Rossner and Sohn Canofer-S Phono Preamplifier Review

Lawrence Lock’s unit with three RCAs, and my unit with only two

Peeking under the hood, I was pleased to see that all three of the front panel control dials are not made of low quality carbon film potentiometers, but actually high quality 24-step rotary switches made by ELMA, similar to the ones used in the high quality DACT (Danish Audio Connect) stepped attenuators. According to Christoph, rotary switches of the highest quality must be utilized because they carry the signal path; computer grade dip switches are simply unable to achieve the low level of distortion which he demands. Each of the contact points on the ELMA 24-step rotary switch is gold plated and the plating covers 90% of the surface area of the PCB, making it virtually immune to oxidation. Oxidation, said Christoph, is the primary source of signal degradation and must be avoided like the plague.

The Canofer-S has no ON/OFF switch on the front panel, it’s instead found on the external power supply unit. The power supply unit houses two vacuum sealed transformer units with separate coils, which reduces cross interference between channels to undetectable levels. Each of the separate power supply units powers two completely separate amplification modules, which are encased in a proprietary polyurethane resin custom designed for Rossner and Sohn by a company called Elalta, which in turn specializes in the development and manufacture of specialized epoxy materials. The resin has been rigorously tested for micro sonic resonance, temperature control, corrosion, as well as vibrational properties. As mentioned before, the entire encasement is suspended in mid-air inside the chassis.

So what makes the Canofer-S so special?

 
I must admit, my decision to purchase the Rossner & Sohn unit was a rather hasty one, brought on by all the “overkill” engineering that I saw. However, I am very critical with every piece of equipment that ends up in my living room. I have had a fair number of phono stages over the past decade, and the Rossner and Sohn Canofer-S was one of the few that I have decided to keep. The following are my reasons for my decision. I have three stringent criteria for phono stages but unfortunately very few phono stages on the market will meet all three requirements.

First and foremost, is quietness. The Canofer-S is the quietest phono preamp that I have owned , including the battery powered Sutherland PhD and ASR Exclusive battery powered unit. At 60 dB of gain, the Canofer-S is also much quieter than the FM Acoustic 122 Mk II, despite that fact that the FM Acoustic has a gain of only 56 dB. It is also quieter than the Ensemble Fonobrio which I also own, even when it’s set at the lowest MC gain setting. Without any signal, you will have a hard time determining whether the Canofer-S is actually turned on or not. Without a record playing, I could detect no hum, white noise, FM signal, or any type of buzzing even with the preamp’s volume dial set at 50%. This is almost unbeatable!

When the Canofer-S was initially launched in 2004, there was a battery-powered option available as an add-on. However, the AC powered unit was so quiet that Christoph decided to stop offering the battery option because it simply wasn’t necessary.