Is upgrading stock tubes standard proceedure?

I'm just wondering if I'm the last guy to realize just how enormous an improvement can be had by upgrading stock tubes to NOS. Most of my system has been in place for some time now and I've sought to improve it's performance by tweaking. Tube changes have resulted in noticeable but subtle results; most of the time involving trade-offs... until now. I just upgraded the 6922s in my cj Premier 17LS to Amperex 6DJ8s with stunning results. I can't find any trade-offs, everything desirable in audio is improved IMHO. This is the kind of improvement I would have been looking for if I bought a new preamp and spent twice the money. As much as I've read about tube rolling, based on what I'm experiencing now, there isn't enough emphasis, especially by professional reviewers.

So, I guess my purpose in writing this thread is two fold:

1) Why don't tubes receive at least the same attention as the equipment they're in.

2) Just a heads-up in case there is anyone else out there who thinks they can't justify $100 or more for a small tube.
I would say so. Most so called audiohiles are addicted to buying equipment and very expensive equipment at that. They would be willing to spend thousands of dollars at a drop of a hat but when you ask them what tubes are you using or have tried, they only have stock tubes and havent even tried vintage tubes because they say it's to expensive but will go out and and just go in a never ending equipment hunt hoping the magic component falls in their lap. In my experience, price has nothing to do with how good your system sounds, but by experience and by not disregarding all the tweeks big and very small. I too had to learn the hard way. Just my opinion.
Speaking for myself :-) that's why I have probably $10,000 worth of tubes,(2 drawers full) of different tubes. They sound different in different gear, so you should always keep a good stash. Some NOS brands and types are getting VERY hard to find.
1) Why don't tubes receive at least the same attention as the equipment they're in.

I don't agree with this premise. Most tube equipment owners give tubes a great deal of attention.

2) Just a heads-up in case there is anyone else out there who thinks they can't justify $100 or more for a small tube.
Phaelon (Threads | Answers)

That's a good heads up.
Up grading (changing) your systems sound by changing tubes is fundamental and I think understood by most folks who venture into tubes today. It is not my intent to rain on your parade but I think your enthusiasm should be tempered a tad.

IMHO the assumption that using NOS tubes is the only way to effectively tune a component or system is fallacious. There are numerous excellent new production tubes available which will meet the needs of many tube users. And they are easy to research, obtain, and usually cheap, so when your tastes don't coincide with those of folks who recommended them, you won't be out much money. This is especially true of power tubes but often some new production small tubes will serve quite well. It all depends on system resolution, balance, and the degree of listening skills/interest.

Whereas buying NOS tubes, which are most often anything but NEW old stock (unusued tubes that is) can be a major hassle and introduce you to the dark side of internet tube sales.

Even when working with a reputable dealer of old tubes, unless he is clairvoyant, or just happens to understand the sonics of your system or your desires, his recommendations will be generic and optomistic. Just read all of the requests for assistance in purchasing different tubes from users which are devoid of information sufficient to guage their needs. Now note all of the folks willing to recommend all of the great NOS tubes that will assuredly serve them well.

Doesn't make much difference when you are talking about $10 to $25 per tube but when you are talking about some excellent Amperex or Siemans, Tele's or Mullards, you had better have a lot of money for tubes and KNOW what you need before you buy.

Like Mofimadness I have a large stash of old tubes but I can assure you I didn't buy them just to have a stash, hord, or resale. They are tubes I bought for use that didn't sound quite right when I actually plugged them in. I'm saving them, confident that their time will come. They include some $200 a pair true NOS Amperex's and Siemans. I'm sure Mofimadness has his gems as well. :-)

IMHO NOS tube acquisition is not for the tube newbie unless they also enjoy buying expensive wire without being able to return for exchange or refund.

I have a simple ARC vs-i55 and changed out the stock tubes. 20 percent improvement! Others may say 20 percent loss. Who know but give it a try.
The glory of tube gear is that you can alter the sound with all the different brands of tubes to choose from, each brand having it's own sonic signature.
Hi Newbee,
If my elation suggested that I believe that my first significant move to one of the classic NOS tubes resulted in the ideal selection, that was not my intention. However, the improvement from my previous Sovtek and Electro Harmonix 6922s shouldn't be trivialized by comparing it to a change in tone control. With all due respect to the subjectivity involved in tube choices, sometimes better is better and what I'm hearing is way better. I'm now hearing musical detail that was formerly obscured; instruments and voices are both more natural and nuanced. I have no doubt that more experienced guys like you, Tvad, and Mofimadness could introduce me to a dozen or more tubes that would challenge my listening skills. That said, I am encouraging people, like myself, who have a piece of equipment that retailed for $4000 and came equipped with $40 worth of tubes to investigate a change in those tubes. I think you might be surprised by the number of people, as T2232 suggested, who upgrade components to realize improvements when a change in tubes would suffice. Many audiophiles put their faith in dealers and audio publications and I've never walked into a dealership and been advised to change tubes instead of components.
Phaelon, for what it's worth, I've been doing this for a lot of years and agree 100% with your comments.

