I finally got all the parts I wanted for the base model of my CMoy++ so I started to prototype it out on a board from RadioShack. (I'll borrow a friends camera to show how it looks later) It's basically a CMoy with a real ground, buffered outputs, bass boost, and a DC jack for charging the batteries (2 NiMH 9V bats) I'm still waiting on a voltage regulator from LT but I have the rest of the circuit ready to go.
There is a question that I'd like to discuss though.
I wanted to make a real ground as it reduces the amount of components needed and also creates less noise and lower output resistance than a buffered ground. (according to this, this, this, this, this, this, this, this, this, and this (to admins: I like to add refrences to my things so I A: give credit where credit is due to people who actually know what they are talking about, and B: to give myself credibility so I am not just talking out of my a**))
The only issue is if one of the batteries were to come disconnected by accident. (I don't mention batteries draining unevenly because before there was an issue you would get distortion making this a non-issue)
If I go with a real ground I think I'd like to implement a circuit somewhat like the O2 that would cut power if a battery came unplugged (or just cut at low voltage so that it retains quality)
I'd like thoughts on this. I don't know the circuit used by the O2 yet but I can easily go look at how its implemented and do something similar. A virtual ground would solve this issue, but would also introduce more problems itself.
So virtual ground or a real ground with low voltage protection?
PICTURES: bro was home from college so I borrowed his S III and took some pics. had cyanagen mod on it though so the camera isnt as high quality as it is with default :/ oh well, they work:
middle line is my ground on the pic below. At present moment its a real ground but can easily be converted.
Its obviously not finished (feedback loop isn't even built) but its a start. This is just a prototype (going to get into etching my own PCBs) but what do you guys think of my placement? Any criticism except incoherent fits of rage are accepted :)
P.S. will label some pics soon and upload them
NEW PICTURES WITH CASE AND FINISHED AMP:
Keep in mind the case is not final. As it says on the front, it is a prototype (and actually doesnt work ;) ) it was a fast print and simple design (the lines you see on the front are supports that used to extend across letters to support certain parts (again, fast print)) and I've already got a new design in the works (I design my cases in solidworks and then print them) tell me what you guys think :)
Side note: Amp's done. has a gain of 4.7 and a real ground (at present moment) i'm going to run it through some tests but measurements of DC offset are kind of high (probably due to one of the batteries being more drained than the other (right channel is 45mV and left is 30mV)) anyway, I think 4.7 might be a bit too high with the amount of bass boost I have implemented (then again in final design there will be a lot less bass boost, I just wanted to see how much it could take) so I'm going to have to play around with some things. Of course, again, this is a prototype. The official design will be on PCBs that I plan on etching soon. Going to try to use Eagle or similar to print out the designs....any recommendations for which is best for printing designs to etch?
Any comments, crtiques, help greatly appreciated.
Edited by backspace119 - 2/24/14 at 6:58pm