Hi all!
I've almost always bought known, identified, tested tubes from reputable buyers, and avoided the lure of the "huge box of mystery tubes".
But yesterday, I came across a giant collection of tubes which seemed NOT to come from a TV repairman, or Soviet MIG engineer, but a guy who collected audio tubes! So I bought them all -- THOUSANDS of them.
I've started going through them and one of the first things I've come across are some Telefunken tubes that could be ECC81/ECC82/ECC83 tubes, but have all the writing rubbed off.
I'm hoping you can help me identify these, and in general help me figure out:
1) How do you know when a tube is an ECC81/ECC82/ECC83?
2) How can you tell (without a tube tester) which of those it is?
Type #1
Four tubes all alike:
- Halo getter
- Smooth plates
- 2 mica
- Diamond with one or two numbers stamped into the bottom
Type #2 - Same as type #1, but almost clear top
Type #3 - Same as type #1, but ribbed plates
Type #4 - An oddball short plates & elaborate structure above the plates. Probably not an ECC81/82/83
Thank you!
I've almost always bought known, identified, tested tubes from reputable buyers, and avoided the lure of the "huge box of mystery tubes".
But yesterday, I came across a giant collection of tubes which seemed NOT to come from a TV repairman, or Soviet MIG engineer, but a guy who collected audio tubes! So I bought them all -- THOUSANDS of them.
I've started going through them and one of the first things I've come across are some Telefunken tubes that could be ECC81/ECC82/ECC83 tubes, but have all the writing rubbed off.
I'm hoping you can help me identify these, and in general help me figure out:
1) How do you know when a tube is an ECC81/ECC82/ECC83?
2) How can you tell (without a tube tester) which of those it is?
Type #1
Four tubes all alike:
- Halo getter
- Smooth plates
- 2 mica
- Diamond with one or two numbers stamped into the bottom
Type #2 - Same as type #1, but almost clear top
Type #3 - Same as type #1, but ribbed plates
Type #4 - An oddball short plates & elaborate structure above the plates. Probably not an ECC81/82/83
Thank you!
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I would build a simple test jig and look at the gain of each tube. Compare against a known sample. Supposedly the pitch of the grid wires can be used but I never looked that closely.
Those all look like telefunkens, just put them in the box, no need to test unless you are planning on resale.
#4 could be ECC88/189 or PCC88/189
1 through 3 are either ECC82 or 83. ECC81/12AT7 has much smaller plates.
If they have a diamond between the pins, they are most certainly TFK if they dont and they have four seams on the top they are most certainly EI.
#4 could be ECC88/189 or PCC88/189
1 through 3 are either ECC82 or 83. ECC81/12AT7 has much smaller plates.
If they have a diamond between the pins, they are most certainly TFK if they dont and they have four seams on the top they are most certainly EI.
Yes, I pulled out all the ones with diamonds on the bottom, and that's the only ones I've mentioned in this post.
I have a whole other box full of marks-rubbed-off 12A*7 tubes, and I worry that there Mullards or who knows what in there!
I have a whole other box full of marks-rubbed-off 12A*7 tubes, and I worry that there Mullards or who knows what in there!
Mullard was just a British Philips plant, nothing more, nothing less. Their tubes were made on Philips machines to identical specs to those made by Philips/Valvo and what have you. A Mullard branded tube may have been made in the Netherlands, and vice versa. A Philips will likely be made on duplicate machines of those used by Mullard.
All Philips plants etched a little code on the side of the glass, the Latin alphabet was exhausted for different plant codes, and Greek was used as well...
Attached a photo of what a ECC82 or ECC83 made by one of the Philips plants looks like, there was an earlier version that has long plates but rare.
The way you can see Philips/Mullard/Valvo tubes at first glance are the four seams at the top. However some equiptment was exported to Hungary and Yugoslavia in the 80's. However those use the same copper coloured lead in wires as all the comb block tubes.
There just tubes, Philips made some good stuff, so did Telefunken but in the end of the day these cannot hold a candle quality wise to some of the professional gold pin series.
If you go on youtube and look for "The mullard story" it is said in passing that Mullard was part of the Philips organisation.
