AZOG AUDIO – High-end Balanced Phono Preamplifiers

For any audio manufacturer, it is easy to design yet another product whose feature set is carefully chosen to fit a predefined price bracket. In phono stages in particular, features are typically placed at the very top of the design agenda. Commonly offered additions include multiple de-emphasis curves, high-pass filters to suppress rumble from warped records, output phase inversion, multiple inputs, and more. All of these may appear useful, but in audio engineering there is no free lunch. Every added convenience comes at a sonic cost, oftentimes far from subtle.

Consider multiple de-emphasis curves. Their implementation not only requires switch matrices that the most delicate audio signal must pass through, but also the use of multiple filter networks, almost invariably forcing compromises in component quality. Would you rather have one painstakingly selected, state-of-the-art capacitor—or several far cheaper ones selected by necessity rather than sonic merit?

More fundamentally, would you choose long signal paths populated by numerous components and switching contacts, solely to support a multitude of rarely used curves, over an extremely short, direct signal path entirely free of signal switching?

Another near-universal feature is the rumble filter. Most phono preamplifiers include one in an ultimately futile attempt to compensate for turntable or tonearm systems of poor mechanical integrity, warped records, or recording defects. What is rarely acknowledged is that no electronic filter can trully resolve these underlying mechanical problems. A rumble filter is merely a band-aid: it introduces additional signal splitting, switching, AC coupling, or—in the worst cases—multiple transmission-zero filters that disrupt low-frequency phase behavior and fundamentally damage the musical presentation.

Yet these compromises have become widely accepted as “necessary features,” largely as a result of decades of marketing pressure and the technical limitations of turntable/electronics systems of yesteryear.

In reality, a properly designed turntable and tonearm, with the right mechanical support, requires none of these corrective measures. In such systems, subsonic disturbances are simply not an issue. For more modest setups, the simplest and least harmful solution is to play badly warped records at low to moderate levels, even if the cartridge itself may not particularly enjoy the experience.