Lightspeed Attenuator - Best Preamp Ever?

This is my first post on Audiogon. I rarely post anything anywhere and I’ve never before posted a review of an audio product. However, I feel that the Lightspeed attenuator is unique enough to justify an exception on my side. So, simply put, I would like to share my personal impressions and my recent experience with the Lightspeed Attenuator.

I will not tire you with an extended background of why and when I decided to buy the Lightspeed attenuator. I also believe that every theoretical explanation or technical detail has been discussed in this thread by now.

So, I’ll get right to the point when I attached the Lightspeed Attenuator to my CD player on one end and to my amp on the other end and played some music (Ayre CX-7e, EAR 534, respectively).

To me, it was evident from the first minute that the music sounded more relaxed, less harsh (especially in the highs), cleaner and the system sounded more transparent.
It was as if the noise floor has dropped and more details came up to the surface, so to speak.
To my relief, I could not hear any signs of stress or degradation in dynamics or in anything else for that matter.
To be certain that I wasn’t fooling myself, I asked my wife to come and have a listen, without telling her what to listen for. She also noticed a cleaner sound overall, more details (although she was not sure about that), but said it was a pleasure listening to the music (that is, more than ever before).
We then had a back to back comparison against my current preamp (EAR 834L), which confirmed our observations.

Honestly, I had my doubts and was not sure that my system would benefit from (any) passive preamp. I heard in the past passive preamps that didn't do good to a system, more than once. I am happy to find out that the Lightspeed Attenuator simply improved my system in a very noticeable way.
This is definitely the best value-for-money upgrade I have ever experienced, and probably one of the most significant and exciting. Well, it seems that this is it – I have crossed the line from active to passive :-) and I am not going back!

Thank you George for this beautiful product and thank you for all the support, patience and courtesy, I truly appreciate it.

Hi,

I am using Lightspeed Attenuator for 3 weeks already and want to share my impression here.

My system are;

Audio Note DAC 3.1 custom modded TC Reference MBX. by Bill Baker, Response Audio.with two separate mono power supply unit as same as preamp L2, Mac Mini, Offramp 5 USB convertor, DIY Duelund wire RCA IC, XLO Purple Rush power cord
Zen Mystery Amp. MIT Oracle RCA IC. Synergistic Research Tesla Reference power cable.
Avalon Avatar speakers. MIT Oracle speaker cable.
Hydra 8. ZSB. Kubala Sosna Emotion PC.

I have modded my Decware Zen Mystery amp by removing volume pot out of signal path. It improves much substantial transparency and dynamics to my system. I don't use any preamp. The source Audio Note DAC is connected directly to Zen Mystery amp. So that I need to have volume control for my amp. I read a lot forum about active premap, passive preamp and all types of volume control from volume pot, shunt resistor volume pot, Auto Transformer volume control (ATVC) and Lightspeed attenuator. My decision to go with Lightspeed attenuator.

I love my system to have amp connected directly to source, no preamp. The sound is fabulous. I temporarily use digital volume control in Pure Music software while Lightspeed attenuator was not arrived yet. The digital volume control is acceptable but still creates some sound distortion that you can hear.

When Lightspeed attenuator arrives, I connect it between my amp and source as a preamp. I hardly hear any different between having lightspeed attenuator in my system and without it in my system. It is so transparency. I give 99.5% transparency to directly connecting between amp and source. The 0.5% transparency short is for need of extra one interconnect cable which affects on sound quality. I am very happy and highly recommend to use Lightspeed attenuator as your preamp if you love your amp directly connecting with your source. Or your source has a very excellent sound and you don't want preamp to change its sound quality. And your system don't have any impedance mismatch with Lighspeed attenuator.

For active preamp, therea re some benefits because there are two more functions in active preamp which passive preamp does not have;
1) Gain stage function. Its function is to increase voltage of signal to improve loud and dynamics of system.
2) Buffer stage, its function is to prevent impedance system mismatch. If your source sound is harsh, buffer stage may help to reduce harsh sound.
Then active preamp is benefit for some hifi system.

You select the best for your system.

I've now been using the Lightspeed attenuator for some weeks with my Accuphase P-500 Amp; and I must say that I am pretty amazed and very happy with the sound quality! I would define it as very "clear" or "transparent", which fits my taste.
As I'm using the LSA on my main system, I will certainly add an input switch just to make it more convenient to use on a "normal" day.
I don't know if this is the best pre-amp ever (I just don't have the means to compare with other real contenders), but I'm convinced that for that price it would be damn hard to find something that comes close to this sound quality.

Hi,

I just modded Light speed attenuator by replacing stock RCA jack with WBT 0210-Ag RCA "Next Gen" Pure Silver in signal path, Female Jack. I have modded my Zen Mystery Amp by replacing stock RCA jack with WBT 0210-Ag (Ms - metal nut) RCA "Next Gen" Pure Silver in signal path, Female Jack. And sonic improvement is huge in term of transparency, transient and micro-details. Then I want Light Speed Attenuator to be modded same thing.

This is instruction from George of how to replacing stock RCA jacks.

below are the opening instruction, if you change the rca’s they must be full bodied metal, as they have to have electrical contact from their body (which is earth) to the Lightspeed chassis on all 4 rca’s.

1: Remove two only top screws at the back
2: remove all 4 screws at the front.
3: Pull out front panel and bezel only about 10mm and lower.
4: Slide top plate out from the front.

But the RCA jack WBT Next Gen Silver 0210-Ag body is plastic, not metal. So that they cannot be ground through chassis contacting point at cut whole bare metal. Then I use silver wire to connect all ground point of RCA jack of both in put RCAs and out put RCAs and ground to chassis at one point only.

Result is that my Hi Fi system can play louder than before. It may be 1-2 dB or easily to hear different loud. Second both hi and low frequency is more extend with better dynamics contrast. The improvement is dramatic better and it is worth every penny to replace stock RCA by WBT RCA jack of pure silver in signal path.

However I think that using direct wire to connect between ground or negative points of both in put RCAs and out put RCAs together has affected better sonic improvement. (instead of using back panel aluminum plate as ground path). The Light speed attenuator owner can do simple modification of Light speed attenuator by using good quality wire to connect all RCAs ground together to improve the sound quality.

Hope this information will be helpful.

Thanks for the heads up on that Vyokong. Give us some more impressions after you have had them a couple of months. Thanks again.