Tube shields question

[MikeSattler]

Just bought a mainline on black friday and cant wait to build it! One question, I want to order some black tube shields for the design I want to do and was wondering whether the shields need to be grounded or not? I see the ones that come with the kit have a base that grounded them, but there are also some slip on ones like this that are ungrounded: https://www.ebay.com/itm/Pair-IERC-TR6-6015B-black-tube-shields-for-5670-396A-2C51-6386-417A-tubes/182897594460?hash=item2a958bd05c:g:CIoAAOSw44BYL1rQ

Does it matter either way?

 

[Doc B]

IERC tube shields are also intended to be used with the grounding bayonet style shield base. If a shield isn't grounded, it's not shielding. And by the way, the ones you have linked are too short for 6C45pis. You want some that are the proper height for 12AX/U/T7s. The 6C45pi is a stout tube and may be a very snug fit in an IERC shield.

 

[MikeSattler]

Okay awesome, thanks Doc that's what I was wondering. I'll just look for some standard shields in black, or maybe spray paint them to match the chassis.

 

[Karl5150]

Doc, along the same lines I received the IERC shields with my Eros kit ("order early and often") and I am not using the bayonet bases. However there doesn't seem to be any anodizing on the bottom surface of the shields that makes contact with the regular socket clamps. That should do the trick, right?
Thanks, Karl

 

[Doc B]

That's not a particularly reliable mechanical connection. In theory it would work if the contact is very good, but to me it seems pretty iffy in that regard.

 

[fullheadofnothing]

Also worth pointing out that the kit will come with the bases (as Karl's did). You can use the bases provided with whatever shield you want.

 

[MikeSattler]

I saw these tube shields by EIZZ and they look pretty sweet: http://www.mableaudio.com/en/productview.asp?sid=7666

Has anyone used these before? One thing thats odd about the specs is that it lists the mounting holes as 22mm, but I have the EIZZ ceramic sockets and the mounting holes are 28mm. Wondering if that's a typo or if they actually don't fit their own sockets 

 

[Paul Birkeland]

Those have to be screwed into the chassis from the bottom.  That will create its own set of problems, especially if the shield happens to not align with the standard mounting centers for a 9 pin socket.

 

[Doc B]

The IERC tube shield was designed for function, not flash. Along with effectively shielding EMI it is the one shield, to my knowledge, that has been documented as lowering a tube's envelope temperature by about 10-15%. And the internal sleeve usually does a decent job of damping vibration, whereas the coil springs common to most shields seem to transfer the energy in such a way that they can make microphonics worse.

If you guys need bling, go for whatever. If you want the most effective shield, use an IERC shield and a bayonet mount.

 

[MikeSattler]

I do like the bling, but i'd rather have function IERC it is

 

[ALL212]

Mainline and IERC covers