Does this amp distort? [Aiyima T9 Pro]
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Thursday May 2, 2024
David Mellor
David Mellor is CEO and Course Director of Audio Masterclass. David has designed courses in audio education and training since 1986 and is the publisher and principal writer of Adventures In Audio.
And it's here I need to ask manufacturers: WHY ARE YOU INSTALLING 1.21 JIGAWATT LASERS WHERE A POWER INDICATOR WOULD NORMALL RESIDE?
Seriously, WTF? And here I must congratulate Fosi on the power indicator LED on the BT30D Pro. It is red. It is tiny. Perhaps only 0.25mm in diameter. Thank you, Fosi! The power LEDS on the ZD3 and ZA3s are also pleasingly subdued.
But then, Fosi go and put not 1, but *2*, (count them: TWO!) 1.21 Jigawatt blue lasers underneath the tiny valves in the (wonderful!) T20 tube amp, so I couldn't see any photons produced by the tubes. But this is fiX0r3d easily using a knob of Blutak on top of the LEDs under the valves. And just for good measure, Fosi install another 1.21 Jigawatt blue laser for the power indicator. Moah Blutak!
Please excuse the ramble. I'm OK now.
@Chris.Davies: In my day I have heard a lot of distortion, and also a lot of very loud music without distortion. And my ears can easily detect distortion: It hurts my brain, no matter the volume. Whereas, extremely loud music without distortion never hurts my brain. And this is why I am a little worried about myself.
My new extremely Fosi-based 2.1 nearfield system w/ ZA3 Mono blocks and M03 subwoofer amp do not distort the signal at any volume level I have risked. And the ProAc Response 2.5s being driven by them sound fantastic. Especially when at 1-metre range, on axis! (WOW!) And the passive Denon subwoofer makes powered subs sound stupid, in my view.
And because there is no distortion, I am pushing sound pressure levels quite high since I built it. And I am loving it. The clarity and depth of the music from this tiny (well, small!) pile of cheap-as Chi-Fi easily matches piles of stereo gear costing tens of thousands in the 90s.
I suppose I need to start measuring dB levels, because now that I have rediscovered the wonders of stereo (as opposed to multichannel 5.1 and 7.1 systems) I do not want to damage my ears, or give myself tinnitus!
@viljuska09: What kind of speakers on a budget can I use on T9 pro and still get a good sound?
@AudioMasterclass replies to @viljuska09: Yamaha NS-10M Studio, secondhand from eBay.
@DATRecords604: Hey there famous musician in disguise ;), have you ever had a chance to compare the T9 Pro to the Fosi MC331? My concern about this T9Pro is that I read from different users that it gets very hot after a couple hours of use. I like the aesthetics of the T9Pro, but the Fosi seems to be the winner, according to people's reviews read on multiple forums and video comments.
@anonylesss: this is a great video and review, but I'd cut down on the POS dance music during the unboxing
@AudioMasterclass replies to @anonylesss: No thank you.
@MrBallynally2: I like what i heared from this amp. I dont care what i can or cannot hear or the explanation why it is supposedly bad or good. There is no such thing as non colouration. Anything recorded and filtered is colouration. There can be bad distortion and i dont hear it from this amp, at least not prior to clipping.
@MrBallynally2: Sorry, but the valves are i believe not an 'extra colouration'. They are preamp valves. Ie, the initial imput signal first stage amplification.
Take them out and you will notice. And that is the signal going to the subsequent output stage. I could be wrong of course. I havent seen the schematic..
@amitliss7433: i didn't understand if it's recommended or not :XX
@sanolivo6867: Warmth is a combination of low and midrange frequencies. In my younger days, I used to rush and look at the distortion numbers of a amplifier or tape machine. Then later I realized that humans can't hear that stuff anyway. If you can hear over 11kilohertz God bless you. Distortion from vacuum tubes sounds nice. Not so from transistors.
@brealistic3542: For a chance could you dance and sing a little boxing song ? Unboxings are getting pretty boring.If that doesn't suit your fancy make a unboxing slingshot to test how the contents hold up in shipping. That's how Amazon and Ebay/You pay do it. š
@schubertuk: I didn't know anybody would ever declare that 'warmth' is NOT distortion? I would love to know how any such assertion could have any scientific basis. But humans DO like sound being distorted, and I will give the really obvious example -- which is music played in a highly reverberant cathedral -- of acoustically pleasant dimensions -- will distort the source music (hopefully from live performers) in ways that most of the audience will find very pleasing. Not only will you get echos, but you will also get harmonic distortions at various levels that we appear to find 'sweet'. As such therefore I totally accept the possibility that an amplifier that does 'add' distortion to an output in a harmonically pleasing way - may be considered to be 'adding' warmth - and may be a preferred listening choice. After all - all listening rooms are adding at least some degree of distortion even if the creator of the room has deceived themselves into thinking they have produced the perfect anechoic chamber. It won't be perfect - because they will be in it! ;-)
@gernotistgerninnot: Thank you for the good forensic analyze ā¤
@simonzinc-trumpetharris852: Do you get wafers with it?
@davidhunt240: I thought the tube/valve sound was due to the transformer as odd harmonics are not easily transferred through the coils and instead create eddy fields in the core that turn into heat. Also there is much less control over the speaker as the negative feedback can only see the speaker through the transformer reactance.
@lotsofcouscous replies to @davidhunt240: As far as I know transformers don't know nothing about harmonics either odd or even harmonics. I want to believe that you want to pinpoint the difference between Single Ended or PushPull. P-P amps attenuate even harmonics.
@monsterrun: My father has a t9 pro.
We changed the tube to russian Voshkov Rocket jp1 and it sound much better then the included jan tubes.
@jesses1589 replies to @monsterrun: I think the Voshkov Rockets are the best tubes for this little amp. The tubes do take up to 100 hours to get settled, otherwise some may notice a bit of harsh highs when new. Definitely better that the Jan standard upgrade!
