I have cobbled many spice models together to work in my Circuitmaker simulator, but I can't seem to generate a set of plate curves within the simulation to check the accuracy of my math.
i have tried setting up a triode model.. say a 12ax7... and sweeping the DC plate voltge parameter from 0-300v in incriments of 10v, while sweeping a negative grid voltage from 1-3v in incriments of .5v, but i can't seem to find a way in the program of generating a graph of the plate current against the plate voltage to actually SEE the curves.
I am running the student version, so it is possible that the parameters I need are not available, but it is more likely that i have just set up the simulation improperly.
Can anyone help out?
i have tried setting up a triode model.. say a 12ax7... and sweeping the DC plate voltge parameter from 0-300v in incriments of 10v, while sweeping a negative grid voltage from 1-3v in incriments of .5v, but i can't seem to find a way in the program of generating a graph of the plate current against the plate voltage to actually SEE the curves.
I am running the student version, so it is possible that the parameters I need are not available, but it is more likely that i have just set up the simulation improperly.
Can anyone help out?
i don't know if I am happy that i figured out my mistake or not... because now i have hard evidence that the models that i have been using are cr4ppy! I laid the generated curves over the data sheets and Sophia traces, and most of them don't match up. Some are startlingly close though... well, time for some good 'ol math!
I never found a trusty ECC83/12AX7 model.
But I have extremely precise models of ECC88, 300B, 6SN7, etc etc...
all can be found here: http://www.geocities.com/koren_model/
See also here: http://www.diyaudio.com/forums/showthread.php?s=&threadid=60360
But I have extremely precise models of ECC88, 300B, 6SN7, etc etc...
all can be found here: http://www.geocities.com/koren_model/
See also here: http://www.diyaudio.com/forums/showthread.php?s=&threadid=60360
I dont know exactly what SPICE models you are using, and I fully agree that some models are better than others, but to put it into perspective, what you may want to do is measure the plate characteristics of some actual 12AX7, for example, and compare them to the Sophia traces, or whatever other data you have. I think you may find many of them wont match up either. My point being that I see as much variation between actual tubes as between models.
Robert McLean said:
Very true. I am trying to make some that are "close enough". I'll probably end up taking some sophia traces and data sheets and averaging the curves together and tracing them out.
If I can get a few of my staple tubes (12ax7, 6sn7, el84, el34, 6au6, ef86, 6922...etc) "close enough" to save a little breadboarding legwork, then I'll be happy.
Here is a confusing little jpg of the curves laid over a 12ax7 data sheet and sophia trace:
Attachments
Giaime said:
I have not been able to hack Koren's models into a form that I can use. I can alter 3f4 and PSpice models to function by rearranging the syntax of the equasions, but the Koren models, unfortunately, won't work. If anyone has altered them into the eqiuvalent 3F4 form, then I'd be happy to give them a whirl.
If you search this forum for "Curve Captor" you will find a very useful program for generating triode spice models. It will output 3F4, Orcad, LTSpice, and Circuit Maker flavours of spice.
It also does 4 versions of Korens model, as well as others
Here is what it spits out for a 6SN7 in Circuit Maker mode, just as an example, see if this works for you :
* 6SN7 CircuitMaker model
.subckt 6SN7 P G K
Bp P K I=(0.0231376265/1.0e3)*uramp(V(P,K)*ln(1.0+exp((7.300912403)+(7.300912403)*(21.38514806)*V(G,K)/V(P,K)))/(7.300912403))^(1.351490772)
.ends 6SN7
Robert McLean said:
I have downloaded Curve Captor... both Mac and Win binaries, but I can't get them to compile properly on either platform. I did manage to get the Windows version to "compile", there were a few errors, so it crashes shortly after startup. I even e mailed Andrei about a year ago, and followed his instructions, but no go.
Maybe that'll be my new year's resolution... to get that program running.
Andrei has a few models on his site
http://home.netcom.com/~wb2jia/tubes/spice3.txt
Most recently I used his 417A model on this page. There are several models for each valve, you need to switch the comment marks to select one. I use Circuitmaker 2000 and I needed to change the syntax (m to e-3) within the line of interest and then imported it.
Korens model is there for the 417. I think the 12AX7 is on the previous page in Andreis site but I don't recall whether Korens version is there.
http://home.netcom.com/~wb2jia/tubes/spice3.txt
Most recently I used his 417A model on this page. There are several models for each valve, you need to switch the comment marks to select one. I use Circuitmaker 2000 and I needed to change the syntax (m to e-3) within the line of interest and then imported it.
Korens model is there for the 417. I think the 12AX7 is on the previous page in Andreis site but I don't recall whether Korens version is there.
i have been tweking the parameters by hand, and I have a 12ax7 and 6sn7 based on a curve captor anode model that someone traced out... almost dead on the data sheets now, but it is a lot of tweaking and trial and error. What i REALLY need to do is get ahold of some traces of new manufacture tubes so that I can design models around them.
I used CurveCaptor to generate models for 6SN7, 12AX7, 12AU7, 12AT7, ECC88, 6C4Pi, and 6C45Pi.
http://www.joeltunnah.com
http://www.joeltunnah.com
Joel said:
hey Joel. I have been meaning to thank you for posting those, but I haven't seen you around in the last few days.
I have been using models based on the equasions in your models quite a bit this week. Since I can't get Curve Captor to work, the next best thing is finding someone else's traces and tweaking them. They are getting pretty close. They were close to begin with, but i am trying to average the curves from a bunch of data sheets and also make the model work better at higher grid bias levels.
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