ELEKIT TU-8200 6L6 Single Ended Tube Amplifier build Part 5

[@12voltvids]

A follow up, running EL34 well aged (and broken in) tubes I have spent the las several hours listening to this amplifier in both triode and UL mode, and A-B comparing it to my studio reference amp, a vintage Luxman LV-103. As you know the Luxman is a hybrid amplifier, using 2 6CG7 dual triode "buffers" that give this 60WPC hybrid amp the sound characters of a tube amp. I have done this AB comparison with other solid state amps, and the Luxman is always the clear winner. Today, listening to several tracks I was really hard pressed to choose a clear winner. This 33 year old hybrid was so close to the new tube amp in every aspect that if I didn't know what I was listening to. I plan to show it off to a few friends and do some blind tests, and see if anyone can pick a clear winner. To my ears this is as close as it gets, and that is a good thing.

[@eggshellskullrule7971]

Last week, I bought this kit at 630 US dollars together with their limited-run TU8600 300B SET amp. Boy aren't they simple yet beautiful?

[@mattsynth]

Great post, I have been looking at building a 8200 and after seeing your post I now know I can handle the job. Thank you so much for taking the time to post this project.

[@12voltvids]

Yes it is really easy to construct, and everything is included. If you can handle a soldering iron and hand tools you can make this great sounding amplifier. I am using it right now as I type this message out, and since building it 3 months ago it has been in use daily for 4 to 5 hours a day every day. I plan on rolling the tubes for a set of NOS KT88 soon. The Electroharmonix sound very nice, but that is the beauty of tube amps. Lots of options for tubes, and changing the tubes gives a different sound.

[@martinda7446]

Nice video, good fun. For newer players. Remember output valves need to see a load connected to OP tranny. If you are switching speakers between amps make sure no drive to valve amp when disconnected - it can be hard on the valves/tubes. Also amazing how little perceived difference between ultralinear and triode, always amazed me that jumping from 4W to 20W(for instance) was not always obvious.

[@12voltvids]

Martin D A The risk is more to the output transformer. If signal present under no load high voltage can develop in the secondary winding which can arc over in the winding and cause a short. When I switch to the other amp I turn the tube amp off and I turn power off when switching between ul and triode. There is a noticeable gain in power (loudness) in Ul mode however I definitely do prefer the sound quality in triode mode. I am seriously considering building the new model which uses 300B tubes. Costs big bucks in kit mode but this one has been so good I am looking at building another even better kit.

[@martinda7446]

Yes, transformer is at risk - that was me writing and not thinking. Great having your efforts here on KZbin.

[@christopheralverson6278]

Thanks for uploading this series 12Volt. It should help any beginner who is wanting to buy and assemble this amp. I did mine in a pretty quick manner ( elec tech , with quite a few years under my belt soldering, troubleshooting, etc.) and I am OCD about my soldering. I run this little amp on my Altec 19's in the winter, I am planning on getting its bigger sibling, the TU-8340, with the xmfr upgrade. I have/need to finish up a HK Citation II project first. I also have a few other amps I need to get up and running too. Again, great video series!

[@12voltvids]

The build would have gone quicker if I was not recording it for sure, but I needed to drag it out for multiple videos so I can maximize my youtube payout. Have to pay for this some how. To the wife this was an un-authorized purchase so it has to come from youtube money. That is all I am allowed to spend on projects. (That's my rule not hers, but I hold her to the same standard. She can blow the extra cash she makes doing her side jobs on whatever she wants)

[@rayfirth2513]

Watched both builds of the tu 8100 and the tu 8200. i lost my amps when i moved in with girlfriend 30 years ago and now id rather have em back instead of the girlfriend before i moved out at home my parents had a Rigonda bolshoi. I managed to buy a pair of williamson's monoblocks running the KT cant remember now if they were 88 or 66 but she wouldn't have em around so ended up buying a Marantz amp and tuner and now when ever any of these williamson's come up for sale i can't believe what the fetch today. Anyway enjoyed watching your videos on these two amps builds.

[@12voltvids]

Have to laugh at KZbin content ID. Used the same royalty free track for the demonstration, the classical piece "The mentor" from Musicbakery. No claims on the first video, and I get a 3rd party claim on this one that is now under dispute.I rolled the tubes to old EL34 pulled from my other amp. Now I prefer the triode setting. That's the beauty of tubes. Change the tubes, change the sound.

