Vacuum Tube Myths and Snake Oil Bull**** Debunking 

To prove your point Mark . The other week I went to see a band. Their guitar player had one of the best guitar sounds I have ever heard. Talking to him in the break, he said his 1970's Vox AC 30 amp had not had a valve change for about three years, (they do two gigs a week) , he didn't know what his connecting cable was as someone gave it to him . He buys the cheapest strings he can when he changes them every 3 months , and the only effect he used was a 1960's Watkins Copycat tape echo. (He knew it was 60's as his father gave it to him when he went to a Strymon tape echo). Hi guitar was a Fender Squire Stratocaster with no modifications at all. He spent his time getting to a high standard instead of trawling the internet for a load of snake oil fixes.

I have learned SO MUCH from you and Mr. Carlson's Lab that wasn't covered in all the electronics courses in school ! Nitty-gritty nuts 'n' bolts stuff not in the textbooks. Thanks ever so.!

The tube damper worked in my guitar amp. The problem was most likely that the metal retainer was vibrating against the glass and causing unwanted noise. They were like a dollar for 2 I think.

The best video to date, lots of laughs. Keep up the good work

I built a Heathkit integrated amp in 1962. That was my last involvement with tubes until recently when I got a new amp that uses tubes in the pre-amp. I tend to be a doubter in much of the audiophile stuff. This was an excellent explanation of these ideas.

Hi Mark, you hit the nail on the head! All snake oil. I've been an electronics technician since I was 13 and I've seen it all. Many newly manufactured tubes are as good if not better than NOS. There's a lot of factors involved with the actual applications that tubes are used in. I repair a lot of vintage electronics...not only hi-fi, but guitar amplifiers, both vintage and new. Newly manufactured tubes, from my experience over the years don't hold up as well in guitar amps. The tubes are put under severe stress as opposed to hi-fi applications. There are many tubes made today that aren't reliable for guitar amp use. Guitar amps made nowadays are biased very hot and as we both know shortens the life of a tube; mainly output tubes. As you said, vibration is one of the issues along with them being over-driven to the point where the plates buckle, or the glass envelope melts. I've had many EL-34's that had holes in the side, or top of the glass. I do agree with you that the Sovtek 12AX7's are a good pick. Also, there are times where I get a shipment of theses tubes where out of 2 dozen, I MIGHT get 3 that are quiet. When you can play a tune on the tops of the tubes, you're in trouble. From my experience, I've had very good luck with JAN tubes in a preamp section. They were made well and are made to rigid standards. I could go on for hours, but to keep it short, newly manufactured tubes are a dice roll when it comes to instrument amplifiers. I had a very bad run of new Tung-Sol tubes where I've sent back dozens at a time either because of them being duds right out of the box, or failed shortly after installing them. Excellent video, keep on keeping it real. PS: I will not do repairs for audiophools...oops, I mean philes :) You end up getting married to them, and they are never satisfied. it's not worth the problems, no matter how wealthy they may be.

You are the absolute KING of debunking snake oil . At 70 years of age and into high end audio since I was a kid, via my father, this snake oil never stops. EVERYTHING you said is correct. My other pet peeve is cables and interconnects. Been there, done that.

OK I play guitar, and have swapped out a lot of NOS tubes in the V1 position Of my tube amps, in order to change the tone. Absolutely makes a huge difference, but I am so glad to hear that perhaps somebody is making good tubes in the present, that will not continue to cost me an arm and a leg. So glad that there are people who are continuing to analyze tube technology. I subscribed!

Many preamp tubes have metal covers/sleeves to prevent RF interference so how does is the heat dissipation argument valid?

what's the best way to protect the life of the components of your tube amp? Turn it on and off fully every time you take a break for 30 min or an hour... or leave it on, but put it in standby?

I find it funny that folks will spend thousands on getting a tube amp, to get that tube sound, then spend more to get rid of the tube sound. People do strange things .. Cheers, - Eddy

Your advise to optimize the end points of the system is spot on.

