Greetings; this is my first post here, as I've been studying the forum for several months to make sure these questions haven't already been answered. This forum is a very cool resource, and I hope my newb questions and (hopefully the answers) will be useful to other forum members.
I'm working (in stages) on an analog summing soundstage for a DAW system.
Before boshing something together this time, I thought I'd ask for some advice.
I've seen references here to using transformers for summing instead of resistors, and how transformers can improve a passive summing design, but I haven't been able to find pointers on this approach.
1. From other posts, it seems prudent to have a cap on the input signal to filter DC before hitting the input xfmr; what value/type would be appropriate? and would it be needed for both phases of the signal?
2. The lundahl xfmrs require(request) a 8k resistor and 1.2nF cap to provide the quoted frequency response; how would this zobel network interact with the mix resistors (if any) and calculating their values? Each buss would have 4 inputs.
3. How would the bus xfmr affect the mix bus impedance, and how can this be tuned for optimal source/bus/mixamp loading?
4. Perhaps the xfmrs can be used/wired for additional gain?
5. PRR has made reference to 'mixing coils' and posted a diagram in which several input xfmrs had their secondaries wired in series for summing; are there any advantages to such an approach?
I'm working on a schematic now, and look forward to any informed comments, insights, questions and suggestions.
Many thanks for the consideration and patience with a fledgling DIYer.
cheers
I'm working (in stages) on an analog summing soundstage for a DAW system.
Before boshing something together this time, I thought I'd ask for some advice.
I've seen references here to using transformers for summing instead of resistors, and how transformers can improve a passive summing design, but I haven't been able to find pointers on this approach.
1. From other posts, it seems prudent to have a cap on the input signal to filter DC before hitting the input xfmr; what value/type would be appropriate? and would it be needed for both phases of the signal?
2. The lundahl xfmrs require(request) a 8k resistor and 1.2nF cap to provide the quoted frequency response; how would this zobel network interact with the mix resistors (if any) and calculating their values? Each buss would have 4 inputs.
3. How would the bus xfmr affect the mix bus impedance, and how can this be tuned for optimal source/bus/mixamp loading?
4. Perhaps the xfmrs can be used/wired for additional gain?
5. PRR has made reference to 'mixing coils' and posted a diagram in which several input xfmrs had their secondaries wired in series for summing; are there any advantages to such an approach?
I'm working on a schematic now, and look forward to any informed comments, insights, questions and suggestions.
Many thanks for the consideration and patience with a fledgling DIYer.
cheers