Without NOS tubes, my system would take a huge hit in performance.

As you say, not just a tonal balance or preference thing, the right NOS tubes make the equipment perform better in every way.
many current-production tube components have circuits which are not tube sensitive. i have encountered many examples of this phenomenon. in such cases, replacing stock tubes is not beneficial.
Back in the day I remember going to a vintage radio collector and repair man for vacuum tubes .

There was no such thing as tube dealers, unheard of.
I don't think you can blame dealers for not recommending NOS tubes. Dealers need to be able to offer products that are in ready supply, and that are consistent in their performance. NOS tubes are neither. It's why manufacturers supply only new production tubes. There simply isn't a sufficient supply of reliable NOS tubes.

NOS tubes are quickly becoming extinct. Available to only deep-pocket audiophiles.

Fortunately, there are companies that make excellent use of new production tubes. VAC, ARC, Conrad Johnson and Atma-Sphere come immediately to mind.
I own a CJ CT6 and have also found that there is a significant improvement by changing the stock tubes. I have tried both Amperex and Siemens with excellent results. It’s also interesting to note that in the CJ Owner’s Manual under Vacuum Tube Replacement they make the following statement when speaking of the stock tubes supplied with the unit.

“We know of no vacuum tubes available which will improve the sonic performance of your CT.”

Just not so, IMO
Gear makers need to have consistency. Every unit they sell should sound the same. So they are going to use a tube that there is an ample supply available. Conrad Johnson does use good tubes and they make an effort to test and match them. There is nothing wrong with using the stock tubes. If you ruin your brand new $5,000 - $10,000 piece of gear fiddling inside the case, you can forget about the factory warranty.

The biggest variation in sound is with simple tube gear. There is not a lot of circuitry, so in many cases you are actually listening to the tube itself. In more complex gear, changing tubes is more of a tweek.

Changing tubes will definitely make it sound different. Better is in the ears of the beholder. Since there will be no agreement on which brand of NOS tube is better for any particular piece of gear, then it really comes down to personal taste.

Once I find a brand of tube I like for a particular piece of gear, I almost never change which tube I use after that. Some people like to tinker.
Assuming that high quality tube design is not a lost art, perhaps they're just not profitable to manufacture at this time, given the current supply of NOS tubes they would be competing with. Forgive me for seeking the silver lining, but man, I don't want to go back.
"Conrad Johnson does use good tubes and they make an effort to test and match them. There is nothing wrong with using the stock tubes."

I agree Sugarbrie, in the same way that I would agree that there is nothing wrong with the standard quality tires one finds on everyday cars. But if you own an ultra high performance car, and ever want to experience its capabilities, tire selection will be critical. The more I think about it, the more it seems to me, that the relationship between tires and race car, have a lot in common with the relationship between tubes and component.
I am with you Phaelon. After all, I do change the tubes myself. And yes, I do have better tires on my Audi. I even upgraded the T tires to H tires on our old Camry when the T's wore out.

The language manufacturers put in their owners manuals is just CYA to put us on notice that they do not warrant owners opening the case (during the warranty period at least). They all know we are going to roll tubes. I'll bet even Bill Conrad and Lew Johnson changed out the tubes at home.

We were discussing the Blue Circle DAR Hybrid Integrated amplifier with Gilbert Yeung at RMAF in October. He offered a customer to make one custom with the tube mounted upright though a hole in the case, so the tube could be swapped without having to keep opening the case.
There are lethal voltages present even well unplugged in some components, safety comes first!
Manufactures are well aware how careless some people can be.

For sure some equiptment respond favorably to select vintage brands of vacuum tubes however some do not as Tvad and Mrtennis point out.
They know what they are talking about...