My tube amp makes noise sometimes, it reminds me of sleigh bells. When I found an audio example of microphonics (sounded like a low drone) it didn't remind me of the sound my amp is making. Any idea what's happening with my amp?

Wish I'd found this year's ago, absolutely spot on and entertaining as well. The most sense I've heard on these various subjects ever. Much enjoyed, cheers :-)

Mark , I use agree with you on the sovtek until yesterday . I bought 2 12ax7lps , supposedly burned in and matched . Both microphonic , very dissatisfied . Any other suggestions ? Using in v1

So I have this question for you, I don't know because I am just a consumer. Just purchased a schitts Frea + pre. amp and have watched 2 videos showing the only down point is the microphonics if barely tapping it. I bought some of those O rings that are supposed to eliminate that. So have you done any test to see if it is snake oil or not?? I haven't received mine yet so I don't know??

I'm wondering if cryo-treatment isn't really damaging the tubes structurally, so that they do sound different, i.e. worse?

I built my first amp using carefully selected NOS parts and expected to see Elvis appear in my living room when finished, but sadly he did not arrive. However, in all fairness it was probably my fault because I failed to use vintage solder and do a proper cryo-freeze of the power switch.

I agree with most of what you say other than the dampers.....they do in fact reduce vibrations the same way a harmonic balancer does on an engine, or touching something that vibrates stops or dampens the vibration.....it even works in a similar fashion to double glazed windows.........anything that can reduce to transfer of vibration/sound to the tube elements will have a positive effect.......not all vibration is started inside the tube itself or its mechanical connection to another vibrating part....if you can tap the tube and hear it in the output and then hold the tube with your hand and tap it again and its reduced you can reduce microphonics with some for of damping.......the more weight an object has also has a damping effect......the only this I will say though, is you have to have the problem for any damping to work to any degree.

Mark, I have been playing live rock music as a weekend warrior for the last 50 years. I fix my own gear, have built six amps and fix stuff for my friends. Nothing sounds better than a re-tubed properly biased guitar amp. However!!!!! After one set your ears can't tell the diiference between preamp tubes. Once the drummer starts slapping the snare drum, kiss your ear sensitivity good by. LOL

The engineers at AUDIO RESEARCH state plainly that newly made tubes experience shifts in their operating parameters for some period of time after being manufactured. They put all their tubes through a 48 hour burn-in cycle so that their characteristics stabilize. I would tend to trust what the engineers at Audio Research say about that. They SHOULD be subject matter experts, and they are.

i have question for you. What is system that your listening to that you say you can't hear the deference in the tubes? Is it a $2000 on your work bench with car speakers or $ 30,000 one in nice set up listing room . In a $2000 system may not show the deference.

Without repeatable instrumentation for sampling and testing performance. I'm skeptical about burn in performance differences unless you can show that using test signals or specific tracks that there is a actual difference. I'd assume that 20 hour burn ins that change the sound are either you getting used to the new sound or not hearing the old sound for 20 hours of time gives you time to adjust and forget what the old sound was like. The cryo stuff I'd have to see someone with lab equipment and sampling do a before and after on a few dozen -> 100 samples, to help weed out cheating and good batch performance.

I recently purchased tube dampeners for my 2x12 guitar combo amp. Haven't got them yet, but do you think the will help considering the speakers are in the same cabinet as the amplifire? I have a power tube that makes noise at idle when struck. I think the vibrations over time playing it have messed up the internals of the tube.

Let me ask you, does the quality of the CD player (or other digital source) make a difference in terms of audio quality (I.e. are bits ‘bits’)? I agree wholeheartedly the end points of the system are the most important but I struggle with the concept that such applies when the ‘front-end’ source is digital? Am I wrong in saying the front end matters far less when such source is digital (as opposed to analog such as vinyl/phono)?

hey bro great video!!! I agree totally with everything you said. I do have a quik question for you thou, being a tube guy. I play bass thru an ampeg svt with 6550 power tubes and was thinking about trying out KT88's in it, do you think there would be any benefits to this? answer if you can, no problem if you don't.

