Tube question


I'm new to tubes, but there is a couple of things (well more than a couple, but for now): Why, with all of our modern technology, is it that we cannot make a tube with the sound quality of the ones in the late 50s to early 70s. What was it about that time, that we cannot seem to duplicate that quality today. I never, when hearing the scoop about great tubes, hear any new tube manufacturers being mentioned. Are there Chinese, Russian, American or the like, companies making very high quality sounding and constructed tubes? thanks in advance. warren
128x128warrenh
The key is the demand. Back before the transistor became popular, tubes were used in many more applications than just high end audio. There was a lot more uses and demand for 6DJ8's, 12AX7's, 6SN7's etc. back in the 40's/50's/60's than there is today.

John
Back in the old days, when tubes were in everything, there were a number of tube manufacturers that built tubes of all kinds, for types of applications. Because of this, tube manufacturers could easily build a specific flavor of a tube number to match the requirements of the device builder or customer, such as the military. Now that low power tubes are considered obsolete for the most part, the existence of a number high-quality tube manufacturing plants is simply not cost justifiable anymore. Tubes are such a specialty item, practically no one these days is willing to invest the big money to start a plant to build low-power tubes that will be sold only to a very limited audiophile market. For that reason, that orange label Amperex 6DJ8 that now sells for whatever the market will bring, used to sell for about $2.50 each back when tubes were in everything from car radios to TVs to broadcast equipment to test equipment. The reason you still see new Russian tubes being made is because the USSR used tube electronics long after the rest of the world went solid state.
Warren, the Penta/Shuguang KT88SC is as good an '88 as anyone has ever made, according to LOTS of folk, so now you've heard about an excellent current-production tube. Western Electric is currently manufacturing excellent 300Bs, KT88s, and others, but high quality is expensive--the 300B is $550 and the '88 is $350!!!!!!! http://www.westernelectric.com/pricing.asp

But things usually work the other way. After rejecting an entire production batch and being out of stock for a while, GrooveTube has those great-sounding 12AX7Ms again, but they're NOT great-sounding or well constructed this time. Read about it on the Tubes Asylum, http://www.audioasylum.com/audio/tubes/messages/188228.html .

Unclejeff is correct too. But there are other reasons, the principal one being costs. It costs a lot of money to, for instance, duplicate the esoteric material combinations and the excellent vacuum pumping used in decades past. Occasionally the Russians or Chinese get it right; the Serbians (Croations?) at Ei got it right for years, but they're now out of the tube business.

Oh well. My 'solution' is to use NP 845s because old ones are frightfully expensive, to keep all the great-sounding Ken-Rad 6SN7s I have, and to continue buying carefully the world's best-sounding 'N7, the Tung-Sol roundplate.
.
[Why, with all of our modern technology, is it that we cannot make a tube with the sound quality of the ones in the late 50s to early 70s. What was it about that time, that we cannot seem to duplicate that quality today.]Materials used,manufacturing techniques? Can anyone answer that question?
It's also about perception, which is hard to look past. If everyone says the old tubes sound better than the new ones, then people who are thinking about making new tubes are in a hole even before they start. In the audio world logic, the higher the price, the better sound; the older the tube the better it's made.

Companies such as CAT, ARC, Berning, Cary, etc., put out excellent products without a single NOS tube. Simple reason is that NOS tubes are inconsistant in quality and unpredictable in supply - the death knell of a manufacturer. Tighter tolerances and quality control cause these guys to throw out tubes that beat their NOS thousand-dollar-a-pair-on-ebay counterparts.

The quality tubes are there, but they come packaged with the rest of the product as they are an intergral part of the sound.