[@umajunkcollector]

Aren't the el34's higher voltage?

[@12voltvids]

The amp has automatic bias set up. It detects the tubes, and sets up the bias accordingly. It uses the higher voltage 6L6GC not the lower rated 6L6.6L6 rated for 250v plate. 6L6GC 300v plate, which is right in the EL34 range. EL34 can go much higher for sure, but this is only driving it to the same power level.

[@Synthematix]

This is true but tubes are only harmonic distortion

[@12voltvids]

Well they have higher distortion on paper, and that is why we expected them to all disappear years ago, and they almost did.There were enough audiophiles that wouldn't accept the odd order harmonic distortion that transistor amps deliver, and that niche market, mostly 40+ men with lots of disposable incomes that didn't mind spending big coin to keep that classic sound they grew up with.Tubes never went away, they did almost become extinct but DIYers and a few bouquet builders kept turning out huge dollar hand built amps. Anyway back to the harmonic distortion, even order, the type that tubes generate is not a bad thing. It actually improves the sound of musical instruments.

[@RobertKohut]

I wish people would stop talking about tube amp distortion. It seems people only have heard about instrument tube amps. That's where tube distortion is relevant and only under saturation of the tube (overdriving it). For guitars there is no doubt to get the sound created from saturating a tube amp is the only way to go (or simulate it with SS). For home, HiFi tube amp circuits are designed to provide for zero saturation (no overdrive stuff) and under normal responsible listening levels (not turning it to 11) tubes don't distort. Looking at tubes at their rated power output, just before clipping, they are typically under 1% (.5%) distortion and the harmonics are negligible (almost immeasurable). My Bob Latino ST-70 amp sounds absolutely amazing and I even prefer it over my Bryston 4B SS amp. There certainly is no distortion on the tube amp and in fact it's clarity is amazing and I have never heard drum cybals sound so real and clear. So please stop confusing "Instrument tube amp design" with "HiFi tube amp design" they are two completely different animals.

[@alexeykokh8240]

Like your videos very much, all the things are explained in detail, and you can understand the material rather well, even if you are not a native speaker.

[@skycarl]

That sounds great,,,, think we can list this one under " Success". Well done.

[@jimsuber6784]

Just heard this. Within the limits of youtube discernability the amp sound great. Great job. "The Mentor" is modern not classical. Thanks again. good video

[@MrTopsoil911]

clean sleek well built. great job. im converting a Northern electric tube intercom in to a small amp just for my test bench. it uses sylvania & westinghouse tubes

[@12voltvids]

VEry nice. One of these days I will bringout my old McIntosh tube receiver and overhaul it.

[@kevinbeckenham3872]

Enjoyed your your documentary on valve amp kit.In ultra linear there was less distortion and more body in the sound.My Bose powered monitor speakers connected to my P.C certainly picked different's between each mode.You could at later date try different out put transformers with higher primary inductance,this lead an improved bass response.I love heavy mental.

[@wadehicks9270]

Nothing like that old tube sound. Great video.

[@russellphillips905]

Just finished building one sounds great had a little problem easy fix.

[@12voltvids]

Russell Phillips Yes it does sound great. They have a new one that uses 300B tubes. That would be interesting to build.

[@BlankBrain]

I'm going out on a limb here, but I think the tube sound is more important in the upper frequencies than lower. I think you can get great sound using a good class A-B below 1250Hz and a tube amp above that. If you optimize the design the output transformers for the higher frequencies, it can sound even better. Solid-state on the bass and lower-midrange can offer a better damping factor, which can result in "tighter" bass.

[@12voltvids]

