I went from a pair of Electro-harmonic 6V6GT to a pair of Bendix 5992s in my VK3i and the sound improvement was like an equipment upgrade with the sound improving on all levels.From the bass which was tighter and more powerful thru the mids to the faster and more open top end the sound was glorious.Check out Brent Jesse as he still might have matched pairs for sale through his web site or the two Audiogoners with these tubes for sale