I remember as a child having a 5 tube AM radio on my night stand. With the radio on and the lights off, I noticed one of the tubes had a blue glowing ring around the outside of the envelope. Obviously related to electrons, I never could understand what was causing it; Any ideas out there?

Does anyone know the answer to this. In the 60s and early 70s Sears had a guitar amp. well several but most were seperate head from speakers. The most common had 2 12" speakers and were dual channel thus great for my friend and I both to plug into. Anyway the two Largest tubes had a blue glowing gas in them. Or possibly Cherenkov AKA Cerenkov glow. When you played a low E note the glow would dissipate for a moment then return. I and two friends had these amps and i never saw any other tubes do this. I know some tubes were lead shielded on part of the tube and others compleatly covered in lead. But ionizing radiation may not be the cause but I think it likely was. Anyone know??

Love all your videos. Thanks

That tube damper ad even as you read it was so hypnotic I almost thought " I need those!" I think I'm going to invest time playing instead of money.

Refreshingly frank and to the point, with added humour. I like listening to music on my tube amps, and my s/s amps. Its all good, even without cryo treated 8mm2 jumbo cables and green glass tubes. Burn in??, that's 20 or 40 hours of lost listening, or whatever, from that new set of tubes. Love your POV on the snake oil.

So if I put my tube amp in the freezer it will sound better?

What about shield cans? I used a tube damper once on a tube that would oscillate at very high volume and it did cut down a little.

I have a guitar amp that was making a ringing sound at certain notes. It was disturbing. The tech I brought it to put heat shrink tubing on to the V2 tube and the noise went away. So I don't know what to think? At least 3/4 of an inch of heat shrink tubing and a match aren't going to cost $30.

when you where talking about those rings and some of them beeing heatsinc looking i tought, what if you actually put a heatsink on there with some propper thermal compound and aluminum fins or something wouldnt that help the longevity of the amp?

Mark. This is the BEST video on RU-vid. Love it brother. Awesome!!! Thanks for this. Seriously! Ron

Thanks for the your views, always interesting. I must say being a guitarist I do use the valve/tube rings in my guitar Amps which I find helps reduces the vibration going through the tubes/valves which I believe/think/hope! Make some last a little bit longer!?!?, maybe. For me it's a cheap and easy way of hopefully prolonging the life of something which is used in fairly hostile environments (loud volumes, being moved all the time, etc)

I love bursting the audiofool's bubble by pointing out to them that the electrons exiting through their multi hundred dollar power cord have to then pass through a tiny little wire inside the glass fuse sitting right on the other side of the cord's receptacle. It's fun to then watch them try to come up with a counter argument justifying their incredibly foolish purchase.

Those rubber tube damps could be a cure for premature ejaculation 👀 JJ are supposed to be made to vintage standards.

How do the Wing C EL34's compare to the JJ's? (for a Marshall JCM 2000 DSL100).

can you recommend good 12ax7 tubes for a guitar amp? also good 6L6 tubes?

Current production tubes like EH, Tung-Sol are favorites for me in my guitar amplifiers. They sound good, and they have good durability. Tube Burn-In is more about removing/revealing problematic tubes that will have early mortality.

Re; Burn-in of tubes. Aren't they already burned in before they leave the factory?

Know this is an old video. But would any one know a vintage tube supplier in the gulf coast area?

I need to replace all the tubes in a AR VS60, what would you recommend? Thank you!

I am an electronics engineer of some standing with Bsc Hons and in the early days all the qualifications I could take and you are correct. Freeze a metal, its resistance goes lower, let it warm up and it returns to where it was, so no change apart from empty pockets! Speaker leads is another myth. OFC and the like means nothing to the sound produced, that is down to your speakers and pickup. Snake oil is everywhere.

