Well thanks, but that would be problematic. If a signal in the chain went positive and started "pulling" the ground reverence higher than the OP amp voltage, it would become like an open circuit since the diode is reverse biased. Not much of a ground then, right? Especially if I'm trying to keep any capacitor there small. But also, consider that I've seen no more than 10mV of difference between two such OP AMP dividers. Better I think to just use a small resistance and live with a few hundred microamps though the resistor. After all, this is audio, so unlike any diode solution, a resistors' response would always be linear and less likly to cause distortion.
An innovation needs to be original and useful. This is neither.
I am not obliged to address your core question. I can address any issue I see raised by your posts.
You will find many instances here where people who are perfectly capable of answering questions sometimes withold their assistance when simply to answer the question allows the questioner to escape asking him- or herself the harder questions. It's not trolling, it's not faintly intended to be antisocial, it's just that I know this subject backwards. When I read your posts, I understand those questions that are running through your head, I've been there, but I also know those questions that you aren't asking, and that you need to ask.
OK, you resent being made to solve your problems for yourself. I can dig that. I hate being forced to think too.
You talk a good fight, but you could have got rid of me way back, if you had shown a single diagram of how you could have achieved just a part of your requirement with a single supply. You know, put your money where your mouth is.
On thing about guitar boxes, those of us who are guitarists prefer them NOT to be DC coupled, because every cap between you and the mains is one little bit less likely that you'll get a killer shock.
I am not obliged to address your core question. I can address any issue I see raised by your posts.
You will find many instances here where people who are perfectly capable of answering questions sometimes withold their assistance when simply to answer the question allows the questioner to escape asking him- or herself the harder questions. It's not trolling, it's not faintly intended to be antisocial, it's just that I know this subject backwards. When I read your posts, I understand those questions that are running through your head, I've been there, but I also know those questions that you aren't asking, and that you need to ask.
OK, you resent being made to solve your problems for yourself. I can dig that. I hate being forced to think too.
You talk a good fight, but you could have got rid of me way back, if you had shown a single diagram of how you could have achieved just a part of your requirement with a single supply. You know, put your money where your mouth is.
On thing about guitar boxes, those of us who are guitarists prefer them NOT to be DC coupled, because every cap between you and the mains is one little bit less likely that you'll get a killer shock.
OK... you're addressing me? Good. Now we can have a discussion. True, you're not obligated to answer any question, and I would be foolish to assume you're not answering means you "can't", wouldn't I. So please extend me the same courtesy.
Regarding diagrams. first of all, what you conveyed (I'll paraphrase) is that its impossible to answer what I'm asking without all the details. I explained that I was trying discuss a methodology that would work independently of some of those details, because in truth its impossible to post ALL the details. Now that you apparently see from other threads that the device #2 in question is meant to interface with at least one other device I designed, a guitar with some unknown electronics, and an unknown combination of up to 8 misc effects pedals, do you believe me now? Drawing all that would have more black boxes than components, and next you'd want to know what's in the pedals! I have no choice to design to the unknowns as best I can. So that means if I have a question, its best for the reader to think of scenarios that could be a problem. the last thing I want is to narrow the scope and cause possibly unwarranted assumptions. (like assuming ALL pedals are capacitively coupled).
Second, in another post you accused me of possibly wanting to turn this into a commercial app, as if that were an evil thing to do. I freely confessed I wouldn't mind turning a profit someday. I honestly wish more designers would have the guts and sense to ask for input as I do, on lots of features and inner workings. But I digress. I DID offer schematics privately to anyone interested. Privately because on a public forum where anyone can join, it should be obvious and reasonable that I might not be quite ready to make my whole project "open source" just yet, just because I wanted to discuss a grounding issue.
As far as resenting being made to solve problems for myself, you obviously don't know ME very well. Nothing could be further from the truth, and you know it! You say you've been there? Then you know darn well the hours, sometimes weeks and months proving out a design, and the literally countless modifications you make until you're satisfied things are going well, and you've covered the bases. But do you really think having the humility to request opinions, when you're doing something outside the box is the same as being lazy about solving your own problems? I'm sorry but people who know so much that they never consult anyone else are bound to make critical mistakes that could have been avoided. I wonder what fool caused the fiasco with the Hubble telescope optics. Oh I'm sure it was an honest mistake, but it was obviously a mistake made by someone so sure of themselves they never bothered to let anyone else take a peek. If that's the way YOU want to design, because you know it all so well, fine by me. Me? I'll listen to and try to learn from everybody. that is, provided they offer me things to learn.
It is true that in a situation like this, where I've designed and tested a device, then committed it to costly PCB prototypes, and now need to consider an add on device, I am reluctant to just throw out a working investment of time, money, and believe it or not a LOT of thought, just because someone says I should, because other people have traditionally done something another way. Being unwilling to abandon work for no good reason is a long way from being close minded, or unwilling to consider other ideas.
Now... you said guitarists prefer things not to be DC coupled because of the shock hazard. Thank you. I SO appreciate concrete warnings like that more than rhetoric. As it turns out, despite my exporting of virtual grounds for signal returns, for reasons I've already defended, I do place capacitive coupling at all my main ins and outs. Though shock hazards are becoming less an issue now with so much equipment powered by isolated supplies, I do agree that a capacitive coupling makes good sense. It also limits some unwanted low frequency garbage that can be generated by magnetic pickups (Limiting the low frequency signal peaks from unconscious slapping the strings for example). For the individual pedals though, I think it is a plus to be able to pass the signals directly from one device to another, with nothing more than the approximate 20 ohms (give or take), of equivalent through resistance within my MAXIM chips. I am, after all, trying to simulate about 16 patch cords there, so it just seems wise to be able to do so without so many extra capacitors. Especially when, as I've said, most of them likely use capacitive coupling too. And I think we both know that we both know why.
But you see? You offered a useful point, and I did you the courtesy of explaining how I'm addressing it. As you said, you have no obligation to offer me anything. But if you know things so forward and backwards as you say, you ought to consider that I'm not the lazy bum you seem to think I am. I put lots of hours into this stuff, and besides the hardware there has been over a year of firmware development that is still being tweaked. I wear a lot of hats, and I'm working my tail off on this stuff. If you want to help, or at least be helpful, much obliged. If not, that's a shame. But that's life. Others that likely know much less than you have been much MORE helpful over the course of this thread.
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