Question about 5u4 tubes ?

I have been looking at 5u4 rectifier tubes. Do the older, wider "S" type tube bottles sound better then the uniform straight bottles? Are the old RCA 5u4 tubes the best of this type? If so, are these RCA's better types in both the above configurations? I guess what I'm asking is for an expert to give me some relative background on which type would be best for my preamp which uses only one of this type...but I want the best sounding one I can find. thanks, Jim
Vintage Tube Services/Andy Bauman.
Talk to Kevin at Upscale.
Check with both Andy at Vintage Tubes Services and Audiogon member Jsautter.

They offer superb and well tested products at fair prices.

Both stand behind every sale which IMO is critical when purchasing vintage tubes.
Hi Jim:

I can recommend one very highly. It's the Tung-Sol 5U4-G. Look only for the ones with these attributes:

1. ST-shape.
2. Top flash-getter.
3. Support rods between the plates.
4. Heat shielding material in the base.

You can copy and paste this link to see a photo of one (it shows everything but the top flash getter):

They are getting hard to find, but it's not impossible.

I'm using a big Ken Rad 5U4G Military type from the early 50's, or it could be the mid 40's. Still works, sounds great
but may be hard to find.