If tube damper rings are useless, why did Marshall include rings on the first preamp tube in both my DSL15C and DSL20CR?

So I like to hear and I agree with all the topics. And one aspect (in my personal perspective) seems to me to be much more important than all that have been mentioned: Perhaps one of the components of great impact in the quality of the transmission of the audio through vacuum tubes is the output transformer, something that is often overlooked by many of those dedicated to tube amplification. A good output transformer continues to make a big difference, at least to my ears. Keep it on, Blueglow!

Awesome awesome advice!!! Thanks for all the help. Funny topic. Loved it!!

Why do people report hum going away after burning in tube amps then?

I built amps for Bob Carver, and he used Russian KT88s and KT120s, and they worked just fine. As far as the sound of tubes, it's mostly the circuit that makes the difference in sound, and the output transformers are critical to the sound of an amplifier. And dampers --- the only damper that actually works in my mind in a good EF86 audio pentode with a heavy disk at the top of the plate, such as in an Amperex.

Here in Brazil we call it E.T.C ....... El Toro Crapo !!! Great vid..... lol need more like this on Sunday.......

Hi ! Mark, excellent video ! Well I have a new phono stage that utilizes 4 Sovtek LPS (two per channel) that I found fantastic on the low end and midrange range but the upper notes are always there but in the background, lacking presence, even though I noticed the cymbals sound very authentic but way in the back and I found myself always tweaking the treble to increase the top end, I would appreciate any advice on similar tubes with better extended highs. Thank you.

I used to work in high end pro audio design, we had every piece of ultra high end test equipment available even some custom made. This topic would bring endless joy in the engineering lab, suckers willing to pay $25,000 for 3 feet of speaker wire when $0.25 of lamp cord was utterly indistinguishable on every level of physics and listen testing... I will say their is at least some value as artwork when it’s a pleasure to look at, so expense is justified there, in my view. We actually had customers in our lab choose the TLO74CN (23 cents) opamp over a $100 ultra fast ultra low noise scientific grade “audiophile” opamp in blind listen testing.

Mark , recently bought a hybrid tube amp with 12ax7's. They have metal bayonet sleeves on them ! Should they be removed !??

I agree with you, but wouldn't a NOS RCA or Panasonic valve last longer and be more durable than a new JJ or EHX?

Re: tube dampers... Everything you say about them not improving audio quality is true. However, here's an experience I had. I have a Fender Hot Rod Deluxe IV combo amp. At a point, I kept hearing a high, glassy buzz from the back of the amp. The sound coming from the speaker was excellent, but there as a mechanical vibration emanating from the tube. I opened up the amp, and with a gloved hand, gripped the tubes as they were vibrating, causing a cessation of the noise. Popped on some dampers, and, boom... Back in business. That said, like you mention, guitar combos are VERY rough on tubes, and, if possible, is recommend to any guitarist that they choose a head/cab setup instead.

Love your videos, I completely agree with your prognosis on audiophile snake oil. Speakers are the most important by far for sound, I've had Carver Amazing Loudspeakers, ESS AMT1A's, Acoustat 1+1's, Magneplaners and now use a homebuilt pair of towers with the ESS Air Motions Transformers reproducing the highs, extremely efficient and sound wonderful. Oh and by the way, still own all the speakers I've ever had except the Carver Amazing's.

At last an expert, I was one of those people who was always reading conflicting views on NOS tubes, in glad I now feel I don't have to upgrade and spend a fortune, thank for this video keep up the good.work!.

Great videos. Keep up the great work and service to your fellow man. Thank you.. I think you are correct about no benefits of cryo treating tubes.. However, as the former owner of an aerospace company, cryo treatment does produce a change to the properties of metals that is maintained even after retuning to room temp.. Much the same way as heat treating produces changes even after the material returns to room temp.. Sometimes these treatments are used for stress relieving materials, often in aircraft parts..This process is used often at GE Aviation. Will it make a tube sound better? Doubt it... Could it damage you tubes, from glass and metal having different contraction levels at extreme cold, temps like Minus 300F? I don't know, but why subject a multi material assembly to those temps? Not me.. I let my tubes stay within the temps they were designed to operate within.

