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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
tradeontheweb
43 posts
 
I'm with Pubul57 on this one.

The Lightspeed has been provoking debate since its inception. Here in Australia, it has had a long gestation period, with some loving it and others the opposite. Similar to what happened over on Audio Asylum I recall. As a 5 year user of one, my experience has been one of many ups and downs through a multitude of systems and components. I now realise many of the downs have been brought about by my own attempts to best it. After all, how could a tiny little $500 black box compete with others costing in the thousands ? Plus it's made in Australia and we all know the best audio equipment comes from overseas - right ?

Those who know me will be aware I have gone through a multitude of gear in the last 5 years. Mainly due to selling on eBay for others with much deeper pockets than I, allowing me the chance to experiment endlessly.

I have directly compared the Lightspeed to the following; (excuse me if I get the model designations wrong )

1. Audio Research SP11, SP10 LS3, LS8, LS2
2. CAT Signature
3. Supratek Chardonnay, Micrex M1.
4. Mark Levinson 380S
5. NuForce P8
6. Musical Fidelity SP3
8. Various Volume Controls in the many CD Players I have used.
9. 3 or 4 home brew preamps, both valve and SS.
10. Gryphon MK II
11. Placette TVC

(Thats about all I can recall for now, but I'm sure theres more)

The most recent comparison was with an Australian designed and made ME25 Preamplifier into a pair of EL34 Monoblocks, into my JBL 4350's. Once the impedances were matched to allow the Lightspeed to operate correctly ( along with 1m interconnect of course), there was no contest. The Lightspeed was cleaner, more transparent, better soundstage and dynamics etc etc etc. Needless to say, the ME was moved on. There was no loss of bass response, or any of the common downsides of Passive Control.

Anyway, the point I'm trying to make is this; Whilst the Lightspeed can be compared to all the above by inserting it into a system already optimized for another preamplifier, to get it to really shine, the system MUST be optimized for Lightspeed use. Often the Lightspeed may sound "brittle: or "shrill" when first used, until the impedances are matched correctly. When I did this, the Lightspeed COMPREHENSIVELY beat out all the above.

This system matching is the difference between the Lightspeed sounding just "good" vs sounding incredible. I have heard it sound pretty good driving 3m plus interconnects, and have done it myself on occasion. But, I have always had large gains when the system is configured properly to suit it.

IMO, using buffers defeats the purpose of having the Lightspeed, altough I'm happy to be proved wrong. I'd rather spend the cost of the buffer in changing the amplifier impedance to suit the Lightspeed. In some cases, in my experience, this has been less that 20 minutes work !

And lastly no, I do not have a financial interest in Lightspeed production and while I do know George well, I'm not into B.S'ing others based solely on that.

IMHO, for the cost, its an absolute no-brainer ........

Cheers

Scott
Post removed 
grannyring's avatar
grannyring
6,592 posts
 
Love to put it up against my unit, but no trial.

Interesting posts however.
pubul57 OP
3,712 posts
 
You may or may not like it better than your unit, we all know that we personally gravitate to what we want, what we like, and what anybody else says doesn't really matter, IF we can trust our own ears and preferences, all I am saying about this preamp (semantics aside, I don't need a source selcetor) this thing is special in away that the other passives I have tried have not been able to match, and obviously has gone up against some pretty renowned tube preamps where at least some folks have concluded that it is preferable. So all I am saying is that as we seek the best sound avaialable, this $450 peramp (thing) is worth a try, even if at the end of the day you decide to stick with your active (tube?) preamps.

Maybe George HiFi will be able to figure out a trial scheme that can make sense to him, though he may already may be limited to how many he can make per month so I may be a moot suggestion. While I will use the Atma-Atma combo with balanced cabling, my other systems combos are going passive with the Lightspeed.
peter_s
1,348 posts
 
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