The LCRMk3 phono preamp comes in an elegant black enclosure but its most distinctive aesthetic feature is a trio of blue LED shining through a plexi glass cover on top. In both the LCRMk3 and Copla, this is purely decorative but in the Copla, the intensity and hue vary  in harmony with the loading and gain settings. Technically, the LCRMk3's claim to fame is the use of smaller inductors in its RIAA correction network which are said to enable better reproduction of the very small signals which carry the data for instrumental textures. When asked why he chose this specific topology, here is how Robert Morin explained it.


"I focus a lot on the circuit excellence of the LCRMk3 because the other options are combinations of RC resistor/capacitor circuits with active or passive RIAA correction. By far the most common method is active RC. This has unavoidable time delays associated with the feedback loop which cause ringing and smearing in the high frequencies. The next most popular method is passive RC. That has the first gain stage drive a capacitor directly to ground to cause stress from loading. The LCR method is much easier for the first gain stage to drive and the passive configuration does not have the problems of active RIAA correction.


"Our LCR network is driven by very fast LT1358 op-amps biased in class A. Extreme care was taken to keep the signal path as short as possible." It may not sound like much but selecting a proven high-quality circuit with excellent parts and executing it as cleanly as possible is what most audio gear revolves around. A lot of the magic does happen between parts selection and implementation, both being intimately connected.


The Copla step-up amplifier comes in a very similar enclosure—although slightly smaller for easy stacking—but holds a few surprises. First, Lounge use diodes to optically isolate the power supply and generate the noise-free power so critical for very small signal gain. The concept itself is not new. I reviewed the Densen DP04 phono preamp about five years ago which used the same principle, shining LED onto photovoltaic chips to generate noise-free current. I have seen a few other components explore the same idea but I can't say that it has become a mainstream solution even to this day.

The rest of the Copla is where true originality shows. By varying the intensity of the LED visible in the hue and intensity of the light shining through the plexi glass, the generated current varies and changes both the gain and impedance of the transistor used to amplify the cartridge signal. As the transistor moves into higher gain, its impedance drops and vice versa. The result of this interesting setup is that one knob controlling the LED intensity now allows for continuous 9-27dB of gain and 40-300Ω cartridge loading. Seeing this kind of solution for the first time, I asked Robert Morin for a little more background.


"Copla started when I read a 1999 paper from Marshall Leach and realized that someone in Europe manufactured an optically powered version of it with a 12V lamp/photo diode combination. I did a lot of experimentation with the circuit. Along the way I noticed how the impedance/gain characteristics changed as I adjusted the brightness of the LEDs. Further exploration led to Copla. The intrinsic operation of the transistor configuration only allows for low-gain/high-impedance to high-gain/low-impedance conversion. Any other operational mode would have meant more components in the very front end of the circuit and a deviation from the loading aspect being a direct action of the transistors." In practice, the adjustment knob did have easily audible effects on gain but loading changes were more subtle as they should be; but also more subtle than what I hear with Nagra's dedicated loading boards for example. In actual use, Lounge's solution gets a good dose of the job done but does not offer the sophistication and range of options that the dual-mono gain and loading adjustments of Ray Samuels' Nighthawk provide which I reviewed a few years ago.


In the end, interesting and innovative design choices only matter if the performance confirms them. So let's jump right in with the LCRMk3 phono stage. I tested it extensively with the Dynavector 10x5 but also spent a few days with the Ortofon 2m Black, both of which are high-output cartridges of pedigree and reputation. The Dynavector is clearly more tonally dense and dynamic while the 2m Black plays it more open with a tighter bottom end. This may be better suited to classical music. In the end, both are tremendously commendable high-output cartridges with the ease of listening often associated with MM cartridges but also with the somewhat lower resolution and absence of the 'illuminated from within' quality exhibited by the best MC pickups.