Whirlwind Mic-Eliminator schematic

[analogguru]

An interesting speaker-simulator circuit seems to be the whirlwind mic-eliminator:

The result was a device containing an analog filter circuit which creates a tonalitiy of the sound far superior to prior art devices such as the DOD Electronics Model 285 and the Hughes & Kettner model Mk III

Ok, here you can find the complete description:

http://analogguru.an.funpic.de/

(scroll down)

analogguru

[George Giblet]

Cool thanks. 

I just realized I d/l that one in 2000 - maybe I should read it again!

[George Giblet]

Here's a plot of the frequency response:
http://www.geocities.com/george_giblet/effects/ww_response.png

Note the dB values in the patent text are for the individual filter stages.

The amount of HF boost is along the lines of the Marshall JTM circuit but the amount of LF boost is higher. I suspect this unit would sound bright when fed with a amp output with a speaker load, an amp output with a resistive load might be better.  The notch filter emulates the amp EQ to some extent.

The unit suppose to be for inputs from, guitar, preamp or amp out but there aren't enough switches to cope with this - the Redbox makes some effort here.

Anyone got the DOD 285 schematic mentioned in the patent?