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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
georgehifi's avatar
georgehifi
10,312 posts
 
I've said many times, and also Nelson Pass in my last post above in so many words.

If your after to change/colour the sound of the source, don't look at the Lightspeed or most passives, go with an active preamp.
As all active preamps sound different to one another, none sound transparent like a "straight piece of wire", only passives or direct can do that.
The only trouble is finding the right active preamp with the right colouration, or combination of colourations that suits what you are trying to achieve. And this gets very costly.

But if you want to hear exactly what your source sounds like you want your preamp to be "true" to that sources sound, and not colour it in any way. Then passive preamps are for you. Then it's up to your amp and speakers to give what you need.

Cheers George
grannyring's avatar
grannyring
6,645 posts
 
Nelson Pass has made and is making some pretty expensive actives.Very expensive. Apparenty he thinks they sound very real. If not, one would say he is not being true to himself and we customers. He sells these expensive actives touting neutrality, fidelity etc...

I don't want to hear what the source sounds like because it is also flawed. A total system is all one can judge George.

Always look forward to your audio religion.
georgehifi's avatar
georgehifi
10,312 posts
 
OK, don't get your back up, you just admitted you don't like the sound of your source and you wish to colour it with your Dude active tube preamp, enough said.

And yes Nelson Pass is a businessman as well, and one of very few of the very best audio designers ever, and it's a brave man to try to call him out, but he calls a spade a spade and tells it like it is as well, as his testament to passive preamps state two of my posts back.

Cheers George
grannyring's avatar
grannyring
6,645 posts
 
You know I said all sources are flawed and they are for sure. Nothing in audio is perfect unfortunately.
georgehifi's avatar
georgehifi
10,312 posts
 

Your generalizing. All sources are not flawed, maybe just the ones you've listened to are.

So instead of getting a source you like, you colour the source you have that you don't like the sound of with an active preamp.
This is a mine field of trial and error and can end up costing a substantial amount. That's fine to go about it that way, but it never ever be as transparent as no active preamp.

Cheers George
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