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.
Well for me the differences were easy to pick up in my particular set up. Remember, my LSA components were placed inside my dac thus turning my dac into a dac with volume control. This eliminated the need for a set of ICs and RCA connectors. I also used some very good silver/gold solid core wire in cotton from Jupiter Condenser to wire the LSA board inside my dac.

I prefer the battery over the wall wart in my system finding it sounded more relaxed and engaging. Just wanted to listen more with the battery. The difference here was slight and some may like the linear wall wart better because it did seem a tad, just tad, more dynamic and upfront.

However the TeraDak supply simply put a big smile on my face immediately. It delivers the best of both the battery and linear wall wart and then some! I immediately heard more powerful and impactful bass. This was evident the moment the first song began playing. In addition, the music in general was more dynamic and alive. One final area of improvement that I found most noticeable was a blacker background with the instruments emerging with more realism, resolution, and sense of space and real estate between instruments. This was quite surprising to me and very fun to listen to. I really did not expect this result.

I use two amplifiers and both revealed the same improvement. An 845 DHT tube SET amp and a Lector VM200 hybrid amp that is direct coupled. Both work great with my set up and the LSA .

Yeah a few now have really liked the TeraDak power supply, good value for what you get $44!!!!, just the chassis would cost me that.

Good to see someone else likes DHT SE transmission tube amps, I managed to get the circuit for these, and built my own 805 mono blocks (40kg each) a few years ago just for mids and highs on my esl's

Cheers George
Do I need to buy anything else other than the item in that link (eg power cable?). I will try one out.

I believe it has all that's needed to power the Lightspeed (is that right Grannyring?) even the cable I believe is correct, 2.1mm plug with positive being centre.
And the Lightspeed works with 9vdc to 18vdc.
If you order don't forget to tell them you country and mains voltage.

Cheers George