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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
miller65
3 posts
 
Although I read a lot of hi fi forums this is my 1st ever post and the only time I have ever really thought about posting , the reason simple the Lightspeed has simply transformed my system and I now believe I am getting the best out of the other components . The following is the mail I dropped to George after listening to the Lightspeed for only a few days ;

What a super piece of kit just goes to show some real bargains still exist in the Hi Fi world and you do not always have to spend a fortune for the best quality components , without doubt the best value for money I have ever spent , thankyou.
Previously I had used active preamps in my system originally a Naim 62 with Snaps power supply and then an Avondale 821 but I was never totally happy with the sound which always sounded a bit muddy and lacked in detail , so I started on my trail of trying passives of which I have had 2 over the past 12 months , latterly an Audio Synthesis Passion which was a decent improvement in terms of detail retrieval but did lack some of the dynamics I got with the Avondale .I really thought to obtain the sound I craved I would need to spend mega bucks but after much reading decided to give your Lightspeed a chance and wow from the first few minute I plugged it in it sounded just superb , I always thought the preamp was holding back my system but the increase in transparency dynamics and detail retrieval far surpassed any upgrade I have ever made in my system ! I did consider various types of passives including Transformer based preamps but so glad I made the decision to try yours ! which I very much doubt could be improved upon at any price .
For the record my system comprises Marantz CD63 heavily modded , Avondale S100 power amp and ATC SCM 7 speakers with Mark Grant interconnects.
George in my mind your product is the bargain of all time in Hi Fi terms and will be my last ever Preamp , once again congratulations on a great product
vyokyong
23 posts
 
Hi,

I just want to report back after modded CSLS.

My Coincident Statement Line Stage Pre-amp is modified by replacing signal cable wires both in put and out put cable wire to be Deulund Hook up wire 2 version 2 (Pure Ribbon Cable wire) in order to gain nuances and micro details of signal back. Because I observe that signal cable wire used in CSLS is very small normal wire.

Result is that new modded CSLS combines best of both worlds now. It has both excellent high definition details of sound as passive pre-amp strength and excellent weight and authority (dynamics) as active pre-amp strength.

However the cost of modded equipment (Duelund hook up wire 5 meters and 3 pairs of WBT pure silver Nex Gen RCA female plug) is USD 1,500 which is quite high also. But it is worth every penny.
musicmuskrat23's avatar
musicmuskrat23
1 posts
 
Hi George,

i am listening your lightspeed attenuator now for three weeks.
The first impression was not very good, but after burning in the lightspeed attenuator works better and better. I think there is a minimum burn in time of 50 hours.
Now there are very transparent mids, deep bass, and fine highs.
The space between instruments and voices is very good.
Definately the best preamp i ever owned.
My system is:
Denon DP 75 with Jelco SA 750E and EMT XSD 15
in a handcrafted very heavy plinth
Acoustech PH 1 phonopre
Goldnote Koala Anniversary tube CD Player
Valvet A 1r2 mono amplifier
Dipol speaker with active dipol bass from Packhifi Berlin, the very best speakers i have ever heard.
It's connected with synergistic research tesla cable.
I am very satisfied, maybe there is a friend, who will buy a second attenuator from you.
Best regards
Joachim
georgehifi's avatar
georgehifi
4,966 posts
 

Hi Musicmuskrat23, thanks for your very kind words.
As for burn in I do believe that the Cadmium Sulphide component of the LDR does take a while to "form" after it's not been powered for long periods of time.
I've seen this on the scope from new, but it's only a short duration. But in HiFi as you know anything is possible.

As my ESL speakers are big ML's, I've measured them with an ESL volt meter, and they are fully charged within 5- 10mins to 5kv, but I swear they sound better after an hour, at which time they are still at 5kv.

Cheers George
whart's avatar
whart
1,930 posts
 
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