Which tubes are the best?


Hi folks, I just got a Muzishare X7 integrated amp. It is beautifully made and sounds like it has a lot of promise. Even though I'm just breaking it in, I am thinking about tube changes. Why? It's just what I do. 
I'd like your opinion on the best replacement tubes, meaning smoothest, most "tubby" and mellow tubes. 
I won't be chasing NOS tubes. I'd like your experience with Gelenlex Gold Lion, TungSol, Mullard, Telefunken, or?,  etc. of current manufacture. The amp uses KT88, 12ax7, 12au7 and CR34 rectifier. 
Any thoughts about KT88 vs 6550 would be appreciated. I used to prefer 6550 way back when. 
Any information would be appreciated. Yes, I could go through all the old posts but I do have vision issues after four operations and that's why I'm asking straight out. 
Thanks in Advance. 
Back in the day, I used to do some serious tube rolling. The absolute mellowest, most laid back and detail rich tubes I ever found were some Mullards advertised in the back of Audio magazine. They had Magnus Organ printed on them. They were amazing. Unequalled. Ten years ago, I was cleaning out stuff and took a box of my small tubes to a local dealer. Some guy gave me $350 for them. Wish I still had them heh. 

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The Psvane KT88 supposed to be very good, but I’ve heard the Gold Lion are the best KT88’s.  The best 12ax7 is a 5751, that’s why cj always specs them in their preamps.
Thanks Lou. I have worked hard to put together a nice solid state system but now That Old Tube Majic has me in it's spell. 
Years ago I tried all kinds of tube stuff. Musical Reference, Cary etc. Nice to be back. I never got the point of having tube gear that sounds like SS. 
as i understand it this muzishare unit is basically a primaluna knockoff with a tube rectifier and downgraded output transformers

so i will share my thoughts on tubey tubes

old stock ge 12au7/ax7

tungsol (new russian) 7581’s if like the primaluna’s this unit can autobias and run 6l6gc/kt66 equivalents - in general i find current russian power tubes less sharp and treble intensive than the chinese counterparts
You can't go wrong with any of the Slovakian-made JJ's! I'd replace the Chinese tubes presently in your amp with all JJ's! 
I've run tube integrateds using 6550 or KT88 for well over 25 years. Yes there are differences between tubes but nowhere near enough to me to be worth changing (rolling) just for the sake of change. Tried it, no thanks, bigger fish to fry.

That said, KT88 are a bit warmer, with a bit more tubey liquid magic than 6550. Enough so the warmest 6550 is still not as nice as the most flat least warm KT88. There's just not enough there for me to be chasing after expensive NOS, so you are welcome to go fishing and good luck landing the big one. But of all the tubes over the years my favorite by far is JJ. Better more 3D liquid than most if not all, and yet still with great extension and control, but what clinches JJ for me is their reliability and longevity. So +1 roberjerman, JJ all the way!
JJ KT-88s are quite nice and hold up well too. They make some upscale versions like the 'blue glass' that seem to be worth the slight extra dollars. The Chinese make a very nice 12AU7. I avoid 12AX7s in my designs so I can't comment about that one. But we've had a lot of nice feedback on the Psvane tubes, and also some nice comments on the Gold Lion (Russian made) 12AU7, so those might be good places to look for a 12AX7 that isn't NOS.
With my Ayon Spirit 2 I prefer the sound Gold Lions or Psvane KT88s to either the clear or blue bottle JJs , but you need to try tubes for yourself to see what sound flavor you like.That amp takes 4 12Au7s , I use two NOS RCA 12Au7s blackplates, and 2 RFT ECC82s.

I have 2 other integrated amps that use 12X7s, in my Line Magnetic I use NOS Tungsol 5751s to reduce the gain a little; in my Finale Audio I use NOS GE 12ax7s

To my ears changing out the respective JJ , Electronic Harmonix or Chinese signal tubes that came with each amp took the sound to another level; worth the expense
For those that like the JJ tubes - what is it that makes them good?  Alos, where do you buy them?  
I get mine at TubeDepot.com.   Not sure I notice worlds of difference, but JJ's aren't very expensive, sound fine to my ear, and have a good reputation, and at least the ones I've bought are not over-priced for what my ears can hear.
Tube rolling can be fun, rewarding, and expensive!

I've got a PrimaLuna Dialogue HP Integrated; your Muzishare X7 seems to be of similar design so I'll share where I've landed.

Disclaimer, I've got XStatic electrostatic speakers combined with a bit of age-related loss of high frequency hearing so I tend to like slightly brighter sounding tubes in my PL.   YMMV...

