The best passive preamp

It's not trying to address any issues per se. You and I are in the minority regarding our preference for a passive design over an active one. Stringreen made a comment in this thread that is shared by many audiophiles and designers. Especially when it comes to which design is better at reproducing dynamic swings. I happen to think the LSA, in all its simplicity beats active designs (actually the perception of them) at its own game. I think the MLA does too. It's a simple design with all passive parts that mimics an active circuit, dynamic swings and all (for those who believe an active circuit is the best at this). Two transformers, an attenuator (pot or resistor design, two if you feel dual mono is the way to go), and perhaps a selector switch if you want more than 1 input.

Perhaps the only benefit the MLA might have over other passive designs is the fixed output impedance and frequency response. Regardless of where the volume control is positioned those two specs are constant. You and I both know that is not true with other passive designs unless they are buffered, and then technically they aren't passive anymore. So the MLA might be easier to match in ones system.

I've been listening to the MLA, Truth, Silicon Arts Design, Slagle AVC, and LSA in my system for a while now. All of them are very good. Sure some do things better than others or work better with specific amps I own. In comparisons I'll hear some differences, but nothing that would lead me to think one is significantly better than the other. They're all a little different, but each is enjoyable.

Thank you spending all that time with all those topologies, and sharing your experiences over the years. I will give the MLA a listen, I'm sure is uses some very fine transformers, given the provenance:) Ultimately, I think the Lightspeed just fits my some system context to a T, so it might be hard to beat its inherent simplicity in terms of parts (but not so easy in excecution, as you know). I do think the dynamic swing issue is based on simply using a passive in a system that for various reasons simply needs an active to perform its best, and maybe the MLA bridges that gap to in terms of a greater degree of "universality".

The circuit for the MLA was originally designed to be incorporated into an integrated amplifier design, like the 45SE we had at THE SHOW in January. Not everyone has a need for a 1.7 watt flea amp though, so there are several out there being used as stand alone line stages and they work pretty well in that capacity too.

The transformers are tiny and you wouldn't think they would be capable of the task, but they are wound by one of the best there is at this art form.

Do you anticipate Joe will try an AVC/TVC as an alternative to using resistors?

You mean Jack? No, he is happy with his design and an AVC or TVC wouldn't work with it as the attenuator. It has to be a 10k pot, series, or ladder attenuator. When I built my AVC using the Slagle autoformers he was curious about them (for reasons I can't mention), but not enough to make him consider changing his design. Jack could easily whip up a few autoformers though if he had reason too. Plenty of resources to do it.