by Angus Baigent | 3,0 / 5,0 | Approximate reading time: 1 Minute

Johan Segeborn presents his EL34/KT66 tube shoot-out  ·  Source: Johan Segeborn/YouTube


So you’re on the market for a new amp… I guess the most important question is: analogue or digital? And if you go the analogue route, are you into the transistor sound or is the good old vacuum tube your thing? If you polled the entire guitar-playing universe, I think valve amps would still carry the day. But in 10 or 20 years, who knows? With all the technological advances and choice available in the realm of digital guitar tone these days…  


If your choice has fallen on a tube amp, one of the key questions will be: what tubes are used in the power stage? YouTuber Johan Segeborn has made a nice little video comparing two famous tube models. He takes a Marshall 1987X 50-Watt Plexi head and plays through two different types to let us compare the two. The amp ships loaded with EL34s, which he contrasts with a pair of KT66s.

EL34 vs. KT66

Johan plays his 1987X through a Marshall 4×12 1960A with stock G12M25 75Hz Pulsonic Celestion Greenbacks. His punches out his bluesy rock riffs on a Gibson SG from the Custom Shop, so quality gear used all round.

Grab yourself a cup of your favourite hot brew and let Johan A/B you some nice vacuum tube tones.


Although I’ve loved playing guitar for years, I’m not what you’d call a tone junkie. And even I can hear a distinct difference in tone here. I thought this was an interesting comparison – which did you prefer? Let us know in the comments below.


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Image Sources:
  • Two TAD RT822 KT66s: thomann/TAD
  • A pair of EH EL34 tubes: thomann/EH

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One response to “KT66 vs. EL34 Tube Shoot-Out: Can you hear the difference?”

    William Paxson says:

    Just swapping tubes without properly rebiasing the amp pretty much invalidates any real insight on the actual sound difference between the 2 tubes. The comment about not being able to crank the gain is sort of like running 87 octane petrol in an engine set for 91 octane and then saying “Well, I can’t give it much stick or it pings (or vice versa and saying it bogs)”. Duh.

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