Math Helper (Updated)

[marcoloco961]

I got tired of beating the calculator to death and thought I would try to make things easier on myself. I don't know if this has been done before, if so, I hadn't stumbled across it yet. To the best of my limited knowledge it is fairly accurate. If one of the resident guru's would double check me quickly I would appreciate it. This just made figuring values for the tone stack a little easier for me to visualize. See what you think. File attached.

I added a small chart of the normal frequencies used in plotting the tone stack. I thought it might be handy to have it right there to look at.

[Structo]

That's cool.

Is there a way to simulate the Dumble tone stack with the 10K pad on the Bass ground?
Probably no way to put the .001uF cap across the bass pot.

[marcoloco961]

That's cool.

Is there a way to simulate the Dumble tone stack with the 10K pad on the Bass ground?
Probably no way to put the .001uF cap across the bass pot.

I was going to try and put the calculation for mid attenuation level in there also, but could not figure out how to write the string for the math.

There probably is a way to add the other options, but I will have to get further in the book before I figure out the math strings for those values. I was wondering if anyone double checked my work to make sure it is accurate. I would hate to post this and have people using it if it is not proper.

If anyone knows how to add to this and wants to, feel free. This is a first crack at using Exel in this fashion for me.

[martin manning]

Interesting! What is the reference you are using for this?

[marcoloco961]

Interesting! What is the reference you are using for this?

The math and guide to the frequency ranges comes from the tone stack section of Merlin's book on Designing vacuum tube pre-amps. I am 90% sure I have entered the equations correctly and the sheet is accurate, but wouldn't mind a quick dummy check from someone with a little more experience than myself for peace of mind. I would feel way foolish if this is wrong....LOL (Hence the dis-claimer in the first post). The math used is basically :

1/ 2*pi*C3*(z out+R1) for upper bass. (Etc. )



The idea of the Excel spreadsheet used to do the math was from your load line plotter program. I use it and the Tone Stack Calculator all the time and love them. This one I put together just helped me visualize the crossover point better. When I am using the TSC and raise the Bass, it also pulls the mids making hard to judge exactly where you are ending the attenuation for the bottom. This is where it all started.


Please don't laugh at my strings and the way I wrote them.
I had a hard time figuring out how to write the strings so some are done in two or three sections. The boxes where these equations lie are over in the O column. When looking at the value of NF, I actually just took that box and multiplied it by .000000001. Probably the long way around the block, but it is still quicker than using a calculator to figure these values.

[martin manning]

Thanks, and thanks for the kind words on the Load Line Plotter. TSC (or similar simulation) is great but I like the idea of having a few discrete values to compare as a quick way to assess the effect of some change or other. The controls in this network are quite interactive, though, and that makes it difficult to capture the result. I'll have to look at Merlin's book again... it's been a year or so since I read through it.

Good work for a first effort! Excel is a great tool for doing things like this.

[marcoloco961]

Thanks, and thanks for the kind words on the Load Line Plotter. TSC (or similar simulation) is great but I like the idea of having a few discrete values to compare as a quick way to assess the effect of some change or other. The controls in this network are quite interactive, though, and that makes it difficult to capture the result. I'll have to look at Merlin's book again... it's been a year or so since I read through it.

Good work for a first effort! Excel is a great tool for doing things like this.

Thanks much Martin. This site and the good folks here have been an inspiration to me.

[David Root]

This has some things that the tone stack calculator from Duncan Amps doesn't. It has the crossover points identified. Maybe you can interpret the crossover points in the Duncan Amps TSC but it's nice to see a hard number.

Thanx very much MarcoLoco!

[Drumslinger]

pretty cool excel sheet. thanks marco!

[marcoloco961]

pretty cool excel sheet. thanks marco!

You are more than welcome gentlemen. I knew nothing about tube amps a year or so ago when someone directed me to this site. I am now about 1/100th of the way to being knowledgeable about these things. But I got to this point thanks to all the great information and help that this site has to offer.

Cheers.

[gearhead]

[quote="martin manning"]Thanks, and thanks for the kind words on the Load Line Plotter. [quote]

Mucho interested. Where to find?

Thanks!

[martin manning]

Thanks, and thanks for the kind words on the Load Line Plotter.

Mucho interested. Where to find?
Thanks!

https://tubeamparchive.com/viewtopic.ph ... highlight=

Cheers!

[gearhead]

Great job, thanks!

Did do a search on "load" and "line" and your nick. Nada.
Load Lines was a hit. Picky search engine.

[tubeswell]

Thanks for going to the effort to produce that and share it marcoloco961 Its always useful to have that sorta stuff

[martin manning]

Great job, thanks!
Did do a search on "load" and "line" and your nick. Nada.
Load Lines was a hit. Picky search engine.

Okay, changed the thread title... it's load line (singular) now.