Modified CMOY amp sounds to low with certain head phones...

rwgast · 19th May 2012, 09:10 PM

So i just built a cmoy the only diffrence is that i used buff634 in the feedback loop and i also used an opa2132 with channels wired in parrallel to create the virtual ground.. Im also using an op2132 to drive the audio.

Anyways it drives my 16 ohm cheapy sony earbuds very well, But i built this this thing to drive a pair of sony mdr-nc7's which are 35ohm. These headphones are getting better volume from my laptop than my mp3 player with the amp connected... I know these arent hi end audiophile sienheisers but they sound decent to me, Im just trying to get more detail and higher volume from them. They say they have a 100mw raiting which is alot higher than my buds 15mw's.

Any ideas why the volume is so bad?? Ive played with the gain the AC coupling caps the power set up... with/without the buff634(to220 not dip) in the loop, I just want to get these things loud with some more detail and brightness there a little flat/bassy with or without the noise cancelling on.

sgrossklass · 20th May 2012, 08:42 AM

So you built a Cmoy that, uh, isn't much of a Cmoy anymore? Mind sharing a schematic?

Anyway, sounds like you've got too little voltage gain there, and possibly a weak output MP3 player (Euro zone?). It is not uncommon for noise cancelers to be less sensitive than passive headphones. What are your gain setting resistors?

19th May 2012, 09:10 PM	#1
rwgast diyAudio Member Join Date: May 2012	Modified CMOY amp sounds to low with certain head phones... So i just built a cmoy the only diffrence is that i used buff634 in the feedback loop and i also used an opa2132 with channels wired in parrallel to create the virtual ground.. Im also using an op2132 to drive the audio. Anyways it drives my 16 ohm cheapy sony earbuds very well, But i built this this thing to drive a pair of sony mdr-nc7's which are 35ohm. These headphones are getting better volume from my laptop than my mp3 player with the amp connected... I know these arent hi end audiophile sienheisers but they sound decent to me, Im just trying to get more detail and higher volume from them. They say they have a 100mw raiting which is alot higher than my buds 15mw's. Any ideas why the volume is so bad?? Ive played with the gain the AC coupling caps the power set up... with/without the buff634(to220 not dip) in the loop, I just want to get these things loud with some more detail and brightness there a little flat/bassy with or without the noise cancelling on.

Thread Tools	Search this Thread
Show Printable Version Email this Page	Search this Thread: Advanced Search

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
High Impedance Head Phones like Vintage Sennheiser Model HD424 - Overview wanted	tiefbassuebertr	Headphone Systems	4	17th December 2011 08:55 PM
Numark DJ mixer sounds awesome in 'phones with MP3 player	Rickh57	Everything Else	0	29th September 2011 08:47 PM
Cmoy with low Z phones.. Problem	Rembrant	Chip Amps	5	9th August 2011 09:20 AM
7868 amp sounds good but low volume	PRNDL	Tubes / Valves	9	9th December 2007 08:53 PM
Low noise head amp (MC)	Jorge	Analogue Source	11	19th August 2005 02:14 AM

New To Site?	Need Help?
Register to Participate Search Privacy Statement Contact Us	Frequently Asked Questions Did you forget your password? Mark Forums Read


	Please consider donating to help us continue to serve you. Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving

20th May 2012, 08:42 AM	#2
sgrossklass diyAudio Member Join Date: Nov 2004 Location: Germany	So you built a Cmoy that, uh, isn't much of a Cmoy anymore? Mind sharing a schematic? Anyway, sounds like you've got too little voltage gain there, and possibly a weak output MP3 player (Euro zone?). It is not uncommon for noise cancelers to be less sensitive than passive headphones. What are your gain setting resistors?