If you read my previous Lefson post about the Lefson resistors provided to me by Xavier Lefebvre, who owns and operates Lefson, you know that I am gearing up to write about the three lines of custom and hand-crafted Lefson resistors for Positive Feedback.

I asked Xavier if he would tell us a little bit about himself and his company, Lefson. Xavier has written up a bio for me, and has also added it to his webpage here.

I've summarized Xavier's audio bio below for you:

Xavier Lefebvre was born in 1984, and has been truly passionate for audio since childhood.

Xavier graduated from ISTS in Paris (Institut Supérieur des Techniques du Son) at the age of 22, and after graduation Xavier followed his passion and worked as a sound engineer in different recording studios in Paris, and was able to meet and work with some of the most experienced French sound engineers.

At the same time, Xavier's personal interest in audio led him to expand his studies in the field of audio electronics, as he wanted to understand and find out more about the inherent characteristics of the devices he uses in sound engineering work in the studios.

Because of Xavier's growing interest for audio electronics, he decided to put his career in the recording studio aside, and now devotes himself to his Lefson audio business full-time.

Lefson officially opened its doors in November 2013 in Boulogne-sur-Mer in Northern France, and in August 2016 Lefson moved to Wormhout in order to expand manufacturing capabilities.

Xavier decided he wanted to work specifically on developing fundamental electronic components, such as resistors & capacitors, according to the specifications he believed that best preserved audio signal transmission for high-fidelity sound reproduction, and the Lefson Resistors you see here are the result of his research & development.

Xavier designs and manufactures audio devices for both personal audio use and for professional recording studio use, including preamplifiers, compressors & limiters, equalizers, microphones, etc., which you can read more about here.

Xavier says his customers have appreciated the performance of his Lefson products, and several of his customers are now using Lefson products during studio sessions.

Xavier also has a service business, Lefson Repair, where he restores, modifies, and performs maintenance for home audio and studio electronics. Above you can see a video from the Lefson YouTube channel on the restoration of a vacuum tube amplifier.

Xavier tells me that Lefson is more than a business for him, it is a philosophy, where all his research and development's end goal is for the preservation of audio signal transmission for high-fidelity sound reproduction, both in the home and in the studio.

As I mentioned in my previous Lefson post, I will be trying the various Lefson resistors in my vintage Altec A5 Voice of the Theatre project's crossovers, which are based on a modified version of the Hiraga-san crossover, with modifications as suggested by Yazaki-san and Pete Riggle-san.

Xavier sent me two each of his 100R (4/6W) Supra Resistor to try in the R4 position, the 10R (6/10W) Premium Resistor to try in R3-1, R3-2, or R5 positions, and 10R (10/15W) Ultra Resistor to also try in R3-1, R3-2, or R5 positions.

The fit and finish of the Lefson resistors is impeccable and impressive, certainly giving me a good first impression of their level of quality. They remind me somewhat of the Duelund CAST capacitors in the way they're potted.

This afternoon I poured a glass of Champagne, made a "Vive la France!" toast, and decided to start my adventure with the Lefson resistors!

First up are the pure silver & carbon Lefson Premium resistors. Before installing the Lefson Premium resistors in the crossovers of my vintage Altec Lansing A5 Voice of the Theatre loudspeakers, I decided to put them on LCR meter that Yazaki-san sent to me during our adventures (Thank you Yazaki-san!), in order to measure them and see how close they came to their rated value. As you can see from the photo above, the Lefson Premium resisters are very close to their rated value, and easily within their specified ±5% rating.

I decided I'd start with the 10R Lefson Premium resistors in the R5 position, and then try them in R3-1 & R3-2 positions (left in the photo between the L-Pad & variable resistor) to get a feel how they compare to the 10R Ohmite 'Brown Devil' resistors I'm currently using in those positions.

After swapping out the 10R Ohmite 'Brown Devils' at R5 with the 10R Lefson Premium resistors in both crossovers, I turned on the system to warm up for a bit, then settled in for some listening across a variety of music.

As always, these very preliminary listening impressions are just a glimpse into the behind the scenes process of reviewing them for Positive Feedback, and they aren't intended to be the final word on the Lefson's performance, but merely a snippet of a moment in time as I begin to figure out how to implement the Lefson's, get the crossover voicing right, and get some run-in time on the Lefson resistors.

I remind you of that because it takes time to properly run-in resistors, get the L-Pads & variable resistors in the crossover voiced to the Lefson's performance, and to be able to fully articulate what I'm hearing from the Lefson's.

In this case I dropped the zero run-in time Lefson Premium resistors into a circuit voiced with the Ohmite 'Brown Devils' that have a year's worth of run-in time on them, with no adjustment to the L-Pads or variable resistors at all, just so I could get an idea of what the Lefson's are about, and give you a behind-the-scenes look-see.

Some time ago I tried the same thing at R5 with the vintage Allen Bradley carbon comp resistors that I became so fond of in my vintage McIntosh adventures, but the Allen Bradley's were a flop at R5, sounding veiled and weirdly phasey, so out they came, and the Ohmite 'Brown Devil' wirewound resistors went back in, and have stayed in at R5 since then.

Given my experience with the vintage Allen Bradley carbon comp's, I have actually been a little worried about what a premium silver/carbon resistor like the Lefson Premium might perform like at R5.

It turns out I needn't have worried, as the 10R Lefson Premium resistors didn't exhibit any of the sins of the vintage Allen Bradley's at R5, and to my surprise the Premiums were significantly more transparent than my Ohmite 'Brown Devils', with little details, like brushes on the cymbals in Getz/Gilberto, sounding much more refined and articulate than I'm used to hearing from the Ohmite's.

With zero time on them, the Lefson Premium's also sounded a little more forward than the Ohmite's in a way that I didn't care for, but in the course of only a couple of hours of listening they have settled down & smoothed out significantly, to where they are now sounding very nice indeed, being transparent, detailed, dynamic, and with excellent tone color. It's really easy to hear overtones and timbral textures, but there's still a little forwardness left.

I suspect that with some more time on the Lefson's they will be superb, and the forwardness will vanish. I'll probably end up running them in on my Audiodharma Cable Cooker for a couple of days to hurry things along, which is a good idea for pretty much everything, whether it be cables, power cords, resistors, or capacitors.

My first encounter with the 10R Lefson Premium resistors in R5 was impressive, and there's a lot I like about them. It will be really interesting to try the Lefson Premium resistors at the R3-1 & R3-2 positions, as well as the 10R Lefson Ultra Resistor in those positions.

Next up is the Lefson 100R (4/6W) Supra Resistor to try in the R4 position.

The Lefson resistor adventure is off to a good start!

I'll be providing more behind-the-scenes updates as I get more time in with the Lefson Premium, Supra, and Ultra resistors, and try them in more positions in the A5's high-frequency crossovers.

As always, thanks for stopping by, and may the tone be with you!