Hello Everyone!
Feels like it's been a while since I've posted anything here, Anyways I've been testing some 300B that I bought back in July of 2020 from Victor. I'm talking about the Nature Sound Linlaitube 300B Black Plate.. now rebranded as Cossar.
If your not in the mood for reading I'll say it here... The Cossar 300B Black Plate are by far the longest lasting mid range 300B I have ever tested!! Up until now tube longevity was mostly dominated by JJ and Psavne with around 2,500 hours roughly. The sound signature of the Cossar 300B Black Plate are somewhere between a JJ 300B and a Gold Lion 300B, it doesn't have the strong bass of the JJ or the high rich highs of the Gold Lion, it's just a well balanced tube.
Now for those of you who are up for some reading here are all the details!
Back in July of 2020 I had one of my Gold Lion 300B lost half of the heater. Thankfully it wasn't catastrophic this time. Victor had recently posted about some new tubes he was offering from a new company. I was very interested in trying these out especially from a new player in the tube market. I ended up going with the Cossar 300B Black plate.
I received tubes that were well above my expectations. Especially for its very modest pricing! It's the very small details that let you know if a product is made with care and it makes sense since Cossar was started by ex Psavne folks. Like Psavne they make sure each tube is alike.. meaning the labeling all face one direction, and even the internals all of the tubes are aligned the same, if you care about aesthetics then you will like these details. Also the construction quality of Cossar tubes feel nice and strong too! But these are just the things you notice from the outside.
Before slapping these tubes into my TU-8600 I needed to make sure that I had some way of testing these tubes before and after. Fortunately I was nearing completion of a major 2 month long restoration project I was working on over the summer of 2020. I fully restored a Hickok Cardmatic KS-15874-L2 tube tester.. every single capacitor and all resistors (except a few wire wound resistors) were replaced, it was a massive undertaking considering that it was 90% stock and someone had made questionable repairs around the 90's to get this tester limping along for a few more years. Functionality was was tested using some 90 plus program cards that tests every circuit and components of the Cardmatic, and it passed with flying colors!
Another thing I needed was a way to keep track of the hours on these tubes and I looked at logging hours manually or something like that and maybe even a meter on the wall or something... but then I realized I had a brand new TV that I had just bought before Christmas of 2019. Through the Samsung app on my phone I can see the service hours on the TV... and my TV is always on when the TU-8600 is on. even when listening to my vinyl, I always throw on a visualizor to go with the music.. one is not on without the other!
Originally I was going to test the tubes every few weeks or maybe even monthly but in the end I decided against that..I would just run the Cossar 300B until they died, I didn't want to mess with them too much.. I was expecting them to last about 2,500 hours maybe less... but here I am almost a year later and the Cossar 300B are still pumping out sound. They are slightly above the 5000 hour mark let's see how they are doing!
Here are the test conditions under which they are tested through the cardmatic, as you can see it tests for Plate current. I allowed each 300B to heat up for 30 minutes before running the test.
So back in late July my TV only had 2193 hours, this is our starting point.
I measured each tube fresh out of the box.
Cossar 300B #1 measured 66mA
Cossar 300B #2 measured 69mA
So not bad, very closely matched in plate current!
Now with 5,000 hours on the tubes
Cossar 300B #1 measures 61mA
Cossar 300B #2 measures 64mA
So output has obviously dropped but only my 5mA each. These tubes are still good!
For the price I don't think you could find a better tube. When you go with cheaper tube you have to make sacrifices in materials and construction quality. Cossar is making some top notch heater filament here while keeping quality high and what you get is a very well balanced tube!
Highly recommend!
My next test on these tubes will be at 8,000 hours!
Feels like it's been a while since I've posted anything here, Anyways I've been testing some 300B that I bought back in July of 2020 from Victor. I'm talking about the Nature Sound Linlaitube 300B Black Plate.. now rebranded as Cossar.
If your not in the mood for reading I'll say it here... The Cossar 300B Black Plate are by far the longest lasting mid range 300B I have ever tested!! Up until now tube longevity was mostly dominated by JJ and Psavne with around 2,500 hours roughly. The sound signature of the Cossar 300B Black Plate are somewhere between a JJ 300B and a Gold Lion 300B, it doesn't have the strong bass of the JJ or the high rich highs of the Gold Lion, it's just a well balanced tube.
Now for those of you who are up for some reading here are all the details!
Back in July of 2020 I had one of my Gold Lion 300B lost half of the heater. Thankfully it wasn't catastrophic this time. Victor had recently posted about some new tubes he was offering from a new company. I was very interested in trying these out especially from a new player in the tube market. I ended up going with the Cossar 300B Black plate.
I received tubes that were well above my expectations. Especially for its very modest pricing! It's the very small details that let you know if a product is made with care and it makes sense since Cossar was started by ex Psavne folks. Like Psavne they make sure each tube is alike.. meaning the labeling all face one direction, and even the internals all of the tubes are aligned the same, if you care about aesthetics then you will like these details. Also the construction quality of Cossar tubes feel nice and strong too! But these are just the things you notice from the outside.
Before slapping these tubes into my TU-8600 I needed to make sure that I had some way of testing these tubes before and after. Fortunately I was nearing completion of a major 2 month long restoration project I was working on over the summer of 2020. I fully restored a Hickok Cardmatic KS-15874-L2 tube tester.. every single capacitor and all resistors (except a few wire wound resistors) were replaced, it was a massive undertaking considering that it was 90% stock and someone had made questionable repairs around the 90's to get this tester limping along for a few more years. Functionality was was tested using some 90 plus program cards that tests every circuit and components of the Cardmatic, and it passed with flying colors!
Another thing I needed was a way to keep track of the hours on these tubes and I looked at logging hours manually or something like that and maybe even a meter on the wall or something... but then I realized I had a brand new TV that I had just bought before Christmas of 2019. Through the Samsung app on my phone I can see the service hours on the TV... and my TV is always on when the TU-8600 is on. even when listening to my vinyl, I always throw on a visualizor to go with the music.. one is not on without the other!
Originally I was going to test the tubes every few weeks or maybe even monthly but in the end I decided against that..I would just run the Cossar 300B until they died, I didn't want to mess with them too much.. I was expecting them to last about 2,500 hours maybe less... but here I am almost a year later and the Cossar 300B are still pumping out sound. They are slightly above the 5000 hour mark let's see how they are doing!
Here are the test conditions under which they are tested through the cardmatic, as you can see it tests for Plate current. I allowed each 300B to heat up for 30 minutes before running the test.
So back in late July my TV only had 2193 hours, this is our starting point.
I measured each tube fresh out of the box.
Cossar 300B #1 measured 66mA
Cossar 300B #2 measured 69mA
So not bad, very closely matched in plate current!
Now with 5,000 hours on the tubes
Cossar 300B #1 measures 61mA
Cossar 300B #2 measures 64mA
So output has obviously dropped but only my 5mA each. These tubes are still good!
For the price I don't think you could find a better tube. When you go with cheaper tube you have to make sacrifices in materials and construction quality. Cossar is making some top notch heater filament here while keeping quality high and what you get is a very well balanced tube!
Highly recommend!
My next test on these tubes will be at 8,000 hours!
