dreamie 0 Report post Posted April 6, 2004 Hi everyone. I would like to view the schematics of some CMOY amp variations, could some kind soul put it here? THank you! I have acquired the following components for the project. 2* Matsush*ta (Panasonic) LXF series 680uF 16V capacitor. 4* 0.068uF Nichicon 'Paper-in-oil' (PIO) capacitor. 8* 1% metal film resistors. 1* 5% carbon resistor. 2* 3.5mm socket. 2* 4-pin DIP IC socket (Made by Texas Instruments... patented. ) Anything I left out? I plan to parallel 2 of the PIO caps to get closer to the 0.1uF. Takes up alot of real estate, but it is PIO. Planning to use the TLE2426 virtual ground driver to obtain ground reference, instead of using a voltage divider ala CMOY style. Please advise. Thanks a million! Share this post Link to post Share on other sites
Firefox 0 Report post Posted April 6, 2004 Looks reasonable.. I hope your R2 isn't 100k since you opted for using ~0.1uF signal caps. Try 220k/ 470k instead. 4-pin DIP socket? That's interesting.. Share this post Link to post Share on other sites
dreamie 0 Report post Posted April 7, 2004 Looks reasonable.. I hope your R2 isn't 100k since you opted for using ~0.1uF signal caps. Try 220k/ 470k instead. 4-pin DIP socket? That's interesting.. Hmm.. how would the R2 value staying at 100k affect the overall circuit? Thanks in advance for the forthcoming enlightenment. R5 is optional, but is it good to have one? Thanks once again. Got that socket from Koba. It is inside the bag of normal sockets... just gotta look hard enough. Share this post Link to post Share on other sites
dreamie 0 Report post Posted April 9, 2004 Hmm... have some questions regarding the TLE2426. I'm afraid it can't supply enough current to the opamp. (most probably OPA627, 637 or AD8610) Are there any solutions to it? Tangent audio mentioned BUF634, but that's gonna eat into precious real estate. The PIO caps have already claimed owner on a large plot on land... Share this post Link to post Share on other sites
dreamie 0 Report post Posted April 9, 2004 Did up something... http://www.villagephotos.com/image.asp?id_...256&sessionkey= Compared with the PPA supply, this has shared ground (not sure if PPA is sharing ground) and lacks a few transistors to attenuate the noise (right?). Would this work? Thanks. (never used villagephotos b4. if pic doesnt show, try: http://www.villagephotos.com/browse.asp?selected=820071 ) Share this post Link to post Share on other sites
dreamie 0 Report post Posted April 9, 2004 Hmm.. after looking at it carefully seems like it wont work... Any idea how much current these opamps draw? TIA. Share this post Link to post Share on other sites
hacknet 0 Report post Posted April 9, 2004 they draw next to nothing on idle. they can draw quite abit depending on the load. Share this post Link to post Share on other sites
dreamie 0 Report post Posted April 10, 2004 they draw next to nothing on idle. they can draw quite abit depending on the load. Thanks for your input. Any idea how much it draws for the worse condition? Thanks. I guess i will settle with a simple voltage divider as per Cmoy schematic. The PIO caps are taking up almost half of an Altoids tin can. Oh yea, I got an Altoids tin can, found it somewhere in the house. Share this post Link to post Share on other sites
jtfoo 0 Report post Posted April 10, 2004 Why don't you read the datasheet? The info are all there if you put a little effort to go thru it. And the best thing is you'll learn something more from the datasheet. From Datasheet, the TLE2426 max current out is +- 80ma Max output from Burr Brown's OPA like the 2132 or 2604 (from memory) is about +- 35ma... TLE2426 is more than enough, coz more than often the OPA don't reach to 35ma, unless you're driving low impedance headphone like the Grado. You're doing a Cmoy right? So I assume you'll be usingn just one opamps without buffer. Share this post Link to post Share on other sites
dreamie 0 Report post Posted April 10, 2004 Why don't you read the datasheet? The info are all there if you put a little effort to go thru it. And the best thing is you'll learn something more from the datasheet. From Datasheet, the TLE2426 max current out is +- 80ma Max output from Burr Brown's OPA like the 2132 or 2604 (from memory) is about +- 35ma... TLE2426 is more than enough, coz more than often the OPA don't reach to 35ma, unless you're driving low impedance headphone like the Grado. You're doing a Cmoy right? So I assume you'll be usingn just one opamps without buffer. Guess I was too carried away to forget to read the datasheet.. my apologies... Hmm... then I suppose I can use the TLE2426 to power a pair of opamps after all. Thanks for your enlightenment. Share this post Link to post Share on other sites
dreamie 0 Report post Posted April 10, 2004 (edited) Completed my CMOY. It sounds like a MALFUNCTIONING RADIO WITH EXTREMELY BAD RECEPTION!!! Lots of static like sound... Tried it on a headphone for a few seconds but my ears begged for mercy so i used it as a preamp and I could hear it more clearly on the speakers alot of static like noise. Could it be because of the PIO? Old caps sound like old radio... My previous CMOYs without any caps didnt sound this bad!! I'm gonna scrap the PIO... gonna save me alot of board space. Are the Evox Rifa caps any good? AHHH... MY WEEKENDS WASTED!! Edited April 10, 2004 by dreamie Share this post Link to post Share on other sites
Firefox 0 Report post Posted April 10, 2004 Looks reasonable.. I hope your R2 isn't 100k since you opted for using ~0.1uF signal caps. Try 220k/ 470k instead. 4-pin DIP socket? That's interesting.. Hmm.. how would the R2 value staying at 100k affect the overall circuit? Thanks in advance for the forthcoming enlightenment. Read the META42 article on the signal cap value and u'd know why.. I'm not about to spoonfeed ya. Share this post Link to post Share on other sites
hacknet 0 Report post Posted April 10, 2004 haha.. gain problems i guess... don`t dunk the PIOs... they are good caps... Share this post Link to post Share on other sites
Firefox 0 Report post Posted April 10, 2004 It sounds like a MALFUNCTIONING RADIO WITH EXTREMELY BAD RECEPTION!!! Lots of static like sound... ............ Could it be because of the PIO? Old caps sound like old radio... More like a wrong connection (or lack of) or solder bridge somewhere. Share this post Link to post Share on other sites
dreamie 0 Report post Posted April 10, 2004 Looks reasonable.. I hope your R2 isn't 100k since you opted for using ~0.1uF signal caps. Try 220k/ 470k instead. 4-pin DIP socket? That's interesting.. Hmm.. how would the R2 value staying at 100k affect the overall circuit? Thanks in advance for the forthcoming enlightenment. Read the META42 article on the signal cap value and u'd know why.. I'm not about to spoonfeed ya. It's in the original META webby I suppose? It's late.. i'll search tmr. Thanks.. seems like there's still hope.. Share this post Link to post Share on other sites
