Why did I wait?

[usc96]

I just replaced the GT tubes in my deluxe reverb ri to NOS JAN tubes. Night and day difference. Much fuller sound. Why the difference? I mean is our technology truly getting worse as time progresses and that's why the old tubes sould that much better?

It sounds like a different amp. :crazyguy

[phsyconoodler]

Not necessarily.It may just be your tubes were not great.Try a set of JJ's or TAD's.And do bias them properly as well.
The factory tubes are less than stellar.

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Where the weather ain't so nice

[John Phillips]

I just replaced the GT tubes in my deluxe reverb ri to NOS JAN tubes. Night and day difference. Much fuller sound. Why the difference? I mean is our technology truly getting worse as time progresses and that's why the old tubes sould that much better?Yes. The manufacturing quality and expertise that was put into tube production up until the early 80s was far superior to today.

The reason is very simple - back in the 50s and 60s, tubes were state-of-the-art technology and were used in critical applications such as avionics and other military systems, medical and industrial control, and other applications when quality was the first requirement, and the best engineers worked on them. The military continued using them up until near the end of the Cold War, because tubes are immune to the electromagnetic pulse of a nuclear explosion, and transistors aren't...

(An interesting political aside here is that the military must have known that the Cold War was over before it 'officially' ended, since tube production in the West stopped in the early 80s, not in '89.)

So the factories that made tubes were set up for quality first, cost second, and all the tubes were made basically the same way, including those with less critical requirements - although many of them were the same types anyway... which is why you get JAN (Joint Army Navy) and CV (British military) amplifier tubes. Huge quantities of tubes were made, and the audio industry was a fairly minor customer. That's why there are still stocks of NOS tubes being found - far more tubes were made than were needed just for guitar amps.

Nowadays, tubes are purely for music and hi-fi, so far fewer are being made, the prime consideration is cost, and they simply aren't built to anything like the same quality. There is no need - no-one will die if a guitar amp tube fails. The lower quality isn't just in the failure rates, it's in the basic electronic performance as well - not just tone, if you measure the power output of an amp it will usually be higher with old-production tubes - but it certainly is audible too... the basic quality of the tone is higher, right across all combinations of gain and EQ.

Welcome to the club of those who can hear it :).

[SatelliteAmps]

Just to throw a my two cents into the ring. I will also say that the actual metals being used inside the tubes are slightly different than what was used before. And this does make an audible difference.

It's the same issue as why Alnico speaker magnets sound different. There are different metals and compositions to make the magnet.

I will also argue about tubes being made purely for music & hi-fi. Our military still uses tubes. As does Russia, and China. There is so much tube based equipment still in use it is ridiculous. Most of the tubes are not made for hi-fi audio, but for transmitter, radio, and test gear. Russian MiG planes still use tubes in their radio systems. Scary.

To me, a lot of the lower quality tubes is also because they can. The tubes work, and so the companies that make and sell them do so, without regard as to whether they can make them better. They call them "Mullard reissues" knowing it will sell, without worrying that they don't sound like Mullards (or Gold Lions, or Tung-Sols, or any other re-labeled or vintage hyped brand name). People that know the difference won't buy the hyped versions. I personally despise all of the new versions of the old brands.

That's just my opinion though.

[PRNDL]

I just replaced the GT tubes in my deluxe reverb ri to NOS JAN tubes. Night and day difference. Much fuller sound. Why the difference? I mean is our technology truly getting worse as time progresses and that's why the old tubes sould that much better? It sounds like a different amp.

There are several issues to consider:
- tube quality (mentioned above)
- tube matching
- tube age (wear, damage)
- bias

Although GT's are factory matched, many techs find that they aren't very close when tested in the actual amp. Most tubes become mismatched with use.

Each tube manufacturer has a unique sound that is characteristic. Switching preamp and output tubes will change the tone of the amp from country to blues to rock.

You may have a preference for the tone from the JAN's, which is more of a vintage sound.
Do you believe that some new bands have bad tone from their tube amps? If so, it may be they're used to the sound from newer tubes.

Bias has a huge influence on sound. Many techs argue that articles on the web recommend way too much bias current, which may explain why tubes don't last. Some vintage tubes (usually military spec) were made to handle higher bias loads, but very few new tubes can handle it. If your GTs were biased hot, they wouldn't last long, and the tone would suffer.