Search found 5471 matches
- Wed Dec 31, 2008 7:44 am
- Forum: Pro Audio Design
- Topic: Mid Side M-S Matrix Uses No Precision Resistors
- Replies: 271
- Views: 638621
Re: Mid Side M-S Matrix Uses No Precision Resistors
I ordered new prototype boards yesterday which should be here Friday. Thanks for updating the layout Roger!
- Tue Dec 30, 2008 12:32 pm
- Forum: Pro Audio Design
- Topic: OTB Mixer Using Current Summation
- Replies: 137
- Views: 216024
Re: OTB Mixer Using Current Summation
You mean like "work?" I got a few orders this week too with end-of-year shoppers. Thanks guys!I'm busy today trying to ship some product before end of the year
- Tue Dec 30, 2008 11:27 am
- Forum: Pro Audio Design
- Topic: OTB Mixer Using Current Summation
- Replies: 137
- Views: 216024
Re: OTB Mixer Using Current Summation
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...
- Mon Dec 29, 2008 4:09 pm
- Forum: Pro Audio Design
- Topic: OTB Mixer Using Current Summation
- Replies: 137
- Views: 216024
Re: OTB Mixer Using Current Summation
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...
- Mon Dec 29, 2008 1:24 pm
- Forum: Pro Audio Design
- Topic: Mid Side M-S Matrix Uses No Precision Resistors
- Replies: 271
- Views: 638621
Re: Mid Side M-S Matrix Uses No Precision Resistors
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...
- Mon Dec 29, 2008 12:08 pm
- Forum: Pro Audio Design
- Topic: OTB Mixer Using Current Summation
- Replies: 137
- Views: 216024
Re: OTB Mixer Using Current Summation
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...
- Mon Dec 29, 2008 10:24 am
- Forum: Pro Audio Design
- Topic: OTB Mixer Using Current Summation
- Replies: 137
- Views: 216024
Re: OTB Mixer Using Current Summation
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.
Thanks for sending it Igor and joining us here in the forum.
- Mon Dec 29, 2008 8:41 am
- Forum: Pro Audio Design
- Topic: OTB Mixer Using Current Summation
- Replies: 137
- Views: 216024
Re: OTB Mixer Using Current Summation
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...
- Sun Dec 28, 2008 2:06 pm
- Forum: Pro Audio Design
- Topic: Mid Side M-S Matrix Uses No Precision Resistors
- Replies: 271
- Views: 638621
Re: Mid Side M-S Matrix Uses No Precision Resistors
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...
- Fri Dec 26, 2008 1:54 pm
- Forum: Pro Audio Design
- Topic: OTB Mixer Using Current Summation
- Replies: 137
- Views: 216024
Re: OTB Mixer Using Current Summation
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...