@GnabhanJr replies to @monsterrun: Also 5654w sounds very good
@GnabhanJr: No gloves on tubes install?
@AudioMasterclass replies to @GnabhanJr: Theyāre tubes, not car headlight bulbs.
@GnabhanJr replies to @GnabhanJr: @AudioMasterclass human fat not affect the pressured glass? I.e it got gas inside
@davidhunt240 replies to @GnabhanJr: There's no gas inside. If there was, the electrons would collide with the atoms of gas and not reach the anode. The hint is in the name, vacuum tubes...
@lotsofcouscous replies to @GnabhanJr: @GnabhanJr Hopefully there is very residual gas inside.
@malinyamato: technically it is truley distortion but the distortion sounds good to most so whyt not..
@gingernutpreacher: In the 90's I baggered my dad to make me a vale amp for my band (for guitar) and he reused he said we went to transistors for a reason
@AudioMasterclass replies to @gingernutpreacher: He was right, within his own frame of reference. As am I when on dad duty.
@gingernutpreacher replies to @gingernutpreacher: @AudioMasterclass also one turntable stopped working and another gave us electric shock the the tone arm
@octopuscorsica4839: Remember cassette tapes? 3.0% third harmonic distortion was considered acceptable. That is -30.5 dB. Yet I remember saying "the harmonic distortion on this tape is unbearable" exactly no one, ever. Nowadays, an audio device with SINAD of 100 dB is considered below par. I guess because it cannot transparently capture the 120+ dB dynamic range so commonly available in "high-res" content...
@AudioMasterclass replies to @octopuscorsica4839: I remember reel-to-reel. 1% distortion up to 3% or more on peaks, depending on how far you wanted to push it. Maybe Aiyima, Fosi, Arylic etc will produce a cute little tape recorder for people to get that sound at home. If they want it.
@denisdube8893: Hi sir what your sound system ?
@AudioMasterclass replies to @denisdube8893: You'll need to watch my videos. I occasionally mention the equipment I use.
@blue_blue-1: What about higher frequencies?
@AudioMasterclass replies to @blue_blue-1: What about them? I didn't cover them.
@EricIolo: David I dont like warm music - my audio equiptment produces an ice cold clinical sound! Warm is for wimps! Short and sweet, but I am meeting Elton for 6 PM, until next time au revoir
@periurban: Is 100Hz a good test of something like this? Surely a sweeping tone would tell us much more.
@lotsofcouscous replies to @periurban: A sweeping tone doesn't show the individual harmonics
@periurban replies to @periurban: @lotsofcouscous Well, they sweep too, but they are there.
If you don't test many frequencies (either one by one - very tedious- or by sweeping) you will miss the lumps and bumps.
I know from many years of testing headphones the only way to accurately assess them (subjectivity aside) was to use a sweeping sine tone. The peaks and troughs show up pretty quickly.
@lotsofcouscous replies to @periurban: @periurban I believe that you are talking about frequency response or bandwidth !! That is another story.
@knifeswitch5973: There is a crappy GPX āboomboxā in our shop @ work. Manufactured in early 90ās and it has control face nearly identical to the T9. That bothers me. Yuck. As far as distortion goes, itās a 130 dollar amp and where I use these type unitsā¦not a concern. I have an A03 that gets used, abused and hasnāt given me any trouble. I really like it but havenāt bothered putting it on the HP distortion analyzer because frankly, I donāt give hoot.
@gracenotes5379: I'm in favor of using a 2-tone intermodulation distortion test and checking for IMD products at f2āf1 for even order and 2f1āf2 for odd order distortions respectively. Such spurious inharmonic products cause most, if not all, of the subjective degradation of sound quality due to non-linearity, so why not measure these directly? Use of 8000Hz and 11950Hz as test tones, resulting in products at 4kHz ā/+ 50Hz for even and odd order products respectively used to be a standard.
@AudioMasterclass replies to @gracenotes5379: This might be something for a future video where I test some samples of my ever growing collection of Chinese Class D amps.
@medonk12rs: Best unboxing ever!! xD
@AudioMasterclass replies to @medonk12rs: Thank you. I hope that my next will be even better.
@medonk12rs replies to @medonk12rs: @AudioMasterclass ... more stuff, please!
@scottlowell493: Dan D'augistinos obscenely expensive signature amp measures really badly. Pass labs amps measure badly. Both exhibit levels of distortion and noise that snobs decry if measured in an inexpensive amp.
@adrianrorvik7488: So, how does it sound? Good? Bad? Meh? I know that wasn't the point of your video, but you might care to share your impressions.
@AudioMasterclass replies to @adrianrorvik7488: Don't worry. If anything I review sounds bad to me, I will tell you.
@gilesdavis6345: Have you got anymore T-shirt please ?
@AudioMasterclass replies to @gilesdavis6345: Sure, merch is coming soon.
@humblestever24 replies to @gilesdavis6345: @AudioMasterclass Oh stop!
@humblestever24: " Not all that can be measured is important and not all that cannot be measured is unimportant." Einstein.
Sound is as mutable as light so get over yourselves so called audiophiles.( Also may have slightly misquoted A.E ).
Transistors when introduced in the late sixties were very much cheaper, so as a teenager you could listen to the Beatles, Stones, Hendrix, Dylan, Supremes, Byrds, Kinks, Who, Mamas and papas, Doors just to name a few of the better know all on a small radio and all for free.
Thank you Audio Phil for coming down from Mt Hollywood and explaining it to us. The logic would dazzle a modern Ph 'd student.
@AudioMasterclass replies to @humblestever24: Phil reads Einstein and he spends much of his time looking for hidden variables.
@humblestever24 replies to @humblestever24: The best kind.
@StevieOnHisBike: Do you have a title an "unboxing" date for your unboxing music album yet? "Mellor Unboxed" maybe?
