA.

I re-inserted the LSA into my system and left it there. Sure enough, I finally had to admit the LSA bettered my Supratek (which, by the way had been considerably improved with a DACT attenuator, V-Caps, better wiring, WE 350Bs, etc.)

In truth, the LSA was only very, very slightly better than my Supratek, but wow it is so much more user friendly without the hassle of tubes.
Quit your whining. Virtually every thread on Audiogon displays this type of "mine is the best because I own it or I built it" post. Why are you so surprised it happened here.

And the posters in this thread have certainly not been cheerleading the LSA any more than you do TRL products. Does this sound familiar, "TRL ST-225 is the best I have owned. No remote however. It absolutely opened up my music collection like no other high end piece of gear I have ever heard. An utter and complete step beyond anything I have heard regardless of price.

I cannot imagine a better sounding set-up. If so, I want it yesterday!"

And this is just one example.
"Seems I am being attacked for no real reason by you."

"This has not been done by all, but by some. It happened to me and Knghifi when we reported our findings in an open and honest manner."

Sure sounds like whining to me.

This is a typical Audiogon exchange seen here everyday where owners or designers defend their equipment, legitimate or not. And I don't see anyone being attacked in this thread. The closest thing I see to someone attacking another person is you attacking Georgelofi.

Georgelofi simply asked a legitimate design question relative to synergy with the TRL and you got your panties in a wad. Apparently Georgelofi isn't entitled to question a TRL product or its specs because as we know, the TRL is, ""An utter and complete step beyond anything (you) have heard regardless of price."

Maybe if TRL was more forthcoming on their website with some specs other than a picture and a price, we wouldn't be having this conversation.
"...purest reflection of the recording..."

Excellent post Pubul57.

When comparing my Supratek to the LSA, I did find the Supratek to be just as transparent without any "usual" tube colorations. I was actually surprised that the Supratek is as neutral as it is being a tube component.

Where I found the LSA to be very slightly better was in the lack of any sibilance. Admittedly, I only heard a very slight amount with the Supratek, but I HATE sibilance. So in the end, the LSA and my Supratek sounded almost identical to my ear. The only area where I thought the Supratek may be slightly superior was in the depth of the soundstage.

In the end, the LSA seems to give me vitually all of the positives of my Supratek without any clearly identifiable sacrifices. The good news is that the Supratek seems as transparent as the excellent LSA passive and the LSA seems to be as bold, dynamic and full-bodied as an outstanding, highly-regarded tube preamp. They both are excellent.
Knghifi, with all due respect, you can move on at any time.

The discussion regarding "coloration" and "alteration" of the original signal by EVERY component is a legitimate discussion here. As much I enjoy some things that tubes do (I have them in my system), there is a limit to the tube "effects" that I am willing to accept.

As I stated earlier, I was surprised to hear just how little my Supratek altered the signal when compared to the LSA. They are virtually indistinguishable. That's why I opted to use the lower maintenance, no-heat LSA instead.

No one is passing judgment here on whether another person should or should not like a particular component's coloration. Clearly there are those who attempt to hear the original source as close as possible and then there are those who prefer the addition of some tube euphonics (I'm one of them). That's not to say that either is right or wrong, it is merely a personal preference.

However, there can be no debate that the LSA adds less to the signal than your VAC preamp if you are hearing more artifacts from the VAC. It is clearly not debatable. Now does the VAC make the music sound more real to you? That is another question. But sounding more real versus accurately reproducing what is on the recording are two different things. Let's face it, some recording are done so poorly that it does sound like something is missing and that something does need to be added. The only problem with a component adding to a bad recording is that the component is also adding to good recordings. The simple question remains - does your ear like what is being added. That's all that matters.

That's why Baskin Robbins sells 21 flavors.

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.

I haven't for a moment felt that Georgelofi was "selling". Defending? Sure, and rightly so.

In my opinion, there have been numerous manufacturers, modders, retailers, etc. that have been egregious in attempting to sell their wares here on the 'Gon, and possibly even Ralph Karsten. I have great respect for Mr. Karsten, but I have ocassionnaly thought that his responses on the 'Gon were as much about sales as defending his products.

If George's motive here was about selling, why would he have given his product away to the DIY community for free? Jump over to DIYaudio and look at the thread there. He gave his design away for free from the very beginning and he made countless posts there trying to help guys with their build. The LSA thread at DIYaudio makes this thread pale in comparison. I reiterate, why would a guy who has freely given his design away for free push hard to sell it here? It doesn't make any sense and it would be counter-productive.