There are a few modern companies that take the time and use the quality of materials that made MOST of the NOS tubes so good. The vast majority of those manufacturing tubes currently, are doing so strictly for fast profit, cut corners anywhere and everywhere they can, and their tubes sound like it. I got back into tubed gear/NOS tubes 18 years ago. I've yet to find a piece of equipment that did not sound more like live music with the right NOS tube upgrade. Here's a list of the companies that are producing tubes that can compete sonically and quality wise with the old stuff. Price some of the pieces and get an idea of the cost of quality manufacturing nowdays:(h ( ( If the signal passes through a tube, it WILL affect it's sound. There's no such thing as a tubed circuit that is not "tube sensitive", in this regard(the tube being the most "active" component in the circuit). Even the rectifier will have a sonic effect on the sound of most tubed equipment, although it's not directly in the signal path.
An extra "H" got in that first URL. Here's a correction: (
I just place my order for these two tubes Mullard CV4004/12AX7 to be used in my VTL 7.5 preamp. I heard noting but good things about these tubes... I view purchasing NOS tubes like purchasing a rare wine some may like it and others may not.
many current-production tube components have circuits which are not tube sensitive. i have encountered many examples of this phenomenon. in such cases, replacing stock tubes is not beneficial.
Going from one tube to another does not guarantee an audibly detected change. The two tubes could have very similar sonic properties. Or the overall system is dimensionally flat to not allow for one tube's refinement to shine over the other.

If you go to the extreme and try for example, a premium Valvo or Amperex pinched waist tube, and compare it to something like Sovtek or Electro-Harmonix, even the most compromised tube design will show this difference instantly. The comparison may result in nearly the same tonality but dynamic contrasts, ambiance and decays of the NOS are significant compared to the newer manufactured tubes. And no, I am not talking about "warmth". The newer stock tubes also tend to sound forward and fatiguing (edgy) compared to the far more smooth and natural result of the NOS tubes.

If the signal passes through a tube, it WILL affect it's sound. There's no such thing as a tubed circuit that is not "tube sensitive", in this regard(the tube being the most "active" component in the circuit).
mcintosh claims that changing tubes will not change the sound of an amp or preamp. i can confirm that when i auditioned and reviewed the c220 preamp.

whatever differences existed were so small as to be insignificant.

the bat vk d5 cd player is another component which does not change its presentation when changing tubes.

the eastern electric mini max cd player is yet another component who's sound did not change when replacing the tubes.
I've owned a BAT VK-D5 for the past 6 years, and the sound has changed markedly(although it's never sounded disappointing) with various tubes I've had in it(no simultanious system changes)!! That's exactly why I won't have it upgraded to the SE version(no tube rolling possible). I've got six Siemens CCa's(NOS two years ago) in it right now, and it's never sounded as lucid, accurate, open and with as much bass definition, extension and slam as it has with them. A system has to be able to resolve the changes that will be manifested by a tube swap in whatever component, and your ears have to be able to recognize/appreciate the differences. I've heard other manufacturers make unreasonable claims to dissuade people from experimenting with designs that they think are flawless. Probably lest the owner find out it can be improved upon.
Rodman99999, Sometimes I think Mr T is just being silly. Of course you can hear the sound of different tubes in the BAT. I do in mine, but I'll cede this to him, I don't hear near as much difference in the BAT as I do in my Raysonic where I think tube choice is critical. I have on one of the originals as well and have not had it upgraded. Very nice CDP I think. It does benefit from tubes with great clarity, as your Siemans. I tried some Bugleboys and it was a bit warm and fuzzy. Probably OK for someone looking for an antidote for a clinical system. :-)
Newbee- I've really been happy with my BAT since day one, and wouldn't trade it for anything but maybe the right Lector, or a Linn CD-12(yeah right!). The tubes are in a buffer circuit and, Yes- the piece can be flavored per someone's tastes. Personally: I've been striving for that last drop of transparency, ambience retrieval, bottom extention and definition. Between the tubes, and now a simple, home grown isolation system, I'm very satisfied. Kimber's KS-1130's didn't hurt anything either.
Generally speaking, it does not make sense for manufacturers to use anything but readily available current production tubes. First, they must be assured of adequate supplies for continued production as well as supplying customers with replacement tubes. Also, because each customer's system is different, and each customer has a different particular taste, a change in tube may not necessarily be better; so, why put a LOT of money into NOS tubes that may not be appreciated by the customer?

I know a lot of manufacturers don't encourage experimentation with different tubes. That is understandable given the sort of trouble inexperienced (or not-so-bright) customers can get into. Some supposedly "drop-in" alternatives for some types of tubes may really not be compatible in the particular circuit design even though the customer had no problem with making a similar switch in another component.

