Amplifier Power tubes - important to sound?


i replaced all the small tubes on my mono amplifiers and now I'm left with replacing the stock Power tubes, kt88.

I like what I hear with 12 new small tubes - telefunken nos 12ax7 and 12at7. 

Now I am left with replacing 16 kt88 stock JJ tubes.   will Probably use Siemens 6550 nos.

How much will this impact what I hear do you think?  I recall hearing that power tubes don't make that much of a difference.

 

emergingsoul

@mulveling

RE: Master II - I misspoke. I meant Signature II. You’d think for as long as I’ve been considering one I would know that. And I do. But my grey matter keeps getting greyer as I throttle down the on-ramp to being an official Geezer. I don’t have an AARP card which means I’m not licensed to fart on airplanes just yet, but I sure do feel my synapses misfiring from time to time. Which frankly often smells the same. This is what I get for not eating all that broccoli as a kid. Which makes it twice I’ve been wrong in as many sentences. But don’t worry, I’m not done being wrong yet. The only reason this whole Internet thing exists is because it feeds off of wrong. It’s what fuels forums like this. Without enough emerging souls to satiate our hunger to be right we’d all starve to death from malvalidation. And I can’t have y’all going starving because then I’d have all the vacuum tubes to myself, which at first blush has many merits. But if you sit with all of it for minute, for long enough anyway, you eventually come to realize there’s a special, irrevocable loneliness that comes with having it all. 

Despite how many tubes I look after, having them all is not why I got into tubes. In fact, it is entirely counter to why and how I became a traveling vacuum tube salesmen. Which, like our friend Kevin at VAC, is not something I ever intended to do. All I really wanted to do was hustle a few tubes to some friends in need to start paying off the mortgage on that pair of mismatched RCA 7025s I bought from the clowns over at TubeDepot. But it happened and when it happened it happened suddenly and it happened without warning. One minute I’m minding my own business, next thing you know I’ve accidentally started a business I need to mind — and I can’t be left alone with old jukeboxes or I’ll give into to the overwhelming urge to tear them apart with my barehands to see what kind of tubes it might have in it. I’ll save you the trouble, the hand injuries and the trips to small claims court: If it’s after the early 1960’s don’t bother. You know why, transistors. And frankly, by default, I don’t hold tubes made after the 1960s with too much regard anyway. But the best mC1s I’ve ever heard came out of a mid 1950s Wurlitzer. That’s the how of it.

The why of it is that I wanted to be an archaeologist as a kid. Maybe I still do, and in a sideways kind of way, tubes scratch that itch for me. Studying them. Knowing them. Being able to determine by the most forensic of evidence who made what for who when. Like someone authenticating a painting by identifying the brush strokes of the master who painted it. That sense of discovery when you find something that was overlooked by generations of people for going on seventy-five years because to them it didn’t matter, it was history not History. Worse, it’s just nostalgia or distortion. I often read sanctimonious comments that preach with righteous vitriol about how buying old vintage gear is just buying nostalgia — like it is some kind of cardinal sin. And why is that inherently bad? Who gets to decide that for everybody else? A bunch of guys with solid state amps, chips on their shoulders and $25K record players? We buy old cars. We play old music. We make grandma’s recipes. We do those things because it helps us connect with and understand where we came from so we can see more clearly who we are and where we need to go. Nostalgia is defined by longing, an unrequited longing for something every rational part of us knows we can’t have while our emotional side finds comfort in anything that brings us closer to being able to have it -– to go back in time. Tubes make for good medicine.

The 12AX7 was born in 1949, just as we turned the corner out of a world war and into a brave new decade that brought with it a nation doubling down on being the greatest. The 1950s were a golden era — definitively, thee golden era for tube production. It was a special time. With the right kind of ears you can hear the same voices that sang along to these tubes sixty or seventy years ago singing along with them today, their voices imbued into every tube from that era. There’s a soundtrack of warmth, sweetness, joy, pride, an optimism that the world was healing and becoming a better place. Sometimes when the music stops playing before the next song begins, listen carefully and you can hear the loud silence of an entire generation sharing a collective awe at the magnificent new technology that brought a unprecedented realism of life to our relationship with the past — photography, film, music – major advancements in recording and playback allowed us to go to new places by providing a way to revisit old places and relive old lives with brilliant fidelity. Never before could we do that. How many are old enough to remember getting their first  color TV? I am, and I remember how much more alive everything felt, how much more connected I felt to what I was watching. I was more alive somehow. Tubes are unique in that they themselves glow with their own life, a life that anyone that sees them cannot help but feel in some way they breathe right back into the music. 

Tubes of this era — the 1950s are just the best, in large part because whoever was making them wanted them to be — and as such, spared no expense in making them. Cheap, efficient, economical weren’t on the menu —yet. Audio tubes are a real a cautionary tale in many ways. They started out at their peak and just started skidding downhill and couldn’t stop as more and more people got to stick their nosy little fingers in the pie to the point that what was supposed to be dessert ended up looking like something that should be exorcised and buried with protective spells in the deepest part of Earth. 

