Difference between Siemens CCa & 7308


Any significant differences between Siemens CCa and 7308 tubes of the same era? I know the CCa is highly regarded, hard to find and expensive. Seems the Siemens 7308 is a bit easier to find and slightly less costly. Does the 7308 give up much in performance? Thanks!
128x128rja
Audiofeil...

A food critic can tell me what spinach tastes like. Sound has much more definable characteristics. Airy, detailed, dimensional says it nicely.

Rather that picking a winner amonst the available 6dj8 variants it might be helpful if the cognoscenti of the CCa in particular could lead the poster and other readers in the right direction. What are the classifications of CCa (date range I presume) and how do they differ in sound from other CCas? I think Andy at Vintage Tube Service could sell a lot more tubes, especially CCas if from these postings people really knew what they were getting. The mystery surrounding this tube is over the top.
Post removed 
An often overlooked Siemens and Halske Tube is the 1960's vintage ECC88/6DJ8. Extremely rare to test one that is not tightly matched between triodes. Just as rare for this tube to be microphonic and even the slight bit noisy. To top it off, no slouch at resolving low level detail, extended on top and bottom. My first choice for sensitive gain stage use in pre-amps.
>>11-05-07: Anacrusis
A food critic can tell me what spinach tastes like. Sound has much more definable characteristics. Airy, detailed, dimensional says it nicely.<<

Those are nice words. Unfortunately, there are no universal and accepted meanings for them. I suspect most listeners have their own personal definition of them based on the equipment they've heard.

I hope that helps and BTW, eat your spinach.