This one is rated 12 - 50,000 Hz within 3db, so it is actually relatively flat, however tube amps are fantastic in the all important mid range.To quote one hi fi reviewer, if you can't get the mid range right then nothing else matters.You are correct though a good mosfet amp has better damping for sure, and I noticed that right away when I went back from using my class AB Yaquin amp to the Luxman. For about 5 years I used a Yaquin MC10, which is a great sounding amp, but not as punchy in the bass. As soon as I went back to the Luxman I noticed an immediate improvement in the low end, and I stuck the yaquin in my living room, more as a show piece, and for background music. I do most of my serious listening in my studio. That said, this new class A has every bit as much bass as my luxman, and A-B testing I have done places the 2 amps so close I am hard pressed to pick a favorite right now. I was listening to some vocal jazz, and I think this one has a little more presence to the vocals. I will have to wait until the new tubes break in before I can do a serious compare. I stuck in some old shuguang EL34B tubes that actually came out of the Yaquin. I had one that went south, popping and sparking, so I bought a new set for the amp and put the bad tube on a tester and cleared the grid short. So right now I am running 2 old tubes that have probably between 5000 and 1000 hours on them, and they sound great. I'll put the new EH tubes in, and burn them in for 100 or so hours and then give it a critical listen.New tubes need to be seasoned, to burn off any impurities left behind from the getter flash. That takes time, and then they open up and sound great for the rest of their life span.

[@BlankBrain]

I get by with the system I put together 1979-1981. I reverse engineered the JBL 4343 and used best practices to come up with the dimensions for the midrange sub-chamber. At the time, some local Tektronix engineers started BiAmp, making good audio gear. I use their SM-23 crossovers, TC-120 amps for bass and mid, and a Sony V-FET for treble. I originally used JBL horns for the 2420 compression drivers, but switched to "The Tube" Karlson-couplers. This eliminated the nasal horn sound, and the need to buy 2405 tweeters. (I crossover at 300 and 1250Hz.) I'm in the process of re-capping everything. I'd like to replace the Sony with a tube amp, but haven't decided on the design and FINANCING. I used to be able to hear bats, but they seem to have gotten a lot quieter.

[@12voltvids]

Yes I hear you for tube gear. It can get really expensive very quickly.Some people don't mind dropping 30 grand on that vacation of a lifetime, that is done in a month. Myself I prefer to spend my hard earned cash on something that I can enjoy for many years to come. A brand new car, high end audio gear, nice cameras ect.

[@BlankBrain]

I agree that finding things that give back over the long run seem to be more satisfying. I went back and finally finished college, which was sort of like an expensive vacation. I got into buying land, and that saved my butt when I was forced to retire early. It turned out for the best because I have time to take care of aging relatives. But I have to separate my wants from my needs. Maybe I can justify a tube amp if I can rationalize that it will extend my hearing into old age. What I'm inferring from your experience is that one class-A stage of tube amplification is enough to impart the (mellow, balanced, harmonious, easy) tube sound to a well-designed circuit, and that the output *can* be class-AB. Is this fair to say?

[@williamsquires3070]

I'd check to make sure that little switch is rated for B+; not only between the contacts, but between any contact and the (metal part of) the switch body, lest you pop the breaker, your bridge rectifier, and you! Safety first. Most of those little panel-mount switches are only good up to 120 VAC, if that, and the DC ratings are usually lower.

[@12voltvids]

Yes I checked when I picked it up. It is rated 250vDC at .5a. Operating voltage with the tube at operating temperature is 280v. Also the power supply is limited to 110 miliamps, so a short to ground isn't going to do much. Put the unit into over current protection, and turn the power light red.There is no real current flowing through the switch under normal operation, perhaps a few microwatts as it is just the bias for the g2 or g3 depending on how you count the tube elements. Also I will note that any that I build for clients will not be going out with any mods. They will be going stock with the red jumpers. If someone wants to mod a unit as shown here they are on their own.

[@gizmothewytchdoktor1049]

the brid amp...we used to sell those at earfood audio.haflers and denons also. that's been quite a while back.

[@gizmothewytchdoktor1049]

the "brid" amp with the led's in the signal path. we used to sell those at ear food in winchester. glad to see one still kicking ;-). also...tube class "a" amps always kick ass as far as clarity and balance goes. the unfortunate part is that they are also a little thin on the low end but it's the nature of the beast. i still prefer the sound of the single ended "a" amplifiers though. ;-)

[@12voltvids]

Gizmo Thewytchdoktor into headphones they sound fantastic. especially in triode mode. I still use the luxman in the studio most of the time but turn the tube A on when I don't need lots of volume or when working with "cans" on.

[@craneoperator4]

nice job on the amp..watched all 5 vids...sounds awesome

[@kunshri]

You are going to damage your output tube if you change the mode with power on. It is advisable to change the mode switch from UL to Triode or in reverse when the power is OFF. And in addition the tubes are cooled down as an additional precautions.