I'm running 8 Tungsol KT150 power tubes.   This was my first big upgrade from the stock PL EL34 tubes.   This brought out much more depth and punch to the bass while still preserving the warmth of the midrange.

I played around with the 6 12au7s and my favorite combination at the moment is: Radiotechnique in the center preamp locations with the Gold Lion's just outside of that.   The Cathode followers are NOS RCA Cleartops.   The Radiotechnique are definitely on the bright side so I may swap them with the Gold Lions and give that a whirl.   These changes significantly increased the high-end extension and energy bringing a nice balance to the overall presentation.

It is remarkable how you can fine tune the sound by swapping tubes.  You can't make a bad device sound great with just tubes, but its all part of the complex system to tweak it to your tastes.

Not trying to hijack this, but don't forget to try a different fuse.   The SR Orange change was also noticeable.   I describe it as making the black parts of the music blacker thereby letting the instruments stand apart and increased the detail.   Electronically, perhaps it just lowered the noise floor?   I don't know, I just liked the change.

Enjoy the experimentation and don't forget its all about the music and your ears.
My new Amps came with two quads of NOS Mullards EL34.  I loved them so much I started replacing the rest of my system with NOS Mullards - preamp NOS 12AT7 and phonostage NOS 12AX7.  They are as you described in your post- liquid smooth detailed rich. Easily heard the improved difference from the stock tubes the manufacturers used.  
Not trying to hijack this, but don't forget to try a different fuse.  The SR Orange change was also noticeable.  I describe it as making the black parts of the music blacker thereby letting the instruments stand apart and increased the detail.

This is why tube rolling is such a waste. For every set of tubes you try the one thing you know for sure is you are out the money. They may well wind up being worse than what you already have. Now you have an extra set of tubes sitting around you don't want to use except for spares. So what? Are you gonna roll the dice again? Just how many spares do you need?? When that same money would buy a new fuse, or maybe a few, or some PHT if you have a turntable, HFT for sure (everyone has a room) or heck Nobsound springs, or even the really crazy good Townshend Pods could be had for what some sets of tubes will run you. All of these guaranteed to elevate, and with zero risk any of them goes bbbllzzzlzlzlsalzlzl SNAP in a blaze of glory like lets face it tubes can do. 

But hey, if you are "that guy" then at least do it right, give Dave Thompson at Raven Audio a call, he totally knows tubes, killer selection too. Can't guarantee he sells if you don't have a Raven, but I bet he would steer you right.
Tubular1- For those that like the JJ tubes - what is it that makes them good? Alos, where do you buy them?  

JJ are just as detailed and extended, yet just a tiny bit more liquid, which adds up to a bit deeper and more palpable sound stage. Compared to what? Tungsol, Gold Lion, ElectroHarmonix, and especially compared to the worst of all time, the only tube so bad I would say AVOID because literally 3 out of 5 failed spectacularly and within barely 2 months (!) tubestore.com "Preferred Series". Preferred?!?!? As compared to a root canal - maybe!! 

Oh well, they did honor the warranty- and gave me some credit when I said you know what, I am just not willing to risk tubes this bad in my amp unattended, which makes them totally unsuitable, so how about give me a deal on the tubes I know are good: JJ. And they did. And they are in there now, year and a half later, and still sound great. Just ask the guys who were here last Saturday.

There's nothing that prevents implementing tweaks and and still getting sq benefits from tube rolling.
Groove tubes from brent jesse tubes.

EL34GT as they are made to be a close copy of Vintage Mullards. Brent mostly sells NOS and doesn’t like a lot of new production tubes but he signs off on these. That itself should say something.
The only tubes I roll are the signal tubes and the only tubes I use for my power tubes are Genalex. I have three different amps and all of them have either the EL34, KT-66 or Kt-88 tubes
Might check the provided link below. I found it to be helpful and reasonably accurate in tube gain. Like millercarbon said, it can get expensive. I was looking for more high frequency detail. I found new production Mullards to lack the dynamics I wanted. I have Bob Carver mono blocks that use KT88s. Purchased used. Previous owner had already upgraded the tubes. The KT88s were Gold Lion. The 12AX7s were some old stock Millard medical grade tubes. After rolling tubes, I ended up liking the sound of new production Gold Lions. Actually have replaced the tubes in Manley Chinook with the Gold Lions as well. The Gold Lions have more gain at higher frequencies. Hope you find what suites. Happy Listening!  
https://www.scribd.com/document/383393010/12ax7-Comparison-of-Current-Made-Tubes-2016-1

