Hey all
In my quest to try and profile Ch 2 of my Matchless DC 30 [ Ceriatone clone ] cranked ..... I just read the following on the Kemper site here:-
http://www.kemper-amps.com/page/render/la…fier___FAQ.html
" .....We spent considerable time researching the dynamic behavior of the tube. It was also necessary to study the interactions between the tube and surrounding circuits, which become very complex when the tube starts to distort. We were lucky to find a way to extract this exact tube behavior by analyzing the intermodulation products of crossing sine sweeps. The relation between the intermodulations and the unprocessed sine sweeps tell us the full story about the distortion shape and dynamic of the tube and the behavior of the surrounding circuit. It can even deliver the information about several distortion stages in a row, so long as there is only one stage significantly distorting. This measurement is independent of the frequency response of the amplifier. Once the distorting part has been analyzed, it can be separated from the transfer function. The frequency response of the cabinet is then easy to determine and separate.Aside from the ease of profiling the whole amp, there is another good reason not .. "
I think this is the reason.
Why does the Amp need to be cranked you say ?
Well .... because that is where its glory lives .... it is the tone it is famous for ... imagine the Top Boost Channel of a classic AC30 with everything just about on full .. then take away the flubbyness and add in punch and clarity and buckets fo harmonic chime ......
If I crank Ch 2 of the Amp it is a glorious mix of Pre-Amp [ EF86 ] and Power-Amp Stage [EL84] - it has to be heard to be appreciated Ch 2 Pre-Vol set to around 1.00pm and the MV set to around 11.00
Bear in mind to it is only a 15w / 30w switchable amp.
However .... no matter how I [studio] profile it - regardless of refining or not refining and regardless of mic's used the result is always the same .... TERRIBLE
I can now only assume (?) the explanation above [ in red ] is the reason why.
If so .... can the Profiling process be imporved to capture [correctly] pre and power amp saturation ?
Ben