Questions regarding building the CMoy

[tropicalrips 0]

i use a digital meter to measure the resistor values, i don't think the values are wrong just need to know which resistor goes where

[jasonhanjk 0]

Still hissing?

Hiss during playing music / input not connected / before turning power off?

[tropicalrips 0]

no more hissing, now is no sound at all

i only get sound when i use 1k resistors as the voltage divider, but it distorts, going to try with even lower resistors for the divider, any suggestions how low i can go?

 

my (+) & (-) on the board is not balance, abt 7v on 1 side and 2v on ther other, i suspect the op-amp is causing the fault, cause it is balance without the op-amp, only when i plug it in the voltage drifts to 1 side

[jasonhanjk 0]

You use the 2 battery method and the centre to ground would eliminate the voltage drift.

[tropicalrips 0]

but i want to keep it to 1 batt so its more portable and can also fit in my case mar

[jasonhanjk 0]

Use TLE2426, rail splitter. $1 plus

[tropicalrips 0]

can get this in SLT? or also need to pre-order?

[jasonhanjk 0]

INTERNET VERY SLOW!!!

 

Ahem, Farnell lol...

[tropicalrips 0]

no other way?

[kenshinz 0]

Jason,

 

Can I connect the batteries as shown in Circuit 2, or do I have to do it like in Circuit 1 as shown in the diagram below ??

 

Thanks

 

[ckng 0]

Circuit 1 and 2 is essentially the same. Whichever you use, make sure the junction of the 2 batteries, the junction of C1/C2, and ground are all tied together.

 

Regards

CK

[kenshinz 0]

Ok Thanks !

[jtfoo 0]

For purist, circuit 2 actually would be better, as it closely resembles a star grounding.. but then for a Cmoy, no diff at all between the 2 circuit.

[huangyong 0]

I think you need an oscilloscope.

that's an easier way to find out the prob.

dun have to buy one, just borrow from someone.

 

you dun have to use rail spliter actually, get 2 transistors and

some resistors will get the job done. cheap and nice.

get this info from headwize.

 

good luck. my first amp = cmoy, it brought me lots

of troubles, but i learnt a lot from it.

[huangyong 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

 

cool....

i think i will put it in my upcoming poor men PPA.

 

kenshinz,

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

 

regarding hissing prob, i encountered b4 when i built cmoy last year...

major prob should be grounding, make sure you ground everything properly;

and also shielding, avoid using lousy wire, try not to touch it, try put it on a metal plate and use wire to ground the plate. i think it helps. my lecturer taught me thuis way to solve that (my cmoy) prob, and tell me a lot of bla bla bla theory... forget bout it...