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Author Topic: Codec in the preamp.Fear or Favor?  (Read 2276 times)

yustech

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Codec in the preamp.Fear or Favor?
« on: September 20, 2011, 01:04:33 AM »

Hello,I came across a Line 6 spider III 3012 that has power power problem,upon checking and comparing with spider II schems,I found some similarity between the two for voltages checking.

upon looking at it I didn't saw op amp near the EQ controls,then I found that they use codec.I am no codec expert but I don't like this,my work came to a stop.There's no such codec in my country.

Who else is using this codec IC?
I don't believe codec is equal to the hard working op amp,trannies etc.
Its a good way to kill us small time tech.

what do you think fellas? :)
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teemuk

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Re: Codec in the preamp.Fear or Favor?
« Reply #1 on: September 20, 2011, 05:36:22 AM »
Every manufacturer that makes amps with DSP use codecs, not neccessarily the exact chips as Line 6 but often chips of same series or at least equivalent models. If I rememeber right, Peavey Vypyrs, Fender G-FLEXes, Line 6 spiders, Vox Valvetronix amps, and bunch of other DSP-relying amps all used Intersil codecs of the very same product family.

The potentiometer DC level sampling varies from amp to amp. Fender used a discrete multiplexer + analog converter, in Line 6 products those two are usually integrated and so on. Essentially the configurations are still more or less about the same.

Quote
what do you think fellas?
I don't believe codec is equal to the hard working op amp,trannies etc.
What is that supposed to mean anyway? DSP is what it is; depending on the overall algorithms and part quality it can be better or worse than traditional analog circuit, the biggest advantage is at least that you don't need a gazillion parts to emulate handful of different amps, distortion effects, and time based effects. I'd rather use an AXE-FX or Eleven Rack with codecs and DSP than Gorilla amps with hard working opamps etc. It's all about how they're made.
Yes, it's pretty mandatory for amps using DSP to have a codec chip; you won't be finding discrete AD/DA converters and building one wouldn't really make any sense. It's also pretty much mandatory for circuits relying heavily on microprocessing to look internally like computers and utilize many integrated chips of specific purpose. To be honest, codecs and AD converters with built-in multiplexers today aren't exactly obscure parts. You can likely order the codec online from some part vendor or perhaps even from the manufacturer itself.

So... You amp has a "power problem" (what does that mean, btw). How did we even get to codecs? Start from verifying that the power supply works, that the analog power amp chip isn't toasted and so on.
« Last Edit: September 20, 2011, 05:44:29 AM by teemuk »