2. amps-preamps
  3. 1276356977

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
Post removed 
grannyring's avatar
grannyring
6,479 posts
 
Array1138

I purchased the Aum passive also. The last unit the builder made before getting out. I love the sound as it sounds very much like the Lightspeed, but has remote volume, balance, and other options. It also has two outputs.

I loved the Lightspeed in my current system, but really wanted remote. The unit is much more expensive than the Lightspeed so I really paid for features not sound quality improvement.
vyokyong
23 posts
 
George,

Thanks for your clarify.

It is not false of LSA in authority in bass and dynamic. Before I mod my ZMA amp, I connect my ZMA amp directly with Accuphase DP77 SACD/CD player. The loudness and dynamics is the same as my current set up playing with LSA.

The nuances and micro details are gained after LSA is modded by
1)Changing internal signal wire to be Deulund hook up 2.
2)RCA female jack to be replaced by WBT pure silver female jack.

This is the reason why I have to mod CSL pre-amp with Deulund hook up wire 2 in signal cable wire and WBT pure silver female jack and check the result in sound quality again.

I still encourage that LSA internal signal wire must be replaced by high quality wire like pure silver Deulund hook up wire 2 and WBT pure silver female jack. This mod provides nuances and micro details like changing HDTV to be 4K HDTV or UHDTV.
georgehifi's avatar
georgehifi
10,312 posts
 

No problems that's fine if owners wish to mod them, with exotic wires and WBT RCA's, warranty of course is voided.
The wires I use are 99.9% oxygen free solid core copper, which to my ear are neutral, and the gold chassis RCA's I use are made in Asia and of good quality.

But I need to keep them at a competitive price ($490aud shipped), which equates to $338usd shipped to the USA.
As our Australian dollar is only worth 69cents US dollar at the moment.

If I used what you have done and also put it into a more glitzy chassis, I would have to at least quadruple the price. And that's before a remote control and receiver is even thought of.

Cheers George
Ag insider logo xs@2x
banquo363
371 posts
 
But I need to keep them at a competitive price ($490aud shipped), which equates to $338usd shipped to the USA.

Curious, I went and looked up what I paid for mine (I'm in the US): $450. That was 5 years ago almost to the day. At $338 (shipped!), it's incredible not only that the LSA is significantly less now than it was 5 years ago, but that it remains woefully undervalued. Good grief, just about everything in my system costs more than that-but after five years, not one piece of equipment (excepting perhaps my beloved Victor turntable) holds nearly the value to cost ratio that the LSA has for me.
More to discover