[@12voltvids]

Shridhar Kunte I do turn it off before I change modes. not that I change modes often. I prefer the triode sound and leave it in that mode most of the time.

[@kunshri]

good luck! Happy listening!

[@and1424]

Thanks for this suggestion. Does it count also when the amp is on but you have no input signal in? Thanks

[@seeburgm100a]

Nice to see a bench that looks like mine.. Albert Einstein would be proud.

[@seans1102]

I couldnt hear a bass increase in linear mode but i could hear a very decent sonic clarity. Darn it i have to build my first tube amp haha.

[@thattubesound2214]

Awesome video series, sir! I recently subscribed and I watched this series first and then the one for the TU-8100. I came back to the TU-8200 series again and it inspired me. Today I ordered the TU-8200DX from Tube Depot. I also ordered the DAC that goes along with it. I wanted the little pre-amp (TU-8500 ?), but the wallet was screaming, so I took a rain check on it and bought a pine-board kit to start with, that I'll set in a box. I can't wait to receive my stuff. The ELEKIT looks like it's first rate. I have a pair of little Aiwa (don't laugh) bookshelf speakers, made in Japan, that I think will work well with this amp. They have a beautiful marbled finish and they'll look great straddling this amp. I need to get some good headphones, next. I 'm dying to feed in some Glen Hansard from vinyl and just sit back & let it take me downstream. Have you thought about painting the cabinet? I am considering it. I like the industrial look of Steel It, so I might just give it a squirt.Thanks for what you do. I know a bit about vintage 1930s and 1940s radios, but almost nothing at all about hi-fi. Your vids have started to change that for me. Good on ya'! Cheers! Michael

[@12voltvids]

It actually looks pretty good as it is, but glossy black would also look great. The 8200 sounds fantastic. I am driving my Altac Lansing 305 floor speakers. Very good sound. The best sounding amp I had was my old vintage Luxman LV103 which is a hybrid. This one sounds as good or better. When I have done blind tests with friends they can't tell which amp they are listening to. Very smooth sounding unit. Using it now as my main amp in the studio, and I prefer triode mode now, even though when I first listened I though that UL sounded better. UL has more bass, but triode sounds more accurate.

[@alainwambergue5005]

Hi 12voltsvid thanks to your videos I successfully assembled the TU8200. To add a subwoofer I have to provide a line output, how do I do it?

[@12voltvids]

You can take it off the wiper of the volume control or feed it off the speaker terminal using a voltage dropper resistor network.

[@ryans413]

It's hard to hear what your hearing threw your camera and you tube but it sounds alright plus it depends what speakers you got hocked up too it.

[@12voltvids]

Yes I know youtube comressses the audio, and the mic on the camera isn't a studio microphone. The sound through my Altec Lansing 305 speakers is fantastic. If I shut my eyes I can sit back and place where the musicians are seated during this live recording session.The imaging, especially in triode mode is as close to perfect as I have heard.Up until building this amp (actually I git my first taste of single ended tube amps when I built the smaller amp last month) I had never experienced a single ended tube amp. I have a couple of push pull tube amps, and I had heard other peoples descriptions of the sound form them, but until I actually built one and listened to it on my speakers I couldn't appreciate what they were saying. Now I know why audiophiles pay what they do in search of the perfect reproduction of sound from a sonic perspective.On paper solid state kicks tube equipment to the curb, and has for years, but there is just something about the sound that the ear really favours on tube gear. It was once explained to me that the way the harmonics work in a tube was exactly the way the human ear responds to them. Good enough for me, I know which amp I prefer to listen to. My favorite was my Luxman 103 from 1984, now it is this one. They are very close in sound quality, but this one, has the edge in terms of musical enjoyment. Even listening to MP3 files it sounds better, Smoother.

[@FreeSpeechWarrior]

I'd like to see you put mahogany wood on the sides, give it little bit of a steam punk look. I really don't like the sheet metal look of the case. The front would look better being a thick piece of brushed aluminum, and that big hump in the back could be Plexiglas, so you can see what's going on inside. Just my two sense. Job well done, I think this amplifier rivals some of the amps that cost thousands more.

[@12voltvids]

It does rival amps costing many times the price (this was not cheap, it was 1120 after tax). The metal case forms part of the shielding to electronics. Yes it would look nice with a mahogany case, but I am not a wood work guy so it lives as a metal box.

