opa 549 problem

jaudio

Member
2004-10-29 1:31 am
Check all ground connections(including signal input ground).

Check the connections from the drv134 to opa549. If the drv134 is not well connected,you will get hiss

What is your gain? It might be too high.

OPA549 has the max voltage list at +/-30,your supply voltage might be too high.
 
tnx..i have fix it already i change the value of the resistor and it works well but because of a little heatsink i have u cnt even touch it because its too hot!!!..and its killing my xformer coz i only got 4700uf caps 50v...and whenever i use my large caps 120000uf 40v it kills the opa..but before the opa crashes u can hear a noisy sound it isnt a hum but its a loud sound like osscilation then my opa burns can u help me with this tnx a lot....:D :D :D
 
my opa 549

here's the pic
 

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Re: Re: my opa 549

jaudio said:
Check all ground connections(including signal input ground).

Check the connections from the drv134 to opa549. If the drv134 is not well connected,you will get hiss

What is your gain? It might be too high.

OPA549 has the max voltage list at +/-30,your supply voltage might be too high.

my gain is 22 is it too high?

carlosfm said:


Nobody noticed yet that there's something missing on this board?
No PSU caps on the OPA549 chips?:bawling:

my PSU is separated..but for now i have no xformer(24-0-24v 5amps) for it was burn by those OPA's after i load that amp 2 ohms..sorry..
 

Alcaid

Member
2003-11-27 1:31 pm
Klepp
1. Like Carlos said: Add psu coupling caps as close as possible to the chips.
2. Have you isolated the chips from the heatsink?
3. Those chips can only take +/-30V DC, measure your PSU voltages when not playing music.
4. Gain is too high! I would recommend a gain of 10-12 max.
 
i use only 4 chips for my subwoofer, 8 chips if you want stereo, used bypass capacitors and zobel network, and to minimize dc offset insert capacitor, you can follow the schematic below if you want, decrease the gain if you want as they say, got this diagram on the thread
 

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