Interesting video! I found most interesting the part about the "Tube Dampers" because although I agree with you about the devices being total BS, there is a bit of sense in doing something about the vibration. But as I began to rapidly think of how to keep the vibrations of a nearby speaker from affecting the tubes, no matter how I configured a "fix" to keep the vibration from the tube, the net result was to over heat the tube! It might be a bit of a hassle, but the best bet would be to keep the amp and the speakers separate from each other!

Thanks Man ! Funny as hell ! Waiting on me Doge 10 tube integrated to arrive 😃 you know of any good sounding 5660 or KT88

About tube dampers: I saw once tubes with silicon rings, which stuck in some perforated metal tubes. The sockets where not on a pcb board but connected with shileded cabels. The device was some kind of radio equipment from a soviet military craft. Those perforated metal tubes where hung up with some kind of spring system. The owner told me, it was for shock absorbtion as I asked him, because the construction looked funny. Maybe that's how they came to the idea.

I agree with pretty much everything you’ve listed. As for damper rings. My experience is, their help is minimal. Personally, I think the metal covers. Like found on fender amps, actually help the most. Largely because it’s somewhat a barrier to the sounds coming off the back of the speaker.

Mark I am not sure if I 100% agree with you on these points. At first I have to admit that I am no technician in any shape or form, I know as much about tubes as a car salesman about cars, so I might be in the land of Dunning&Kruger here but I worked for a hi-fi manufacturer back in the 90s and we were the distributors of a Chinese tube manufacturer in Germany. However we had a nice tube pre-amp with ecc82 ecc83 and my demo amp was equipped with proper Telefunken tubes, not the real old ones with a swastika printed on but reasonably old like 50s 60s that kind of thing. My amp at home was equipped with the Chinese counter fits and it worked ok too. But what I have noticed is that at home I had to change my tubes relatively often coz after like half a year or so they always started to make trouble and started to degrade noticeably. One of our technicians/developers was a real hi-fi nerd with Onken speakers and multi cell horns and that kind of thing and he always refused to build a 300b coz he said he is not willing to spend 1200 for a proper GE tube. For his own amps he only used these old Wehrmacht tubes. So I guess there must be something to it. Why do people say that Shindo stuff sounds so awesome? (And they are right it really does) It is not only because it looks cool and is exotic and expensive, I think that one secret is exactly using the right old components. It does not mean that all new stuff is crap, I am not claiming something like this at all, but for sure it sounds different.

I made some tube dampers out of hummingbird taints and it made “ tiny little” differences in mine.

Love this video. You mentioned the Sovtek 12ax7. Can you say that the other Sovtek tubes are equal if not better?

I’m still chuckling, you’re a brave man burning down myths using snake oil as a accelerator.

Great honest video that I totally agree with! Love your channel and all your content!

A+. I am not an audiophile, but have been repairing, designing, building guitar amps since the 70's. What you say translates over to that world 100% according to my opinion and what I have personally experienced. Entertaining!

Thank you for creating & sharing such a nice & informative presentation for us.

I like the old blue glass Arcturus tubes. The 27 is my favorite. I also like the 833-A for the final SET stage even if it is tricky to get the 10 Volt 10 Amp heater filtered 4.5 Farads in the final filter and using it with Magnepan speakers.

As a reference: as of April 4th 2022, ONE Sovtek AX7LPS is going for $85.00! Bad times for tube enthusiasts.

Good Job on this one! So True! Keep putting out the videos. I Love Them! Well Done Mark!

