Genalex - Gold Lion KT77

12 Reviews

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USD $‎55.95
After extensive research and engineering, New Sensor Corp. has reissued the famed Genalex Gold Lion KT77. This tube has been recreated down to the finest detail for exceptional performance and sound quality.

For audiophiles, the Genalex/Gold Lion KT77 tubes have full, yet tight and dynamic lows. They have great clarity in the mid-range as well, and extended highs. Many audiophiles that have previously enjoyed the Winged "C"/SED EL34 tubes have reported that these KT77 tubes are noticeably better.

From our review in guitar amps: "The Gold Lion KT77 is a drop in replacement for an EL34 or 6CA7. The sound however is not typical of an EL34 or 6CA7. It is more of a hybrid. The tube delivers all the mid punch you would expect in an EL34 but also has a top end that is more open and bright. It’s definitely got a bit of a 6L6 designed into it. I tested it in Marshall 2205 50w head and was able to get that 70’s rock sound but with some bias adjustment could also dial in a VOX-like chime."

If you are curious about how these fare in a hifi stereo amplifier be sure to read the Wall of Sound EL34 tube comparison for details.

Other Genalex - Gold Lion tubesEL34 Tube Types

Additional Information and Downloads

EL34 Tube Review for Guitar Amplifiers
EL34 Tube Review for HiFi Audio

Tube Matching Information:
Power Tube Matching FAQ
Perfect Pair System

Genalex - Gold Lion KT77 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

12 reviews

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An excellent tube that puts NOS tubes to shame but looses out to the original GEC KT77.


These tubes are phenomenal. I'll say they sound even better than many NOS EL34 and 6CA7 tubes, but that's where the party ends. Compared to EL34, 6CA7, and the deplorable sounding JJ KT77 these KT77 tubes sound amazing, but I compared them to original GEC KT77 and they do lag behind the original GEC KT77.
Don't get me wrong the high end and low end response, and the clear mid-range of these tubes put many of the NOS EL34 tubes to shame but when you put them against the GEC KT77 they do sound lackluster.
First difference is the low end clarity, it's not as clear and deep as the GEC KT77. Mid-range detail isn't as clear as the GEC KT77, and the high end does exhibit some distortion compared to the GEC KT77. The original GEC KT77 just sounds bigger.

Awesome upgrade for my Blackstar Club HT-40 MK1


I replaced my matched set of Mullard EL-34's with these matched KT77's in my Blackstar Club HT-40 MK1. After a good bias setup, these things changed my amp's tone to what I've been searching for. A massive improvement all around. Worth every penny and now my go to tubes for all my other amps!