Why do old tubes sound better than current tubes?


just wondering, is there something in the design, materials, or fabrication that makes old tubes sound better than those being currently produced?

it seems nearly universally held that old tubes are superior sounding to those made today - is there something specific about the old tubes that make then sound better?

-Scott
128x128srosenberg
Hi all, I do believe that the overall voicing of the system or the component and related things (cables, cartridges, etc.), all help set the stage for what tube or tubes will sound better. In my current system with my new phono stage, Fosgate Signature and Lyra Lydian Beta cartridge, I've found that two JJ Gold Pin 6922 tubes, sound wonderful. I am also using a mix of one JJ Gold Pin 12AX7 (ECC803 S) followed by one electro-harmonix 12AX7 Gold pin, then one NOS Mullard CV4024 (12AT7),and finally one electro-harmonix 12AT7. I love what I hear.

I tried using NOS Sylvania 6922 and NOS Sylvania 12AX7 as well as Mullard 12AX7 remakes, Sovtek 12AX7LPS, and of course the tubes supplied with the unit, all were less than desirable or even awful. For what it's worth I have discovered that with phono stage tubes it's worth paying extra for low noise and microphonics. So at least with this application it seems that for the most part, current production tubes out perform NOS tubes.
When folks are making $$$$ finding pulled tubes from old TV shops and where ever they of course will say the best. I heard several new tubes that sounded better, some of the NOS tubes can have a warmth to them, but dynamics just are not there or tight bass, also the NSO can go to the other side and side bright and lacking mid-bass/bass.

In the end it is system depended and what you enjoy. I just ordered a set of the ECC83 Gold Lion reissues and I am looking forward to seeing what is what with them.

Will newer tubes last as long as Tele's who knows, but if they sound better who cares, just stock up on them. My friends had his stock McIntosh tubes in his preamp for several years and he says still going strong.

So myth vs. fact. Like LP's always sounding good, just not true.
Vacuum tubes require, as should be obvious in their name, vacuum. Over the years, vacuum tube manufacturers and suppliers have turned to lower quality vacuum to cut costs. The high-quality vacuum supply is harder and more expensive to acquire.

As vacuum was mined, the easily reached sources of good quality vacuum (near the surface) were quickly exhausted leaving only more expensive and dangerous mining operations as the only source. As a result of several large and devastating mine implosions the larger vacuum mines that produced good quality vacuum were closed leaving only small boutique vacuum mines to supply the vacuum. Often, this vacuum contains impurities that must be removed (by what else than a vacuum cleaner!).

In the mid-80s, the Russian Kamakiskorvitchski brothers (Kamis for short) had a corner on the vacuum market. They had several tanker cars on a railroad siding in Siberia that contained most of the high-quality liquified vacuum available at the time. They carefully supplied only the Soviet and Eastern Block tube manufacturers with the high quality vacuum. Some smaller tube manufacturers were forced to use counterfeit vacuum containing large amounts of impurities. Again this vacuum needed cleaning.

Unfortunately, the supply of good quality vacuum has dried up in recent years. Only the older tubes still used high quality vacuum in their manufacture, but some tubes of the same era used counterfeit vacuum.

So one must be careful. Check your tubes and don't forget to use your vacuum cleaner.