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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.
phaelon
jaffeassc
166 posts
 
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
sugarbrie
3,854 posts
 
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.
phaelon OP
1,049 posts
 
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.
phaelon OP
1,049 posts
 
"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.
sugarbrie
3,854 posts
 
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.
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