Gyraf Headphone Amp is WAY TOO LOUD :o

[mihailojocic]

Hello  good people!

I made this beautiful HP AMP and it is generally OK, but, as I said in subject, it is too loud. How can I force this HP AMP to be more gentle?

My guess is to change R7 and R8 to grater value, but i'm not sure. Also, if my guess is good, which resistor i should put.

Thanks in advance
Mihailo

http://www.gyraf.dk/gy_pd/hpamp/HP-Amp.pdf

 

[Andy Peters]

Hello  good people!

I made this beautiful HP AMP and it is generally OK, but, as I said in subject, it is too loud. How can I force this HP AMP to be more gentle?

Pad the input?

-a

 

[mihailojocic]

Can you please tell me the best way to do that!?!

 

[Harpo]

... it is too loud. How can I force this HP AMP to be more gentle?

use the volume pot ? This is a log taper pot. If you mistakenly fitted a lin taper pot, this might have this 'too loud' effect in the lower rotation° pot settings.

My guess is to change R7 and R8 to grater value, but i'm not sure.

decrease gain by increasing R3. Voltage gain is 1+R4/R3.

 

[mihailojocic]

Thanks Harpo!

I order log pot, but to be honest I didn't check.  :-\ This is exactly what happening. On lower range to loud, and nothing happening  on second half of rotation.

Also thanks for R3 tip, i will do that if log/lin  likely mistake don't help.

greetings
Mihailo

 

[mihailojocic]

OK, I just checked my pot and it is logarithmic, BUT after measuring I realize that it is some strange type. Curve is oposit from what it suppose to be. When I do some google stuff i found that there is reverse or negative log potentiometers.

So my problem would be solved (probably) when I change this pot.

 

[mihailojocic]

Solved! I put ''normal'' logaritmic pot and everything works fine. Thanks again Andy and Harpo!!!