[@brandonsingletary1340]

Might have to do this, any easy way to map the LED? UL = Green, Triode = Blue

[@12voltvids]

Well an extra pole on the switch would do it. Notice that the new version of this amp includes a switch to change between triode and UL mode. Do you think the designer saw this video and thought hmmm, good idea and designed it into the replacement model. I like to think so.

[@apmdavies]

Love the way you say 'Pentrode'

[@zx8401ztv]

Well that didnt take too long to add that feature, and you have done it in a non distructive and fully reversible way :-). With my knackered ears i could not tell a difference, just listening to the music at low level started up the tinnitus tuning forks in the head, and i could not hear past it, also it distorted the audio, so im sorry i cant comment on the sound difference. For the amount of assembly work, i didnt take you very long to assemble really :-D

[@12voltvids]

The difference I notice is ultra linear has more bass. However when I put in some well aged EL34, I actually prefer the triode sound mode. Once I age the 6L6GC Electro Harmonix then I will be able to judge the sound from those. As most tubeheads know, tubes been a break in period like a car engine. That first 100 or so hours they sounds rather rough. I suspect that impurities in the cathode material restricts emission properly and as the tube heats those impurities burn off the surface.

[@zx8401ztv]

Can i ask a daft question? I have heard the phrase "The sublime sound of valves.", i dont really know what that means, do you know?

[@12voltvids]

It refers to the tone, or warmth that a valve amp brings to the sound as opposed to the cold harsh sound of a transistor.

[@zx8401ztv]

Thank you, ive allways wondered what the hell they were talking about. If they said frequency response and harmonic plesentness i would have had a better idea. A warmer less harsh sound hmm :-D

[@glenngoodale1709]

I surely enjoy these video's . I always learn a lot

[@13thstreetnl]

great - one of the best how to videos I've seen...tempted to get one and build !! What switch do you use for UL to triode toggle?

[@12voltvids]

It is just a small double pole double throw switch. The one I have is not rated high enough in voltage but so far no issues with it. It isn't handling much in the way of current, but is running about 330 volts and is only rated 300.

[@hixyhicks]

Hello, I love watching your vids, Can you give me a link for buying this also could a novice who has done some soldering make this.

[@Synthematix]

Happy new year mate, hope you have a great year!

[@tautvilasi]

may I ask you what song plays at 14:55? good for auditioning the amp though.. thanks

[@DAVIDGREGORYKERR]

That just sounds like my TECHNICS SU A900 MKII integrated power amp which seems to get very hot at the back of the unit for some weird reason when it was driving a set of MISSION M70 speakers with an Impedance of 8R0 in direct mode bypassing the tone-control.

[@12voltvids]

I believe that unit was an auto class A, where it could switch from Class AB to class A at low power levels. When it was in class A (up to 8 or 9 watts) it basically turned into a small room heater, as class A is not very efficient, but much more accurate. The big problem I found with those units is you could hear the transition. If the volume was set at a certain level there was a transition point that if you knew what to listen for it was audible. Most people didn't notice it, but once you picked it out, usually on quiet passages in classical music or on the fade out then it was quite annoying, as the tonal quality shifted slightly.

[@UNSERALVUJUDE]

I enjoy your vídeo. Thank you! Have a wonderful New Year!!!

[@pointdexter3606]

i would like to see your old McIntosh tube receiver. Did you make a vid for that? Thanks point

[@12voltvids]

It will be overhauled soon. I have many other projects that I am working on, but the MAC will be a total recap as it is my unit, and worth a small fortune these days. I am not using it, it is in storage right now so that is why I have not done anything with it. Our of sight out of mind.

[@BlankBrain]

DiMarzio model EP-1111 is a 3 Way 4 Pole Double Throw Switch (On-On-On). I can't find the voltage spec.

[@12voltvids]

That might work for all 3 modes, but I am happy with just 2 modes. Right now I am set up for triode and UL, but I may switch to triode / pentrode just to hear the difference, but I am waiting to break in the tubes before I make any changes or do any serious evaluations. I have abut 12 hours on the tubes now. I will wait until I have at least 100 before doing any serious evaluations, as new tubes need to season, preferably at very low, or no volume. I threw in a set of old EL34 to listen yesterday, but they are back in their own amp in the living room, and the new EH tubes are back in this one baking as I write this..

