300B's for the BeePre

[mp9]

OK so it's recommended to use ST shaped over Globe to help reduce noise^, vibration and micro-phonic issues^^, something i've read to be inherent with DHT 300b based preamps^.

Any idea if the new Psvane marketing claim, "Due to the use of TEFLON as its base material, the Psvane Mark 2 becomes more stable and durable.", makes a positive difference with aforementioned concerns then other 300B's, or would that be more a function of the bee kits O rings/tube socket then tube type?

^ http://www.zenn.com.sg/DHT%20preamps.htm
"The reason for the scarcity of such designs is the problem of noise which is difficult to overcome in using a direct heated triode as a preamp stage."

^^
http://www.theabsolutesound.com/articles/audio-space-reference-2-linestage-preamplifier/ "To further isolate the tubes from vibration-induced microphonics, the 300Bs are seated in what Audio Space calls

[Doc B.]

^ http://www.zenn.com.sg/DHT%20preamps.htm
"The reason for the scarcity of such designs is the problem of noise which is difficult to overcome in using a direct heated triode as a preamp stage."

I think he is primarily concerned with filament supply noise. Aside from the rather vague info on that page that preamp seems a bit scarce itself. Is there another page somewhere with more info? Couldn't find anything on the zenn web site. I do like the guy's article about damping small signal tubes in oil. Buddha and I talked about doing that years ago, but never followed through with the idea.

[mp9]

- that was all i could find too. Thought it interesting to compare ideas with those of the TAS Audio Space Ref 2 review.

[Doc B.]

BTW I acquired some rubber isolation mounts to try with tube sockets. But their construction was such that we felt that they would probably not hold up to tubes being pushed into the socket. I suspect the best approach may be isolating the entire preamp via a good equipment rack. I have noticed that my lack rack is transferring vibration from our suspended listening room floor if I stomp around. Might be time for the old inner tube trick.

[xcortes]

The only non-standard tube that will work correctly is the 6A3, or a 6B4 with a different socket. That is not so much by design as a fortuitous accident!

interesting them being 6.3v vs the 5v of the 300B.

[johnsonad]

^ http://www.zenn.com.sg/DHT%20preamps.htm
"The reason for the scarcity of such designs is the problem of noise which is difficult to overcome in using a direct heated triode as a preamp stage."

I think he is primarily concerned with filament supply noise. Aside from the rather vague info on that page that preamp seems a bit scarce itself. Is there another page somewhere with more info? Couldn't find anything on the zenn web site. I do like the guy's article about damping small signal tubes in oil. Buddha and I talked about doing that years ago, but never followed through with the idea.

I wonder if you could get away with trying this with a power tube like the 300B or would it need to dissipate heat faster than the oil could manage?