cmoy question

[blippster 0]

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..

[alvin1118 0]

seems like you are having the same problem as mine? i uses audio technica es5 with my usb dac headamp, there are irritating noise. while i use sennheiser hd201, noise are gone. after doing some research, the possible causes is sensitivity and impedance of the headphone XD

[blippster 0]

yup seems like it.. i'm inclined to think it's an impedance issue, but no idea how to resolve it.. =\

[heady 0]

Hi,

If the Shures is too sensitive and you get hiss, reducing gain will work. If impedance is low, then need to increase current output of the amp. Select an opamp with better current output. If impedance is high, you will need more voltage and thus will need more than one 9V battery for power.

 

Regards

[alvin1118 0]

hmm..meaning a headamp is not universal for all headphone? or just select a 'universal' OPA will do ? lol

 

havent have chance to try AD/LT/NS OPA, should order some sample and see how it performs.

[heady 0]

hmm..meaning a headamp is not universal for all headphone? or just select a 'universal' OPA will do ? lol

 

havent have chance to try AD/LT/NS OPA, should order some sample and see how it performs.

 

Actually, there's only so much a CMOY can do. Eventually, if you want more, then you got to pay for more. There are lots of amps out there you can try.

 

[blippster 0]

thanks heady

 

the e3s are 26ohm, with the mylars at 16ohm and the creatives presumably less than that, so i suppose it's the second case..

 

now the noise seems to be mostly when turning the pot (but again, only for the shures - the rest work fine) will try resoldering the pot in and see if that settles it..

[heady 0]

blipster, I think the differences in the impedances of the phones are not significant and you are right that this is not the reason. Does the Shure sound louder than the others at the same volume setting? This will indicate that it is more sensitive.

[alvin1118 0]

agreed, cmoy is too simple that it cannot be pair easily with various headphone.

 

btw, heady have you heard of headmaster ? ppl said it's sound very good for headphone even use it as preamp.

[heady 0]

agreed, cmoy is too simple that it cannot be pair easily with various headphone.

 

btw, heady have you heard of headmaster ? ppl said it's sound very good for headphone even use it as preamp.

Alas, I am member of Team Low Budget which means almost all my amps are DIY, self built. Also not much time to browse forums, mostly here. So, I am not familiar with the amp you mentioned although I remember reading something about it. Sorry, I couldn't be more helpful.

 

 

[williamneo 0]

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..

 

Try change the gain, i assume your current gain is 11 if you follow instruction base on my side and tengent side. For gain 11 is basically stable for the op-amp operation. For most headphone compatiblities try use gain at 5-6. so how to change the gain? Just change the R3 to 2k ohm will get you a gain 6. Good Luck! Hope this would help ya!

Edited March 24, 2008 by williamneo