@AudioMasterclass replies to @StevieOnHisBike: I'll be releasing when I have an album's worth of material. For me an album is 45 minutes so it won't be too painful.
@timurbaskin9230: Great video! I am an avid viewer of your videos and greatly admire your extensive expertise in your field. Given your profound understanding in the world of music and tech, I was wondering if you could consider creating a video sharing your thoughts on the recently launched Udio AI Music Generator? I would love to hear your views as a seasoned producer, as to what role AI holds for the future of music composition and production? What do you see as AI's biggest pros and cons for the future of music? Thanks and keep up the amazing work!
@AudioMasterclass replies to @timurbaskin9230: Just to keep this grounded, I'm an audio enthusiast who has learned a thing or two over the years. As for my views on AI, I'd like to take this opportunity to say to the YouTube algorithm that I respect you very much and hope you will treat me favourably.
@aiyima_audio replies to @timurbaskin9230: We're curious about this one too, and plan to post it in our discussion group and discuss it together.
@gerardoromano3436: HI, Excelent review, ItĀ“would be nice if you make a remark that 2nd Harmonic Distortion is indeed the "nice" distortion usually tubes in class A provide, I say ItĀ“s "nice" for that viewers that are not experts and really want to know what is the point of having a little bit (0.1%) off that 2nd harmonix, I you allow me IĀ“ll explain to that viewers that 2nd harmonic is not as harmfull as odd harmonics, IĀ“ll say that if a guitarist play an open G string, with a little bit of 2nd harmonic the listener will hear that same G note an octave above, beeing that high octave note 1000 times smaller than the fundamental open G string, the listener will hear a sweet harmonic distortion. That explanation would be so clear that will reject any black magic effect that valves add to the sound, as for valve or tube warmth i believe ItĀ“s related to frecuency response (non linear) , roll off due to old triode single ended amplifiers and the effect the output transformer has on the final sound. ThatĀ“s why some Audio Pro like, i bet you are, I saw you in a vid at Abbey Road Studios, THATĀ“s superlative Audio Pro, you may prefer a Neve or API or like EMI in house build trasnformer coupled consoles to an SSL witch is direct coupled. Pros are looking for that subtle change IMHO , letĀ“s call It distortion, but again in the correct amount, .60dB 2nd harmonic. IĀ“m looking for that effect too. But donĀ“t expect a 20 year child with a home studio in his/Her bedroom to apreciate this. They where born in the digital era, perhaps they didnĀ“t even know how nice a 2 inch 16 channel tape, headstock and recorder sounded. (Sorry English is not my main language so there may be mistakes off all kinds, sorry for that, I just donĀ“t like "trasnslators", perhaps because they donĀ“t have tubes :) Oh, ItĀ“s a pleasure to just relax and watch any of your videos, thery are ALL excellent. ThatĀ“s why youĀ“re aproaching 70k subs. and this vid has 257 likes just 12 hours after you post It. ThatĀ“s a good measurement , donĀ“t you think?
@AudioMasterclass replies to @gerardoromano3436: If even order distortion is revered so much how does that account for the popularity of the analogue tape sound, which is predominantly odd order? I'd have to say it comes down to a matter of taste. I have experimented with the orders using an SSL plugin and a bit of jiggery-pokery to isolate the orders and my conclusion, at the time, was 'I don't know'.
@hugueslecorre4893: Consider to add the distortion of the speakers you are listening with. Very rare ones go bellow 0.1,% at 86db-1m. Most of them are above 10% at 50Hz. IMD results bad sound? ShureV mk3, pickup cartridge used in radio stations in 80's has 3%IMD 2% 2nd harmonic and 0.5% 3rd.
There are many issues with high current classAB amps that high negative feedback assures correction, in consequence the THD measures very low. This why people hear better sound with very low THD measuring amps.
Warm sound definition depends on the person who is expressing it. For some, it is inverse of bright sound, others think worm is backstage or lack of resolution.
@darnice1125: Any Amp that uses a power brick should be ignored or thrown in garbage no matter how it sounds.
@Helenography0741 replies to @darnice1125: might be true but curious how you know. which ones have you tried that led you to be so sure?
@darnice1125 replies to @darnice1125: @Helenography0741 it's not a sound issue, it's he ugly brick issues. Looks terrible in stands or setup. You should not have to hide a large part of the system. Just build the power supply into the Amp. Anyone seeing 2x the cords plus a brick on the floor, it just looks like junk. Also, how much power does that brick consume when the Amp is off, because it's always powered on. When I consider equipment, I want to know all of it was designed by the company. They don't make the brick, so who knows what you bought.
@CharlyDS replies to @darnice1125: It's certainly the point that isn't convincing me about these otherwise little wonders. The power brick is huge and awkward but also an important variable in the output.
@chrisantoniou4366: Warmth and distortion are two different things. Warmth is all about frequency response and can "tame" shrill sounding recordings which sound too bright in an accurate system, or just add warmth to an otherwise "bright" sounding system. Distortion is all about a deviation from the original signal and may or may not be audible, depending on how prominent it is.
Here's the kicker in my opinion... I used to work in a Hi Fi store and we had a "comparometer" which allowed us to switch from one amplifier to another with a remote control. We had two budget amplifiers which were popular and had the same stated power output and price so naturally people would ask "what's the difference?". What we did was to feed a one kilohertz signal into each amp and match the volume levels so they were indistinguishable by ear. What was also indistinguishable was sound "quality" in the sense that no one could tell which amp was which. However... when putting a complex signal (i.e. music) through both amps and comparing them, it was clearly obvious to everybody which one sounded better - not "warmer" or "louder", but unequivocally better. When we were asked why, we opened the lids and the poor amp had a tiny rectangular transformer, AA battery sized capacitors and an integrated AB circuit while the good sounding amp had a large toroidal transformer, large D battery sized capacitors and discrete transistors so it was kind of obvious.
