I have tried to capture all the different version, iterations and the chronology of the vintage Tung-sol 6550 tube to the best of my knowledge. The coke-bottle 6550 was manufactured by Tungsol and was re-labeled for many other manufacturers. I have personally come across RCA, GE, Sylvania, Stromberg-Calrson and Raytheon labeled Tung-sol 6550 tubes. I have come up with a versioning system to better understand and document all the different variations and iterations of this tube, you can find the versioning in this video. Tung-sol manufactured these 6550 tubes from ~1955-1976*. *Dates are approximate. Please add your inputs in the comments section if you have any additional context or information. Thanks!
Needless to say, it's all going to be subjective but there is a discernable difference between the tubes as the gap gets wider. As far as percentage goes, it's hard to tell. I had a methodical way to A/B the tubes. Keeping everything else constant, I kept swapping out the tubes and critically listened to the same music on each set of tubes for at least two weeks before I swapped them out with a different set of tubes. I went from a set of current gen tubes to 70's tubes to 60's tubes to 50's tubes. I personally prefer the earlier tubes only because I'm able to hear the difference. As we all know it's very difficult to describe sound in words, it just has to be heard and experienced. The 1.1's were simply the best sound I have ever heard. It's like veils were lifted and I was in a studio listening to music being performed/recorded. Vocals and instruments just sounded so organic and real.. it felt like the 1.1's held the note a split second longer, the reverberations on the strings and wind instruments lasted split second longer, the noise floor dropped and the blacks were darker if that's even a thing.. the music on 1.1's either brought a smile to my face or tears to eyes. Speakers, amp, gear, equipment just disappeared and I was in a private concert. I'm sure the Tannoys had a a lot to do with it as well, along with the MI-75s, MX110z and the Tele 12ax7 in there. So, I just happened to have found my bliss in the coming together of all the equipment in the chain and I'm keeping it. :) The other revelation I have had through this process is that the- tube. is. the. amp! The amplifier with the transformers and the design allows for the tube to do it's job and a well designed amplifier will keep the distortion at a minimum and be functional for long periods of time without causing undue stress to the various components of the amp. That's why some of the best amps from the 60's - the Macs and the Marantz have stood the test of time with their impeccable design. Once you get the design of the amp out of the way.. the actual amplification happens within the tube. Think of the tube as a lens for the DSLR, the DSLR will define the limits for the camera.. the megapixel, the features etc.. the amp is the camera body but ultimately the lens will have the most impact on the quality of the image. Similarly, as you change the tube and the sound changes. It's as if various brands of tubes and tubes from different periods are EQ'ed differently. Some bring vocals forward while others sparkle at the top while some render the bass differently. So finding the right tube for you will require some A/B'ing and will also depend on your preferences for sound. Having said that, 1.2 is closer to 1.1, 1.3 is closer to 1.2 and so on. I don't know why the tubes from the 50's sound best on my system but they do. However, it's hard to justify the price of these tubes these days. I only got into tubes a couple of years ago so I have paid premium price for these tubes. I would say, start with the later tubes from 70's or 60's and then- IF your system, your ears, your wallet allow for it.. upgrade to older set of tubes and see if you can hear a difference. I definitely do not want to promote the 1.1's as the best but that has been my experience on my system and who knows - maybe someone will like the the 2.2's best or the current gen tubes best. To each his own.. everyone's journey is going to be unique. As long as you are enjoying the music, the system you have is the best system. Cheers!
I am building an amplifier using the output transformers from a ma230 using the 6550. I have the Russian Tunsol 6550. Have you noticed any difference within the Russian versions of tubes or are they all the same. I will try to get a set of black plate 1.1 or 1.2 versions but they aren't easy to obtain. How much difference do you note in your amps between these groups, ie the 1.1-1.2 versus the Russian tubes. Also i since I'm building the amps I can change the idle current and negative voltage on the screen grid. I don't know if you can or have messed with these parameters but if so what were your findings? Thanks in advance for your input.
The current Russian TungSols are not the same as the vintage American made TungSols. I have heard the Russian tube and they sound good for the price but the problem with current generation tubes I have encountered is that they are not consistent, both sound wise and quality/longevity wise. Keep your Russian tubes and try the most affordable vintage TungSol 6550 - v2.2 - grey plate with 3 holes. If you notice the difference there then you can upgrade to the more expensive and rare vintage solid plates. If your system is resolving enough and you can hear the difference then it makes all the sense to try to obtain older more expensive tubes. In my experience 1.1 and 1.2 are exceptional in their sound and they are best sounding 6550 tubes followed by 1.3 and 2.1. Followed by the TungSol 2.2, Sylvania 6550 straight bottle and GE 6550A. These vintage tubes sound better than any current production Russian or Chinese tubes. Regarding the amp current/voltage, I haven't messed around with it since I use the McIntosh MI-75s, you can look up the specs of that amp but when I checked last I read 430V at the plate with at average plate current of around 26mA.
