KT77 sound like someone turn on the loudness. Ugly and expensive.

Agreed

Could you suggest tubes for cayin mt45 ?

And they look gorgeous in the A10/A12, don't they ? I bought JJ 6CA7:s, and the visuals , with the fat glass bottles, and fantastic filament glow, is truly to die for. Looks so damned good that I get tears in my eyes , nearly. Like a cosy camp fire to gather around almost...! Indeed mightier bass, but to my liking slightly lacking midrange fullness. That for me is a fact that i mourn every time I try them, since they look so damned good.... And so a few days passes, and then I feel I have to try them again, and man, do they look awesome ..... But again, the EL34:S win when it comes to midrange fullness and bloom.

Alot of the new tubes these days have metallic sound I don't like

I have had reliability issues with the KT-77.

There is a little bit of difference. To my observation, the kt77 gives a little bit more punch on the bass. The stock EL34s are great sweet sounding. They are both good, it just depends on the taste of the listener. I will do another video with the el34s, kt77 and 6ca7 to compare.

I haven't tried the tubes in this video but I use the Tung Sol EL34 and they are a real step up from the stock tubes. Hope it helps

Avoid the gold lions unless you're prepared to replace them after about 300 hours. They do sound good though

Hi guys. I have done massive tube rolling since I got my A10, as my first HiFi tube amp ever, New Years Eve 2020. I had already been tube rolling incredibly much in my guitar amps for almost ten years, so I "knew" which tube brands and tube variants I liked or didn't like. That guitar amp tube knowledge turned out to be kind of useful when navigating in the HiFi tube amp world as well, but unfortunately had put undesireable limitations to the range of tube brands/variants I chose to try out in my little beloved A10. In my guitar amps, with focus on fat crunchy and harmonically rich tones in classic hard rock from 70's and 80's, I did not care at all for JJ tubes, and was rather fed up with almost everyone who had bought a new Marshall head or combo, and had swapped stock tubes for JJ's and thought they sounded fantastic....... "-If those mainstream jarheads only had spent some time and money trying other brands and tube variants, they also would have realized that JJ sound at its best good, but absolutely not fantastic in a Marshall head. " was my humble opinion..... Since less than a fortnight I have the hard way learnt that tubes in HiFi amps is another thing than in heavily distorted rock guitar amps...... It started with a guy telling me he had swapped the A10 stock Chinese 5Z4 rectifier tube for a cheap 20$ JJ 5AR4 ( = GZ34 ), and had experienced very big improvement in sound quality. Hence, he was planning to buy a higher quality, more expensive 5AR4, like the Gold Lion at approx 60$. I listened to his advice and bought a Mullard Reissue 5AR4, in the same league as the Gold Lion, and paid about 65$. It gave a massive boost in power over the entire frequency range, but I thought the amp lost much of its sweet and airy sound, and got hard and solid state alike. Up to that point in time, I had had no clue that the rectifier tube actually influences sound quality, I thought it was merely "the voltage rectifier" ..... Since that guy had really liked what the JJ 5AR4 did to the A10, I ordered one too. Wow! The same airy and lush presentation as with stock Chinese 5Z4, but with loads of more power , detail, dynamics and authority. And at 20$........ And JJ, WTF?? Just for the hell of it, I swapped my 120$ matched pair of PSvane 12ax7-T-Mark II preamp tubes for a lousy pair of standard JJ 12ax7:s that I had rejected in guitar amp tube rolling years ago. WFT ??? Midrange tonality and fullness just got so much better right off. Hhhmm...... JJ again.... With both loads of more power on tap with 5AR4 rectifier, and drastically increased dynamics and detail, I realized that is was sensible to start output tube rolling all over again.... The Shuguang HiFi EL34:s , that had distorted very early with stock rectifier, and had had to leave place for PSvane HiFi UK, now worked just fine with the JJ 5AR4, and.... gave a much more open and shimmering top end! I had now mentally surrendered to the fact that JJ tubes had turned out to both sound superiour in my A10, and to be dirt cheap..... As you probably have guessed, I saw no other alternative than to a few days ago order both a pair of JJ EL34 II:s , and a pair of JJ 6CA7:s. They both arrived yesterday. Yes, they sound god damned just fantastic.... Of course, a highly subjective opinion, but for me a lesson learned, regarding being limited by my own prejudices. If you have not tried it yet, I would recommend trying this setup: * Pre amp tubes: JJ ECC83 ( standard 12ax7:s ) Adapters Ebay: "12ax7 top-6N2/6N1 bottom" * Rectifier tube: JJ GZ34 = 5AR4 * Output tubes: JJ 6CA7 , Tighter but a little less pronounced bass response, or JJ EL34 II , Big bass response, while a little less tight, or Shuguang HiFi EL34 - " - - " - + Very nice open top end www.tubeampdoctor.com/en/jj-6ca7-jj-electronic My A10 tube rolling since New Years Eve: PREAMP TUBES: * Stock Chinese 6N2 * Russian made 6N2 * PSvane 12ax7-S Art Series * PSvane 12ax7-T-Mark II * Electro Harmonics 12ax7 * Electro Harmonics 5751 * JJ 12ax7 ( ECC83 ) * JJ 12ax7 ( ECC803S long plate ) * JJ 5751 * Sovtek 12ax7 WA RECTIFIER TUBES ( Amp internal voltages stayed safe=well below 400V in my A10 with all them) * Stock Chinese 5Z4 * Brimar NOS 5Z4 * Brimar NOS 5V4 * Mullard Reissue 5AR4 (GZ34) * JJ 5AR4 (GZ34) * JJ 5U4 OUTPUT/POWER TUBES: * PSvane HiFi EL34 ( Stock in my A10 ) * PSvane HiFi UK type EL34 * TAD EL34 STR * Gold Lion KT77 * Shuguang HiFi EL34 * JJ EL34 II * JJ 6CA7 ** A lot of people seem to have rolled tubes to increase bass response of the A10 ( or later the A12 ). I can say that bass response is much much more affected by: A) Output tube plate voltage under load: This changes with rectifier tube. 5AR4 having the lowest voltage drop under load of the above mentioned , thus allowing output tubes to putting out more power before clipping. Improvement of bass response when swapping to 5AR4 rectifier was infinitely much bigger then when swapping stock EL34:s to Gold Lion KT77 B) Speaker design and sensitivity than which output tube you for instance use. With the crossover wise fully upgraded Wharfedale Lintons I bought in March this spring, the A10 produces both volume levels and bass response that is way more than "barely sufficient". Kills my NAD 317 2*80W in each and every meaningful aspect. P.S. I am now upgrading tha A10 with remote volume control, rosewood front and sides, and new machined aluminum knobs. All from Ebay, of course... D.S. Cheers, Magnus, Sweden

Thaks Magnus from sweden for the information,. Im German from Spain and Im in love with this amp that made me sold mi Naim Xs . Is paired with BW 706S2. Preamp tubes are 6N2P-EV ( something called Rocket ) . Those can be changed without using an adapter and the souds preforms much better. The power tube I prefer are KT77 JJ ( more bass and attack) and Electroharmonix EL34 that sounds just as a EL 34 single ended class A amplifier thougt would sounds, sweet mids, airy and extended treble and tight ( but not much extended ) bass.

6ca7 is basic same as el34

i believe it will run them but if you run them loud there will likely be some form of distortion. you might try the rectifier tube swap and maybe 6v6 tubes with the speakers in the 4ohm taps

If you really need to save power for solar reasons, a class A tube amp is literally the worst thing you can buy! 100W in, 3-5 Watts out! A few percent efficiency in general...

@@vespass225 Are you serious? 100w dissipated into just those tubes to put out 6wpch? That's an incredible amount of heat it would have to dissipate. If that's the case, I'm guessing class d solid state is the way to go? Do you know where I can find recommendations on the best sounding class d then, in budget price ranges?

