tube

[Q_tube]

Hello....
i had just finish my power amplifier design with 4 tube EL34 and 3 tube 12 AU7. i want to know equivalen circuit for pentode an one can help me?

 

[Giaime]

Why? Can't you find the EL34?

You can try subbing it with KT66, 6CA7, or by changing some component values you could use 6550, KT88/90/100, 6L6GC, 5881... just find what you can obtain cheaply and tweak the circuit!

My database also says that CV1741 is a good sub.

 

[SY]

If you really mean a pentode equivalent circuit, the simplest one for the purpose of signal analysis would be a Norton current source (with i = g_mV_gk) in parallel with the plate resistance.

You can determine plate resistance and transconductance at your operating point by examination of the tube curves on the data sheet.

 

[Radames]

Norman Koren's model

Hi.

If you would like to model the behavior of triodes and pentodes, I suggest you use Norman Koren's models. I have implemented triode modelling in Matlab using his model and find it really good.

Norman, together with Stefano Perugini and Mithat Konar have information about the models in their web sites:

http://www.normankoren.com/Audio/Tubemodspice_article.html

Spice Models Survey

http://www.birotechnology.com/articles/VTspice.html

If you want more information in model implementation, I may be able to help.

Cheers,

Rada

 

[Giaime]

Oh sorry I completely misunderstood your question...

Bye!