[thefallenangelx]

Hi!!
 
i did my first (and at least other 6) cmoy over a year ago for portable use with my headphones...and now im stuck with my cmoy with ad8620 with my alessandro ms1i!
id like to diy something more advanced than a cmoy...but simply as the cmoy was!
something which is portable, simple to do, powered by 9v battery for my alessandro!
Any suggestions?
Thank you

 

[Mad Max]

Another CMOY?

 
Swap that 8620 with 8066?
 
Perhaps OPA1642 or AD746?
 
You might just love your cmoy even more xD

 

[Avro_Arrow]

here is something to get you interested...
 

 

[Spacehead]

47 ohm resistors can be lowered to 10 ohm to lower output impedance

 

[thefallenangelx]

 
Quote:

Another CMOY?

 
Swap that 8620 with 8066?
 
Perhaps OPA1642 or AD746?
 
You might just love your cmoy even more xD

Already did it...but the 8066 kinda oscillate...how to get it stable?

 
Quote:

here is something to get you interested...
 

Oh, i heard its suitable for grado headphones! Do you have links to see some about it?
It it powerable by a single 9v so that it can be portable?

 

[particleman14]

mini3...http://www.amb.org/audio/mini3/

 

[Avro_Arrow]

You would build this as a three channel amp.
I would use a rechargeable 9 volt or maybe
an RC battery pack. Drive the center channel
with a TLE2426. I can draw you a complete
schematic if you need it. It sounds better
than you might think.
Of course, if you don't want to go to that much
trouble to build something from a schematic,
I would recommend the Mini^3, as above...
 
Quote:

here is something to get you interested...
 

 

[Spacehead]

please draw the schematic

1. Avro_Arrow

 

[Fred_fred2004]

This might be what you're after
 
http://www.sgheadphones.net/index.php?showtopic=3220&hl=cmoy+2
 
cheers
FRED

 

[thefallenangelx]

Quote:

You would build this as a three channel amp.
I would use a rechargeable 9 volt or maybe
an RC battery pack. Drive the center channel
with a TLE2426. I can draw you a complete
schematic if you need it. It sounds better
than you might think.
Of course, if you don't want to go to that much
trouble to build something from a schematic,
I would recommend the Mini^3, as above...
 

 

 
Its not a problem doing it by schematic!if you please can draw me the schematic for it (supply and audio section) with a 9v battery supply and no potentiometer please!!
 

 

[Avro_Arrow]

OK, give me a day or two...it's busy on the weekends...
 
Quote:

please draw the schematic

1. Avro_Arrow

 

[thefallenangelx]

Quote:

OK, give me a day or two...it's busy on the weekends...
 

 

thank you!i'll wait so!

 

[kvant]

 
Quote:

here is something to get you interested...
 

It is not nice to take a picture from the other site without providing a link to the source or at least saying where you took it!
Quote:

Oh, i heard its suitable for grado headphones! Do you have links to see some about it?
 

 
Apheared's Project Scrapbook on HeadWize.

 

[thefallenangelx]

oh, before doing the a47, i read somewhere that i can have more current for my low-z alessandros by adding [size=xx-small][size=x-small]buf634 added to the amp...so id like first to improve my cmoy: [/size][/size]
 
- 470uf power caps instead of the 220uf
- tle2426 rail splitter
- 5.7 gain
- 9v battery powered
- dec caps cap 0.1uf
 
and should i add another 9v battery in series?

 

[nikongod]

I built a CHA-47 as a home amp once. It was a fun build and a very good sounding amplifier.
 
Quote:

47 ohm resistors can be lowered to 10 ohm to lower output impedance

 
Edited:
never mind. I checked elsewhere, and it seems I am wrong. jan meier used 10ohm resistors in his 50W opamp amplifier. Id still proceed with caution, but perhaps slightly less than I recommend below.
 
I would be careful about changing these parts significantly.
 
Although part of the reason 47 ohm output resistors were used was so that every part in the amp would be a 47(multiplier) or 10(multiplier) part they are important. They prevent the 2 op amps from seeing each other directly and trying to drive each other under certain conditions.
 
At the very least, they are effectively in parallel, so they only contribute 23ohms to the output impedance before feedback is applied. BUT!! they are in the global feedback loop, so a great deal of their impedance is compensated for by that.
 
Perhaps something in the 37ohm range would be a better compromise, but I would be afraid to go below that without an oscilloscope.
 
Quote:

 
It is not nice to take a picture from the other site without providing a link to the source or at least saying where you took it!
 
Apheared's Project Scrapbook on HeadWize.

I agree with you, but the huddler forum system makes it very difficult/unintuitive to post a photo without loading the photo into the head-fi database (the only way to do it is to write it in the code, on the "source" page) which makes back-tracking photos to other sites nearly impossible unless you already know where the came from. I suspect that the way the system "encourages" you to load things in while making linking pics difficult has something to do with SEO and page ranking but its a situation that does not favor the end user either way.
 
I'd cut him some slack, but agree that a link to the original article in the same place as his original photo post would have been nice.
 
PS:
the freedoms afforded by manualy entering code are far far far greater than in phbb where what you could do was restricted (although all much easier for the end user who cant write code).