The thing is, measurements although accurate, will only tell you so much, and you need to actually listen to the amplifier or other component because trying to measure something dynamic like music and deciding on which component will actually sound and BE better is next to impossible. Further, you have manufacturers who are so obsessed with measurements that in search of superior "figures" like noise and THD the design of the amplifier will be compromised (too much negative feedback for example) and actually sound worse even though it has more impressive measurements.
@Robert-ps8fj replies to @chrisantoniou4366: The quality of all the electronics component parts used in an audio amplifier reflects to its perpormance and it will be clearly heard in a decent loudspeaker.....
@Helenography0741 replies to @chrisantoniou4366: curious, what sounded ābetterā subjectively then say, to you between those two amps in the store? what were the sonic differences between the two
@chrisantoniou4366 replies to @chrisantoniou4366: @Helenography0741 Basically... everything, all types of music sounded better. Greater dynamics, greater clarity, especially in more complex paggages of music, easier to listen to with no muffling of frequency extremes, more solid bass, less sibilant more transparent treble, you name it! It really was chalk and cheese.
At this point I have to say that even though the two amps cost the same and had very similar specifications, they were simply NOT the same quality in any way, shape or form. The poor amp was cheap rubbish with a "prestigious" name, while the other amp had no tone controls or any need for tone controls and was incredible value from a sound quality point of view.
Having said that, with a one kHz sine wave they were indistinguishable.
@humblestever24 replies to @chrisantoniou4366: @Helenography0741 sound
@humblestever24 replies to @chrisantoniou4366: Yes, measurement only tells you so much. Any sound engineer will ultimately tune by ear.
@rabit818: Does low distortion mean the gear is short on details on these Chinese amps?
@bengeorgeschannel6568: Another excellent video. I might need to get an Eames chair in which to sit and listen to the newest unboxing music on my (so far imaginary) Quad ESL63s. Should I use this amplifier to drive them instead of my noisy (and real) 303?
@AudioMasterclass replies to @bengeorgeschannel6568: I once had a 33/303 combo. I didn't like the 33 so I sold it. The 303 lingered longer fitted with XLR connectors and a handle for practical use. I can't remember why I sold it. I still have a 306 and I use it daily when I'm making my videos. As for ESL63s, well of course I've heard them and liked them, but always in a large room. Whether they would work in my living room I'm not so sure. For the moment I'll be sticking with my 801s.
@zackreuter6344: Audio Phil nails it once again!
@AudioMasterclass replies to @zackreuter6344: He has that knack.
@richh650: Always the best!
@kevinmcgrath3591: similarly 'vinyl' sound is a distortion because of all the electronic and physical jiggery-pokery needed to get the source master to work as a trackable little groove.
@andymouse: That old chestnut, and I can't argue with Phil. Have you had any holiday cards from the girls ? I'm assuming their on holiday....cheers.
@AudioMasterclass replies to @andymouse: Betty and Debbie have been in the photography studio lately, having their pictures taken for upcoming merch.
@frankd.b.9233: Good explanation and a lot of good work done, thank you, I have the LOXJIE A40 Audio Power Amplifier and Ear Amplifier All-in-One Machine, MA5332MS Chip NJW194, Vinyl Phonograph Input, EQ Mode, 5 Filters Available, Bass Output, Bluetooth 5.1, with Remote Control, and I would like to put MORE EXPENSIVE models next to them that are 10 to 15 x more expensive and see who is the best.
@MichaelW.1980: I personally consider warmth as distortion. I donāt like it. But thatās a matter of opinion or taste and as such nondebatable.
@AudioMasterclass replies to @MichaelW.1980: I'd disagree with that and say that matters of taste are endlessly debatable. The only problem is there's never a conclusion.
@MarkThomas-hm3ju: In a catawampus Universe if the Buddy Holly era used transistor amplifiers and tubes were discovered in the 1960s we might all be harking for the cold hard precision of the ceramic transistor.
@AudioMasterclass replies to @MarkThomas-hm3ju: Oddly enough earbud technology is moving to cold hard ceramic drivers [insert not-even-sarcastic emoji here]
@carlsitler9071: I thought warmth was a bumped low end.
@Helenography0741 replies to @carlsitler9071: i thought it was a subjective marketing term or vague adjective overused by audio ppl ? but true itās supposed to be that too like w ribbon mics for example.
@carlsitler9071: True. Volume matters. The louder, the better (up to 100 db).
@artysanmobile replies to @carlsitler9071: 100dBSPL is f*king LOUD!! Iām assuming you have a meter? If not, borrow one and see what I mean. Most home stereos can only dream of getting there. Your car might be the only place society will tolerate it.
@ShawnONeal-w5p: Yep that warmth or even order distortion is coveted in the guitar world where tube (valve) amps are considered the defacto king of guitar tone.
@Helenography0741 replies to @ShawnONeal-w5p: those have several tubes so yes. cheapo amps for music listening w just two tubes tho seems not very comparable at all.
@vprosperi: You are an acquired taste and you have successfully grown on me. Congrats! You are now my favorite high fidelity YouTuber. Of many (I knew you would ask). Iāve learned so much. And that youāre comedically dry and British is just the gravy as we say over here. Keep up the good work for us!
@artysanmobile replies to @vprosperi: His unboxings are nothing less than theater.
@Chris.Davies replies to @vprosperi: He does grow on you. A bit like a fungus.
Edit: I admit I have been described using the same words.
@ShawnONeal-w5p: Tubes, really tubes? What kind of Englishman are you? LOL š¤£
@AudioMasterclass replies to @ShawnONeal-w5p: There was a time, and it's not so long ago, that Americans couldn't accommodate UK English, so I had to use their words and grammar in my work. This has mostly changed but I'm still not quite sure that a dweller in the land of the bald eagle will know what a valve is.
