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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 first would like to thank Richard also for that very in depth (War and Peace) review, keep up the good reviewing format, I think you may have missed your vocation in life.

As for any tweaks that tradeontheweb asked that may have been done to the "MkII" Lightspeed Attenuator since it’s release, it’s still the same save for minor cosmetic changes.

Though in the power supply area, "some" have found a small benefit using this power supply to power it, instead of the supplied one.

It’s is very nicely made and not too expensive at $44usd, myself I have not heard it, and think it could be a bit of overkill, but in this game who knows, I know it’s 9vdc instead of my supplied 12vdc, but the Lightspeed Attenuator can run on 8vdc to 18vdc no problems.

http://www.ab-system.hk/index.php?route=product/product&product_id=64


Thanks again Happy New Year

Cheers George


tradeontheweb
43 posts
 
Thanks for the link to the TeraDak, it’s cheap for what you get, I ordered one and will let you and others know what it’s like compared to the standard linear wall wart.

Also how well do you think a battery 12v supply will go in comparison against the standard wall wart or the TeraDak?


Thanks.

georgehifi's avatar
georgehifi
10,312 posts
 
tradeontheweb 
Thanks for the link to the TeraDak, it’s cheap for what you get, I ordered one and will let you and others know what it’s like compared to the standard linear wall wart.

Also how well do you think a battery 12v supply will go in comparison against the standard wall wart or the TeraDak?


Thanks.


You can also try these Li-ion rechargeable batteries, these do have something that is detectable when compared to the linear wall wart.

What the difference is no one can quite put their finger on, they just say there is something different. Even Sam Tellig from Stereophile says the same when he reviewed his Lightspeed, same went for his son a guitar teacher with his.

What’s really good is, as the Lightspeed consumes so little power, these rechargeable Li-Ion batteries give a good couple weeks of use before you need to recharge them. Worth a try also as they are only $10 - $20 with charger shipped.

http://www.ebay.com/sch/i.html?_from=R40&_trksid=p2050601.m570.l1313.TR0.TRC0.H0.XCCTV+12v+battery.TRS0&_nkw=CCTV+12v+battery&_sacat=0


Cheers George

tradeontheweb
43 posts
 

Those batteries are cheap, there are so many different ones to choose from, which would you recommend?
I’ll get one of these as well, as they say one of the purest form of power, is battery power.
And over two week of listening between charges, is not too much hassle.

Thanks.
georgehifi's avatar
georgehifi
10,312 posts
 

Hi, this is the one I sometimes use, it's encased in black plastic and is also 6800mAh's which should see around 3 weeks of Lightspeed listening before a recharge is needed, which only takes around an hour.

http://www.ebay.com/itm/EU-DC-12V-6800mAh-Portable-Rechargeable-Li-ion-Battery-Pack-fr-CCTV-Cam-Monitor-/151467667559?hash=item23442d3067:g:5UkAAOSwDk5T5Mia

There is something about the sound of pure battery power with the Lightspeed you sense something is different compared to the linear powerpack, but you just can't put your finger on it.

It's subtle but there, sometimes you can make the mistake of thinking your listening to battery power, when in fact it's being powered by the linear mains power pack.

Let us all know the differences you hear of the three different way of powering the Lightspeed? 


Cheers George   

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