ckng 0 Report post Posted October 25, 2003 one more thing... in the drawings of Kenshinz & CKng, where do i put the volume control if i want it? Wrong person, jtfoo is the one who posted a corrected version of kenshinz's drawing. For the volume control, jason has already answered. And if you want to add volume control, the potentiometer should be included too. BTW Jason mentioned that if we're gonna use 2 9V batts we could omit the 4.75K? 1/4W metal film resistor (R2/R3), so that's 1 part off the required list Hmm.. I remember reading somewhere in tangent's docs that this is not recommended as it could become unstable or something. Theoretically, it should, but I suppose if the batteries drain at a different rate, you will end up with unbalanced power rails. (e.g. +8 / -6V ). Using the R2/3 voltage divider resistors will ensure a more or less even split regardless of battery voltage. Using a TLE2426 rail splitter is even better. Regards CK Share this post Link to post Share on other sites
kenshinz 0 Report post Posted October 25, 2003 (edited) Using the R2/3 voltage divider resistors will ensure a more or less even split regardless of battery voltage. Using a TLE2426 rail splitter is even better. hmm.. all right, maybe I'll add that in. Doesn't cost much in the 1st place anyway, and get extra pratice for soldering Thanks Edited October 25, 2003 by kenshinz Share this post Link to post Share on other sites
jasonhanjk 0 Report post Posted October 25, 2003 The circuit that I teach you at Suntec does not require any voltage devider resistor or TLE2426. The offset of the voltage supply is due to the usage of voltage devider resistor. When current flow into R2 and R3 are different, thus voltage offset. If you want to use the TLE2426, do not use the circuit that I taught you, it will kaput... Anyway, if use 1 9V battery gives you 5 hours of listening time; 2 9V battery will give you around the same time. The theory behind this is even the voltage source had increase in voltage, the current consumption remains. Since battery power is calculate through mAH... Could you help me to prove this theory is correct? First 1 9V than 2... Thanks. Share this post Link to post Share on other sites
kenshinz 0 Report post Posted October 25, 2003 OMG i'm blur liao .. so Jason, if I follow what you taught me, the layout I uploaded before is correct rite ? if so, I'll follow that. And as for you theory no problem will definately try out once I've completed the amp. Share this post Link to post Share on other sites
jasonhanjk 0 Report post Posted October 25, 2003 Yup, follow the drawings would be an OK. Share this post Link to post Share on other sites
tropicalrips 0 Report post Posted October 25, 2003 if use 1 9v batt the layout will still be the same? or need to change something? Share this post Link to post Share on other sites
jtfoo 0 Report post Posted October 25, 2003 (edited) if use 1 9v batt the layout will still be the same? or need to change something? One 9 volt, you need at least two identical resistor to divide the voltage. Something like this from Headwize site. R2 & R3 are the voltage divider. Edited October 25, 2003 by jtfoo Share this post Link to post Share on other sites
tropicalrips 0 Report post Posted October 26, 2003 ok i see it now , thanks JTfoo hey Kenshinz u found the Op-Amp yet? let me know when u do, i want to get a few for myself too hav to prepare for the thing becoming "chao tar" for first try Share this post Link to post Share on other sites
kenshinz 0 Report post Posted October 26, 2003 (edited) Not yet, use the DIP 8 IC socket, its like the cpu socket on the motherboard.. just solder that one on the board, and plug the op-amp in can liao, as least if solder wrongly wun have "chao tar" op-amp...op-amps are abit ex to have becoming "chao tar" Edited October 26, 2003 by kenshinz Share this post Link to post Share on other sites
jasonhanjk 0 Report post Posted October 27, 2003 (edited) Just came back from SLT. Bought the 2N5484 $1 each... Edited October 27, 2003 by jasonhanjk Share this post Link to post Share on other sites
kenshinz 0 Report post Posted October 27, 2003 Yo, u were there today? I went today too, got some parts for tropicalrips and tried to find the op-amp.. but couldn't find any shops selling...I tried Federal Component, but they checked and told me they dun have too. Jialat sia... how ?? Anyone else have any ideas where I could find them?? BTW could I go down to Farnell's at Ubi to buy the part just like that? Wonder if they do walk-in purchase, could save on the delievery charges this way.. Share this post Link to post Share on other sites
jasonhanjk 0 Report post Posted October 27, 2003 Federal sell RS and Farnell items, you need to flip open the catalogue and tell them what you want. Nevermind since you will go there again tomorrow. Share this post Link to post Share on other sites
kenshinz 0 Report post Posted October 27, 2003 Actually when I asked them.. they went to a computer to check, I thought they were checking against Farnell or RS's catalogue....kena fake liao .... don't think going back anytime soon this week...need a breather. Share this post Link to post Share on other sites
jtfoo 0 Report post Posted October 27, 2003 BTW could I go down to Farnell's at Ubi to buy the part just like that? Wonder if they do walk-in purchase, could save on the delievery charges this way.. Yah, you can go down their trade counter. Just give them the stock number. And if you have a student card, you're entitled to 10% discount. To check the stock number, you can flip thru the catalogue at the Farnell trade counter, or via internet. Share this post Link to post Share on other sites
tropicalrips 0 Report post Posted October 27, 2003 (edited) done liao not sure if i got everything rite heres a shot of my Cmoy without the OP-amp still need to trim the board, looks a little too big Kenshinz, when can see yours ? oh and thanks for helping me get the parts Edited October 27, 2003 by tropicalrips Share this post Link to post Share on other sites