[@dedskin1]

oh wow , sounds nice even over this mic and video, sounds analog

[@12voltvids]

Single ended amps always have the best sound.

[@dedskin1]

@@12voltvids glad to hear from you . Im just entering in that world and all im skeptical about is bass response . Some say there is no SE amp with good bass , then i check frequency response testing of one and its even higher bass then it should be , bit og gain on bass. So those are contrary information's , what do you say about it ?Thanks

[@12voltvids]

@@dedskin1 it's all about the speakers. You need really efficient speakers. I use technics sb7000 with big 15" woofers. Bass is clean. Also the tubes used make a big difference. Swap the tubes for different sound.

[@petr8068]

Hello, please what kind of sensitivity does your Altec Lansing speakers?

[@12voltvids]

They are not that sensitive. 86dB but they do go loud enough for what I listen to on them.

[@umajunkcollector]

with my Sony phones, the AL's were great, didn't like something about the shop speakers. I had the gain up too much on my Surface. Much better at half vol. I agree, triode is a good sound, I was thinking opposite untill I heard it. Of course Sony headphones on a tablet from YT won't be anything like the amp and AL's there. I like to hear a vinyl LP on it sometime. You were right. Perhaps a three pos rotary switch. Don

[@12voltvids]

The speakers in the shop ate PSB mites. Small little book end speakers with a 4" driver. Not the most efficient of designs.

[@umajunkcollector]

I have some Rad Shak Minimus 7's, they have a small woofer. But I use them with a powered sub. Lansing, AR, and EV were the cat's meow in the big speakers of the old days. EV still makes great pro stuff. JBL is kewl. AR gone. But those small Altec Lansing PC speakers with small subs are something else, but for under 100$, they sound OK. I still would like a pair of Empire end tables with marble tops, back when speaker systems were furniture too. Pioneer also made nice looking good sounding systems. Magnavox and Zenith did same with their consoles. I still dislike the modular component systems for astetic appeal, sort of like all those dam black plastic case common TVs. The flat TVs arem't as ugly. Funny thing, I see more Magnavox tube consoles well under 100$ that work, just need some clean and lube, than any other TUBE things. It's a great way to get a half way decent cheap tube system, plus a nice chunk of furniture.

[@12voltvids]

Absolutely. I used to have a set of Rat shack speakers, and I chucked them in the garbage years ago. Wish I had kept them. The foam around the woofers rotted. Same thing happened with my Altec 305s in the studio. I got these speakers back in the mid 80's. Did a video for a guy that owned a stereo shop. He had me produce a video for a local politician that was running for re-election. I followed him around on his campaign for a day as he was going door to door meeting people, and then put together a video that was shown at his election headquarters on a loop. The business owner didn't want to pay me for the video shoot and said I could pick out anything in his shop worth 2,000.00 I always wanted a nice pair of speakers, and this is what I got, and I have enjoyed them ever since. About 5 years ago I had the foam surrounds replaced at a speaker service shop. That cost me about 300 to have both woofers and mid range foam suspensions replaced, and they now sound as good as new. That's the thing about speakers. Look after them, and maintain them, and they will last a lifetime.

[@umajunkcollector]

rubber rot pisses me off, that's why I replace with bass guitar speakers, much better too

[@12voltvids]

The new ones are silicone, and according to the speaker technician they should never need replacing again.

[@dedskin1]

im not the engineer but running signals close to the big transformers , i doubt that is a good design choice , some go so far to spin the wires and move signal to the one side , and power to the other , if they so much as touch they will throw the chases away , that is what i saw , its first time i see signal that close to the Iron core , or what thet is , that middle transformer round core , again im no engineer but i know a thing or two about electronics

[@pointdexter3606]

is this a kit? And what is the kit called on eBay? Thanks point

[@12voltvids]

Point Dexter It is a kit. Sells for about 1000 can. Available directly from the distributors. Don't know about fleabay, never buy anything from that. It is the elekit tu-9200

[@12voltvids]

In Vancouver BC it is available from Lees Electronics.

[@psionl0]

Have you ever considered building the J Lindsay Class A amplifier for comparison? (Original article here: sound.whsites.net/jll_hood.htm ). I believe it is available in kit form today.