Philips had three or four plants in the Netherlands.
All Philips plants etched a little code on the side of the glass, the Latin alphabet was exhausted for different plant codes, and Greek was used as well...
Attached a photo of what a ECC82 or ECC83 made by one of the Philips plants looks like, there was an earlier version that has long plates but rare.
The way you can see Philips/Mullard/Valvo tubes at first glance are the four seams at the top. However some equiptment was exported to Hungary and Yugoslavia in the 80's. However those use the same copper coloured lead in wires as all the comb block tubes.
There just tubes, Philips made some good stuff, so did Telefunken but in the end of the day these cannot hold a candle quality wise to some of the professional gold pin series.
If you go on youtube and look for "The mullard story" it is said in passing that Mullard was part of the Philips organisation.
Philips had three or four plants in the Netherlands.
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For comparison i have made some pictures of mine. If you need more or from different angels just let me know.
Best regards, Frank
Best regards, Frank
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goto: www.tubemuseum.org
left column: Tube Information
click: Siemens or Telefunken or Philips or Mullard
and get all the information on all those little numbers and markings ...
left column: Tube Information
click: Siemens or Telefunken or Philips or Mullard
and get all the information on all those little numbers and markings ...
Wow, very helpful info. Now I will go through my box of tubes with markings rubbed off and look for seams!
Lampie519 - for some reason I can't quote your post. Thanks for the pics!
Your fourth pic looks like my tube type #4. What kind of tube is that?
Your fourth pic looks like my tube type #4. What kind of tube is that?
Mullards are easily identified by the smoke inside - they came that way new. Not kidding!
Telefunkens with any readable lettering are so rare as to be suspicious, but here's some notes:
Telefunken Tube Date Codes
I've seen valves with Telefunken printing, diamond bottoms and gold flashed pins that were fakes, and performed very poorly. I don't know the source, but the valves they started with weren't Chinese. (Pretty sure.)
YOS,
Chris
Telefunkens with any readable lettering are so rare as to be suspicious, but here's some notes:
Telefunken Tube Date Codes
I've seen valves with Telefunken printing, diamond bottoms and gold flashed pins that were fakes, and performed very poorly. I don't know the source, but the valves they started with weren't Chinese. (Pretty sure.)
YOS,
Chris
Interesting details of the internal connections to the heaters etc. In the ECC803S theses are flat not round wires. Not sure if this can be found in other tubes as well. I will check tomorrow.
Thank you all for your help. This thread gave the general guidance and confidence I needed to try the tubes in amps, and I have results.
Type #1 & 2
- The smooth plate tubes had 4 tubes with the "getter strut" on pin #1 (counting counter-clockwise, with the gap in the 9 pins at the bottom facing me). These were all ECC83/12AX7.
- There was one smooth plate tube with the "getter strut" on pin #2, and it was an ECC82/12AU7.
Type #3 - The ribbed plate tubes both had the "getter strut" on pin #2, and both were 12AU7 (they sound FANTASTIC, by the way)
Type #4 - the short plate tube was correctly identified by several here as an ECC88/6922
And finally, the threads people linked to taught me that many Mullard/Philips/Amperex tubes had two or four "seams" on top, and this allowed me to find two sets of Mullard/Philips/Amperex ECC88's that also sound FANTASTIC.
Hope this helps some people in the future trying to ID tubes.
Type #1 & 2
- The smooth plate tubes had 4 tubes with the "getter strut" on pin #1 (counting counter-clockwise, with the gap in the 9 pins at the bottom facing me). These were all ECC83/12AX7.
- There was one smooth plate tube with the "getter strut" on pin #2, and it was an ECC82/12AU7.
Type #3 - The ribbed plate tubes both had the "getter strut" on pin #2, and both were 12AU7 (they sound FANTASTIC, by the way)
Type #4 - the short plate tube was correctly identified by several here as an ECC88/6922
And finally, the threads people linked to taught me that many Mullard/Philips/Amperex tubes had two or four "seams" on top, and this allowed me to find two sets of Mullard/Philips/Amperex ECC88's that also sound FANTASTIC.
Hope this helps some people in the future trying to ID tubes.