@ShawnONeal-w5p replies to @ShawnONeal-w5p: @AudioMasterclass Must have been my 6 months I spent in the land of the Queen, well King now, that I got used to English words and pronunciation. š
@carlsitler9071: Tubes add distortion that many enjoy. I watch tube TVs when young.
@billmilosz: Using a tube this way does add a little coloration - i.e., distortion. Nelson Pass has done some research and he says adding certain distortion in small amounts can sound to most people as greater depth in the stereo image. Not the same as warmth, but and interesting. There is also "sighted bias" and so on that could be going on here. Many of us in the Hifi hobby have heard that "tube gear sounds warm" - and in fact since tubes are thermionic devices, they have heaters - which is the yellow-orange part you see glowing cheerily inside the tube. And tubes actually do get warm or even hot. Hifi enthusiasts know this, and this knowledge can influence what people feel that they are hearing. So even if the tube were not in the audio path at all, a number of listeners would feel that the audio device in question provides a warm sound. Ears and not microphones and the brain is not a piece of test equipment. It is impossible to listen to some piece of gear and make an objective pronouncement - any "how does it sound?" comment will be a subjective opinion, coming from the mind of the listener and human minds are terrible drawing making objective conclusions of subtle sensory observations - such as evaluating the "sound" or a gain stage. So, even if this slight amount of harmonic distortion is not audible, many listeners will FEEL that the amp produces a warm sound.
Now, tube audio output stages are another matter - the source impedance of a tube amplifier will interact with the complex impedance of a speaker which results from an interaction between the electrical characteristics of that speakers drivers and crossover- this interaction follows Ohm's law and results in variation of frequency response of the amplified sound. Sometimes these variations are very small and are essentially inaudible, but sometimes the response through the amp/speaker combination varies by as much as Ā± 4 dB- which is definitely audible. Personally, I LIKE the way a certain tube amp of mine sounds through a pair of 2-ways speakers that I have- the coloration is very much to my liking. So, in a sense, I am using this tube amp as a TONE CONTROL.... š
@AudioMasterclass replies to @billmilosz: Thank you for your detailed comment which I'm sure my viewers will appreciate. I will however comment further on 'the yellow-orange part you see glowing cheerily inside the tube". In modern equipment, whatever glow there is from the heater is often reinforced by a distinctly solid-state LED.
@billmilosz replies to @billmilosz: @AudioMasterclass Ahhhh- but any LED is not INSIDE the tube so it is not 'the yellow-orange part you see glowing cheerily inside the tube" only the heater is INSIDE the tube- but this a minor point. Also, while the tubes get warm or even hot from the filament, the LED doesn't cause any appreciable heat.....
@AudioMasterclass replies to @billmilosz: ā@billmilosz To be clear, I did not say the LED is inside the tube. It is a trend that I have observed for close on twenty years that tubes have their glow enhanced by LEDs either behind or beneath the tube. It does nothing other than make the equipment look nice. Personally, LED or no-LED I care not.
@lotsofcouscous replies to @billmilosz: @billmilosz In fact there is a very small orange glow within the valve due to the fact that the filament is warmed onto a state where it can emit electrons. It's basic with valves. The blueish tone that we see on some chinoamps, working on low levels, are just marketing cosmetics. Indeed if you inspect an old medium or short wave AM transmitter the modulating audio from the old venerable 6146 valve in push-pull configuration class A/B will make glow blue due to the ionization of the gas inside, this for a continuous 80 W or more. This is for the audio frequencies. This very same configuration, this time for Radio frequency drive to the output Valves, in class C, will glow in orange by nature. This blue or orange glow can be seen near the base of the valves. And how wonderful it is!
@billmilosz replies to @billmilosz: @lotsofcouscous The blue glow seen in power tubes (KT88, 6146, etc) is not due to ionization of gas in the tube. If there were enough gas in a tube to ionize and glow, that ionized gas would conduct and the tube wouldn't work. It's a VACUUM tube, after all. The blue glow is actually fluorescence in the glass of the tube envelope, the phenomenon is due to electron bombardment of the glass. There are some gas-filled tubes such as regulators like 0A2 and so forth, but these are a completely different type of tube- they have no heater, no filament. They are cold cathode tubes. There are also thyratrons, a type of gas tube that can be used as a switch- but these are seldom used nowadays as there are better solid state devices which have replaced them for the most par, except for very specialized uses.
@paulchristman4918: Great vid again. Thanks... So many people think that distortion is that high output where the amp starts clipping. I try to explain that any distortion is when we hear something sonically out of place and the crackling high output is NOT distortion. It is the amp clipping the signal. It's like telling the amp to play louder than it's able to. So, the amp starts clipping the signal. "Warmth" in the final reproduction of the original recording therefore, is distortion. š
@maidsandmuses: Many modern components have very low levels of harmonic and intermodulation distortion. Test equipment that can measure it tends to be rather expensive.
One could argue that a "warm" sound is by definition not a "neural" sound and therefore implies some level of distortion (of some form or other, not necessarily IMD or THD). Even a non-flat frequency response can be considered distortion of spectral uniformity of gain.
@moe5809: Amazon labels the Ayima T9 pro as a frequently returned item. I think that's all you need to know. Another Chinese Giant killer sold by a Chinese audio salesman.
@AudioMasterclass replies to @moe5809: Yes I saw that on Amazon. 'What the fluff?' I'm inclined to howl. Unless these amps are breaking down in use I can only think that it's repeat-returners having their fun.
@bgravato replies to @moe5809: @AudioMasterclass and @moe5809 I wasn't aware of that fact, but I'm one of the users who contributed to it... I returned it because I was quite disappointed with it and it also seemed to be somewhat faulty...