If the choice of tubes made by the manufacturer turns out to match YOUR own "ideal," that would be pure luck. Besides, you could not possibly know this without doing some experimentation. I own a pair of amplifiers that actually comes from the manufacturer with NOS tubes that are not cheap: RCA 5692 red base small signal tube, RCA double-plate 2a3s. I've talked to the manufacturer and he agrees that, even by his own personal taste, these are not the "ideal" tubes. He thought that NOS single-plate 2a3s sound better. But, they are very hard to obtain in near-new condition and are crazy expensive (about $2,000 a pair in decent condition, and I would need two pairs). It's not hard to see why the manufacturer would not consider supplying this amplifier with the "best" tube.

Are there current production tubes that sound as good or better than the best NOS? I don't know. I currently run EML meshplate 2a3s in my amp and like them MUCH more than the stock RCA double-plates. But, I have not had the chance to hear NOS single-plates in my amp. As for some other tube types, in my system, I have not found any current production tubes that I really like: for 6sn7s I like old Tungsol round-plates or the French Neotrons (copies of Tungsol round-plates); for 12AX7s I like Telefunken ECC83 or ECC803S.
Mr L- I've got a pair of the TungSol round plates, and a pair of Sylvania 6SN7W(tall bottle) in my Carys. Rest assured: You won't find anything current that can come close(or anything better, NOS). From that and the choice of Teles- You must appreciate an un-colored presentation of your music. I can understand the manufacturers having to use current production. Especially with the cost/lack of consistant supply of NOS tubes. Have you seen these?: (
How long does it take NOS tubes to break in?
A few hours, perhaps 10, at the most.

Dave Mitchell posted the following and he is spot on. It is quite excellent in its explanation:

07-26-07: Davemitchell
The answer depends upon whether you are referring to the tubes themselves or an entire tube-based circuit.

First, lets clarify that the popular term burn-in really refers to forming dielectrics. This is where electrons find and groove a path of least resistance through the insulation materials surrounding the conductors. Dielectrics (teflon, polyethylene, glass epoxy boards, etc...) act as an impediments or road blocks to the free flow of a signal.

The actual vacuum tubes themselves require little or no burn-in because they have so little dielectric material to form in the first place. The conducting elements are surrounded primarily by a nearly perfect vacuum, which is a superior dielectric to all others including air.

Tube circuits like all circuits which contain capacitors, resistors, wire and circuit traces, require significant burn-in because all of those passive parts contain all kinds of plastic dielectrics which need to form to sound best.
Thanks a lot this is very good info.
The NOS Mullards 12AX7 just awakened my sleeping giant, my VTL 7.5 preamp never sound so good.

I just purchased another set of NOS Mullards 12AX7 & (1) GE 5751 for the phono stage of my CJ PV-12. With all of the recent modifications I had completed to the phono stage the CJ will rock even more. :O)
While it is true that McIntosh amps don't show as much improvement when changing power cords, I beg to differ on tubes.

My McIntosh 2102 amps do embrace NOS tubes and yes it does show...perhaps not as much as with my Audio Aero Capitole amp, but anyone still running the stock Chinese Tubes with this amp needs to go shopping for NOS.
Hi Jmo,
Who did your mods?
Boy I wouldn't have thought that a NOS tube could make a difference but now I have found religion.

My expience with a Monarchy NM24 that has had some very favorable reviews. They come with some Phillips military spec NOS.....not bad and for a reasonable cost...a good choice. I just thought I would try to improve the sound and puchased some NOS tubes.

Amperex Holland bugle boys 1960's
Amperex 7308 USA PQ's
1950 D getter Amperex
and another early Phillips NOS

The difference between all was a eye-opener and the winner by a mile was the D-getter followed by the BB's although not nearly as open....The 7308 PQ's were good but 3rd and the Phiilips 4th.

In the Monarchy the D-getter was a relevation and if the stock tubes get good guess is current production standards are what they used to be and that is sad because there's got to be a market as NOS tubes just keep going up. Alas like all good things.

And another observation.....the D-getter Monarchy gets blown into the weeds by my newly upgraded Accuphase C200 manufactured in 1975-76 go figure.

06-17-08: Wavetrader
Boy I wouldn't have thought that a NOS tube could make a difference but now I have found religion.


Bob & Gary Backert RHB Sound Dezign. Bob is an awesome guy.

With the addition of the the 12AX7 Mullards NOS tubes & GE 5751 the CJ PV-12 phono stage is sweeter then before. The NOS tubes I purchased were the icing on the cake.