@vintagetannoy Thanks for the info help. I'm putting around 830v on the plates and a very regulated 320v on the screen grid. The idle current is close to 38 ma. The test circuit is extremely resolving playing through an Altec 515 woofer, Altec 311-90 with a 290E giant voice compression driver and a Electrovoice T350 super tweeter. I will endeavor to obtain several sets to roll. I can confirm tube parameters with my calibrated Hicock tester.
Between version 2.1 and 2.2 is that the big sound quality diffrent? Im planning to buy 1 set of those, but the 2.1 is more expensive than the 2.2 version, can you tell me what the diffrent between version 2.1 and 2.2? By the way right now im using 6550 svetlana B2, on my audio research I/50. Thank you in advance
Audio Research I/50 looks like a nice amp. As far as the tubes are concerned, I would broadly categorize them into three based on how closely they sound to each other: 1. Black plates with D getters (1.1 & 1.2) 2. Solid plates with halo getters (1.3 & 2.1) 3. Three hole with halo getters (2.2) You can't go wrong with any version of these tubes, the sound gets more refined as you move up the chain with older tubes. 2.1 is closer in sound to 1.3. I believer the reason why the solid plate tubes are expensive is because: 1. Fewer of these were manufactured when compared with the 2.2's. Tung sol went through 4 different iterations from 1.1 to 2.1 in a span of 8 years which averages to about 2 years of production for each iteration from 1.1 thru 2.1. Whereas, the last version 2.2 was in production for well over a decade. 2. The 3-hole grey plate is a great tube but the solid plates and D getters do have an edge on sound that is discernible on a system that is resolving enough. I would start with the tubes I could afford and then try the next older version of the tubes when time and wallet permits to see if the sound difference is noticeable and then keep the tubes I like based on sound and value. I also have some tubes to sell that I usually list on USAM. You can contact me at vinttannoy@gmail.com if you have any further questions.
I have tried to capture all the different version, iterations and the chronology of the vintage Tung-sol 6550 tube to the best of my knowledge. The coke-bottle 6550 was manufactured by Tungsol and was re-labeled for many other manufacturers. I have personally come across RCA, GE, Sylvania, Stromberg-Calrson and Raytheon labeled Tung-sol 6550 tubes. I have come up with a versioning system to better understand and document all the different variations and iterations of this tube, you can find the versioning in this video. Tung-sol manufactured these 6550 tubes from ~1955-1976*.
*Dates are approximate. Please add your inputs in the comments section if you have any additional context or information. Thanks!
Starting with ge6550A to use in ZMF Aegis headphone amp.
please tell us your preferences...It gives us a guide...❓
please help me get a quartet of these...😁
Cheers for that , great info . In % terms, how much better is your favourite version from the version 2 grey plate ?
Needless to say, it's all going to be subjective but there is a discernable difference between the tubes as the gap gets wider. As far as percentage goes, it's hard to tell. I had a methodical way to A/B the tubes. Keeping everything else constant, I kept swapping out the tubes and critically listened to the same music on each set of tubes for at least two weeks before I swapped them out with a different set of tubes. I went from a set of current gen tubes to 70's tubes to 60's tubes to 50's tubes. I personally prefer the earlier tubes only because I'm able to hear the difference. As we all know it's very difficult to describe sound in words, it just has to be heard and experienced. The 1.1's were simply the best sound I have ever heard. It's like veils were lifted and I was in a studio listening to music being performed/recorded. Vocals and instruments just sounded so organic and real.. it felt like the 1.1's held the note a split second longer, the reverberations on the strings and wind instruments lasted split second longer, the noise floor dropped and the blacks were darker if that's even a thing.. the music on 1.1's either brought a smile to my face or tears to eyes. Speakers, amp, gear, equipment just disappeared and I was in a private concert. I'm sure the Tannoys had a a lot to do with it as well, along with the MI-75s, MX110z and the Tele 12ax7 in there. So, I just happened to have found my bliss in the coming together of all the equipment in the chain and I'm keeping it. :)
The other revelation I have had through this process is that the- tube. is. the. amp! The amplifier with the transformers and the design allows for the tube to do it's job and a well designed amplifier will keep the distortion at a minimum and be functional for long periods of time without causing undue stress to the various components of the amp. That's why some of the best amps from the 60's - the Macs and the Marantz have stood the test of time with their impeccable design. Once you get the design of the amp out of the way.. the actual amplification happens within the tube. Think of the tube as a lens for the DSLR, the DSLR will define the limits for the camera.. the megapixel, the features etc.. the amp is the camera body but ultimately the lens will have the most impact on the quality of the image. Similarly, as you change the tube and the sound changes. It's as if various brands of tubes and tubes from different periods are EQ'ed differently. Some bring vocals forward while others sparkle at the top while some render the bass differently. So finding the right tube for you will require some A/B'ing and will also depend on your preferences for sound.
