My Tube Collection, Welcome to share yours
- Thread starter adrian cheng
- Start date
What would you guess is in these boxes? RCA 6922?
Upon closer inspection .... Siemens 6922.
Upon closer inspection .... Siemens 6922.
I am beginning to think that vacuum tube production was a conspiracy and that there was only one manufacturing facility but multiple companies applying their own labels.
Well, too many well known tubes, I need to bring again equilibrium to the universe.
Here we have some STC 5B/254M beam tetrodes with 5A/152M pentodes. Excellent sounding all of them. They are in their adapters, tetrodes towards 6V6 used in my amp output stage while the pentodes are towards 6J5 in my input stage.
And here we have some Eindhoven made double beam tetrodes QQE03/12.
These are also very good but I have to use these with both sections in parallel, towards 6V6 in my amp.
I love all these. Since my photos are not very good I'll add some detailed ones.
Here we have some STC 5B/254M beam tetrodes with 5A/152M pentodes. Excellent sounding all of them. They are in their adapters, tetrodes towards 6V6 used in my amp output stage while the pentodes are towards 6J5 in my input stage.
And here we have some Eindhoven made double beam tetrodes QQE03/12.
These are also very good but I have to use these with both sections in parallel, towards 6V6 in my amp.
I love all these. Since my photos are not very good I'll add some detailed ones.
Yes, Andy color codes in four categories with blue the quietest, then green, red/green, and red. Regardless of the noise grading, his tubes are always the quietest. A couple decades ago, I was able to get some of his time to test, sort and grade some of the tubes I had acquired from other sources. That really helped me get better performance from my amp and especially the phono stage.
Miniature tubes have the paint on the tip, octals on the base. He also marks the boxes. It is great for quickly identifying the tube grade, but not so great for collector that wants a pristine tube and box.
Andy also gets the pins remarkably clean.
Blue grade. The four on the right were sorted/graded by Andy. The two on the left were not. I can't get the pins as clean as he does.
From Vintage Tube Services web site. The noise grading is microphonics. This shows the suitability of the tube for various circuit applications. He also notes: "I know that no one else is doing any serious noise measurements on glass mini tubes because you CAN'T until you clean the pins! You cannot get a good enough connection to the tube with all that scale in the way to even check the noise floor!"
| Red | = | LOW Mic. LINE level tube | 100 X |
| Red-Green | = | VERY LOW Mic. SUPER-LINE level tube | 1,000 X |
| Green | = | VERY VERY LOW Mic. Moving Magnet PHONO input | 10,000 X |
| Blue | = | ULTRA LOW Mic. Moving Coil PHONO input tube | 100,000 X |
These are blue, green, red/green and red coded on the box (on the tube too):
Other examples on the tube:
These have me guessing. They were sold as Amperex ECC88. But, the tags in the tube look like Tungsram. I did not find any of the usual Philips tube codes etched in the glass.
Tungsram?
Actual Tungsram ECC88 for comparison:
Tungsram?
Actual Tungsram ECC88 for comparison:
I may not be an ECC88 user but that looks like a tungsram tag on the getter.
Yes, the flat getter support is an indication for me that it's a Tungsram Hungary one. I have seen similar tags on Telam/Polam tubes. For example Telam EL86.
Similar threads
 | Steve Williams Site Founder | Site Owner | Administrator |  | Ron Resnick Site Owner | Administrator |  | Julian (The Fixer) Website Build | Marketing Managersing |