Original owner; original shipping boxes and internal packing. Includes VTL booklet by Manley Sr. (The Vacuum Tube Logic Handbook) that describes VTL products circa 1990. This amplifier has been in a cool, dark storage closet for at least 12 years. Extra set of unused KT-90 output tubes included. Mint physical condition. Sound is typical VTL for its vintage = punchy bass, slight glare in upper midrange, excellent signal/noise ratio, low distortion, stable imaging.
Review Magazine: Stereophile
Reviewed: May 1990, vol 13, iss 5
Reviewer: Norton (unable to locate this review online)
From Stereophile's Harley interview with Manley: We worked out a way of using a lot of existing former sizes and jigs to originate an entirely new tube particularly for us, which we will supply to others if anybody's interested. We called it the KT90 because it was designed in 1990, and KT stands for "kinkless tetrode." It exceeds the KT88 in performance. The Chinese build a KT88 but it's more correctly an 8850 because they use the same interior for a KT88 and a 6550, but they're different tubes—one's a tetrode, one's a pentode. Then again, they don't build them rugged enough. Not because they can't, but because they want to build them to a price point, to sell lots of adequate ones rather than a smaller number of really excellent ones.
But we've got an excellent tube here. The KT90 will be our staple tube. We also use a Russian KT66, which is not identical to a KT66 but it's very close. It's a very robust and well-made tube. We're really excited about this KT90. We've had them on test for nearly three months, and at cruel voltages—50% higher than we normally use. We've tried to break them and we can't. That's going to be an astonishing tube. We're not worried about the demise of tubes. We've got plenty and are getting plenty from wonderful sources. Sadly, though, they're not American sources.