IO Phono Stage高增益/低雜訊特性，其中的真空管RIAA電路，可以提供極優異的低音輸出。可調整的音量增益以及負載，提供lo的完美性能，IO Phono採用Aesthetix音量控制設計，是最優秀的前級放大設計。其中包括3組主要放大器結構，首先為高增益、低雜訊、零回授單端放大器，內部具有2組特選低雜訊12AX7真空管。之後再連結2組高增益、低雜訊放大器(另外2組12AX7真空管)。因此，lo可以透過輸出線路，在第2組放大結構中，產生平衡訊號。之後訊號會傳送到第3組放大結構中，3組放大結構與第2組的結構大致雷同，同樣包含2組12AX7真空管。整體RIAA電路的訊號路徑極短，並具備高品質設計原理以及高等級電容器與電阻器。在後方面板位置，具有兩片獨立的單音電路板、以及全平衡架構。

IO 特别版唱头放大器[IO Eclipse] 与IO签名版唱头放大器[Callisto Eclipse]同属美国[雅士]旗舰级机种。高增益/低噪声、无负回输真空管单端放大级无源式RIAA均衡网路，选用最上乘电容及无电感电阻灵活多档增益及负荷阻抗切换，可与市面上所有低输出动圈唱头达完美匹配。第二、三级差动放大器，驱动全平衡输出缓冲级。分体供电，多组独立次级绕线。各级独立稳压供电滤波主机可多接一台分体供电其，每台负责一个声道，成为真正双单声道结构。
 

產品規格：

IO同时提供3个版本：IO MK II唱头放大器，IO签名版唱头放大器及IO特别版唱头放大器 
Inputs: one phono input, RCA and XLR jacks provided
Inputs (with volume control option): one line level balanced input, RCA and XLR jacks provided
Outputs: 2 RCA (SE) and XLR (balanced)
Gain: 80dB maximum
Volume control (optional): switched resistor network volume control with 46 steps
Frequency response: +- 0.25 dB, 20 Hz - 20 Khz
Signal to noise: 70 dB minimum, A-weighted (ref 1 mv input, 80 dB gain setting)
Input impedence: 10 ohms - 47K ohms (adjustable)
Output impedence: 1K ohms SE, 600 ohms balanced
Recommended load: 10K ohms or greater (SE), 20K ohms or greater (Balanced)
Tubes, each channel: V1-V6 (12AX7); V7 (6DJ8 / 6922); V8 (6SN7)
Power consumption: 350 watts

Physical dimensions:
Main unit, MkII or Signature: 5 5/8" high, 19" wide, 18 1/2" deep including jacks
Main unit, Eclipse: 5 1/2" high, 17 1/2" wide, 18 1/2" deep including jacks
Power supply, MkII or Signature: 5 5/8" high, 19" wide, 18 1/4" deep
Power supply, Eclipse: " high, " wide, " deep including jacks

Shipping weights:
Main unit, MkII or Signature: 32 lbs.
Main unit, Eclipse: 37 lbs.
Main unit, MkII or Signature w/vol: 38 lbs.
Main unit, Eclipse w/vol: 45 lbs.
Power supply, MkII or Signature: 50 lbs.
Power supply, Eclipse: 55 lbs.