AlexanderGrant 0 Report post Posted December 20, 2010 (edited) cmoy question.... just finished building a cmoy based on williamneo's layout and tangent's circuit using for the tle2426.. for some reason everything sounds fine with the creative stock earphones & mylar x3i's, but when i use a pair of shure e3g's the sound starts have a lot of distortion & noise (the shures are working okay when plugged into other things). any suggestions on what the problem might be? thanks in advance.. __________________________ mother of the bride discount wedding dresses mother of the groom dresses Edited December 22, 2010 by AlexanderGrant Share this post Link to post Share on other sites
dacboy 0 Report post Posted December 21, 2010 Hi , Googled the Shure e3g, what an exorbitant priced pair of earbuds,even the pdf broshure does not explain what technology or how it works.So secret that people believe the marketing.The specs say it is 29 ohm impedance just a little shy of the standard 32 ohm so this should not pose a problem to any well designed/proven headphone amp. Since I believe the Shure e3g is new the wires should be in good condition so that leads me to suspect the earphone jack on the cmoy or components may have come loose on the pcb.Check with your multimeter or visual inspection. Good luck. Share this post Link to post Share on other sites
bpribadi 0 Report post Posted December 23, 2010 Distortion sometime caused by clipping, when the supply voltage is too low, or too low for the op-amp to work properly, or sometime when the op-amp cannot supply enough current to the driver. Try to increase the supply voltage, like using 2x 9 volt batteries, or try other op-amp that has higher output power. Share this post Link to post Share on other sites
SvenMZ8 0 Report post Posted January 12, 2011 the opamp goes into oscillation caused by capacitive load from the shure earphones. same thing happens as u described with the fxc-70s (dynamic) no prob, but q-jays have problem. problem can be solved with voltage buffer after gain stage in opamp, or simply increasing the gain. Share this post Link to post Share on other sites
Xn2 0 Report post Posted January 12, 2011 Hi , Googled the Shure e3g, what an exorbitant priced pair of earbuds,even the pdf broshure does not explain what technology or how it works.So secret that people believe the marketing.The specs say it is 29 ohm impedance just a little shy of the standard 32 ohm so this should not pose a problem to any well designed/proven headphone amp. Since I believe the Shure e3g is new the wires should be in good condition so that leads me to suspect the earphone jack on the cmoy or components may have come loose on the pcb.Check with your multimeter or visual inspection. Good luck. Absolutely agree with this post. Sometimes its just gain problems. But usually if its diy and PCB it could be as simple as a bad solder on the Earphone Jack or the internal of the earphone jack has erroded. Share this post Link to post Share on other sites
idjoel 0 Report post Posted May 18, 2011 sorry if OT.. anybody here has spare amb mini3 pcb? the one from amb, not hohodiy..i figure i'd ask here since buying from amb is quite expensive for building 1 unit only sorry again if i'm out of topic, i don't find it appropriate to make new topic just for asking this Share this post Link to post Share on other sites
alamakazam 0 Report post Posted May 19, 2011 sorry if OT.. anybody here has spare amb mini3 pcb? the one from amb, not hohodiy..i figure i'd ask here since buying from amb is quite expensive for building 1 unit only sorry again if i'm out of topic, i don't find it appropriate to make new topic just for asking this this ? http://glassjaraudio.com/product.sc?produc...25&categoryId=2 frankly get a kit easier, u run around sim lim tower, here and there, is not worth it all(sometimes cant find too), maybe save $20 only Share this post Link to post Share on other sites
idjoel 0 Report post Posted May 19, 2011 this ? http://glassjaraudio.com/product.sc?produc...25&categoryId=2 frankly get a kit easier, u run around sim lim tower, here and there, is not worth it all(sometimes cant find too), maybe save $20 only my intention was actually asking for fellow members here who maybe happen to have spare or extra mini3 board..not asking where to get the board from local shop if someone has the amb mini3 pcb, not the one from hohodiy, or alvin (the one with slightly wider pcb), please PM me Share this post Link to post Share on other sites
alamakazam 0 Report post Posted May 19, 2011 my intention was actually asking for fellow members here who maybe happen to have spare or extra mini3 board..not asking where to get the board from local shop if someone has the amb mini3 pcb, not the one from hohodiy, or alvin (the one with slightly wider pcb), please PM me well too bad, u miss my order... my amb sigma22 stuff just arrive 2days ago Share this post Link to post Share on other sites
idjoel 0 Report post Posted May 19, 2011 well too bad, u miss my order... my amb sigma22 stuff just arrive 2days ago oh man, not my lucky day i guess.. if you don't mind, plese let me know if you order something from amb again Share this post Link to post Share on other sites
jmwreck 0 Report post Posted August 27, 2011 (edited) I have a question for the CMOY I found here: http://diy4fun.blogspot.com/2010/03/cmoy-f...ltoids-box.html Based on the comments, I wanted to add/alter the power supply scheme and change it into the MINI3 power and ground scheme, http://www.amb.org/audio/mini3/ Is it possible? Edited August 27, 2011 by jmwreck Share this post Link to post Share on other sites
alamakazam 0 Report post Posted August 27, 2011 no problem Share this post Link to post Share on other sites
jmwreck 0 Report post Posted August 28, 2011 no problem did you mean it on my post? if so, thank you I hope its going to work fine Share this post Link to post Share on other sites
heady 0 Report post Posted August 29, 2011 did you mean it on my post? if so, thank you I hope its going to work fine You do understand you need to implement the virtual ground portion of the circuit as well, right? Share this post Link to post Share on other sites
jmwreck 0 Report post Posted August 30, 2011 (edited) You do understand you need to implement the virtual ground portion of the circuit as well, right? the mini3 schematic presented the POWER, GROUND, LEFT & RIGHT. On the CMOY, it has POWER, LEFT & RIGHT. So you mean, did I put the ground of the mini3 to the cmoy scheme? If so, yes I integrate it to my revised schematics. Is it correct? Thanks ------------------------------------------------------------------------------------------------------------------------- I have a problem on the bass boost that I have added, this is the one I found here and the schematic is this one: (for each channel) and i followed that scheme and make my own: Left Right now the problem is, i dont know why it doesnt make any changes when i turn it on/off. questions are: 1. is the original schematic (1st image) correct for bass boost? 2. are my own schemes (2nd & 3rd image) correct? 3. did i burn or damaged my "bass boost" resistor and cap? 4. it is still working perfectly right now, even with the bass boost switch is on/off, its just that it doesnt make any changes when i select it. if it was damaged (#3), does the amp still work? 5. as you can see, the values in the original bass boost circuit, especially the cap is different from the one i did? I know the fact that the higher its values, the lesser it cuts off the low frequency. but at least i can hear difference because of it, am i correct? thanks Edited September 4, 2011 by jmwreck Share this post Link to post Share on other sites