@@jimbob3030 Well, Jim, I might have exaggerated slightly, but I am almost sure it draws like 75W in idle, and being real "hard" class A, that's the power the amp draws regardless if it plays music or just idles. Class A amps work like that per definition. A class AB amp runs a lot cooler while the tubes only conduct part of the input 360 degrees cycle. Imagine a 50W class A amp.... No need for more heating (500-750W idle draw) in a moderately sized room in the winter!!

Maybe can drive your Klipsch try please integrated italian amplifier Unison Research Triode 25 - 2x45W per channel, power consumption between 100-300W. It's push-pull. Or something from solid state like Hegel 300 with similar power consumption. Unison and Hegel sounds very good on rock, jazz, vocal or electronic music. Remember Klipsch have horn tweeters and midrange they can hard sounding and need warm sounding amplifiers.

Hi Matt, When I just got my A10, and tried it with new stock Wharfedale Linton speakers, the A10 distorted very early ( at relatively low volume ) . First I experimented with different powertubes. There was a slight difference in tendency for distorting, with Psvane HiFi UK type being better than stock Psvane HiFi, Shuguang HiFi being a little worse. TAD EL34 STR and Gold Lion KT77 roughly equal, with the Gold Lions having slightly more bass response. Slightly more bass, not much.... The really, really big steps were taken by swapping rectifier tube , from stock Chinese 5Z4, to JJ 5AR4 ( GZ34 ) or NOS Brimar 5Z4 or 5V4, with 5V4 delivering more power ( less distortion ). Mullard reissue 5AR4 gave the most extreme power boost, but I did not really like the sound characteristics of it, at least initially, being to my ears too hard, and kind of Solid State sounding. Rectifier swap gave not only big power improvement ( less distortion tendency ), but a also a huge increase in bass response and overall detail. It also changes sound stage and overall presentation, in ways you may like or not, so I would actually really recommend experimenting with different rectifier tubes , since it not only powers the A10 to another level, but also change overall sound presentation to a larger degree than swapping power tubes, or preamp tubes on their own. Don't take so much for granted as I did, assuming rectifier tube was a negelectable player when it comes to sound presentation. Even differences between brands and models of rectifier tubes are big. Compare a Mullard Reissue 5AR4 to a JJ 5AR4 for instance. Huge difference, where I prefer the JJ. Possibly the Mullard Reissue has better measured electrical performance, but you don't listen to measured characteristics, you listen to how you yourself experience the music, that's what matters. I first thought the Brimar NOS 5V4 indeed had power, especially in mid range, but had a shallower less airy sound stage than JJ 5AR4, and therefore have used the JJ most of the time recent weeks, when listening mostly to rock, soft jazz, soul, funk and pop. Yesterday though I listened some hours to classical music, tried the Brimar NOS 5V4 and found that it sounded much fuller and much more convincing for violins, cellos etc in classical music. In other words, keep experimenting, and include a sortiment of different types and brands of rectifier tubes. Some will warn you for possibly damaging the circuit by the higher voltages, and rightly so, that is a sensible remark, but I did measure internal voltages, and the Mullard reissue GZ34 that gave the highest voltages in idle ( more significantly lowest voltage drops under load ) did not get close to rated max voltages of filter caps etc.

check out "skunkie designs electronics" videos. you need to keep the volume low or it will badly distort. the more efficient your speakers the better

@@vespass225 be careful with the rectifier tube swap. it will increase the power but may also burn out some of the resistors. this amp does run a very low power tube voltage which is likely causing the distortion to drastically increase at 1 watt and up