By the 1960s the acronyms began to take over. The MBAs got together and did two things; first those smarty pantsed masters of business started hacking away at tubes to make things more efficient, more economical, last longer, produced quicker, produced using cheaper parts with less labor intensive processes. And they spent just about as much time to doing that bit as they did on calculating just how much their brilliance would equate to on their bonus checks. Because that’s what they cared about, saving the company money, because the more money saved, the more they got paid. They didn’t care that short plates didn’t sound as good as long plates because what sounded good was a bigger bonus. They didn’t care that black plates cooled better and thus were more musical, because the only music then wanted to hear was the sound their checks being cashed made. They didn’t care that welded plates sounded better than rivets because what was most riveting was themselves. Me, my money and I.

And with no one looking, the transistor came along like a daisy cutter and blew everything up. Our minds want to equate progress with better, but it isn’t always that way. Progress just means you’ve moved forward. And forward doesn’t mean better, either. You could move from a turd swamp to a beach or a beach to a turd swamp and both are forward movement, by definition progress. In the chaos and frenzy for something ever newer nobody stopped to ask if it was actually better. And they didn’t notice either when the transistor snatched the life from our music, tucking it away, locked up inside a box which by any other name is a prison. At least Intel told us they did it.

Thanks for reading and have a wonderful day.

 

 

@darkblacksmoke 
Lovely, entertaining read! Agree / relate with most of that - though I am a young kid in this hobby (mid 40s) and only caught the tail end of analog tech (film, tape, CRTs) in my youth. Thanks for clarifying on the Signature II. Also don't forgot when they went from those artfully bent square and "D" getters to stamped out halos. Though the structure itself probably has no impact on sound, the earlier square / D getter variants always sound better. Also RIP triple micas and smoked glass :( 

 

@mulveling 

I agree. Nearly all of my favorite tubes have D-Foil getters. I just found a pair of code matched Valvo 45° Long Plate Getter D-Foil 12AU7 that were sold to me lumped in with a bunch of Bugle Boys because they were labeled Bugle Boys. They are excellent, wonderful tubes. Very simiilar to my Valvo mC2s.

I run GEC Triple Mica Black/Welded/Long Plate A2900s exclusively in my MC275s (both for 12ax7 and 12at7, so 7 per amp) and then I use them as my default tubes in my soon to be upgraded Mc C22 preamp. The GEC A2900 is my hands down favorite tube of all time. Nothing beats it.

 

 

 I have the rogue Apollo monoblocks which use 12 Kt88

I have 3 sets of tubes. Golden lion  Electro Harmonix Kt90 and  Kt120.

The 120 are colored in my application.

The kt90 and sharper and firm the gold lion I give the nod to good luck

I have the rogue Apollo monoblocks which use 12 Kt88

I have 3 sets of tubes. Golden lion Electro Harmonix Kt90 and Kt120.

The 120 are colored in my application.

The kt90 and sharper and firm the gold lion I give the nod to good luck

@hiend2 I’ve also used all 3 of those tubes in Apollos. Totally agree with your assessment there. EH KT90 were bright / sharp. Gold Lion KT88 was the best, and my fiend with Zeus (now he has my Apollo Darks) agreed too. The effect of power tube rolling is typically VERY clear! Tung-Sol 7581A sucked by the way. Now I feel stupid for trying it, and I still have 12 of the damn things. 

KT120 was my favorite with all of VAC’s amps, though. You could definitely say it’s a bit colored, but the way it turns out in the VAC amps really works for me lol. I can see why most prefer the GL KT88 there too. But I simply can’t understand how anyone liked KT150 in these amps.

Recently bought a matched quad of 1st generation Genalex KT88 to replace some Winged C 6550 that I thought were terrific; paid what I felt was stupid money for the Genalex (of England) but had to give them a shot given their description. The Genalex are from 1955 and came in crumbling boxes. I mean these things are OLD, lol but I have to say, two weeks into them now and I've realized the hype is real. Just a thicker, more robust sound in every way. Hard to use superlatives that havent been beaten to death but they are muscular and broody tubes that really changed the complexion of my system and I'm totally smitten by the way they play. Like realizing a new set of speakers or cartridge for the 1st time; they are impactful. I'll agree the prices on some on these old tubes is getting out of hand however in my instance, was worth the spend but, I do still believe that swapping out small signal tubes yeilds the highest level of change, in my linestge & DAC anyway. If you've got the means, and many on this site do, find a reputable tube guy, listen to what he has to offer and take the plunge. These old tubes wont be around forever and non of us are getting any younger. Just my experience 

Do power tubes affect the full freq spectrum or is it more focused on below 250 hz?

Do power tubes affect the full freq spectrum or is it more focused on below 250 hz?

Of course it is a full spectrum impact. Who is claiming otherwise, and how? If I cared most about below 250Hz, I’d run solid state.

