Questions regarding building the CMoy

[jtfoo 0]

This is the discrete rail spliter i mentioned, 100mA max output vs TLE2426's 47mA.

 

http://headwize2.powerpill.org/ubb/showpag...d=4381&fdays=20

Thanks for this link.. At least learn something today..

[kenshinz 0]

kenshinz,

i think you should use a better IC socket, this 1 is hard to work with.

U refering to me or tropicalrips ?? My amp is not even done yet sigh....

hopefully wun have any problems.

 

 

[tropicalrips 0]

what would the transistor values be for the rail spilter?

i think its true u can learn a lot from the problems of the Cmoy i now hav the circuit in my head, my second board was done without looking at the drawings

but i still can't figure out the problem...

i know the voltage is driffting to 1 side, but this only happens when the op-amp is in place, when i take it out, the voltage on both sides is the same +- > 0.3v

so i think i need another op-amp to confirm

anyone hav extra op-amp lying around?

[huangyong 0]

get a cheap opamp to try first.if spoil wont loose so much $$.

[kenshinz 0]

Here's a quick update on my Cmoy, have just finished soldering all parts together, except for the wires connecting the batteries to the board (My soldering iron decides to give up the ghost at that point ) My soldering sucks this time round, and the board is not as neat as my 1st board.

 

Tried to use scotch tape to tape the connections together to test the amp, and it works . Except now got the same problem as tropicalrips regarding the hissing sound

 

Another thing problem is that when i tried to connect the 2 batteries together in series without grounding them, they work fine, but when I tried to ground the centre of the 2 batteries ( (-) from the 1st batt and (+) from the 2nd batt) to the board's ground, 1 side becomes muted, and I keep hearing a click click sound coming from it when there's no music playing. Any ideas why this happens ??

 

BTW, I'm not using the R2/R3 voltage dividing resistors to the board following Jason's advice, will adding them in help ?

 

Thanks !!

[jasonhanjk 0]

Did you connect your input output correctly?

[tropicalrips 0]

kenshinz, i think we hav check all our resistor value one more time to confirm everything, we may all be mislead by the list on Tangent's site

 

anyone can list the exect values for a basic CMOY without any optional parts & tweaks? jason?

 

is the original design using all 4.7k (including the voltage divider) except R4 (10k) which is on the output side after the cap. we should hav made up a list of the values from the begining, i was very confused by the list on Tangent's site, and all the other writings and drawings on the net, had to keep going back & forth just to figure out which resistor goes where

[kenshinz 0]

I think the hissing sound is due to improper soldering...was playing around with the voltage connections.. at certain angle, the hissing sound was reduced abit. Therefore I presumed that the soldering was not done properly somewhere on the board.

 

BTW, Jason, what happend when I don't ground the voltage ?

[jasonhanjk 0]

You would hear mono sound on both phone. Kenshinz, I think your amp is picking up stray noise in the sourrounding. Try adding 10nF ceramic at the supply and see does it help.

 

At tangent's site, he recommend the best way to fix the unbalance rail problem by adding a TLE2426 and another buffer.

[tropicalrips 0]

i hav ordered another op-amp from federal today, collecting it tomorrow, then i'll know if the fault is in the op-amp or somthing else

can get the rail-spilter off the shelf in SLT?

wish me luck

Edited November 6, 2003 by tropicalrips

[tropicalrips 0]

Finally done, my first Cmoy

[tropicalrips 0]

all the problems were caused by the op-amp, everthing work fine when i put in a new op-amp

[tropicalrips 0]

did not hav to use the rail-spilter, i think i will try it when i change a new board, need to redo the wiring

[N@Z 0]

Nice. Would it be neater too if the headphone out socket is built onto the enclosure. Or is there not enough room for that?

 

I'm beginning to like the Portapros looking at yours in the photo!

[jtfoo 0]

Nice job.. The knob looks a little big. But still better then my knobless cmoy..