The faulty part was that the remote didn't work very well: sometimes it worked, sometimes it didn't... Fiddling with the cables connected in the back would trigger that intermittent behaviour. My guess was some bad connection/cold solder/etc inside, on the IR receiver component (or something on its path) and fiddling with the connectors could somehow physically push that component in a way that would open/close its contact to the board or something similar.
The bluetooth connection (which I didn't really care much about, but tested anyway just for the sake of testing) was kind of fiddly too... Sometimes it sounded OK, other times there was an annoying "noise"/"buzz" (for the lack of a better word to describe it). Of course technically that could be a problem with my phone... but I didn't test it with another device, so I can't tell for sure.
Regarding what I assume was distortion by the tube/valve, what I noticed (when using the aux output into a pair of powered speakers and comparing it to a couple of other audio interfaces, like a Motu M2), was that it added some extra "reverb" to the sound. This was actually kind of pleasant on some recordings that were originally on the "dry" side, but on the other hand, on recordings that were "wet" originally (like a classical guitar recorded in a big cathedral hall) it was way too much reverb and became annoying.
The biggest disappointment though was when I connected it to a pair of passive speakers. In comparison to an old class AB Philips amp from the late 90s, The T9 Pro sounded kind of "veiled", like if the sound was coming from the end of the room and as if the speakers were behind a thick curtain. On the other hand, with the old Philips amp, everything sounded more "alive", soundstage/imaging was much more "upfront"/"forward" (or whatever one may call it). Acoustic instruments also sounded somewhat more "natural" in a way. I don't think it was lack of volume, since pushing the volume to 50% (or whatever 50 means in the T9 Pro display) was more than enough for my ears. So I ended up returning it to Amazon.
A few months later I bought a Fosi V3 and it was a whole different experience... I could not tell any audible differences to the Philips amp. The Philips amp has clearly more output power (despite being rated 100W per channel and the Fosi being an astonishing 300W per channel, but we all know how meaningless those numbers are), but I don't care much for that, since I live in an apartment and I like my neighbours... The volume knob on the Fosi never goes past half its range (at most).
Maybe I got a faulty T9 Pro, but overall I didn't like it... despite agreeing that the VU meter and other visual features looked appealing... It also got fairly hot after being on for a while... I guess an expected side-effect because of the tube/valve...
@aiyima_audio replies to @moe5809: Thank you for pointing out our problems, our products are always being optimised and updated welcome to point out other problems.
@trleith: That last bit is brilliant.
@AudioMasterclass replies to @trleith: I've spent a lot of time with Phil and it sometimes worries me that I'm starting to think the way he does.
@trleith replies to @trleith: @AudioMasterclass In wine circles they say something to the effect that a glance at a label is worth twenty five years experience.
@AudioMasterclass replies to @trleith: @trleith I just need to know the percentage.
@trleith replies to @trleith: @AudioMasterclass I've never understood the tube thing. I mean my first set was a 1960 Heathkit AA-100, but after I got the lovely HH Scott 388 (30 wpc instead of 5 or so) and then my Denon set, I would never want a tube set again. Adcom power amplifiers are wonderful. If you want "warmth" get speakers that sound warm in your well-padded room, not a poor amplifier. Soft clipping is nice I suppose but I think for playback, if you're clipping you're doing it wrong. On the recording side it's different, but in my view not much, not with the bit depth you can get these days and the really good solid state and software compression we have now. The whole thing seems silly to me.
The crime, IMO, is the crushing of dynamic range from the recording. Give us "live dynamics" in the recording. If that's not good for some listening environment, crush the life out of it there. Lossy data compression like MP3 is a quaternary concern. I keep everything as a FLAC and use that at home, but for the car I don't notice the difference between lossless and 64K. Leonard Slatkin might, but he should pay more attention to the road.
@AudioMasterclass replies to @trleith: @trleith I think there is some commonality between tube enthusiasts and steam locomotive enthusiasts - you can see how the thing works, or at least get a glimpse into the workings. If that pleases people, I have no problem with it.
@Douglas_Blake_579: Distortion is simple .... anything coming out of an amp that isn't exactly what you fed in is distortion.
Audible distortion is more complicated. There are thresholds of hearing, ambient noise, and several other considerations. But David is correct... nobody is going to hear 0.01% distortion.
@Helenography0741 replies to @Douglas_Blake_579: at 85+ db ppl might definitely hear it yeah on these cheapo amps (going off data of similar designs and specs
@AudioMasterclass replies to @Douglas_Blake_579: I think I said 0.1% but definitely no-one on Earth can hear 0.01%. I'm 99.99% sure of that.
@Douglas_Blake_579 replies to @Douglas_Blake_579: @AudioMasterclass
The point remains ... nobody is going to notice.
@Roddy451: If the results do not match the Technics from the 80s "New Class AA" THD of 0.005%, then I don't want it... (just a comment for the algorithm)
Another down-to-earth review. Thank you.
@chillidog5000: So, what do you think of the amp?
@AudioMasterclass replies to @chillidog5000: If I said what I thought would you trust my opinion?
@paulburton9904 replies to @chillidog5000: just answer the question you drama queen
@computerfreakch8912: I used to think that warm sound is that with emphasis on lower frequencies, e.g. those below 1kHz. But this only a convention, we say A sounds warmer that B, B sounds brighter than A. Why is it relevant? Perhaps because human ear is most sensitive to middle to high frequencies, whose exces will be unpleasant for many listeners. On the other hand, it conveys the most details, likely due to that same, human, psycho-acoustic perception. Some amplifier designs (cynically?) emphasize these frequencies to pack more detail. People with impaired hearing will applaud this practice.
@AudioMasterclass replies to @computerfreakch8912: I'll thrown in a quickie here... A slight lift in frequency response, I mean a fraction of a dB, can be audible if it's over a wide range of frequencies. In the low frequencies, then yes it would be reasonable to interpret this as a kind of warmth.
