Microphonics?

[adeep42]

The Eros 2 that I've been on the forum with mostly with PB is my second. The first, an original Eros is in my main system. After the new one is completed, one or the other will go into a new second system that I am working on.

The subject line is my only issue with the current Eros. During about the first half hour that the Eros is on, it is subject to extreme sensitivity to even the most minute vibration. A light touch to the top or any tube will stop it. I believe it is either the 12AU7 or the 6922 as both channels are affected.

Any thoughts?

 

[Jameson]

Could you swap in the tubes from your other Eros and see if it's the tubes?

 

[Doc B]

Sounds like the 6922. If it goes away in half an hour I would live with it, as the system won't sound its best until it's been on that long anyway.

 

[adeep42]

Thank you Doc and Jameson. Sometimes I just don't have the patience to wait a half an hour. The noise from the microphonics actually makes me worry about my speakers. It can be that loud.

 

[Tom-s]

You've got yourself an excuse to get those fancy Siemens or Telefunken E88CC's    :-X

 

[adeep42]

Didn't go all the way with the Siemens or Telefunkens, but did get a new Genalex from Tube Depot. Definitely better, but still slightly prone to some issues. Did notice that the tube shields on that Eros, the older one, do not have springs inside while the shields on the new one do. Could that be a contributing factor.

Best to all, Nice to have the forum back.

 

[Tom-s]

Tube shields are easily found ebay. Complete with springs.
These fit the socket/shield that come with BH kits.
I've used them on Mainline with good succes.

https://ep1.pinkbike.org/p5pb16498303/p5pb16498303.jpg

 

[adeep42]

Thanks Tom,

Just ordered some.

Alan

 

[Paul Birkeland]

Didn't go all the way with the Siemens or Telefunkens, but did get a new Genalex from Tube Depot. Definitely better, but still slightly prone to some issues. Did notice that the tube shields on that Eros, the older one, do not have springs inside while the shields on the new one do. Could that be a contributing factor.

You can pull the springs out of the new shields.