Mr Blueglow - I have a question for you pls. Do you believe that separating the chassis of tube pre amps / amps from hard substrates by using rubber mounted pads or mini air cushions under the chassis feet to limit vibration transfer is a gimmick? As you mentioned it briefly towards the end while laughing, suggesting it’s a joke / gimmick? Repeatable and verifiable tests in physics demonstrates a reduction of vibration transfer from one object to another by separation and or vibration absorbing contact points. If you believe it is a gimmick then please provide evidence of why, not personal opinion but fact to prove basic physics and energy transfer wrong - vibration is energy..... after all.

Could you do a video on cartridges and speakers? I would like your opinion on them.

Agree with you 100%. On the tube wear in, you are correct that people are looking more for tube wear out. The problem is that tubes wear slowly so the sound changes and they don’t notice it. Then, when the tube is down to 20%, that is the sound they are used to when the amp fails. Putting in a new set of tubes sounds different, so they think it is bad. Another myth is that a tube with a mesh plate sounds more open, as if the physical holes in the plate make sounds, and open sound comes from physical holes.

Thank you so much! Now I'm even more certain about these things. Great you're able to talk about these things without letting your emotions get in the way xD which may be difficult, but people who especially aren't good at physics or electronics will appreciate it.

From Leo Thanks for your video. There is lots of snake oil in any hobby. I am always up to learn. I have been repairing guitar amps since 1969, of course mostly tubes. The vast majority of tube amps wrap the preamp and phase tubes in metal shielding. the heat build up must not hurt. Some have slotted metal cages around the power tubes where heat is definitely pretty high. A pair of KT88 or a quad of EL34/6L6 output tubes make serious heat. Higher power guitar amps that hang the tubes upside down in the same cabinet with multiple speakers are poison to tubes for microphonics. The same basic design where the tubes are upright in a separate cabinet is way better on tube reliability. I'll bet I have 30 12ax7, 12at7, 12bh7 or 12au7 tube that test great on the tester , but rattle like a tin can full of broken glass in the amplifier. They are fine for many stationary amplifiers, but are junk in a guitar amp. The upside down tubes are even worse where they mount the tube sockets directly to a circuit board, so now the vibration hurts the tubes and the heat burns the circuit board, but that is another story. It is like the designers willfully take the reliability out. I have ham radios from the mid 1950's that still have some of the original tubes, including the high voltage rectifiers.

1/2023: I absolutely love it! I totally agree with your logic. And your honesty. Count me Subscribed. Thank You and Happy New Year

it's NOT the tube, it's the electrical circuit around it !! Buy an old book like Radiotron Designer's Guide, if it is not in there DON"T believe it. Those people were operating valves when they were state of the art and their knowledge was unparalleled.

What is the best new production 6SN7?

One tube that I have found that benefits from the rubber rings is the JAN6418 miniature pentodes that I have in a tiny, battery powered headphone amplifier :) Wonder if you've ever used these!

I totally agree with you. Only thing probably worth investing in to improve tube amp aside from better tubes which is obvious is ensuring they get proper cooling to ensure they ideal operating state. It won't make them sound better but certainly will extend their life expectations. I personally like hybrid tube pre amp designs (when done properly). Certainly the best way to improve the system is investigate in analogue listening device. Best regards.

I never fell for the "buy NOS or used vintage tube" game. I was playing guitar in the seventies and beyond and there were some amazing amps and tones for sure. I'm suspect there are times where finding the right older, original tube may serve an amp well. However, is it worth the cost better? Not for my needs. I do tend to buy the premium or at the least Russian made reissues. My favorites are Gold Lions and Mullards, but I just ordered a Sovtek 12AX7LPS because that's one I don't have in my collection. Thanks for this video

Refreshing and candid. Thanks, Mark.

Excellent. As an old radio tech who plays guitar through tubes it warms my heart to hear you call BS on these blatant sheep milking devices. I have spent hours debating audiophiles. Very frustrating. Great video. Cheers.