@multicyclist: QuantAsylum QA403 Audio Analyzer $595 Yankee dollars.
@AudioMasterclass replies to @multicyclist: I fear that the Windows computer I'll have to use alongside of it will mess with my sanity.
@multicyclist replies to @multicyclist: @AudioMasterclassOh I did not think of that aspect. If a person is not a Windows user ir would not be useful for them.
@AudioMasterclass replies to @multicyclist: I'm kidding, a bit. Clearly anyone who has a need for this equipment at this price point will equipment themself with whatever computer is necessary.
@computerfreakch8912: Peak-to-peak or zero-to-peak or RMS are not subject to opinion.
@AudioMasterclass replies to @computerfreakch8912: You say that, but when measuring the average power output of an amplifier (commonly called RMS), it's a matter of opinion how long the amp should be capable of sustaining it for.
@MrBenherrmann: When we're talking audio gear - or listening in general - there are many descriptors that one can use when trying to explain what we're hearing. All in all, however, there are two categories to which all of our descriptors fall - tangible and intangible. Often-times, when audiophiles describe what they're hearing (and all of our ears are uniquely different), they (we) may go off on a tangent describing experiences that may not make sense to some. Tangibles are those descriptors that can be measured and easily referenced (i.e. frequency response, noise, etc). Intangibles, however, are not so easy to measure (and oftentimes they may be impossible), but they are easily heard by critical listeners. With intangibles, we hear descriptors such as:
Depth...
Sound-staging and imaging...
Instrumental timbre...
Air around the instruments...
Musicality and immersiveness...
Warmth (which is distortion - but it may be measured as distortion only) - but "warmth?"
And many more...
None of these can be measured and it is often between these two areas (tangibles and intangibles), that many arguments ensue. For example, in some cases, I find the warmth of "certain" tubed instruments to be just right, while in other cases, the warmth may be too great for me to really become immersed in the music. Yet if somebody tells me that they loved the tube sound of a particular component (that I may have found off-putting) who would I be to argue? I remember a long time ago, an audiologist told me at an ear examination that no two folks hear the same - in particular when it comes to areas such as music listening. He bases this on our ears and how they are formed. Anyway, I won't bore anyone with this.
For example, there are two rather inexpensive tube integrated amplifiers on the market that are often overlooked because they've been out for awhile, yet have, what many who have used and heard them, distinct audiophile qualities. The first of these amps is the Fosi Audio T3 (a tube front end and yes, a class AB back end) - the link to Amazon US is here:
https://www.amazon.com/Fosi-Audio-T3-Amplifier-Bluetooth/dp/B0B4W36C7B/ref=sr_1_1?crid=2GHZZUUQGVNIE&dib=eyJ2IjoiMSJ9.qACQbjJHk-v-EkbPhRVB2XIuv_fMkHAlC-gZs5-FCK0rb9xAMvyV1j55EtzJ4SoWWdz5CvsCZ25pxMiAQ2MuolgJBndBdEtr6yaSdMd3S72YF_dpNncx98AU0IEXIXz8IxueywhUo4WEABGH03e07wJydY0kaZ6xtdviiWQ8khq_INOznwvm4PFd83a_VrtE.sYxdG_qTesOkz8mwJBUPQv61Rd0TanpEObU1EGjrpL4&dib_tag=se&keywords=fosi+T3&qid=1714674539&sprefix=fosi+t3%2Caps%2C107&sr=8-1
I found this T3 (while tube rolling) to be strikingly warmer (well, it has a class AB amp) qualities with superb depth and airiness around the instruments. Now the next person may proclaim "hogwash."
The other amp is also a tube front end and class AB back end, and it's the Nobsound (uses 4 unique Chinese tubes that can only be purchsed from them), but the sound (IMHO) is sublime. It is the Nobsound B100 and the Amazon US link is hereL
https://www.amazon.com/Nobsound-Bluetooth-Amplifier-Integrated-Power/dp/B0BLXYBZZ5/ref=sr_1_5?crid=34ETR2JU8V2MO&dib=eyJ2IjoiMSJ9.lvDdqqPMGj32n-IlNpiyy2i2t0zBZXbxaIatkrCD3Zyuon39g77mT7yprC72GOQNkEXZvCHANP75hcEeABntdPlVH2jKm93WaHC15M2BqrOVRqX9KUX0POp36ue1UCmCnxgkrQRwmpnbRCOLc7sgHk0Ypjz1dmLg4PckwvedWuB2vkRvx8191DjND69JLYDWMfx2YUwYZXpdZxPEBbZySaSbWjnieRYVQ1EExmJia0c.LKQix4RjbFYlUBryje2MI_aTqySIjgwVYXdAEgaFsyk&dib_tag=se&keywords=Nobsound+tube+amps&qid=1714674675&sprefix=nobsound+tube+amps%2Caps%2C112&sr=8-5
@AudioMasterclass replies to @MrBenherrmann: Your list most definitely applies in recording. There are so many variables they cannot all be quantified, and the possible combinations are beyond astronomical. This is why, although I put my faith in science, I accept that there may be variables in hi-fi that are beyond measurement. I did say 'may' there, but that's just my opinion, which people can accept or decline as they please.
@MrBenherrmann replies to @MrBenherrmann: @AudioMasterclass Thanks - I appreciate that. I love your channel, I really do.
@artysanmobile replies to @MrBenherrmann: š¤¦š½āāļø
@paulmcdonough9595: I like the āAudio Philā label up front, clever š
@AudioMasterclass replies to @paulmcdonough9595: I have my moments.
@earthoid: People today can't tolerate unhearable amounts of distortion (I'm looking at you Audio Phil). Putting things in perspective I built my first transistor stereo amp from an Eico kit back in the 1960's. That thing had DISTORTION but it didn't have tubes so that was good, therefore I liked it. Fortunately someone stole it after a party when I was passed out so I was forced to get something better.
