Bottlehead Forum

Bottlehead Kits => Eros Phono => Topic started by: adeep42 on July 17, 2019, 05:03:37 AM

Title: Microphonics?
Post by: adeep42 on July 17, 2019, 05:03:37 AM
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?
Title: Re: Microphonics?
Post by: oguinn on July 17, 2019, 05:30:48 AM
Could you swap in the tubes from your other Eros and see if it's the tubes?
Title: Re: Microphonics?
Post by: Doc B. on July 17, 2019, 05:33:15 AM
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.
Title: Re: Microphonics?
Post by: adeep42 on July 17, 2019, 08:29:28 AM
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.
Title: Re: Microphonics?
Post by: Tom-s on July 17, 2019, 09:20:58 AM
You've got yourself an excuse to get those fancy Siemens or Telefunken E88CC's  :P  :-X
Title: Re: Microphonics?
Post by: adeep42 on July 23, 2019, 11:52:13 AM
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.
Title: Re: Microphonics?
Post by: Tom-s on July 23, 2019, 09:03:09 PM
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 (https://ep1.pinkbike.org/p5pb16498303/p5pb16498303.jpg)
Title: Re: Microphonics?
Post by: adeep42 on July 24, 2019, 06:54:52 AM
Thanks Tom,

Just ordered some.

Alan
Title: Re: Microphonics?
Post by: Paul Birkeland on July 24, 2019, 10:11:40 AM
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.