Genalex - Gold Lion KT88

10 Reviews

Availability: Usually ships within 24 hours.

USD $‎99.95
Only matched pairs and quartets/quads in stock. No matched octets until further notice.

In 1957 Marconi-Osram Valve Co. (Genalex) introduced the "King of Power Tubes", the legendary Gold Lion KT88. This tube became the heart and soul of such classics as the Dynaco Mark III, McIntosh MC275, and Marshall Major. Unfortunately, Genalex ceased tube production in the early 1980s and the Genalex Gold Lion KT88 has become very expensive and hard to find. After extensive research and engineering, New Sensor Corp. has reissued the famed Genalex Gold Lion KT88. This tube has been recreated down to the finest detail with gold plated grid wire, carbonized screen grids, and a tri-alloy clad plate structure for exceptional performance and sound quality.

Other Genalex - Gold Lion tubes       KT88 Tube Types

Additional Information and Downloads

Tube Matching Information:
Power Tube Matching FAQ
Perfect Pair System

Genalex - Gold Lion KT88 Datasheet (PDF)

Download Adobe Acrobat PDF reader

Warranty Information and Return Policy

Warranty Period: 3 months

All our tubes are guaranteed for 3 months from the date of purchase. (Any exceptions will be noted on that tube's Warranty tab)

If you receive a tube that does not perform to the manufacturer's specifications, please do the following:

- contact us to get a return authorization
- return it via regular mail within 90 days from when we shipped it, and we will provide an exchange or refund of the full purchase price of the tube.

Returns not related to warranty or defect will be considered at our discretion, and are subject to a 15% restocking fee.

We can not accept returns that don't have an authorization, are past 3 month, or are returned improperly.

These guidelines may be updated without notice.

Ratings & Reviews

10 reviews

My Review


Overall, the Genalex / Gold Lion KT88 tube is simply a more refined tube and does not call attention to any of the frequency range while remaining under control with all types of music. I notice that from top to bottom it is very coherent and has a wonderful sense of ease with anything you throw at it. It reminds of something that has more power and control than the others.

I let it play for 3 days as the first 24 hours the tube sounded slightly bright without bloom. Now after 3 days it has a very high degree of refinement….is relaxed and smooth….and leans toward warmth. For me it is a real step up in my system.

My Review


I'd like to confirm your advice tubes for my McIntosh MC2102 Amplifier -
This tubes set is working surprising better than the producer's originals in my
Sound is more pure, precise, and selective, bass more deep and completely
under control. My ProAC D80 loudspeakers work without any effort. They lightly
give a thick and heavy sound - classical or jazz music. I play all my
records again and discover new music - for example very demanding for
equipment Cassandra Wilson records from "thunderbird" album, electric and
acoustic bass and drums in lower-most now really sounds together and as
individual instruments at the same time, before tubes change it was more like
bang than music. I taste Patricia Barber records as new surprise...

Outstanding Sonics; Tube Failures


Originally purchased eight of these for my two monoblock amps. First tube failed after 90 days, unwarranted. Bought another matched pair.. After about 200 hours another one failed. Luckily my amps are fused. Love the sound, not sure this tube has longevity. Tubes were biased slightly lower than specified for my amps.

Superiror Sound No Problems


I have a pair of these Gold Lion KT88 Tubes that I've been running in an original 1973 Marshall 100 watt super lead amp. The 1973 Marshall amps are notoriously bright, ear splittingly bright in fact, and these tubes have cured that problem. I have been, frankly, abusing these tubes in that amp for about 2 years and I've had no reliability problems. The amp is a fixed bias job that runs a very high plate voltage - the transformer in my amp supplies 485 volts to the power tube plates. This will kill (and it has) most other new KT88's I have tried (except the Gold Lion, Electro-Harmonix and the JJ). Each tube is biased at 60-62 mA.. Its a Marshall so its job is to give the overdrive distortion. I run the amp wide open 10-15 hours per week. I was very, very surprised to hear that some people are complaining of reliability problems with this tube.

Quality tube, great performance


Installed a pair of the KT88’s in a McIntosh MC60. Please with the performance. Clean crisp sound, no distortion, no hiss or noise. The tubes have very little “blue glow” from traces of gas left in the tube which ionizes under high voltage; this is one indication of good manufacturing techniques. Some other brands of KT88 tubes (and 6550’s) have had considerably more blue glow when used in the MC60.