@@landienikolaisen7897 Hi Landie! Yes I know of the very low both plate voltage and bias current, and follow the work of Skunkie as well. I will rebuild my A10, but likely not by using excisting power transformer as Skunkie plan to. I want full power and sound quality out of the EL34:s, and will do what it takes to raise platevoltage to 400-420V and bias up to the level of real "HARD Class A", i.e. half way between cut-off( No plate current, --> max plate voltage ( about full B+ ) --> Clipping of upper half of sine wave in oscilloscope) and saturation current (Max plate current, cathode can't deliver any more electrones , no matter how high grid voltage you apply. Max plate current --> Min Plate voltage --> Clipping of the lower part of sine wave in an oscilloscope) Meanwhile, I don't mind the risk of burning any resistors or what ever, since the improvement in sound when swapping rectifier tubes is so significant, and any component fault is very easy to both trouble shoot and fix yourself. Component costs are ridiculously low for such things as resistors and even the caps on the cheapo side in this machine. Honestly I don't consider the risk even present since voltages I measured borh before swap and after are just about some percent, which would under normal circumstances not destroy any component, and even if it did , a minor problem. Regarding the hot topic if a Single Ended tube amp really sound differently with rectifier tubes instead of a solid state rectifier, and differently when using different type/brand/quality rectifier tubes, I think you should judge yourself, Some may say they hear no difference, maybe because their system does not reveal it, or of personal physiological reasons. But you may, and if it is a big improvement to you , that you could identify even with a blind test, then it is of course real, no matter what anyone says. Skunkie said that when trying a JJ GZ34 instead of the stock Chinese 5AZ4 in the A12, significant improvement in sound quality were observed, but saw no changes to measured figures. Now, when planning this"gut rebuild" of the A12, with focus on minimizing voltage loss downstream the low voltage stock power transformer, Skunki plans to use a solid state rectifier. To my comment, that I don't wan't a change to solid state rectifier, since tube rectifiers to me sound better, Skunkie says that it does not affect sound quality..... ! Maybe Skunkie means, that the overall improvement in sound quality, when lifting the internal design and measured performance to a decent state, is so profound, that the possible minor loss of sound quality due to the use of solid state rectifier, is a very sensible and reasonable price to pay, given you stay with the stock power transformer, which I don't intend to do, and likely won't My experience is, that tube rectifier really does matter, and I am sure many would agree if they made serious comparisons themselves, but of course to various degrees. Anyway, I have tried 5-6 different rectifiers, swapping back and forth, time after time after time. and without a doubt hear significant differences. Depth of sound stage and general openness changes, extension of mid range and /or low and high register changes Just out of curiousity I did try Skunkie's "quick Fix 6V6 thing" in my A10 with 6V6:s, TAD CZ:s and Electro Harmonic. Both present a rather big improvement not only of useable power, but also a big jump in overall sound quality, getting much cleaner, clearer, punchier and a lot better tonal qualities. Even if Skunkie did not think anyone should spend money on that intermediate testing of that "Quick Fix" , I think it was well worth it, waiting for final conclusions and recommendations for the major rebuild . If this "quick-and-dirty" 6V6 thing ( 6V6 14W max plate dissipation) gave such large improvements, imagine what a well designed cicuite for full EL34 plate voltage (400-420V or similar then, EL34 max 25W plate dissipation..) and proper hard Class A biasing could do. With so much more power on tap, you could even consider a triode to ultra-linear switch if you like.

@@vespass225 Nice work! You definitely know your stuff! I Just ordered the a12 and a bunch of tubes to play around with, I cant wait to hear it myself! I got all the tubes you mentioned, and also the solid state tube replacement to try. I have a pair of cornwall iv and the audiolab 6000a play ill use as my DAC. Maybe one day I'll rebuild it also, I'm an electrician and a guitar player so I've delt a bit with tube amps before but never too deep.

Yeah, I had a GL KT88 with an intermittent issue, a cathode short, it cleared itself and is still going to this day. Also have GL KT77’s in an Elekit TU8200 and they are making some weird glass creaking noises as they heat and cool. Probably 100 hours max on them. Time will tell, I guess. May be replaced with TAD’s if they fail.

Out of new production tubes they seem to be rated as most reliable though.