2. amps-preamps
  3. 157957-134614

Expanding questions about tubes in a preamp

Hello to all...

Started with a (helpful) discussion titled "How to select tubes for a line level preamp"... Expanding questions that have generated from that...

Have learned that hum/noise from tubes is a major consideration - now trying to figure cheap ways to address quieting the 12AX7s and the EF86s.

Would like to try "banding" the tubes with rubber ring washers - one?two?three per tube?

Where should the rings be on the tube: Top? Mid? Bot?

Can you over dampen a tube?

Knowledgeable tube users/ Masters input/suggestions please...

insearchofprat

Showing 5 responses by insearchofprat

insearchofprat OP
189 posts
 
... So just putting some rubber rings (O-Rings) picked up at a local hardware store would not be a good idea - or is it just again an experiment worth trying?
insearchofprat OP
189 posts
 
... Phew! - this is getting more complicated - may have bitten off more than I can really manage at the moment...

Thanks to all for obviously educated and experienced info.
insearchofprat OP
189 posts
 
DeKay

Thanks for your clarification - probably the route I will go will be to
change to 12au7s

Can you suggest changing the EF86 to ?
insearchofprat OP
189 posts
 
ieales

Sound improved greatly adding the preamp in: better defined bass, voice
/ vocals more clear and moved "vertically up" in soundstage; veil over sound lifted slightly; soundstage expanded in width and depth with most instruments more clearly defined in the soundstage, rhythm and ’ toe-tappin ’ factor greatly enhanced...

Today’s Music: Dixie Chicks, Grateful Dead (especially Franklin’s Tower, on repeat), June Christy " Something Cool (both mono and stereo), Best of Blondie and Best of Van Morrison...
insearchofprat OP
189 posts
 
... wanted more sparkle (cymbals) and discussed doing some tube swapping to 12au7s instead of 12ax7s... May try in the future.

Have always been experimenting with isolation, and swappng out interconnects: so I went in the closet, pulled out some old Harmonic Technologies interconnects - and POP! out came the cymbals, clearer more defined voice and PrAT I hoped for...
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