[rosgr63]

I think TS started with round mica then went to the oval mica and then back to the round one again.
 
I have been told that the round mica has a stonger less microphonic structure.
 
I agree with Rob about the sound signature.
What is more important is the material the grid posts are made from.

 

[Xcalibur255]

 
Quote:

What is more important is the material the grid posts are made from.

 
Fully agree with this.  It's a shame whenever a pair is sold with mismatched grid post material, which is pretty often.

 

[rosgr63]

The TS round mica has one more well kept secret, I wonder how many people know!

 

[rosgr63]

 
Quote:

 
 
Fully agree with this.  It's a shame whenever a pair is sold with mismatched grid post material, which is pretty often.

 
 I am stealing your words xcalibur.
You have said this before and to me it's the most important factor when choosing from otherwise similar tubes.

 

[Silent One]

Secrets... revealed.

 

[rosgr63]

 
Quote:

Secrets... revealed.

 
Some, not all yet!

 

[Silent One]

You mean 

 we're on our own? I would have guessed copper grid posts but seems like you two already mentioned that. Not sure what else the difference could be.

 

[Xcalibur255]

It's news to me as well.  I never really investigated the differences closely.  It has to be something non-essential that doesn't affect sound like getter style.  A round mica combined with the black coating would make it nearly impossible to see, which would certainly keep it a secret. 

 

[rosgr63]

You are close Xcalibur, it affects microphonics but not the sound that much.

 

[Silent One]

Amazing! Here we have a coating the color Black. Which is actually the absence of color. To bring about the absence of microphonics... who knew?!

 

[rosgr63]

This is not the difference SO because they both have Black Glass, right?

 

[Silent One]

For some reason, I thought Xcalibur255 was talking about a coating within the tube but not the envelope. Like on an internal part. Now, I'm really wondering... Perhaps, you could share more about your discovery. Something you observed looking at photos? Pulled one of each out of your well stocked collection?? Or was it merely pointed out to you by someone else?! 

 

[rosgr63]

I was told by one of my tube suppliers.
One might have to destroy one of each different mica tubes to find out.
I could never do that, so I cannot confirm whether it's true or not.
 
However if somebody has two dead tubes with the different micas then we can find out, I'll let them know what to look for!

 

[Silent One]

Think I'll go to bed early for once. Instead of counting sheep 

 I'll ponder the difference until I get v-e-r-y sleepy! Have yourself a most brilliant day/night, rosgr63!

 

[rosgr63]

Oh, I can't have you thinking about this!
 
The oval mica have an extra support rod I was told.
That makes them less microphonic!
 
Good night SO!