Glasware Tube CAD

[Structo]

Has anybody tried the Tube CAD program by Glasware?

It's only $36 and was wondering if it would be a good tool to help understanding circuit design better.

Specs:

What does it do?

Tube CAD includes 13 types of tube circuits, divided into four variations each - 52 circuits in all. The circuit types are:
Cascode
cathode follower
common cathode
differential amplifier
grounded cathode
grounded grid
I to V converter
long tail phase splitter
plate follower
push-pull
split-load phase splitter
totem-pole
white cathode follower

How does it work?

The metaphor used is that of a notebook with 13 pages, one for each circuit type. Clicking on the tabs at the bottom of the program brings up that circuit page. Circuit schematics and plate curves require just a button click to be seen. Circuit variables such as tube type, B+ voltage, plate and cathode resistor values, and coupling capacitor value are entered in field boxes or changed by sliding a horizontal slider control. After the "Calculate" button has been pressed, the AC and DC results are then displayed.

What special features does it have?

A built-in tube manual, with tube plate curves, tube base pin-out, tube envelope outlines - and it prints spec sheets. It also does circuit evaluation, with circuit error listing and auto load of corrections. Circuit reports can be made for single circuits and scenarios.And scenario comparisons can be made among four circuits per page.

http://www.glass-ware.com/tubecad/

Antique Electronic Supply sells it.
http://www.tubesandmore.com/

[skyboltone]

I've got their old Single Ended Amp design software around here somewhere. It is over 15 years old and very limited, but my thinking is if they have survived this long they must be doing something right.

[Andy Le Blanc]

been wanting to check that out for a long time. saw it first in
glass audio and audioxpress which are great resources.

its for the others, who cherish tube tone evenmore than thou

the best home amp Ive built was a stereo that used 6sn7 mu-followers
driveing single ended 6v6s.
could have arrived at the final design a lot sooner with a tube cad.
the tube cad journal is a trip. check it out.

[FunkyE9th]

I just received my copy on Friday. Haven't installed it yet. I'll try and post a review when I get enough experience playing with it. I did not see power tubes listed on their supported list. I was really hoping they would. It would be nice to get plots at different screen voltages.

They have a 30 day trial period. So you can always return it if you don't like it.

[drz400]

It is a no brainer for the price, only program of it's kind I know of and supposedly more accurate than Spice.
For that alone it is worth the active plate curve plots.
I have owned it for some 10 years, just don't expect any support. You are pretty much on your own after the purchase. I had some questions about a few of the options and recieved a 1 sentence answer that really didnt answer the question. I was never able to contact the writer again. Dont expect any updates either. I have all their programs though, it is useful.

[Merlinb]

I have Tube Cad, SE cad, and Audio Gadgets.
I don't find them particularly easy to use, there are some labels that don't make much sense, and I haven't quite figured out what some of the power calculations are telling me. I certainly wouldn't bother to use it for guitar amp design, and I don't think it teaches you anything- it just crunches numbers. Handy for hifi, to some extent, but I still prefer to use SPICE and load lines for most stuff.

[FunkyE9th]

Well, I started playing with the Tube CAD last night. So far I'm not happy with it. I've only played with the grounded cathode circuit.

What I don't like...

-They do not offer a model for the 12AY7. I did not notice this at the time I ordered it. I probably should have paid more attention to it. Maybe Hi-Fi guys don't use it.

-It requires that you enter the idle current. I guess, if you are designing something from scratch, you would pick your idle current based on the loadline you have. The software then spits out the Rk and Ck. My problem is, one of the things I wanted to do is model an existing circuit for an amp that I do not have. So I do not know the idle current. I was hoping I could enter the circuit variables and somehow the software will give me AC and DC results. It does not do this. Maybe it's not possible to do, but that's what I was hoping I could do.

-So now lets say your entered all your circuit variables and you want to get a plot of the loadline showing quiescent conditions for the given circuit variables. It does not do this. It has some fancy GUI way for you to click somewhere in the plate curves and it will draw a loadline, but for some reason, it can't generate a plot for the variables you already entered! What's up with that?! That's ridiculous IMHO. Also the GUI to click the plate curves is difficult to get the exact plate voltage. I was trying to set it to 325V and it was a pain.

