Genalex - Gold Lion KT77

19 Reviews

Availability: Usually ships within 24 hours.

USD $‎81.95
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

19 reviews

NOS replacement


These are fantastic tubes, I put them on the same level as the RFT's or old Teslas made at Trinec or any other of the great Eastern European EL34's from the 70's and 80's. In my experience they are exceedingly well made, handle current and voltages well over their published spec, operate quitelty and with predictable reliability. Those are the qualities of the best NOS tubes. As for Sound, these tubes dont add much coloration, maybe thats why they are becoming 1st choice tubes for Audiophiles.In guitar amps that lack of coloration is almost a sort of color itself. They are a great choice if you like 6550 's but dont have an amp that should use 6550's - like a Marshall 3203 Artist or Blackstar 20, for example. These tubes provide headroom and the treble bite and detail of the 6550 and also that cracking-ice overdrive cruch of the 6550's without the high current demand. Not a soft clipping, saturated EL34 , its a ballsy old school metal sound. If you want a saturated, midrange forward EL34 sound , then buy the SED EL34, its the best of that type.

Excellent tubes!


I've been running a quad of these in my Dynaco Stereo 80 (90's NY manu) power amp and a pair in my home-made Marshall 1987x 50 watt plexi for about 4 years or so now. Both amps put over 500+ vdc plate. Tone in both applications is outstanding! Cranked tone in the Marshall is stupendous! I rechecked values last year on a Hickok 539C and they still tested like new for transconductance. These will last for years. A great buy no matter how you look at it...especially with the cost of NOS KT-77!!!!

Ian from Aus


These valves are brilliant. I have a Prima Luna integrated amp and have tried a range of valves including KT120s, KT150s and Winged Cs both KT88 and EL34s. These have a sparkle in the upper mids and the definition of instruments is amazing. Great valves and highly (VERY) recommended. Thank you thetubestore for great service to us here in OZ - not like some.

Great Gold Lion


I have a Anthem amp 1 tube and i replace my el34 Mullard by 4 kt77 gold lion Genelex What à difference in all . Thought first the price was too high but alter listening to the Gold Lion They are a low price for the result you get.

Better than an EL34!


While the KT77 is a "drop-in" replacement for any EL34 tube, the Gold Lion (GL) KT77 is better than an EL34. How you say? While I have always liked EL34 tubes for a glorious midrange, I found the EL34 a little lacking in the extremes, not quite the sparkle on top and a somewhat anemic in the bass. The Gold Lion KT77 almost seems like a hybrid tube, an EL34 with perhaps a little 6L6 in it. Almost as soon as I dropped these into my EAR 534 amp I heard the bass that before was missing with the EL34. The top end had more air, more "life" and the midrange, well, it was there in spades! The sound in the mids was fuller, more real and had more punch. These do not sound like any EL34 I have heard before. I would even consider these better than my old Mullard EL34 XF2 tubes!
This is a tube well worth its price.