Hey Mark,

A nice tube. Just depends if you like it with rest in your setup. I have not used them in quite a while, but liked them!

Compared to RCA 5U4G-STs, it has a more solid, big, and less shimmery "signature," while having increased sense of spacial information. And like other 5R4s I have tried, it pretty fast, solid, dynamic, spacious, and neutral. The Chatham is big, a bit warmish, and mellow, but revealing, sort of like a bigger brother of Euro GZ32s, but with less fine-fine detail, though still good at fine detail. A good tube. Why not try it?

Nice. The ones I have are marked Chatham 5R4WGY...not sure the vintage, but guess they are a little different like various Mullard made GZ32s are different, but with a similar flavor. It would be interesting to play some reference tunes replacing a GZ32 in your CSP3 with a Chatham..all else the same.

I used all Philips made GZ32s for years and really like the tube. For quite a while though, I have been using an engraved base Philco Type 80 Globe in the CSP3 and some early B4 (British 4 pin) versions of Telefunken AZ1s in the Torii. Both of these require special adapters, and in my setup, sound really right. But then, with a little mixing and matching, I love a lot of tubes!