Wednesday, September 21, 2011

A review of the Tungsol 12AX7 vacuum tube

This 12AX7 tube, also made in Russia, features a much shorter plate structure than the Sovtek LPS 12AX7 made by the same manufacturer. It closely resembles current Electro-Harmonix 12AX7 tubes, but we are told by the distributor that it is made from premium materials and undergoes additional factory selection as compared to the Electrio-Harmonix to weed out any inferior examples.

We installed a set into an EAR 834P, and during the initial warm-up for the tubes selected an LP to begin the evaluation. We cued up a first pressing of the Steely Dan classic “Aja” and placed the stylus on track one. The original USA pressing of the “Aja” LP is extremely well known in the audiophile community as a “golden ear” record and indeed is a favorite of the review panel. We thus anticipated a strong rendition of the crisp, dynamic, and very much 3-dimensional recording. However, it was immediately apparent that the Tung Sol 12AX7 simply was not up to the challenge of retrieval and reproduction of the tremendously detailed and dynamic recorded sound present on the “Aja” LP.

Put simply, the Tung Sol is just not an engaging, musical 12AX7 tube. The bland soundscape presented by the Tung Sol is quite two dimensional in comparison to the Shuguang 12AX7B, and even made the slightly flat sonic image of the Sovtek 12AX7LPS seem rather deep by comparison. At this point we ceased all evaluation of the Tung Sol 12AX7 tube because it cannot be recommended for use.

Note: This review is actually from a multi-listener session of new production vacuum tubes. Notes were summarized by my good friend Chris James.