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
Ditto. Have not checked in here in a while. Was floored by the bad news. We'd corresponded back and forth but had not yet managed to get to the same show at the same time. Rest in peace, cyber-buddy!
Yes, I was also floored by this news about Paul. He has emailed me offline and I have always found his posts thoughtful and friendly. Goodness we will miss him. My sympathy to his family.
Paul was soul of these forums. Had several offline discussions with him. He introduced me to Merlins. My sincere condolences go out to his family.
May he rest in peace.
I was just told about Paul's passing and i was deeply saddened. Goodbye old friend, i will miss you. Your kindness will never be forgotten. Rest in peace.
My sincere condolences to the family.
Bobby Palkovich
Thank You Bobby and everyone else posting on this board and the Pubul57 board on Best Of.

I'm blown way by the beautiful humanity of the audiogon community. Not to diminish the any other posters in the least but I am glad to hear from Bobby.

Paul talked about you all the time, Bobby, and no matter how hard I tried he would never listen to another speaker.

It wasn't that I didn't love your work as well, we spent many afternoons listening to his Merlins. I was always focused on trying hear as many pieces of equipment as possible.

I do think that what he appreciated in you and all great designers was that you took a idea and kept working at it and refining it.

He definitely appreciated thepursuit of perfection as you do Bobby and I know many of the other members and manufacturers on Audiogon as well.

'Philes of every ilk search for these ideals, its something Paul helped me focus on in audio and life, most of all he taught me not to fixate on the equipment and to always make time to listen to the music.