SPL Tube Set consisting of four tubes for Iron 1520

The IRON uses four tubes in its circuit. A parallel connected pair for each channel. To receive mastering grade sound and performance it is necessary to use the best tubes available. It is not only crucial to use perfectly matched tubes – they also need to stay true to their specs as long as possible. Therefore IRON is equipped with matched 12AU7 tubes, which get paired with preselected matched pairs of Wathen CryoTone™12AX7-WCM Long Plate tubes at SPL.

Wathen Audiophile’s CryoTone™ tubes are cryogenically treated tubes. Cryogenics is the study of how to get to low temperatures and of how materials behave when they get there. Cryogenic treatment modifies the molecular structure in electronic components by reducing or eliminating voids and imperfections in the material. Wathen utilizes a cryogenic treatment process that is specifically designed to maximize all aspects of the sonic performance in audio tubes. Wathen CryoTone™ Long Plate versions of the 12AX7-WCM have unequaled soundstage, depth and frequency balance. Silky, clear and large from top to bottom with the quietest noise floor and an extended life-span.

All four tubes in the IRON are a specially matched set to the overall system.