@mulveling 

 

Maybe I should’ve said do they impact the lower frequencies more? You own interesting speakers

Maybe I should’ve said do they impact the lower frequencies more? You own interesting speakers

@emergingsoul

Ok, I see. If you are jumping between types like from KT88 to KT90 / 120 / 150 then YES, it will usually have more notable impact on bass response - but still contributes a LOT in midrange and HF too. If you are just swapping sub-brands of New Sensor tubes of the same type (e.g. KT88: Gold Lion, Mullard, EH) then the changes are a bit more subtle overall, and not disproportionately noticeable in bass. Swapping NOS versus new production (of the same type) is probably between the 2 - I don’t have experience doing this with KT88, but some with EL34.

@mulveling 

Interesting reply, thank you.  Along with incredible knowledge about tubes, you also must have incredible hearing sensitivity.  You conveyed you listen to your music very loud I hope you are appreciative of the likelihood the sensitivity will diminish rather quickly overtime. Or maybe not.

I guess since I'm using an MC 901 amplifier, changing the smaller tubes made sense, but because the solid state section of amplifier focuses on 350 and below maybe new Power tubes to replace whatever the heck is used for the stock tubes which I think is JJ may not be that meaningful. However it appears they do impact upper frequencies in a meaningful way so probably Worth doing.

I keep in mind that there is considerable value in higher priced NOS tubes because presumably they will last a heck of a lot longer, sound a lot better and hopefully the quality will hold up better overtime.

 

@immatthewj Apparently you're the only one not oblivious to the fact that OP started an identical thread to this back in February...and responses have been pretty much the same....maybe this is a test?

@emergingsoul Another excellent discussion. You folks know who you are. Thanks.

The most significant tube roll I evet did was to go from KT88’s to KT170’s. They do something magical to the bottom end and low mids. Their shape will not fit in all AMPs.

The chillaxed EL-34s don’t punch as hard but are like a first love, gone but not forgotten.

@immatthewj Apparently you're the only one not oblivious to the fact that OP started an identical thread to this back in February...and responses have been pretty much the same....maybe this is a test?

@wyoboy , I have come to the conclusion that OP's questions are not serious and that he is not interested in serious answers.  

@emergingsoul OK so you started this same discussion in February of this year--did you not like what you heard at that time?  Or did you forget?  Or were you just seeking confirmation of what was said back then?  And if the answer was different this time then what?

My thoughtful niece tells me that having Alzheimer’s can lead to a wonderful experience of being able to watch really great movies over and over again.

Of course when she drops me off in the middle of nowhere or in a shopping mall I wonder why.

Yes very important also important is coupling capacitor(s) for cleaner sound quality of the amp

Right out of the Mc 901 manual:  

The MC901 will function optimally with any correct tube type that is functioning within the design specifications of the MC901. Only when a Tube falls outside of the acceptable range will any diminishing of performance be heard. Because McIntosh Tube Amplifiers are engineered to use Tubes in a way that does not rely on the Tube’s individual character and can perform perfectly provided the specifications are met, there is no advantage to seeking out expensive esoteric tubes.

"Because McIntosh Tube Amplifiers are engineered to use Tubes in a way that does not rely on the Tube’s individual character and can perform perfectly provided the specifications are met, there is no advantage to seeking out expensive esoteric tubes"

I don't have these amps but he already stated that he changed the signal tubes and the sound improved , aka the character of the tubes came through, so why wouldn’t that also occur with the power tubes? I’m not aware of any tube amp, or other tube component where the character of the tubes doesn’t come through. I presently have 3 tube integrated amps, had a couple of others previously, and have a tube DAC  whether it's the signal tubes, power tubes or rectifiers they all impact the sound in the respective  sound. All their statement reads to me is marketing hype.

Or a way to justify them installing mediocre tubes with their amplifiers. Somehow commentary in manual does them less good service because having the ability to modify sound using different tubes is an important feature and why someone buys a tube amplifier.

What did they do that prevents a tube character from coming through? Is this a good thing?

Well that is a perplexing concept… engineered in a way to prevent the tube character coming through. The only way I can think of doing that is to just power them but not put them in the audio circuitry… so, make them for show only. 

I've heard that before - various incarnations of "rolling tubes in this slot won't affect the sound", because "they're cathode followers with 100% feedback" etc. Still haven't met a slot that doesn't affect the sound. It's directly in the audio path.

You can have components that are "voiced" for the specific tubes it ships with. Sometimes components have a strong voicing on their own. In these cases, tube rolling may not readily yield satisfying results - but it WILL affect the sound. Always. Now is it a useful endeavor; a good use of time & money? That's for you to decide.

It's not surprising some manufacturers would discourage rolling. When you owe warranty support on these heavy, complex amps - do you really want users rolling them with power tubes willy-nilly, from unknown sources and questionable matching? Plus they may sell their own branded (labeled) replacement tubes, at healthy markup. 

"In the chaos and frenzy for something ever newer nobody stopped to ask if it was actually better."

It's better in a lot of ways but some of them are not related to the sound of the audio output.

Do any tube sellers match tubes at real world plate voltage and current under load?

I'm sure Jesse does. This is the greatest place to buy tubes in the entire whole wide world

I'm sure Jesse does. This is the greatest place to buy tubes in the entire whole wide world.

I sure he's good, but unless he knows what gear you are using, how does he know what the tubes will be operating at?