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Create new tube in LTSpice
Posted: Sat May 23, 2015 11:41 am
by Argentum
Hi. I just got LTSpice very recently. I am trying to build a circuit with two 6AW8As, and since its a tube that isn't commonly used for audio, I need to make a model for it in spice (Its a triode / pentode). How do I make a model to reasonably simulate the tube? I have the datasheet handy.
I don't want someone to do it for me, I just want to learn how.
Posted: Sat Jun 27, 2015 12:18 am
by cogsncogs
You can try Dmitry's Model Paint Tools to trace pentode and triode curves from the datasheets. To trace only triode models, I've used Curve Captor with very good results as in the 6AW8 triode section model below.
Code: Select all
* 6AW8AT (triode section) LTSpice model
* Modified Koren model (8 parameters): mean fit error 0.115916mA
* Traced by Wayne Clay on 10/19/2014 using Engauge Digitizer
* and Curve Captor v0.9.1
.subckt 6AW8AT P G K
Bp P K I=
+ (0.03960037226m)*uramp(V(P,K)*ln(1.0+(-0.02810705112)+exp((5.049360412)+
+ (5.049360412)*((71.53397072)+(-1430.15241m)*V(G,K))*V(G,K)/sqrt((60.13556928)**2+
+ (V(P,K)-(11.95246653))**2)))/(5.049360412))**(1.130546864)
Cgk G K 3.9p ; 0.7p added (3.2p)
Cgp G P 2.9p ; 0.7p added (2.2p)
Cpk P K 0.52p ; 0.2p added (0.32p)
Rpk P K 1G ; to avoid floating nodes
d3 G K dx1
.model dx1 d(is=1n rs=2k cjo=1pf N=1.5 tt=1n)
.ends 6AW8AT
I would have posted the URL's but, it's telling me I need to have posted a least 5 posts to do that.