Tonestack Calculator 1.3 software help.

[daryl]

I'm looking at the big muff tonestack design and playing with the 'Tonestack Calculator 1.3' software.

http://www.duncanamps.com/tsc/download.html

I'm after some basic help, understanding what i'm looking at and how to relate it to the whole big muff circuit.

Here is a graph from a standard big muff tonestack with tone knob on 5:



What I don't understand is how to relate this to the whole big muff circuit?

Because if you look at the line on thr graph none of it is within human hearing.

So if anyone can shed some light on using this program and relating it to a real big muff it would really help.

[daryl]

I just found this graph which seems to show that what I thought was correct. The line on the ABOVE graph is mostly outside of human hearing.



The Tonestack Calculator software seems really great, I just need to figure out how to apply the rest of the circuit to the tonestack results.

Because the signal is obviously shaped and amplified etc etc before it hits the tonestack.

So how do I account for that within the program? Or work out how to alter the results to account for the input coming into the circuit?

Otherwise I can't see how you can get any really usefull info from the program other than a general point in the right direction.


Any other software that will do this kind of stuff?

[Ronan]

The dB scale on the left in tone stack calculator is relative to 0dB, i.e. 0dB is a reference voltage level that represents the voltage level going into the tone stack, and you can see you will lose about 11dB at 800 - 900Hz. Do a google search on dB vs voltage level, or similar, for more info.

The dB levels that your ears hear have nothing to do with the tone stack calculator, that would depend on your amp/speakers etc.

[PRR]

dB is always *relative* to a specified reference level.

However in real life, people forget to specify the reference level.

In Hearing Tests, the reference level is "softest midrange sound the average person hears". (There's some debate about what this should be, and in the past different levels have been used, but zero dB _SPL_ is indeed a hardly-audible sound.)

In Amplifier Tests (and similar, such as tone-stack calculators), the reference level is _usually_ "unity gain". A 20dB amplifier puts out 20 dB more than you put into it. A tone-stack showing 9dB average loss puts out 9dB less than you put in.

The electronic tests do NOT directly tell what you hear. For that you need microphone distance and sensitivity, amplifier gain, tone and volume loss, power amp gain, speaker distance and sensitivity, room factor.

However if you already have a happy but flat amplifier, and insert a tone-stack, the TSC tells you that _this_ tone-stack has average loss of 9dB (you will want to find or add 9dB of make-up gain) and it is non-flat (which is usually why you were inserting a tone-stack, you wanted non-flat) with an audible slump in the middle of the audio band (or conversely: more bass and treble when mids are boosted back to original level).

[goamp]

Hi daryl,
my I say that your way of seeing things seems a bit too complicated. It's not really necessary to understand how the tonestack relates to the rest of the Big Muff. Just use your ears and switch the tonestack in and out of the circuit, a possibility that some versions offer anyway. The replies you got from Ronan and PRR are excellent explanation of the concept of Dezibels, but let me add that the most important question is if it sounds good.