I ordered what was supposed to be a Tung Sol 5998 last week, the box arrived yesterday and what I pulled out is a Chatham 2399. I spend a bit of time searching for information on this tube and what little I did find seems to indicate that the 2399 is like a 5998 but a little different. Can anyone here clarify just what this tube is? It definitely is not exactly the same as a 5998, to quote from a posting on Head-fi.org,
"There really are a number of differences. Most easily appreciated is the presence of a 3rd spacer tab holding the top mica against the glass, probably to improve on microphonics. There is an additional coating of some kind on the plates that was sprayed on after the micas were fixed in place, because you can see where the overspray, blocked by the plates, forms a cross on the bottom of the mica. There is also an additional coating or jacket on many wires which are normally bare in the 5998 and 6AS7G. Most obvious would be the copper grid posts and grid wires in place of the normal steel ones. It looks like the pins have been tinned for some reason as well..."
I did a visual comparison, well as good as I could comparing what I had in my hand with pictures of a 5998 I found online and I verified the statement I quoted. I'm leaning towards keeping it because the one thing most could agree on is that it is a good sounding tube. But, does it sound as good as a 5998, and is it worth the same money I paid for a 5998?
On a different topic, I just finished installing the speedball upgrade and it was hard to imagine the Crack sounding better than it does in stock form, but the speedball is a killer upgrade. I am totally amazed at how great it sounds in my Beyer DT990's. Great job Doc and all of the others at Bottlehead.
Terry
Crack/Speedball, Beyerdynamic DT990 Pro 250, Sennheiser HD6xx, Wiim pro plus