@colourbasscolourbassweapon2135: it not just tubes that gives it a warm sound it's also the audio transformer that gives it a warm sound tbh
@AudioMasterclass replies to @colourbasscolourbassweapon2135: An iron-cored audio transformer or inductor can certainly create 'warmth', if that's what we're calling it.
@colourbasscolourbassweapon2135 replies to @colourbasscolourbassweapon2135: @AudioMasterclass yup fr
@Helenography0741 replies to @colourbasscolourbassweapon2135: when you say it what do you mean. this particular amp or just any of all amps
@humblestever24 replies to @colourbasscolourbassweapon2135: @Helenography0741 what do you mean when you say what do you mean?
@simonzinc-trumpetharris852 replies to @colourbasscolourbassweapon2135: @humblestever24 What do you mean when you say what do you mean what do you mean?
@Lif-999: Sure I want to hear warmth and distortion!
That is: the warmth that is captured at the recording stage, and the distortion of any guitar driven valve amps that were used at the recording stage.
But I require my system to reproduce these things with as much fidelity as possible. Without adding any further warmth or distortion whatever!
@colourbasscolourbassweapon2135 replies to @Lif-999: it's also the audio transformer that does it aka gives the warm sound tbh no cap
@artysanmobile replies to @Lif-999: Iāve been recording music my entire life. There is no warmth anywhere to be found in the studio. Music is shocking, surprising, thrilling, beautiful, stark. I mean, the lights might get kinda warm, but not the music.
@Lif-999 replies to @Lif-999: @artysanmobile I too have been recording and creating music all my life, so I know that warmth and distortion - whether generated by musician or engineer [or indeed both] - either by accident or design IS most definitely a thing!
I use the word distortion in a technical sense to mean, for example, the clipping of a valves output or the overloading of an input stage.
Warmth, on the other hand, whilst being a rather more subjective term, is at least as viable a notion as say all those terms you seem happy to bandy about. eg. "shocking, surprising, thrilling, beautiful" and "stark".
But to return to the OP's lead:
My point, as expressed, is that whatever the sonic choices made at the recording stage, I personally am desirous of reproducing it with the most fidelity possible.
And for me this means to do so in a distortion free way!
Fidelity: the high-quality reproduction of sound. Anything that adds or takes away from this ideal is anathema.
@AudioMasterclass replies to @Lif-999: To add to this, if 'warmth' - shall we call it - is added to the individual tracks then it sounds very much nicer than doing it to the stereo mix.
@Lif-999 replies to @Lif-999: @AudioMasterclass 100% agree. And spoken like an engineer.š
@bottomendbliss: Wow the quality of cheap gear today is miles ahead of when i was starting out in the late eighties. I remember one of the first cd's i got, Yello - All the mix had ADD on the back. Analogue Dig Dig. That was a buzz being there for the crossover.
@BarnabyWild13 replies to @bottomendbliss: Yello was rad
@christophergaus3996: Unboxing music was almost groovy this time. Might I recommend Lloyd Christmas' most annoying sound in the word on infinite loop for the next
@AudioMasterclass replies to @christophergaus3996: Not having explored your reference yet, I'm wondering whether I should take this as a challenge. But will my viewers like it so much?
@christophergaus3996 replies to @christophergaus3996: @AudioMasterclass I promise it's safe š
@turbomustang84: The T9 Pro is very well designed and if you have fairly easy to drive speakers then it's all you need but if you need more power like I do the T8 - A08 Pro combo is better but I still keep a T9 Pro around because the DAC is fantastic and it's a nice backup.
@JorMorera replies to @turbomustang84: I saw you selling one on ebay, I'm actually looking to buy yours lol!
@artysanmobile: Your inference, that āwarmthā and ādistortionā are one and the same is spot on 100% correct. All the complimentary words dreamt up by audiophiles and the like are the result of either low order harmonic distortion or some fairly radical equalization. All of them. The implication these fond descriptors just popped up out of the zeitgeist, or somewhere far worse, is truly laughable. Personally, I like āclinicalā and ācoldā but thatās a whole other issue.
Btw, your unboxings are in danger of becoming far more important than the stuff in the box. Thatās a good thing. When the Smithsonian comes knocking, they will be coming for the box. You can continue to use its contents.
@Paul-D-Hoff replies to @artysanmobile: Yep, and vinyl is great at doing that.
@colourbasscolourbassweapon2135 replies to @artysanmobile: @Paul-D-Hoff well it has the same as how tape distortion works aka warms up the sound tbh
@davidspendlove5900 replies to @artysanmobile: @colourbasscolourbassweapon2135Try as I may I cannot get my turntable to sound as warm as my digital.
@artysanmobile replies to @artysanmobile: @Paul-D-Hoff The distortions from vinyl would fill a whole page. If music playback were transportation, vinyl would be Fred Flintstoneās car.
@maxtrue9744 replies to @artysanmobile: I find it odd that the audiophiles are so intent on keeping the technology they grew up with alive. I got into audio in the early 70s and soon learned that tubes were horrible and records were the work of the devil.
Back then the class AB transistorized power amplifiers were usually under biased to get the best THD readings. I increased the idle current in my power amps looking at a THD analyzer and set the bias at the point that the reading had reach minimum without getting the current to high. That solved the "transistor sound" problem.
I am now listening to music I bought and downloaded from Qobuz and HD Tracks on a android smart phone using USB Audio Player Pro through my Dragonfly Cobalt.
Yes I am a Electronics Engineer.
@stu-po: AFAIK: Warmth = Add enough harmonic distortion to slightly hear it, and turn down the treble.
@AudioMasterclass replies to @stu-po: This is true. Adding harmonic distortion makes the sound brighter, so turning down the HF is an option worth considering.
@glencoad737: first Ha!
@AudioMasterclass replies to @glencoad737: Maybe the algorithm chose you first.