
mshilarious
Banned
FALKEN said:mshilarious,
I have been staring at this post for days (2nd one on this page) trying to figure out what your nomenclature means. I assume the 12.7k refers to a fader at half tilt? I dont know where the 10k vs comes from and what the || means... (in parallell with?) I guess I just don't see how these expressions match up with the diagram.
x||y is two loads in parallel, and I was using x : y to show the ratio of resistance that forms a voltage divider. There were three loads I was considering there, but one of them, the 12.7K, is a parallel load itself: the 10K mix resistor of the other channel in series with the parallel load off both sides of the fader, 5K||6K (5K from 1/2 the fader plus 1K output impedance of the input device), so written all the way out: 10K : (10K (other channel mix resistor)+ 5K (1/2 fader)||(5K (other 1/2 fader) + 1K (output impedance of input device)))||1K (shunt)||10K (input impedance of output device).
have a link? or can I get this at radio shack?
I posted one in #38:
http://www.homerecording.com/bbs/showpost.php?p=1830055&postcount=38
frederic suggested the addition of some resistors to bleed off power from the big caps, so maybe put a 1K/1W resistor in parallel with each cap. Also I would add a LED off the +15V side across a 3.3K resistor as a power on indicator. Make it a blue one


You can get most of the parts at RS. However RS doesn't sell a transformer big enough to feed a +-15V regulated supply, and they don't sell negative volt regulators. So you could either go unregulated, or get some parts from digikey. Of course RS doesn't sell quality opamps, so you'll have to order out for those, but if you are just building a test circuit, I believe they have TL082s.
This tranny:
http://www.radioshack.com/product/i...atId=2032058&kw=transformer&parentPage=search
This rectifier (they have a 50V version listed, but this one is always at my local stores):
http://www.radioshack.com/product/i...ctifiers&fbc=1&kw=rectifier&parentPage=search
This cap:
http://www.radioshack.com/product/i...wCatId=2032058&kw=capacitor&parentPage=search
plus the fuse, fuse holder, switch, resistors (and LED!) should get you to between 15-16.5V, so I'd watch the opamps' ratings.