Pro Audio Design Forum

I ordered new prototype boards yesterday which should be here Friday. Thanks for updating the layout Roger!

I'm busy today trying to ship some product before end of the year

You mean like "work?" I got a few orders this week too with end-of-year shoppers. Thanks guys!

John - I think we would need full attenuation on pan. People are so used to that. Maybe we should consider a "dual slope" pan law with -20 dB/V below center (-5V FS for -100 dB) and +1 dB/V above center (+5V FS for +5dB). The opposing channel could follow the inverse of this. The breakpoin...

WRT to extreme boost we probably wouldn't need more than the +4 to 6 dB from pan if even that. I still think that if we can save an op amp or two per input in the pan circuit using both ports we ought to do that. IIRC when we last visited that you were going to have a beer and think about. How did t...

I also tried the precision bypass mode and the crosstalk improved. I swapped the L&R channels from prior measurements. By hand picking 1246/1240 combinations I can make the L to R as good as the R to L numbers. Unfortunately on this prototype the left channel 1246 is soldered to a flying lead. T...

They were advised by THAT to use separate pads and buffers at + and - control ports. One inverting buffer and one non inverting buffer. This prevents hitting the VCA with a correlated noise source (in first buffer?). This seems like it should be a modest phenomenon but perhaps measurable with noisy...

I do want to forward Igor's article to THAT however and ask about the differntial Ec drive. I really need to print it but I don't think I've seen that approach used before - just differential audio path and parallel is what I've seen.

Thanks for sending it Igor and joining us here in the forum.

Wayne, have you ever discussed something like this with lads at THAT? The schematics you posted shows the typical parallel up a bunch, but that's to drop into some old sockets to make up for smaller geometry transistors. I wanted to show the Cv pads and buffers. The parallel-up-a-bunch doesn't make...

When I originally designed the matrix I was concerned about gain build-up during encoding in the Mid (L+R) channel and also in the decoder which produces not L and R, but 2L and 2R . In anticipation of that I designed the following circuit and then allowed myself to get talked out of using it off-fo...

The LM833 is compared by Douglas Self to the NE5532 with slightly higher noise and somewhat less drive capability. I think the 833 was National's answer to the 5532 and it's not a bad choice either. There may be a modest need for speed and output current in this stage to keep the output impedance fr...