Lightspeed Attenuator - Best Preamp Ever?

The irony about "simple" designs, with fewer parts, etc, is that it really requires some design chops to execute a great, simple circuit and I suspect it requires a master like Nelson Pass to design some great First Watt and XA.5 amps with such apparent simplicity in lack of complexity.

Or as my fellow Nutmegger Samuel Clemens once wrote:
"I'm sorry that this letter is so long, but I didn't have time to write a shorter one".

Translating this to the post I quoted, it's usually easier to fix a problem by adding a bandaid than it is to go back and rework the design to eliminate the problem.

Clio09, nice job indeed and I have a question for you and all. Seems then all the high end preamps, tube or SS, costing up to $100,000 that are not passive, just can't get it right? Or should I say as right as a passive?

Wonder why all of these manufacturers even bother? Wonder why they are considered by the "experts" as the very best.

Perhaps a passive conspiracy..just kidding.

Let's assume my active preamp is more noisy then the LSA. If it outperforms the passive in many other areas, then it may still be a preamp truer to the recording. Benefits outweigh the short comings kind of thing.

I so want a $450 passive to sound as good, or closer, to my active. I tried several passives with no luck yet. Perhaps I need a tube amp like the RM10 and some high efficiency speakers. While the Atmasphere Ma1 amps had a 100K ohm input impedance perhaps my Soundlab's just did not like the signal from that combo. It was 2D and quite thin. Very clean, quiet and detailed, but kind of white - washed. It reminded me of some Nuforce amps I once owned.

I will say the LSA had great promise when I first put it in my system. I did take notice of how much quieter it was for sure. I also noticed it was smooth and extended in the highs. I also found the bass to be pleasing. Over time the white-washed nature seemed to reveal itself on every CD I played. If I played the LSA and had to make a decision after 30 minutes it would hard to pass it up. After longer listening I became fatigued.

Something tells me my Soundlab speaker/Atmasphere amp combo just preferred an active unit. It would have been very interesting to hear the LSA on my previous Silverline Bolero speakers with the same amps.

If I can take this tube microphonics a step further for those who have tube preamps.
Try this little experiment.
Take the top off the tube preamp and turn on your system and set the volume control at your normal listening position. Then with your finger nail flick down the tops of each tube and have someone listen at the speaker for any sound comming through the drivers. This will show which tubes are microphonic. And in the case of really bad ones it will be heard out in the kitchen. And really really bad ones will feed back to the said tube and cause a runaway effect that can't be stoped.

Cheers George

Just to add to my previous post on microphonic tubes, if you hear a bonk in the speaker because of a slightly microphonic tube/s, this in turn when playing music will give and artificial effect of adding ambience/echo to the music, if that your bag so be it.
But I will always be in the camp of what goes in should be exactly what comes out, nothing added nothing subtracted, warts and all.
Cheers George

Seems then all the high end preamps, tube or SS, costing up to $100,000 that are not passive, just can't get it right? Or should I say as right as a passive?
Grannyring

Well, I think there is a lot more to it than meets the eye. Let's just say designers have their preferences just like the audiophiles that buy their equipment. What's "right" for one may not be "right" for another. Also, designing something that makes you stick out like a sore thumb, regardless of the quality is always riskier, and in many cases less profitable. Especially when your peers are following a certain formula and marketing hype (eiher from reviewers, manufacturers, or other "experts") is telling the public what their expectations should be. This is not specific to home audio either.

Now I'm really going to throw one out there. These designers that market uber expensive amps. How would it come across from the consumer perspective if they matched it with an inexpensive little preamp? Bearing in mind that us consumers, regardless of whether it's audio components, cars, etc. have certain expectations for how $$$$$ translates into perceived quality or perhaps more accurately, status. IMO, these designers wouldn't be taken so seriously. In much the same way as if Ferrari came out and said you don't need top of the line Pirelli's on our cars, we're now going to supply generic Acme Brand tires and all will still be the same. Really?

Let's assume my active preamp is more noisy then the LSA. If it outperforms the passive in many other areas, then it may still be a preamp truer to the recording. Benefits outweigh the short comings kind of thing.
Grannyring

Again, there are specific definitions and preferences in play here, but this is precisely the point.

The truer to the recording thing aside, I'll give a personal equipment example. I've been playing around with a Transcendent Sound T-16 OTL. No one could ever confuse this amp with the term "graveyard quiet." First, there is a low noise upgrade option for it. That in and of itself should tell you something. Second, its pretty well documented that the layout of the wiring does cause some noise issues, and its slightly louder in one channel than another (and we're talking just at the speaker, not out into the listening room/position just in case anyone was wondering). The designer took some measures to rectify this as best as possible, but even he will admit the amp is not dead silent and doesn't apologize for it. In the end he replies with a simple question, "So how does it sound?" Indeed it sounds great, the benefits far outshine the shortcomings.

Ralph Karsten designs his amps to be used with an active linestages and while I've used mine with the LSA I will say it sounds better matched up with The Truth preamp I have that uses active buffers, and the Berning Micro ZOTL that is a true active preamp design. The LSA matches up much better with the Music Reference RM-10 and VAC Auricle Musicblocs.