Heck yeah! These cryo treated tubes I'm sellin' are genuine! I stuck 'em in my freezer last week, and they're still in there, just next to my vodka, right now! You'll be cry-oing tears of joy when you here 'em!

you are 100% right the cartage & stylus is the key to a good turn table not a '' special '' power cord

SOVTEK 6L6 WGC and 6L6 WXT What is the difference?

Great video. Agree on Sovtek 12AX7, use them and the standard Sovtek EL84 in my guitar amp. Have tried many others... Not NOS admittedly... But always go back to the Sovteks. They sound great.

What about Mesa claiming that you can only use their own Mesa-brand tubes in their guitar amps because they have a fixed bias. Is that false?

I have a pair of NAT se2se 211 PSE monos and the tall envelopes of the 211s ring like crazy at around 800hz. I can have the amps on, no music playing, sing an 800hz tone and the speakers play the tone. That's remedied by some Pearl tube coolers/dampers. No more ringing/feedback and the midrange became much clearer. I can't say that I notice any difference in other, smaller tubes but there is likely a small improvement if my experience with the larger tubes translates.

Put all this right along with the $125 duplex outlets with gold contacts, little telephone poles for the speaker wires, pointy pyramids to support the speaker cabinets and on and on . . .

Great great info! I'm not so sure on tube dampers in a guitar combo amp. If I hold a tube that audibly rattles when I shake it by the plug end, but then hold it by the glass and it doesnt ring anymore, or is more quiet I'd say they are doing something. Now I dont think its neccesarily through the audio signal. There's also a difference between tube rattle and microphonic tubes. I've had tubes that rattle that sound fine through the audio signal, but rattle loud enough to be picked up by the mic on the speaker at the gig. That's where attempts to quiet that rattle are warranted, especially when tubes can begin to rattle in a guitar combo amp in relatively short time.

With the talk of vibration to tubes-I can remember in some mic preamps-TT preamps the preamp chassis was mounted on rubber-and spring suspension mounts from the main chassis-this worked well-and NO snake oil-specifically Ampex Re/PB tubed amplifiers in their 350 series tape machines.

Awesome video ! You should make a snake oil series , can't wait to read the comments. Merry Christmas.

The Law firm of Bashed, Slashed, and Trashed

I'd like to learn more about the "burn in" philosophy because to my ears I hear a difference in power tubes after ~10-20 hours of "burn in." Most notably, I hear it on my Mullard 20W that I built with KT77 tubes. The highs mellow out and the bass/mids opens up in a more 3D way to my ears. I agree there's no reason to pay for "burn in time" though, since you'll get there after just a dozen or two records, but I'd be surprised if a brand new tube sounded the exact same as a 20 hour tube. (I'm an EE, but I do make my living using my ears).

I totally agree with you, I worked in Hi-Fi retail for years and although the products 'in the middle' was Transistor based and it always amazed me the amount of BS there is even in the Enthusiast publications. The critical factor is the delivery and that is upfront and speakers. The amplifiers I would suggest are of say 70% good to perfection and most speakers vary widely from 20% through at a push to 50%. Over the years I have built my own speakers and always modify the drivers. Even after running in period there is way too much resistance in the suspension and I cut away most of the spider and remove the dust cover. The enclosures I have made are 1/4 wavelength twin parallel pipes in a transmission folded horn and resonance damping and speaker chassis fixings are by magnet support while the chassis surround is held against the cabinet by foam. I glue a ceramic piezo onto the apex of the cone on light supports and rewire the pigtail wires and balance with Bi-Polar caps and resistors and a few millihenries air core inducers. This method enables the speaker to more accurately follow the signal path and the harmonics and imagery is second to none and single point source providing the amplifier is well balanced and also has good harmonic figures and good imagery and leaning toward a softer than harsh output. Now am retired am thinking about Tube amplifiers and so far my first bit of kit is a Capacitor discharge wand using a 10 Watt ceramic 470 Ohm resistor. Great videos and Seasonal Greetings from London UK