radiance
Well-known member
Wet / dry = crush & Blend.
Do a search, lot's of info to be found...
Do a search, lot's of info to be found...
Simple active summing mixer.
- Thread starter radiance
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Hi Radiance,
Maybe a bit later, but The 1243 inputs ¿can be built just like the datasheet ? or they need some other parts like the 1203 input.
About relays i know the panasonic, but are there other ones for unbalanced changeover signal switching?
Thank you,
JAY X
Maybe a bit later, but The 1243 inputs ¿can be built just like the datasheet ? or they need some other parts like the 1203 input.
About relays i know the panasonic, but are there other ones for unbalanced changeover signal switching?
Thank you,
JAY X
radiance
Well-known member
Well, my answer is also a bit late.....sorry.
Yes, the 1243's don't need any extra parts except for proper power decoupling caps but those ARE mentioned in the data sheet.
All extra parts needed for the 1203 are also mentioned in the data sheet AFAIK.
Sorry, I don't understand your question...
JAY X said:
Yes, the 1243's don't need any extra parts except for proper power decoupling caps but those ARE mentioned in the data sheet.
All extra parts needed for the 1203 are also mentioned in the data sheet AFAIK.
JAY X said:
Sorry, I don't understand your question...
horvitz
Well-known member
Hi Radiance,
Question for you on your input side.. have you had a look at your crosstalk performance? I built 16 channels of input using THAT1200, so the architecture is a little different, but maybe some of the same concerns. I've been seeing about 65db at 10k, which is OK but I think it could be better. I'm fairly positive that it has to do with the input side since if I remove all those components except for two channels, crosstalk improves to 80db.
So, I've been scratching my head about how to make it better, and perhaps it's as good as it gets but I'll pursue improving it until I'm convinced that I can't any more.
My thinking is that it's all the ref (pin 1) connections from each chip to the same ground plane. I can measure about 85k resistance between the input pins from one channel to the next. That makes perfect sense given the internals of the IC.
What I'm asking, I guess, is if you've been able to achieve anything better with your design, and if so then I may want to pick your brain a little about how you did so.
Thanks! And excellent work on this, hope you're enjoying it.
Brian
Question for you on your input side.. have you had a look at your crosstalk performance? I built 16 channels of input using THAT1200, so the architecture is a little different, but maybe some of the same concerns. I've been seeing about 65db at 10k, which is OK but I think it could be better. I'm fairly positive that it has to do with the input side since if I remove all those components except for two channels, crosstalk improves to 80db.
So, I've been scratching my head about how to make it better, and perhaps it's as good as it gets but I'll pursue improving it until I'm convinced that I can't any more.
My thinking is that it's all the ref (pin 1) connections from each chip to the same ground plane. I can measure about 85k resistance between the input pins from one channel to the next. That makes perfect sense given the internals of the IC.
What I'm asking, I guess, is if you've been able to achieve anything better with your design, and if so then I may want to pick your brain a little about how you did so.
Thanks! And excellent work on this, hope you're enjoying it.
Brian
To manage crosstalk you can review the difference between crosstalk at 1kHz and 20 kHz to gain some insight into possible mechanisms and /or paths.
HF crosstalk can follow a number of different paths from wiring dress to power supplies, to....
JR
HF crosstalk can follow a number of different paths from wiring dress to power supplies, to....
JR
horvitz
Well-known member
Thanks, JR. In rough numbers, 1k=86db, 10k=64db, 20k=58db.
I don't want to hijack Radiance's thread here so I should probably start a new one, but I was trying to get some feedback from others on similar architecture to see if it's even worth discussing before doing so. I've been having a very hard time finding any references at all which discuss any more than two inputs. We're kind of getting outside my limited experience, so I wanted to make sure I did all the research I know how to do first. At least if I can solve this, I will have a good leaning exercise!
I don't want to hijack Radiance's thread here so I should probably start a new one, but I was trying to get some feedback from others on similar architecture to see if it's even worth discussing before doing so. I've been having a very hard time finding any references at all which discuss any more than two inputs. We're kind of getting outside my limited experience, so I wanted to make sure I did all the research I know how to do first. At least if I can solve this, I will have a good leaning exercise!
The rising level with frequency suggest capacitive coupling pumping the crosstalk electrostatically into the wherever you are measuring it, "or" a rising inductive reactance failing to attenuate the crosstalk (wimpy shielding or shield termination) .
I don't know what topology you are talking about, perhaps you should start a new thread.
One other piece of advice. Measure the crosstalk from Path A to destination B, C, and D, for more insight into the transmission mechanism, and the obvious, wiggle wires and lead dress while measuring at HF, or add some passive shielding (like a grounded hand). Also, make sure adjacent channel inputs are terminated or if connected to sources that the separation of the sources are good.
This was a PIA part of console design to insure fader kill on a channel was killing more than just that channel.
JR
I don't know what topology you are talking about, perhaps you should start a new thread.
One other piece of advice. Measure the crosstalk from Path A to destination B, C, and D, for more insight into the transmission mechanism, and the obvious, wiggle wires and lead dress while measuring at HF, or add some passive shielding (like a grounded hand). Also, make sure adjacent channel inputs are terminated or if connected to sources that the separation of the sources are good.
This was a PIA part of console design to insure fader kill on a channel was killing more than just that channel.
JR
radiance
Well-known member
Hey horvitz ...sorry, I don't check this thread on a regular basis. Should use the "show new replies to your post" link on top more often I guess.
honestly, I've never measured the cross talk of my unit.
Would be interesting to see what schematic you used and how you did your PCB layout.
honestly, I've never measured the cross talk of my unit.
Would be interesting to see what schematic you used and how you did your PCB layout.
horvitz
Well-known member
Hi Radiance. I've forgotten to do the same on my own posts ;D
Mine is basically the reference design from THAT's datasheet and from there it goes to some relays for bus assignment. Nothing too fancy. You can see the board at the other thread I started to discuss crosstalk if you like:
http://www.groupdiy.com/index.php?topic=42055.0
Brian
Mine is basically the reference design from THAT's datasheet and from there it goes to some relays for bus assignment. Nothing too fancy. You can see the board at the other thread I started to discuss crosstalk if you like:
http://www.groupdiy.com/index.php?topic=42055.0
Brian