I suspect, based on results, George could be selling the LSA for easily twice what he is selling it for.

Given the facts, your accusation appears hollow, in my opinion.
Teajay, I get the problem now. You aren't carefully reading the posts here .

I didn't say you were being nefarious. Re-read my post. "Nefarious" was related to George's "defense".

And you are still implying that George is marketing his wares, "difference between someone like Nelson Pass who gives things away to the DIY community but does not use Audiogon threads to market his wares..."

As I said before, you haven't given one example of George, "marketing his wares". You just keep twisting words to try to defend your position.

And when did I ever imply you were an SOB? More twisting of words.

And talk about being silly. You clearly know that when I said, "that George has given it all away", that I was talking about his IP. I even used "IP" and "design" in my posts. I think it is clear who is being disingenuous here.

"Gee whiz, guys lighten up."

Take a little of your own advice. Had you not accused George of "selling" here in the first place (once again, without one example to back the charge up) we wouldn't be having this conversation.

And BTW, George isn't a friend or hero. I've never met the man, seen the man or even talked to the man. I simply don't like to see people falsely accused without one speck of evidence being provided to back up the claim.

And I agree it is unfortunate that this thread got sidetracked from the OP's question which was offered with a lot of caveats:

"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."
This thread was way more fun before you guys all turned into pantywaists!
"That is lost on a lot of sound systems that I have listen to."

"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."

I think that is what those of us who prefer the LSA to our actives have been trying to say. For us, the music sounds "for what we believe to be" more true to the actual source. (SOURCE being defined as the actual medium we spin vs. SOURCE being defined as what happened in the studio.) We have no control over what happened in the studio, therefore, that discussion is a non-starter for me. I can't change a single decision made during the recording process. I can only try to extract the information from the recording as accurately as my equipment will let me and change the sound of it to the degree that I want to KNOWINGLY change it.

I have tubes in my system. However, I do understand what they do to the sound; how they change it. That's what tube-rolling is all about. I don't try to kid myself. I can change the sound of my system with just two tubes and I am sure you guys can too. That's why I don't understand the debate about actives (tubes) versus passives as far as which one is more true to the source.

There is no debate in my mind that adding more and more caps, resistors, wire, tubes, etc. change the sound. The addition of more or different parts may make the music sound more appealing, but those same additions will never be as true to the source as a straight wire or as close to a straight wire as we can get. Parts have sounds.

After modding some of my own equipment it is abundantly clear what a difference parts make. No need to talk about caps, wire, tubes, interstage transformers, output transformers, etc. Simply swap out a cheap Alps pot with a DACT attenuator and hear the difference. And that's a difference of simple resistors!

For me, the LSA is much closer to a straight wire than my active. I can clearly hear more subtle differences with the LSA whereas my active lends a slight sameness to the sound depending on which tubes I am using (which by the way is the joy AND frustration of tube-rolling.)

If you have a Lightspeed, open it up. Then open your active. See which one is closer to a straight wire. You already know the answer. It's not even close :)

You keep arguing with conventional and accepted audio design that the ultimate attenuator would be a straight wire. You can argue all you want about extracting this and that, but your argument flies in the face of generally accepted wisdom.

You may prefer the sound of your preamp. Fine. But it is not extracting more of anything. It is simply adding a particular color and artifacts to the original source that you find appealing. Nothing wrong with that, I like tubes too, but that's simply the fact of the matter.

And I don't understand why you continue to argue when in your own words in another thread you make the case, "In general tubes will get you more midrange warmth and bloom. But this is not always the case. I am sure the TRL will give you this while also improving a host of other things we all want in our sound systems."

Once again, in your own words you are "sure" the TRL Dude, "will give you" ... "more midrange warmth and bloom." That is additive - end of story! And don't even try to say it does that by extracting more of the signal. That's simple nonsense. And it's easy enough to prove. Just roll some tubes and listen to the subtle or not so subtle changes.

You can't have it both ways. Either you were wrong in the thread I quoted or you are wrong here. Which is it? Conventional design wisdom says you are wrong here.

You are beating a dead horse.
"Fiddler, you are for some reason quite short with me in your remarks. No reason to be so strong with me..."

Wow, are you an overly-sensitive guy or what, Grannyring! Like I said earlier, "Quit your whining."

(BTW, if you haven't seen it, look for this commercial. "Ask your doctor, it may be as simple as Low T.")

You said, "You take these past posts and apply them to a current thread totally out of context."

Nonsense. Your quote from that past thread was in perfect context here. Go read the thread. You just don't like it because you got busted in your own words. "You took me out of context" is the last refuge of a desperate man.