[@NotMarkKnopfler]

You're getting claims on your videos because you're not including the music track/publisher attribution in the description on your videos, which is a requirement of the licence and a YiouTube requirement. Second video of yours that I watched with beautiful music that I wanted to follow up, and no info in the description. At least you mentioned it in the comments.

[@12voltvids]

License requirements for music bakery do not require it in the description. I am getting claims because other 3rd party fraudsters try to copyright non exclusive music. I has happened where I have listed the track and license info too. I have to, when a claim is made dispute it, and just put "Musicbakery" or Smartsound if I used that program to create a custom track. Then it gets resolved, but it is a pain in the ass every time I have to do it, and it happens time and time again. Even after the music is cleared after a dispute there is no guarantee that someone won't make a claim again, and I have to go through this a second or 3rd time. The crooks know that 95% of people will not dispute because, perhaps they didn't purchase it, and used a bootleg copy of smartsound, or used the "preview" copy that the web site hosts. In those cases the fraudster makes a claim and offers to share revenue. Many that don't have a license or are unsure where they stand just leave it and don't dispute. Since I have my license I do dispute and win every time.

[@RobertKohut]

Nice!

[@dambuster6387]

I wander how hi fi buffs would rate this amp in a blind test with manufactured amps costing mega money

[@12voltvids]

Dambuster Just search ELEKIT TU8200 review to find out. Here is one review www.head-fi.org/threads/elekit-tu-8200-dx-headphone-speaker-amp-review.722633/. And another www.kenrockwell.com/audio/elekit/tu-8200.htm That should answer your question. The experts agree, that this sounds as good as anything out there. It is the best sounding amp I have heard.

[@MarkTillotson]

I don't really see the point of showcasing an amp through tinny little speakers and a video camera microphone and some random video codec and YT's own compression scheme. All I can tell is what YT streams back sounds pretty terrible with heavy bass breakup on some of the loud sections.

[@12voltvids]

Those wern't tinny little speakers, they are a pair of nice Altec Lansing 305 floor speakers that are solid walnut, and stand about 2 feet high. These units rock, and sound beautiful. When they were new they sold for over 2,000. I had the surrounds replaced on the carbon fiber woofers and mid range drivers a few years ago. They sound absolutely fantastic in my studio, and any distortions are caused by compression, and youtube re-coding.

[@grahampinkerton2091]

Factj is semiconductors have overtaken valves years ago. Fact is valves are inefficient. Valves dont live as long as semiconductors.

[@alssilva8496]

Transformadores teroidais

[@grahampinkerton2091]

Basically Tubes belong in the Museum.

[@mr1enrollment]

and your proof of fact is what?

[@DAVIDGREGORYKERR]

Class AA MOS

[@RobertKohut]

Great amp!! You might want to read the review at 6Moons here... 6moons.com/audioreviews2/elekit/1.html Also he warns about using a mode switch and switching while the power is on. Read that here...(Quote) "Nevertheless switching back and forth between the three modes on the TU-8200DX is not as simple as it appears. The selection is done by manually resetting a pair of jumpers (one per channel) on the PCB inside the chassis instead of through a three-step toggle switch from the outside. Elekit does not encourage the latter modification as changing the mode setting under power might damage the output tubes and output transformers. The manual further advises to unplug power and wait 10 minutes to let residual high voltages dissipate before changing the jumper settings. A word of caution: Read the inscriptions on the PCB. Be very careful when setting the jumpers for triode and pentode. The left and right channel are not mirror imaged. A good trick is imagining yourself to be a pilot flying this amp and those jumpers are your gyro horizon."(end quote)

[@12voltvids]

I am fully aware about the manual warning about installing a switch, and yes I am aware that the tubes could be damaged by switching under power. I turn the power switch off before I change modes.The power tubes can also be damaged by disconnecting the speakers under load too, that is why my modified luxman amp that I talk about in part 5 having a pass through from the "B" speaker terminals to the "A" so I can switch between 2 amps by toggling the "B" speaker switch has a pair of 8 ohm 10 watt resistors that get switched across the "B" speaker terminals when the relay is in the "luxman" on mode. That way there is no induction generated back through the output transformers.Running a tube amp under no load cam damage output tubes and the output transformers.The chances of popping a tube changing the mode when the power is on and there is no sound playing is low. If the switch was flipped under a full load the changes increase, but turn the power switch off before changing modes, and the risk of damaging anything drops to zero.