In 2007, Sovtek abruptly ceased production of the 7199 (Triode/Pentode) tube. The remaining supply of these tubes have already become increasingly scarce and costs have risen sharply. NOS types of this tube will soon become unobtainable. Accordingly, Dynakit has selected the 6GH8A (Triode/Pentode) tube as a direct replacement for the 7199 tube.