Lightspeed Attenuator - Best Preamp Ever?

Genuine TDA1541R1

I/V converter based on the special gold plated low noise vintage transistor

My review….. As an ex-owner of many hi-end audiophile hardware from speakers such as Kharma, Dynaudio, Vandersteen, Magnapan, Sonus Faber, to amplifier such as Audio Research, Plinus, Rogue, etc I am experience and qualify to review hifi component, up to S$50K if putting a value to a piece of hardware means anything to you.

Lightspeed is a product that appeal mostly to the diy community. By saying diy community I don't mean only those who seek to build an attenuator only but also those who are constantly searching for tweaks to their hardware such as Caps and tube roll or optimising an amplifier circuit. The writer is one such person.

LS did no active advertising and I chance upon the LDR circuitry in a diy forum only recently while seeking to improve my channel imbalance with the Alps variable resistor swipe type volume control. I assembled a 23 steps attenuator and realised my Alps variable resistor was indeed a bottleneck to my system. The 23 steps attenuator was like from winter to spring in my system. But I believe much can still be done to improve the performance.

Than came the LDR attenuator. A simple and logical concept of using an isolated LED light intensity circuitry to vary resistance in another circuit hence producing a clean signal through the amplifier circuit resulting in crisp, clear, smooth, transparent and quiet layers of music only limited by the quality of the equipment downstream to the LS. The use of the stereotype audiophile jargon such as soundstage height/width, imaging, timbre, etc... is to me irrelevant in describing the LS. I believe an attenuator's aim is not to have a sound but to vary the signal level and pass-through effortlessly and not impeding the potential of your equipment. Any improvement gain is due to your equipment and LS is just an enabler.

But I will certainly get bomb to claim the LS do not have a sound because the signals do run through some circuitry before it gets transmitted to your equipment. My point here is that if the LS produce a negative effects to your setup or swing towards certain attributes that is not to your liking, most likely the cause is a mismatch in impedance or you have a coloured attenuator and not the LS being inferior.

Is the LS a plug and play component? No and maybe. First you need to make sure you don't have an impedance mismatch issue which is rare but not impossible. I have also a tube pre and SS power system and I lost the much preferred "tube sound" by putting the LS in place of my tube pre. This is not to say that it is terrible but not my preferred sound. I have now bypass my tube pre 23 step attenuator and use it as an over glorified tube buffer. If you are using a passive preamp the LS is a no brainer upgrade. If you have and like your SS pre, you will likely like the LS in place of your SS pre. Comparing my Alps to the LS is like winter to summer. It doesn't sound thin or dry on the contrary to some who have reported their experience. I recommend it highly if it fits you bill.

A working LS circuit is available from a diy forum if you are a diy-er or are hell bend for saving up for other upgrade and only if you can find a match pair of LDR out of the many required for a project. I believe I can also make one from the available info from the internet but I choose to support the inventor who is passionate and generous enough to share his circuit and know how to the diy community in the numerous forum in the internet. His generosity proved that he is not a money grabbing person and in today's world such character is few and far between.

The LS is where I stop my search for a better alternative for now. Buy it if it fits your bill before you consider an interconnect upgrade, tube roll, power cord upgrade, component upgrade. Most likely it is cheaper than other conventional upgrade path. DIY if you want and George will throw you his float when you are drowning. I hope the Lightspeed reach commercial success in a huge way in the future not that George care if it did or not.

 PS: I am not affiliated to the Lightspeed product.