I made an error when explaining the heating of the cathode. The heater is always inside the tube. The difference is that sometimes it's a directly heated filament whereas other examples have a separate heater assembly right near the cathode. Sorry for the mix up!

Thank-you both for an informative and entertaining video. I tried a 6AS7 in my Crack amp and found it to be very microphonic. Not a problem for a headphone amp but the 6080s I have sound better. With the constant current source upgrade, the 12BH7 in place of the 12AU7 is worth a listen too. Some of the tubes I used in my Foreplay preamp were microphonic and were significantly improved by adding a couple of O-rings.

Tubes are like tone controls theirs no one best tube only synergy matching your system and your Taste ! Thanks for the video 😆

Enjoyed the conversation on microphonics. I have a Bottlehead Quickie. I have tried several ways to dampen, and in all, it's a fun set of experiments :-)

Thanks for the video. Just getting into audio, and hope to see more recommendations for beginner.

Thanks for the non-trivial work you do to bring us these interviews and your review content. I do very much enjoy them and appreciate the effort it takes to get it all together, so please don't take this critical feedback as negative. Often times your "layman's explanation" is approximate and while not exactly right, conveys the broad gist of the idea. However, your explanation of linearity in tubes is incorrect in the way engineers refer to linearity when talking about whether a tube is more or less linear compared to another tube. You refer to linearity with respect to circuit frequency response, but typically, when we speak of linearity in circuits, or in this case, tubes, we're talking about the plate current to plate voltage linearity at a given operating point. There is an interrelation between operating point, IV linearity at that given point, and frequency response, but frequency response is influenced by other factors of the circuit design beyond the tube part of the circuit alone. So, the linearity and frequency bandwidth has more to do with the design of the circuit than just the tube. "Linearity" of tubes is talking about their plate current and plate voltage behavior at a given operating point. Googling + "plate curve" will get you these charts in Google Images. The misconception that when engineers talk about tube linearity, that they are talking specifically about frequency response happens a lot in non-engineering audio discussions-well before I was born, and I'd imagine well after I move on. In the meantime, I thought I'd take a moment to clarify it here. Translating technical to non-technical isn't easy work. Keep at it! You're doing a lot better than I can! :)

Have you heard of the Loxjie P20 ? It's one of the very few tube amps which is affordable to me. Hope you can review it. Thanks.

Very informative video!

Hey man would you say that on a R2R Dac vocals and instruments sound better and on pwm/FPGA digital sounds better and with a R2R Dac a tube amp would be a better combination or solid state? Also it would be nice if you can check it with aresII with tube amplifier and solid state

Can you please review more budget level gears especially those great value ones from China ? TQ so much for your videos.

Zmf products ,verite closed if possible

I am sorry but my ears can not support head phones