-It does not allow you to set the value of Ck.

-It does not do Frequency response plots. It just gives you 3dB points. I mean how hard is it to get the plot?

-I was gonna try the Long Tail, but the circuit I had did not match the their sample so I just skipped it.

What I liked...
-It allows you to enter parameters for tubes that are not on the list. But it will not have the plate curves for the tube.


Anyway, maybe I was expecting too much from the software. I was really hoping to get some nice plots. It seems to be a just a fancy excel spreadsheet. I can do all that stuff myself on a spreadsheet and then use Matlab or equivalent for freq plots. Actually, the Valve Wizard does a good job. Its free and it does frequency plots and loadlines. Granted the Valve Wizard only does one type of circuit and it just draws the loadline without the quiescent point...

That's all I have..

[Structo]

Thanks for the review, sounds like something I will not get.

Too bad they did not keep developing the program and listen to user input concerning updates to the program.

[drz400]

I have Tube Cad, SE cad, and Audio Gadgets.
I don't find them particularly easy to use, there are some labels that don't make much sense, and I haven't quite figured out what some of the power calculations are telling me. I certainly wouldn't bother to use it for guitar amp design, and I don't think it teaches you anything- it just crunches numbers. Handy for hifi, to some extent, but I still prefer to use SPICE and load lines for most stuff.

I think it is worth it just for the active load lines
BTW You can add your own tubes and you can play with the current until the cathode resistor matches what you are using.

It is true though it would be nice for an update
Also the input impedance is a bit confusing.

[Structo]

I guess what I'm getting at is for the casual amp builder who's tube theory is not very advanced, it wouldn't be a plug and play type program.

I would think someone could make a program with a much more advanced GUI that would show a technician type amp guy what the different circuits look and sound like.

Say, you swap the plate loads and bypass values or coupler values, a graph really doesn't tell me a whole lot how the circuit is going to sound.

[drz400]

I guess what I'm getting at is for the casual amp builder who's tube theory is not very advanced, it wouldn't be a plug and play type program.

I would think someone could make a program with a much more advanced GUI that would show a technician type amp guy what the different circuits look and sound like.

Say, you swap the plate loads and bypass values or coupler values, a graph really doesn't tell me a whole lot how the circuit is going to sound.

Calculations do not usually follow the real listening world anyway.
I find TubeCad handy to double check you are in the ballpark and didn't miss something catastrophic

[David Root]

I use TubeCad all the time, it is very useful. If you go to "other" in the tube selector and plug in the 12AY7 specs, it will do the calcs, but it won't do the graph of course. SECad is only useful for SE circuits, even though it shows beam tetrodes and true pentodes, ALL the calcs are for triode connected mode.

I too wish that Mr Broskie would come out with a proper push-pull
P-PCad. His website shows he is getting more questions about P-P designs from the Hi-fi crowd (because the scrawny 4-8W you can get out of most SE hi-fi designs won't power most of the best hi-fi speakers around to any realistic spl), so let's hope he gets the message. He could easily do it, he is a real giant earth brain.

[Structo]

I went ahead and ordered a copy since I needed some other stuff from AES.
I hope I can actually use this program to learn more about the different stages.

[Structo]

I installed it this morning.

First impressions is that I need to read the help file immediately.

But it will be fun plugging in different values.

Funny thing is when I plug my D'Lite values in it says I am exceeding a lot of things...... Whats up with that?

[drz400]

I installed it this morning.

First impressions is that I need to read the help file immediately.

But it will be fun plugging in different values.

Funny thing is when I plug my D'Lite values in it says I am exceeding a lot of things...... Whats up with that?

What values? I would be surprised, sure you have all the settings correct?
I just plugged in a 12AX7 Grounded cathode .83ma 300V B+ 100K plate 2K2 cathode 500K load everything comes out A OK