Pro Audio Design Forum

I'll dig for it.

There was a PAR article about DSP vs. Analog summation about a year ago. The guy that wrote it - and I'm paraphrasing a 4 page article - basically said that DSP-based mixes had a very narrow "fader" sweet spot. His opinion was, after doing the same mixdown both ways, was that analog soluti...

Thanks John for the post and info.

But as you know I have a better plan for high performance summing.

Yes I do. I'm looking forward to that. We all are.

Another compensation question for you John: Some time ago I saw a schematic for a distibution amp and in it they had used a 5534 as a polarity inverter with a signal gain of -1. It was an internal stage without external loading (cable). IIRC the Rin and Rfb were 10K. What was different about it was ...

Yes Roger Rbias will factor into the precision of the attenuator as the pot (or switch) is rotated towards the -3dB position. And, it will shift the 0 mark as drawn. Consider that portion visual short-hand. I originally considered using two Rbias resistors. Both connect to the wiper. One connects to...

I decided to prototype a quick +3 dB gain stage with a 5534 to check the resistor values. With 6K19 and 15K at their ideal values we hit 3 dB within 0.08 dB. I confirmed exactly 3 dB via measurement. THD isn't bad although I really don't have the instrumentation to measure beyond 6KHz. Near the clip...

In the above drawing it's not clear whether the AD797 is inverting or non-inverting. It's non-inverting Paul. So there's no additional re-inversion required. Because it's non-inverting, the CM performance of that stage requires careful op-amp selection. That's why we looked at the AD797 vs. a Natio...

Have you looked at the moon recently?

Here's the view from Australia. In the northern hemisphere it's inverted.



http://www.theage.com.au/national/smile ... -6p8d.html

Isnt eaiser to have a switch to select between Cut/boost ? So when the pot is fccw there is 0 gain eihter way, in cut mode fcw this would mean 3dbcut and so on. I might have missed if you discussed this already. That could be done too but it doesn't eliminate the need for a "fixed" gain s...

Paul G wrote: What about having the decode line receiver 1240 feed a switch that is an attenuator with a maximum output of -6dB and have 6dB of makeup gain from an opamp afterward? The output of the opamp would have a low enough impedance to feed the decode circuit. I think it's almost exactly what ...