Having fixed the bias offset problem in my tester (actually my oscilloscope). I took again the curves this evening to get a better model….
If you want to read how did I manage to get here, please read this post
Updated 6e5P SPICE model
Tag: Dmitry
6e5p triode-strapped
The 6e5p is high-frequency indirectly-heated tetrode from our friends in Russia. The specifications can be found here. Anode can easily dissipate 8W and screen can take up to 2W and has a high transconductance of around 30 mA/V
Wired as triode this chap becomes very attractive. The anode resistance drops to around 900Ω – 1KΩ and effective mu is about 30-35. This turns this valve into a low anode, medium mu and high transconductance fellow which is highly regarded as a driver in SE amplifiers. Check out there in the jungle and you will find many good examples of how this valve is being used effectively.
When testing this valve on my curve tracer I found that it probes to be a challenging device. You need to leave this guy running on its own for a while (Lars recommended 30 min to 1 hour). I found that indeed after 20-30 min it stabilise.
Dmitry came up with a very good model. When I created a model based on my curves found a mismatch between my notes and simulation. Checking my notes I think I set up the tester to start plotting curves at 0V with a step of -0.5V, however looking at the model produced by Dmitry’s tool, I got this:
It looks like the curves starts at -2V. Need to re-check and probably trace this valve again. Either way it does match very well and not far off from Dmitry’s model from above.
Here is my model.
I’m planning to use this valve in my OTL (cap-less) headphone amp. Stay tuned…
Continue reading “6e5p triode-strapped”
Improved 46 triode-strapped DHT composite model
My initial attempt to get a reasonable SPICE model for a 46 triode-connected DHT has proven to be ok considering it was my first try. I got better accuracy with my second attempt using CX-301a. With time, I should learn the skills of Dmitry Nizh to master the great tool he has developed. For the ones who haven’t seen his website and great material Dmitry has produced around DHT, SPICE and other good stuff, I recommend you to read his article about composite models for DHT here.
Dmitry kindly produced a very accurate model for the 46 (and also shown clearly that I’m a still a rookie at this things ):
And here is the equivalent Spice model:
Using a simple circuit in LTspice we can test the model and trace the anode characteristic curves:
And the curves can be easily generated:
Note that grid voltage starts at 0V in -10V steps.