Variable-mu and JFET data.

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Ribbledox

Active member
Joined
Oct 15, 2004
Messages
33
Location
London
Hola!

Does anyone have a good source giving distortion values and temperature dependance (and other data) for both a typical Variable-mu valve (perhaps the 6386) and a JFET, just to compare?

Cheers!
 
> a good source

No.

In both device types, noise, distortion, and max-gain-reduction are all inter-related. So you can get pretty good noise and distortion if you only need a few dB GR, and none of them will allow large max-GR with low noise and distortion. You pretty much need to specify what-you-want first, and then design and test the various topologies.

Vacuum tubes are "not temperature dependent": they live around 600 degrees so any room you can work in is all the same to them.
 
Thanks PRR!

Yes, that makes sense;)

The reason why I am asking is because I was reading an article where a distortion graph of a JFET "gain reduction circuit" was given for different amounts of gain reductions. So it would just be intresting to see a similar graph or table for a variable-mu valve. But I guess it is not that simple...

About the temperature dependance, I really learnt something new. I've always had this picture of tubes as very unstabile when it comes to temperatures. But what you are saying makes sense. But when ones states that the JFET showed a very small amount of temperature dependance, is it then perhaps compared to a bipolar?

Cheers=)

/R
 
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