JJs are available from CE Distribution cedist.com
a few points i’d like to make here

1 - there are basically three makers (factories) of tubes today, china (shuguang and other brands, in changsha/guangdong), russia (sovtek and related brands bearing many old names, in saratov, se of moscow), slovak (jj, town of cadca, using old czech tesla tooling) - all had very rough starts making tubes for the high audio market and all have had various waves of quality challenges.... those of us who have been tube users over the decades have bad memories and scars from ALL of them as they got their respective acts together, many fits and starts affecting different tube types at different models

2 - as time passes these makers have evolved, their processes have improved (for their own good, more than ours, as they can’t make money with poor quality/high reject rates at their plant or from their distribution channels), so quality has been steadily improving - as always, this is a moving target -- now with covid, the supply chain has been interrupted again, so more uncertainty on tube output and quality - still, all these makers take shortcuts in materials used (a critical aspect) and manufacturing steps to save $, the quality mindset is not what it used to be, when tubes were made for critical/military applications

3 - given the above, it is key for us as intensive users to have a steady dialogue with trusted vendors... the few good ones properly test what comes in (they don’t want customer returns either) to see what is what, if the batch is good, if they sound good -- the not so good ones who don’t test themselves at least see what comes back when they ship product to customers - they will tell us what is good, what is iffy...

4 - all three makers are utterly savvy capitalists, so they rebrand (some bulk distributors rebrand too... mesa, groove tubes), make ’premium’ tubes, using premium or old lovely brand names they bought rights to (tungsol, genelex...)... some of these are worth trying as these represent the best of what these makers can do -- more qc/screening etc etc... so if the prices are within reach for us, it is a win win - they sell their best stuff for more, make more $, we get their best stuff even if pay through the nose for it

5 - the notion of the best tube is a non starter - it is personal, situation specific and gear/system specific - what is the best wine? best steak? best car? --- in general i would say chinese tubes seem to play a little brighter/thinner, russian tubes have a fuller more solid sound, but maybe less ’air’... jj/slovaks are closer to russian tubes, but to be honest it has been a few years since i tried new ones, as they burned me quality wise most recently -- there are always exceptions and ymmv, as always
FWIW, I've been using Tung Sol 6550's for quite a few years. They are a good match with my system, better than a lot of other KT88/6550's I have on hand. Out of curiosity I tried a set of the JJ KT88. I found them very smooth but a bit warn for my taste. Nice tube though.
I believe Muzishare comes off the same line as Line Magnetic. So that’s really good news right off the bat.

For now, I’d wait for the tubes to break in. Good thing is that it runs a single quad of KT-88s

I would try the Suguang WE KT-88 Plus. They sounded great in my Don Sachs Kootenay and was highly recommend by the man himself.


IME rolling tubes generally makes for a huge upgrade in the sound.
Tube Depot is a decent source for good NOS. But I recently have bought and used several new Psvane (how the hell do you pronounce that!). They have introduced several lines of tubes which have been carefully tested and they toss 90%. These can get a bit pricey but I have found Themis to be super. Grant Fidelity is the best source for the best ones. Cool to get new, new stock.
Huge upgrade, you say. Compared to..... what, exactly?
Another vote for Psvane 12AU7 tubes. I have used Gold Lions. But the Psvanes bettered them. Both are better than the new Mullards in my system. I got mine from Viva Tubes. They have an online shop and have fast shipping.
@akiravelvet,
Obviously Brent does not like new tubes. His business is to sell NOS :-)
I have not heard NOS in my system. But after hearing the difference between the new Mullards and the Psvane/Genalex Gold Lions, I am more than happy with the new tubes.
If « really » NOS tubes last between 6000 and 10000 hours and a new one only 2 or 3000, which is the more expense ice in the end ?

Sorry, just a novice here. Got a PrimaLuna amp that started to whiz a little so I went to get some new tubes. (This was just two weeks ago) After some research and reviews choose the "Natural Sound 6CA-7" which is a Shu Guang Perfect Pair. So while I was in the mood to spend some money I figured what the heck, I'll replace the 12AU7 as well. Landed on the Gold Lion Genalex ECC82/B749. Yay.
So put them in and loaded up some of my best music recordings. Well. Spent the next three days relistening to music that literally blew me away anew. I thought, dang, these Double Impacts ARE pretty good. Dang, this PrimaLuna IS pretty good. Everything went up to like double as good. Nothing changed but the tubes. And quiet, wow. But like I said, I'm no expert but I know what my ears hear.
My amp calls for 6550 output tubes so I auditioned them against a couple of other brands. I ended up preferring the Gold Lion KT88s by a significant margin so I bought them. And then I bought a back up set!