"You seem to suggest I am not worthy of this topic and to stop having input on this thread." Nope...didn't suggest that anywhere. I simply said you are beating a dead horse and your argument flies in the face of conventional audio wisdom.

And if you feel I have been short with you, I didn't mean to be - I meant to be direct.

"No reason to be so strong with me..."

This statement concerns me a little. Would you prefer I use a feather boa next time? Please refer back to the aforementioned commercial.

If you want to continue to tilt at windmills here - knock yourself out.

I may indeed craft a scintillating response if you have anything of significance to add here. However, at the moment the motivation is absent.
"...George keeps pushing for his own finacial gain."

How do you know what George's motivations are? Maybe you should set up a psychic hotline.

Seems to me if a guy was interested in financial gain, he would price his unit more in line with other passives (read: higher priced) and that same guy wouldn't put his design out there for free on

Doesn't make much sense does it?

Next conspiracy theory...
All we need now is some cheese...
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!
I have to eat a little crow.

I posted earlier that I preferred my Supratek linestage to the LS due to an added dimensionality and warmth that tubes offer with all other thngs being equal between the two.

Well, reading this threat spurred me to put the LS back into my system for another listen. I'm glad I did.

The first time I compared the two I simply connected the LS to my system with it sitting on a cardboard box on the floor. This time I went to the trouble to take my Supratek out of my system and I put the LS on the same shelving and footers I use with my Supratek.

This time I must say the LS is slightly more transparent, with equal slam, warmth, tonality soundstage width, etc. The only area that may be up for grabs is on some recordings the soundstage is slightly more forward with the Supratek. I'm not saying that is a better thing, but rather a simple difference.

To be honest, the two are so close that I have to really, really, really try hard to tell the two apart. I listened to several recordings that I know exceedingly well and I swear had I not known that I took my Supratek out of my system, I don't think I would have noticed.

The biggest problem I have with my Supratek is getting good 6SN7's, both NOS & current production, that don't have issues at some point, i.e. microphonics, loud hissing (not typical tube noise), whistling, cracking & popping, etc.

I just purchased a pair of the new Shuguang Treasure CV181-Z to try. They sounded as good or better than any NOS 6SN7 I have ever tried, including TS RP and 52 Bad Boys. However, one went extremely microphonic between 30-40 hours. As much as I love tubes, they frustrate the crap out of me at times.

So, I am sticking with the LS for the time being. I tried to be as objective as I could between the two preamps and when comparing apples to apples (same shelving & isolation) I have come to the conclusion I don't think I could tell them apart in a blind test.

Thanks for an incredible product George at an unbelievable price.
Teajay, you posted, "I have no historical awareness that Ralph or any other well known designer has ever pushed as hard to sell his product as George has, if you can remember someone please share."

You didn't just "share your opinion". In your own words you flat out accused George of pushing hard to “sell his product".

And the fact that Nelson Pass has given much to the DIY community has nothing to with this discussion other than to offer some misdirection and a weak attempt to justify your accusation after you were made aware George had given his IP away.

And in your last post your accusatory tone continues by saying, "...and secondly this not DIYaudio, but Audiogon were threads normally are not used by designers to sell products, and if they do they are rightly called out on it."

If anyone is being negative and bombastic here, it is you. We can both agree that designers should be called out here for shilling their products. I'm with you on that one. But it is my opinion that your accusations against George have been grossly unfair. Considering the fact that you haven't given a single, concrete example of where George has attempted to sell his product to anyone, combined with the fact that he freely gives his design away; it appears you are left with a rather untenable position.

Teajay, I will be the first to join in with you when someone is truly shilling here (and it happens often), but I think you may simply be misinterpreting George's defense of his baby as something more nefarious, especially in light of the fact he has given it all away.

Why are you so worked up over how George says what he says. He has every right to voice his opinion whether you think it is arrogant or not. And simply because you don't like his "absolutes", who are you to question his right to post however he wants. Your haranguing of George sounds a lot like an attempt at censorship and censorship is not at all what makes your "home base" thrive.

My OPINION is that you come across just as arrogant as George does at times. If you aren't interested in the Lightspeed, why bother continuing to come into the thread to stir the pot? Just like George, you are free to post however you like, but where's you dog in the fight?

Your constant haranguing of George is clearly a veiled attempt to stifle and build consensus against what you don't like about George's posts, otherwise you wouldn't be here wasting everyone's time.

"Being the arrogant bastard that I am..."

Well - finally you offered something worth reading.