Lightspeed Attenuator - Best Preamp Ever?

Considering Nelson has freely participated and contributed schematics on the Lightspeed thread over on DIYAudio, I'd have to say he must feel this is a pretty good design and it certainly got his attention (as it has other designers of note). Problem with most Pass/First Watt amps is they are not ideally suited to passive designs due to their low input impedance (this is obviously why Nelson designed the First Watt B1 buffer and Pass Labs markets an active line of preamps).

Here's a good read from Nelson:

http://firstwatt.com/articles.html

Click on the B1 Buffer Preamp link.

Seems Nelson reiterates a few things we've been saying around here about ideal conditions (impedance matching) and offers his method and design to avoid that.

Here's an excerpt:

So here we are in the New Millennium, and thanks to Tom Holman and THX we’ve got lots of gain in our electronics. More gain than some of us need or want. At least 10 db more.

Think of it this way: If you are running your volume control down around 9 o’clock, you are actually throwing away signal level so that a subsequent gain stage can make it back up.

Routinely DIYers opt to make themselves a “passive preamp” - just an input selector and a volume control. What could be better? Hardly any noise or distortion added by these
simple passive parts. No feedback, no worrying about what type of capacitors – just musical perfection.

And yet there are guys out there who don’t care for the result. “It sucks the life out of the music”, is a commonly heard refrain (really - I’m being serious here!). Maybe they are reacting psychologically to the need to turn the volume control up compared to an active preamp.

I suppose if I had to floor the accelerator to drive 55 mph, maybe I’d think the life was being sucked out of my driving. Then again, maybe I like 55. Nice and safe, good gas mileage…

Is impedance matching an issue? Passive volume controls do have to make a trade-off between input impedance and output impedance. If the input impedance is high, making the input to the volume control easy for the source to drive, then the output impedance is also high, possibly creating difficulty with the input impedance of the power amplifier. And vice versa: If your amplifier prefers low source impedance, then your signal source might have to look at low impedance in the volume control.

I especially like the use of the terms "just musical perfection", "really - I'm being serious here", and "reacting psychologically" in the article to emphasize some very interesting points (and all of this of course coming from a genius).

Would be nice to have a First Watt Lightspeed/B1, with the ability to toggle between straight and buffered (when needed), along with multiple inputs (3?)

yep;)

I think the XLR is a bit of a reach though. Alas...

Seems to be heating up again. Teajay, you're bold to try and speak for some middle ground on this thread. Many that post here are very reasoned and good folks. Like you have said in several of your recent posts, the issue is not with most of the seasoned, good-hearted posters here, but rather the builder of the LSA. On more than one occasion he has said active designers and those that prefer actives, do so for one of these (less than righteous) reasons. Yes, I am paraphrasing a tad, but spot on in intention.

- have a tin ear
- like distortion
- in it for the money only
- charging tooooo much
- LSA is absolutely THE standard

Fact is many Aphiles like actives because well executed ones sound more like music to us. No, we are not tin eared or crooks. No, we do not like distortion. Yes, we like natural sounding music. Fact is, many roads lead to this musical end!

Absolute statements by the builder are absolutely out of bounds here. He can argue his point if he like, but stay away from absolutes! The rest of us are free to use absolutes - to our own peril :-) Not the builder. Just my opinion.

"...fact is, many roads lead to this musical end!"

Very true - there will always be a place and purpose for well designed active line stages, and I have no doubt that there will be systems in which they sound much better than any passive might, for a variety of reasons.

Having found the LSA through the DIY thread, the one thing that never seemed to be the case was that George was primarily interested in making much money on this, or really making a business of it. Sounded to me like if he could pull it off, he would rather license his patent to other folks who might too think it is a good idea, collect some royalties, and spend some time surfing. And he seems to be a true believer in his approach - rightly or wrongly - which as you suggest, doesn't mean it is the only approach to musical satisfaction.

First to Grannyring,

Thanks for pointing out that the major and really only criticism, with a few exceptions regarding other posters nasty responses about me and my opinion on Paul's thread, has been the repeated posts of George not to educate and inform in a respectful way, but his arrogant position that only he knows what really produces music the right way which justs happens to be his linestage. You might have paraphrased his frequent putdowns of anyone who does not agree, but your spot on at seeing it. I also have brought in the subject of him using this thread for pushing and marketing in a way I have never really seen on an AudioGon thread before. If it's not for financial reasons then he must really be a total egotist and thinks his opinion and device are a true gift to the audiophile community. If you think it's bold of me to share my opinion on this ongoing love letter to George, thanks for the support and compliment.

Secondly to Paul,

I never participate and rarely visit any DIY sites on the web. I admit my ignorance regarding how George comes across on those boards in his statements. My home base is this forum and this community, that's what I care about. You who never in any of your writing comes across with either dogma or any arrogance at all, why do you chose to be an apologist for this designer over and over again on your thread? Not the position that he's of course entitled to his opinion like we all are, but you seem unwilling to address the kind of remarks that Grannyring pointed out that run totally through George's remarks on your thread. You just say,"George thinks he has a great idea, and will argue its merits", implies he does this in a respectful and tolerant way towards people who don't see it his way. I don't think the facts back that up. I just don't get it, are you dear personal friend of his? Just not your nature to give him some feedback about his arrogant and condescending remarks on this forum? Some how your support for his LSA would be negated by being more blunt regarding how he comes across? Maybe by nature you are talented diplomat and just want to stay above the fray, and stick to the subject of your post. However Paul, in my opinion, George has really screwed up your very good and informational thread for the above stated reasons. So my respectful request to you is instead of another "spin" like, "he seems to be a true believer in his approach-rightly or wrongly", share what your honest opinion is regarding his writing here, just a passionate fellow or an arrogant blow hard regardless if he would rather be surfing or not.