[Radio Wrangler]

Going back to GJ's first post and the plotted responses, the graph seems to invite looking at the difference between the plots and the black line which I take is the RIAA equalisation curve?

In this case there seems to be more bass boost and more treble cut than I'd ever want.

But, with a pizo-electric cartridge, is RIAA appropriate? They usually get flat amplification, so the plotted responses look even worse.

I was just thinking that the cocktail cabinet was a good idea, anyone listening to that would want to be seriously drunk, when a memory surfaced. Wasn't there a preamp design (transistor) in WW by Bailey/Burrows/Quilter that loaded a piezo cartridge into a low-z, and then applied bass boost to compensate for the resulting roll-off?

Is something like that going on? An audio analyser will probably be a much lower z source than this amp is intended to work with. I think you need to create a drive network to model the characteristics of the original cartridge to get plots that give the real picture. There's probably interaction with the cabinet and speakers too.

I now have this mental image of the upper management of Blaupunct deciding on the wanted tone of this beastie as it bounces around their board room playing oompah band music flat-out as they also test the cocktail cabinet...

Blau-punk'd

David