Most Decca-family cartridges have their styli slanted backward as in Figure 1. Naturally, one would assume the tone arm should be raised to achieve better sound. When using AnalogMagik's VTA function to test my London Reference, I found just the opposite. When the top of the cartridge was level, the IMD measured in the 8% range, and jump to ~12% if I raised the arm slightly higher. Only when I tilted back the cartridge to the extreme (as in Figure 2) did I get the best IMD numbers. The sound? Surprisingly delicate, detailed and clean with super dark background, very different from the rough-around-the-edges character that most people expect from Decca cartridges.
Decca 系列唱頭，針尖看起來多數是後仰的，我的 London Reference 也如此，如圖一，所以多數人都會把唱臂調高。但用 AnalogMagik 的 VTA 功能測 IMD， 唱頭上緣水平時 IMD竟然高達8%。再調高更不好，到 12%。反方向把唱頭調低到不能再低，後端快碰到唱片表面（如圖二），才出現不錯的數字如圖三。聽起來如何？出人意料的細膩乾淨又安靜，以前以為 Decca 系列唱頭固有的，稍微不修邊幅個性，竟然都不見了。這真是令人跌破眼鏡的結果。