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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
4,966 posts
 
Wow!! Your guna make me work for it, I'll try my best, in point form.

1: For 1mt anything below 100pf per foot is fine
2: Yes a number of my customers use quality xlr to rca adapters
3: Not much lost with quality adapters from what they say, the gains out weigh the the minuses big time
4: The signal only passes through one special passive fixed resistor that can change it's resistance (re: volume) according to the amount of light shone on it. but the light is control by solid state components.
5: The Lightspeed Attenuator is true to the source, it adds nothing and detracts nothing, it is the most transparent/dynamic way of controlling the volume of the source to the power amp/s. The only way that can be more so is to plug the source directly into your amp, but then you have the problem of no volume control.
6: There is no gain it is unity gain.

Cheers George
clio09
2,978 posts
 
Get the Lightspeed, get the adapters, and be done with it. Given what you probably paid for those cables the investment here is minimal and the reward factor is very high. I bought a pair of adapters from a pro music store for another set up I have and use them with my second LSA unit. Works just fine. In my system the sound stage varies by recording. Most of the time it is set back, but that also has to do with how I set up my speakers as well. I have never heard a Lightspeed make a system forward sounding. Only way for you to know for sure what it will do in your system is to try it.
audiolabyrinth's avatar
audiolabyrinth
4,483 posts
 
@ Georgelofi, I am sorry, I did not mean for you to work for it!, I have been thru so much heart ache over audio the last 13 months!, regardless of cost of eany unit, I am tired!, It seems like nothing is what its said to be!, I hope you understand my point of veiw here,Thankyou for all the post from you, I will most likly buy from you,I have to waite till my amp comes back from Krell, I have to pay them first, then I will get in touch with you, Do not worry, you got the sale, Its just I have to give Krell 2 or 3 thousand dollars for what they are doing to my amp!BTW, My Ayon 2s is running directly to my amp!, It has a high quality digital volume control!, Like I said, A r-core transformer for each channel after the signal leaves the out-put tubes, and the third R-core transformer is for the digital domain, Thankyou, cheers!
audiolabyrinth's avatar
audiolabyrinth
4,483 posts
 
@ clio09, I agree, the adapters, and try the lightspeed!, You have been great here!, A true asset to us all!, Thankyou so much for your time, It will be some time before I buy the unit, As the post above tells why, regarless, I will be buying the Lightspeed!,, cheers!
georgehifi's avatar
georgehifi
4,966 posts
 
If your Ayon has a digital domain volume control and you are able to use it within it's top 1/3 of it's full output range, so you are not "bit stripping", then only this will be even better than having a Lightspeed.

Cheers George
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