U dont use MC1458 and LM358,those are normal general purpose OPAMP,not perform well for audio,and the TL072,ok for audio but not enough driving capability..

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Added on October 29, 2011, 3:24 pmBoth with different virtual ground scheme,refer to this article for further reading:

Virtual Ground Circuits

Cmoy itself is a normal non-inverting OPAMP circuit,basic stuff u can find inside a text book

This post has been edited by Leolabs: Oct 29 2011, 03:24 PM

Wow.. Now i know what's the -V and +V for..
Ok, so i decided to go with this and change the virtual ground circuit to the TLE2426 based.. one more question, how is the ground connected to the pot?
is it like this? (open spoiler)



This post has been edited by BanG_DeaD: Oct 29 2011, 05:39 PM

check this out,and compare to your drawing:

Oh.. ok.. so my 'from source' and 'to circuit' should switch places...
tq...

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Added on October 30, 2011, 3:15 pmI currently have a unregulated AC-DC adapter which have a 12V output (i tested it with a voltmeter) and is 500mA max. Can I plug this to replace the 9V battery (using TLE2426) so it will provide +-6V ?

I know I'm asking a lot of question.. That's because i'm a newbie...

This post has been edited by BanG_DeaD: Oct 30 2011, 04:22 PM

No worries, we are once a newbie at one point or another...

Short answer, NO, the adapter ( unregulated AC-DC adapter ) can ONLY supply +12V , not the -12V needed by the op amp..

Long answer, you would need some power supply unit that can supply BOTH + and - voltage.. one I can think of is the PC power supply, but I m not sure if these noisy switching power supply is suitable for audio circuits..

Read the below for details..
http://tangentsoft.net/audio/opamp-ps.html

no no no.. i dont mean i straight plug the adapter to cmoy.. i mean, i use the adapter to plug to the rail splitter (tle2426) then only to cmoy.. so instead of the 9v battery pluged to the tle2426, i plug the 12v to the tle2426.. the only thing i worry is the 500mA ... the adapter can use right?


This post has been edited by BanG_DeaD: Oct 30 2011, 11:52 PM

hmm.. can, but better put regulator first before the splitter circuit.. 500mA is the maximum current that adapter can provide.. nothing to worried about that

Ok.. thanks..

Oh.. i c..

Some of the 12V adapters ( usually with a 220V to 12V transformers inside ) , the voltage can fluctuate between 11-17V or more... test it with a multimeter and "see" the voltage goes up and down...

So the other replies suggest that you put a voltage regulator before the TLE2426 to get a stable voltage.. LM7809 will give you a 9V input into the TLE2426.

goto http://octopart.com/ and search for the datasheets...


I would like to guide you when giving an answer.. so next time u can ALWAYS refer to the datasheets when looking at the IC specs..

According to the datasheets, TLE2426 : http://www.ti.com/lit/ds/symlink/tle2426.pdf

Page 4, absolute max rating is 40V, output is half of input voltage.. so u r "safe"...


I assume the input IC is OPA2227, the dahasheet : http://datasheet.octopart.com/OPA2227PA-Te...heet-149651.pdf

Page 2, OPA227 is +/-5V to +/-15V and max input voltage is +/-18V..

So you are in safe range too..

Haha.. Thanks for the info.. I had already made up my mind to connect the AC-DC (set at 15V) to a 7812 voltage regulator..

Do post some pics of yr project once it is done...

Where do u order the TLE2426 and the Op Amps IC ??

element14 or RSOnline

I bought it from RSonline and went to collect at their trade counter..

they do FOC delivery de lo, why not use it? they use FDEx to send

pay cash mah

im using debit card..

Had some problems with my Cmoy on a stripboard , so I decided to make another one using a breadboard and it worked.. Then, I soldered all the components on a new stripboard and still had problems . After touching the circuit, shaking up and down, moving here and there, and brushed the flux off with a little bit of water; it finally worked. I abandoned the TLE2426 as it was causing me problems too (bad soldering) and used the resistor divider instead (470uF). This Cmoy uses a TLE2072 op-amp, 0.15uF input caps, 2kΩ resistors (gain 6), 2x10kΩ Pot (each controlling one channel). My Cmoy can be powered either by battery or AC-DC adapter (controlled by switch). The AC-DC jack on the Cmoy is connected to the resistor divider through a Voltage Regulator which throws 12V as the output while the battery jack is connected straight to the resistor divider. Enjoy the photos...

Is there a reason why the battery is external? Wires looks like spaghettis.. Congrats on a job done.

I made this to be used on desktop, so I don't really need the battery but I can still use the battery if I wanted to... About the wires, makes my job easier

Nicely done..

A few comments...

1. Why didn't u use the same DC plug for both AC Adapter & 9V battery.. and save some components ( I guess u didn't buy an extra DC jack for the 9V snap on )

2. Use single-core wires for components on the prefboard, easier to solder ( I guess you didn't have single-core wires during yr constructions stage )

3. I notice the wires leading to audio in and out is different sizes joint by heat shrink wrap... this is not good for impedance matching, just use a same type of wires across... from a thick wires to thinner wires , the signal might change a bit..

How the sound quality compared to without the amp ?