Having said that, 1.2 is closer to 1.1, 1.3 is closer to 1.2 and so on. I don't know why the tubes from the 50's sound best on my system but they do. However, it's hard to justify the price of these tubes these days. I only got into tubes a couple of years ago so I have paid premium price for these tubes. I would say, start with the later tubes from 70's or 60's and then- IF your system, your ears, your wallet allow for it.. upgrade to older set of tubes and see if you can hear a difference. I definitely do not want to promote the 1.1's as the best but that has been my experience on my system and who knows - maybe someone will like the the 2.2's best or the current gen tubes best. To each his own.. everyone's journey is going to be unique. As long as you are enjoying the music, the system you have is the best system. Cheers!
Does the newer ones like manufacturered 2008 sound just as good as older ones?
In my experience, none of the new production tubes of any type sound the same or as good as the NOS tubes unfortunately.
@@vintagetannoy Ok cool. Thanks for the info. Watching a separate video you explaining that.
I am building an amplifier using the output transformers from a ma230 using the 6550. I have the Russian Tunsol 6550. Have you noticed any difference within the Russian versions of tubes or are they all the same. I will try to get a set of black plate 1.1 or 1.2 versions but they aren't easy to obtain. How much difference do you note in your amps between these groups, ie the 1.1-1.2 versus the Russian tubes.
Also i since I'm building the amps I can change the idle current and negative voltage on the screen grid.
I don't know if you can or have messed with these parameters but if so what were your findings?
Thanks in advance for your input.
The current Russian TungSols are not the same as the vintage American made TungSols. I have heard the Russian tube and they sound good for the price but the problem with current generation tubes I have encountered is that they are not consistent, both sound wise and quality/longevity wise. Keep your Russian tubes and try the most affordable vintage TungSol 6550 - v2.2 - grey plate with 3 holes. If you notice the difference there then you can upgrade to the more expensive and rare vintage solid plates. If your system is resolving enough and you can hear the difference then it makes all the sense to try to obtain older more expensive tubes. In my experience 1.1 and 1.2 are exceptional in their sound and they are best sounding 6550 tubes followed by 1.3 and 2.1. Followed by the TungSol 2.2, Sylvania 6550 straight bottle and GE 6550A. These vintage tubes sound better than any current production Russian or Chinese tubes. Regarding the amp current/voltage, I haven't messed around with it since I use the McIntosh MI-75s, you can look up the specs of that amp but when I checked last I read 430V at the plate with at average plate current of around 26mA.
@vintagetannoy
Thanks for the info help. I'm putting around 830v on the plates and a very regulated 320v on the screen grid. The idle current is close to 38 ma. The test circuit is extremely resolving playing through an Altec 515 woofer, Altec 311-90 with a 290E giant voice compression driver and a Electrovoice T350 super tweeter. I will endeavor to obtain several sets to roll. I can confirm tube parameters with my calibrated Hicock tester.
Between version 2.1 and 2.2 is that the big sound quality diffrent? Im planning to buy 1 set of those, but the 2.1 is more expensive than the 2.2 version, can you tell me what the diffrent between version 2.1 and 2.2? By the way right now im using 6550 svetlana B2, on my audio research I/50. Thank you in advance
Audio Research I/50 looks like a nice amp. As far as the tubes are concerned, I would broadly categorize them into three based on how closely they sound to each other:
1. Black plates with D getters (1.1 & 1.2)
2. Solid plates with halo getters (1.3 & 2.1)
3. Three hole with halo getters (2.2)
You can't go wrong with any version of these tubes, the sound gets more refined as you move up the chain with older tubes. 2.1 is closer in sound to 1.3. I believer the reason why the solid plate tubes are expensive is because:
1. Fewer of these were manufactured when compared with the 2.2's. Tung sol went through 4 different iterations from 1.1 to 2.1 in a span of 8 years which averages to about 2 years of production for each iteration from 1.1 thru 2.1. Whereas, the last version 2.2 was in production for well over a decade.
2. The 3-hole grey plate is a great tube but the solid plates and D getters do have an edge on sound that is discernible on a system that is resolving enough.
I would start with the tubes I could afford and then try the next older version of the tubes when time and wallet permits to see if the sound difference is noticeable and then keep the tubes I like based on sound and value. I also have some tubes to sell that I usually list on USAM. You can contact me at vinttannoy@gmail.com if you have any further questions.