n0on3 0 Report post Posted March 22, 2007 That's the good news I've been waiting for!!! haha. thx heady, Im using ipod and i don't think i need that. i just have to remove it completely right? dun have to replace it with any resistors or anything? Btw, i figured out a way to "earth" the things already. Got the design done, and when ther's time, i'll start the wiring and soldering The schematics i seen shows 2 9V batteries... but it's ok to use just 1 9V battery right? Cause dats what i did, just 1 battery... but of course it's easy to add one more, just want to check if it's really needed to use 2 of em' Share this post Link to post Share on other sites
zhang_junyang 0 Report post Posted March 23, 2007 default gain of the amplifier based on the default values of the resistors is quite high for you to remove the pot completely. u will find it difficult to adjust ur volume. u will either have to reduce the gain or add the pot. wat is the opamp used? Whether 1 or 2 batts have to be used depends on this. Share this post Link to post Share on other sites
n0on3 0 Report post Posted March 23, 2007 i'm using JRC 5532D dual opamps. err... mayb i shall try to make one w/o the pot first? if there's any prob, mayb i'll get it... i am not pretty sure abt d pot's connections... mayb i also can tune the gain from tangent tutorial, just as u said. http://tangentsoft.net/audio/cmoy-tutorial/tweaks.html#gain Share this post Link to post Share on other sites
zhang_junyang 0 Report post Posted March 24, 2007 the 5532 opamp operating voltage range is ±3V to ±20V. 1 battery is fine. Share this post Link to post Share on other sites
n0on3 0 Report post Posted March 24, 2007 oyeah! thank you so much! Share this post Link to post Share on other sites
n0on3 0 Report post Posted March 25, 2007 LOL!!!! I just blew my op-amp!! ard 3 seconds after i switched the whole circuit on, smoke started to come out of the amp. LOLOLOLOL!! thk god i have another one... but b4 i m going to risk this other op-amp.... may i know if anybody out there can tell me all the possible reasons y my op-amp blew? I want to check my whole circuit first... which is.... bloody messy..... er..... i can't possibly put a pic to show my final product ...i bet all of u will vomit at the look of all my connections n solders... well.. most likely my prob is a short circuit( since it is so messy , probably the electrons had a hard time finding it's way round..lol).. but if there're other reasons, pls tell me... would really like to know. Share this post Link to post Share on other sites
heady 0 Report post Posted March 25, 2007 Most common reason is wrong power connections. You need to know that dual opamps and single opamps have different connections. Share this post Link to post Share on other sites
n0on3 0 Report post Posted March 25, 2007 i connected the red wire to number 4 and the black to the 8th pin. i followed the pic on tangent soft. http://tangentsoft.net/audio/cmoy-tutorial...layout-0150.pdf i made my board almost indentical to that design they have there, only that i manually split all wires,( so 1 hole can have as many as 3 wires tapping from there...) and the "virtual ground" part was also done manually. Oya, i also left out the LED... i thought it wouldn't affect the whole circuit as it's connected in parallel... or maybe it does? i blew it up too in my first few steps and since i didn't get xtra, i decided to drop it out.( my idiot self took control of me today, so i blew out 3 things today, namely my LED, op-amp, and the fuse in my multi-meter.) Mayb i have to visit koba again sometime to get replacements... n some better parts.. i don't get how to use the SPDT toggle.( the one with 3 lugs.) It seems to be always swtiched on no matter how i position the actutator. ... or hopefully i can find some things in a nearby DIY shop. Not as big as koba though(in terms of variety of items). I still have one op-amp anyway. Just have to say this... i am happy that i blew my op-amp. lol. at least i know im making a progress somehow. Spent 4 hours soldering all these and another hour troubleshooting. it seems to be getting nowhere(no electricity seems to be running in my circuit),until the op-amp blew. lol. at least i know there's current running in my circuit... Share this post Link to post Share on other sites
heady 0 Report post Posted March 26, 2007 If you post pic of your built, maybe we can help better? When your MM fuse is replaced, measure the voltage from leg 4 to virtual ground and then from leg 8 to virtual ground. Of course, please measure without any opamp in the socket. :-) Share this post Link to post Share on other sites
n0on3 0 Report post Posted March 26, 2007 haha. I'll post a pic of it soon... thx Anyway, i already got my fuse. However, b4 i blow up another fuse...which one should i use to measure Voltage: i have DCV, ACV, DCA, C(uF). sorry for the "for dummies only" question..... I'm thinking of building a new one all over again , since i just got a new board, which have pattern, pretty similar to the one on tangentsoft. Unless i can easily fix this prob, i would most likely b restarting. the wires underneath are too messy to deal with. lol. Must learn to be neater next time... Share this post Link to post Share on other sites
heady 0 Report post Posted March 26, 2007 (edited) To measure voltage, it should be DCV, for Direct Current Voltage. Making a new built may be a good idea. Every attempt is a learning experience. Don't know how many failed builts in my resume. Edited March 26, 2007 by heady Share this post Link to post Share on other sites
n0on3 0 Report post Posted April 16, 2007 ok.. i failed to do it again. yet finally i understand what's wrong... my soldering is not right. The parts are not connected properly. hahaha. Just realised this after watching the videos on how to solder, on tangent. Ok, so i think i might have damaged a few parts of the cmoy( i have redone the thing twice , so most likely a part or two will be damaged right?) Anyway, i am looking to get new parts. i hope it won't cost much again though. I'm thinking of going to SLT cuz der's a direct bus from my house. rather than going all the way to koba( Im at the other side of Singapore).Any suggestions of which shop to go to and may i know the business hours? I heard they'r closed on weekends. I'm buying the whole parts all over again, except for the board.(switches, resistors, caps, film caps, op-amps, sockets, stereo jacks etc.) How much should it cost me? I didn't take note of how much i spent on the parts the last time. Thx for the help. Share this post Link to post Share on other sites
heady 0 Report post Posted April 16, 2007 What's good about Koba is that they stay open till 9pm on weekdays. The shops in SLT starts closing from about 6pm and by 7pm, most are closed. SLT shops mostly open Mon-Sat only. Some may be open on Sundays but I don't know, as never been there on Sundays. Share this post Link to post Share on other sites
n0on3 0 Report post Posted April 17, 2007 hmm. icic. ok. Thank you very much Share this post Link to post Share on other sites
n0on3 0 Report post Posted April 18, 2007 Ok, done up the cmoy up to the amp section and tested them with croc clips. the chips didn't blew, and sound managed to get through the amp...... however.... 1. there's a quiet hiss whenever it's on( i think i can fix this by using the R5) 2. there's ugly distortion when i turn up the volume. I'm not sure how to fix this distortion.. any advices on this? My current amp is using JRC5532D. The voltage between V+ n V- are equal. I tested with my px100, sportapro n one cheap headphone. Distortions happens in all headphones.... but not when i play it low volume.i use a single 9v battery Anyway, may i know what's this flux thing? is it thing that would stick to my board n is a bit shiny2? Do i have to get rid of it n if yes,how? One last question, would a cheap op-amp like 5532D cause significant changes to the quality of sound? Cause i dun hear much difference when i play it through the amp(at low volume though). Would really b interested to know... Share this post Link to post Share on other sites