But that was on my power amp (CJ Premier 11a) - YMMV with other amps.
   Fist off , I’m a strong advocate of premium NOS driver tubes . Yes they are expensive, but they’re  a long living tube and worth the investment. I must disagree with the “ JJ “ crowd , as my Rogue pre amp came with JJ 12AU7’s . I tried numerous tubes , with RCA being the best domestic and Telefunkens bettering everything I tried . I haven’t owned your particular amp , but I’d speculate that in a 3 driver tube configuration,  your middle tube will influence the sound significantly more than the other 2. That’s how it works in amps like  Bob Latinos. The sound is all based on system synergy , room character , and your taste . So you have driver tubes , power tubes and a reciter tube . Your driver tube(s) will have the biggest change in tonality . Your power tubes will matter in accordance with what speaker you have . Now I have about 10 different driver tubes , Including RCA, Seimens silver plate and CCa, Tekefunken Tektronix, G73-R, and standard, PHILLIPS, EI , and I can keep going . Now as for power tubes I have new production JJ, Gold Lion, Tung Sol and the Psvane Ti. NOS power tubes GEC KT88 and KT 66, Tungsol 6550 3 hole , and SED Winged C . And about 6-7 reciter tubes , mostly NOS . So here’s my recommendation. Driver tubes on a budget , Tungsram NOS , Or Tesla ( nos ) . Telefunkens are the best . I’ve tried nos Mullard and it’s like throwing a blanket over my speakers .  The sonic signature of all drives tubes is perfectly described on Brent Jesses site. Then for power tubes,  new production Gold Lions are the overall best at providing a flat response  and still provide good bass . In my system they are only bettered overall by KT -120’s and SED Winged C’s . The higher level Psvane Ti’s are too bright . Now with your rectifier tube , it’s important to see what your amp can accommodate. Mine will handle many . I have all of the good ones except a NOS GE 274b. I prefer a 5U4GB over the higher voltage 5AR4, as it smooths  out my system . So for you a modern Gold Lion or a vintage RCA or TungSol coke bottle if it’s compatible with your amp . About 15 years ago, when I got back into tubes, I had an Antique Sound Labs 30 Wpc integrated that had a SS power supply . I went with Tungsram drivers and Svetlana ( SED ) winged C EL34’s and the sound quality improvement was substantial. So junk any cheap Chinese tubes , skip over JJ’s and go to something that you can live with . Happy hunting , Mike . 
NOS tubes almost invariably beat out new production stuff....in both sound and life span.  There are a bunch of NOS brands that beat the snot out of JJ's, that's for sure.  I bought a Carver Crimson 275 that had the JJ 12 xx 7 signal tubes and I put in Telefunkens from the late 50's in and it was a revelation.  The I changed the Tungsol KT88, although the Tungsol are a pretty good power tube, with the Dawning Series Shuguang WEKT88 PLUS tubes.  I had an entirely different amp.  Just stunning.  Now in the past I wouldn't give you a nickel for any Chinese tube but I had tried the WE6SN7 PLUS Shuguang tubes in the Don Sachs pre at Don's suggestion and it was a stunning change.  I also prefer the NOS PHILLIPS  5U4G or Mullard GZ34 rectifier in my tube DAC.  Both from the 60's I believe.  In the DAC I also use NOS Siemens or Telefunken as the signal tubes.  The new production tubes just  have no comparison.  They are more expensive but well worth it in my opinion.  Brent Jesse and Andy at Vintage Tube Services are my go to guys.  And if what you order isn't the sound for you?  Just send them back.  But both these guys will put you in the right direction if you tell them the sound you're looking for.
Way back when Gold Aero were the best. That company got tubes from all over then tested and would only sell the ones that tested the best but good luck finding any..
I will agree that, once you’ve decided what tubes sound best to your ears, you’re probably going to keep your fav tubes in and not keep rolling them. 
In our Leben CS600, we rolled a bunch of stuff (including Russian Military Grade options) and finally decided that the GGLs sounded best for the type of music we listen to in that room (acoustic folk and acoustic country). 
That’s not to say it wasn’t fun hear how the different tubes sounded with different musical styles—especially thru Leben electronics. 
@milpai,exactly! And for him to put his name with the aforementioned new tubes says a lot itself. That he will go into something he doesn’t like and swallow his ego and say that he likes them. 
I’ll try those out for sure. Just not at his prices lol. I buy enough nos tubes off the guy