Hiss and noise issue
Hi i have been able to get away with the hiss issue it might not be a great solution but i added a 2.2K between the input of the amp near the 4.7uF cap and ground and the hiss dissapeared. Its definitely due to layout issues. But i am still figuring out how to get that brightness in the sound coming from the amp to be reduced. I am building a new PSU to check the difference. About scope, is there any freeware you might know that i could use to make traces of the amp on a pc without adding additional hardware?
Thanks
Hi i have been able to get away with the hiss issue it might not be a great solution but i added a 2.2K between the input of the amp near the 4.7uF cap and ground and the hiss dissapeared. Its definitely due to layout issues. But i am still figuring out how to get that brightness in the sound coming from the amp to be reduced. I am building a new PSU to check the difference. About scope, is there any freeware you might know that i could use to make traces of the amp on a pc without adding additional hardware?
Thanks
Hi, i really recommend etching a PCB, it's very likely that your amp is unstable, resulting in bright sound. You should add at least my mentioned emitter resistors to q1/q2, this should help.
Veroboards are really not suitable for high gain amps.
About PC based scopes, a good soundcard can measure up to ~96khz, but to really check an amp you need at least 20mhz, otherwise you won't see the oscillations and other problems.
Mike
Veroboards are really not suitable for high gain amps.
About PC based scopes, a good soundcard can measure up to ~96khz, but to really check an amp you need at least 20mhz, otherwise you won't see the oscillations and other problems.
Mike
5,000 4 CH digital ones aren't too shabby either
)
Pre-pcb test
Hi i did a final test with the headphones. Well i added a 220R resistor in series with the amp's output and a 100R in parallel, basically a resistor dividing network and sound is great with the headphones. I'll go ahead and do some further test with a loudspeaker. Bias is set to >50mA. Am confused how it might sound bright with the loudspeaker in the previous test i did. But a re-check will not harm.
Hi i did a final test with the headphones. Well i added a 220R resistor in series with the amp's output and a 100R in parallel, basically a resistor dividing network and sound is great with the headphones. I'll go ahead and do some further test with a loudspeaker. Bias is set to >50mA. Am confused how it might sound bright with the loudspeaker in the previous test i did. But a re-check will not harm.
inductance/capacitance solution
Well back to the test with loudspeakers there has been an improvement but i think i might know where my problem is from when comparing the my yamaha amp with the sym-a-sym. I tried a woofer with the yamaha. It sounded muffled, but with the sym-a-sym it gave a bigger increase in mid-band and high freq region. In case i am correct might it be due to the inductive rise of the loudspeaker in tghe high frequency region.If so is there a means of counteracting this with the sym-a-sym by modifying the zobel network or the damping inductor? (The AVX 496 seems unaffacted by inductive rise irrespective of the woofer i used)
Well back to the test with loudspeakers there has been an improvement but i think i might know where my problem is from when comparing the my yamaha amp with the sym-a-sym. I tried a woofer with the yamaha. It sounded muffled, but with the sym-a-sym it gave a bigger increase in mid-band and high freq region. In case i am correct might it be due to the inductive rise of the loudspeaker in tghe high frequency region.If so is there a means of counteracting this with the sym-a-sym by modifying the zobel network or the damping inductor? (The AVX 496 seems unaffacted by inductive rise irrespective of the woofer i used)
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