[Akilisk]

Firstly, sorry if there are already threads like this, i can't find them.
 
I've just finished a cMoy BB DIY kit
http://www.ebay.com/itm/190742044923?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1497.l2649
 
But the sound is too loud for my low impedance headphones. How can I reduce this loudness while preserving the same sound quality?
Will increasing the potentiometer halp?
 
Thanks

 

[MisterX]

Quote:

How can I reduce this loudness while preserving the same sound quality?

Changing a couple of resistors will lower the gain but telling you which resistors to change is rather difficult without a schematic or close up pics of the PCB.
Ask the seller.... 
 
 
Quote:

Will increasing the potentiometer halp?

No.

 

[Akilisk]

Here you are...

 

[Akilisk]

If i'm not wrong, I should change R11 and R15, shouldn't I? If yes, how much R should I use?

 

[MisterX]

You can change either R12/R16 or R11/R15.
 
http://tangentsoft.net/audio/calc.html
 
R13/R16 translate to R4 on Tangent's gain calculator.
R11/R15 translate to R3 on Tangent's gain calculator.
 
Here's a calculator to give you an idea how changing the gain effects the bass boost:
 
http://tangentsoft.net/audio/ppa/amp/calc.html
 
(R7 = 33K, C7 = .068uF)

 

[Akilisk]

Thanks a lot. I will check it out
 

 

[Akilisk]

Do you mean "R12/R16 translate to R4 on Tangent's gain calculator."?

 

[MisterX]

Yep. Some day will have to fix that short circuit between the brain and the fingers.

 

[Akilisk]

hahahaha.....
 
I think I understand the circuit now.
So, now, my gain is G = R4/R3 + 1 = 10K/1.5K +1 = 7.67
with fc = 255 Hz, fs = 76 Hz, Boost 3.9x (12dB)
 
If I want gain = 4, I choose R3 = 3.4K and R4 = 10K(the same).
Then I can preserve fc, fs, and boost to be roughly the same. Am I wrong???
 
Do you think gain = 4 good for 16 or 32ohm headphone?
Are those fc, fs, boost good for listening to music pleasantly?

 

[MisterX]

Quote:

Do you think gain = 4 good for 16 or 32ohm headphone?

I would go even lower.
2?
 
 
 
Quote:

Are those fc, fs, boost good for listening to music pleasantly?

 
It's a little  "fat" for my taste but it's what the seller chose so.....

 

[Akilisk]

Oh.. Thanks
 
I've just ordered some resistors for gain = 4 ,and am gonna order some more soon for gain = 2.
But... ah... why is shipping of small electronics parts so expensive? I wish there was an electronics store next to my apartment. - * -
 

 

[Fred_fred2004]

Hi
Why didn't you ask me?
 
I have no problem sending you a couple of resistors
 
trust me I have spares
 
cheers
FRED

 

[Akilisk]

Sorry for late reply.
 
That will be greatest service ever.
Next time I'll ask you then
 
Thanks