100W Ultimate Fidelity Amplifier

With input connected, am not getting any issues

Only problem is it’s not center voiced, left channel gain is more than right channel

as suggested previously here by member, check RMS voltage at output when both channels are supplied with 0.5-1VRMS input at 1kHz.

if they are different, then start checking all resistor values , especially NFB resistors, emitter resistors, and others.

hiss when no input is connected , means amp is picking up some RF OR it could also be oscillating.
for oscillation, check zobel resistor for heating up.

there is definitely something wrong with components/wiring/surroundings/ grounding on PSU.

Have you by any chance connected the input ground to chassis earth?

also do you have volume control?, I do not believe in any volume control except for high quality stepped volume control.
if its ordinary 16mm pot, has its body been grounded?
also is every wire is twisted properly and no high current / AC wires near input section and signal wiring?
 
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as suggested previously here by member, check RMS voltage at output when both channels are supplied with 0.5-1VRMS input at 1kHz.

if they are different, then start checking all resistor values , especially NFB resistors, emitter resistors, and others.

hiss when no input is connected , means amp is picking up some RF OR it could also be oscillating.
for oscillation, check zobel resistor for heating up.

there is definitely something wrong with components/wiring/surroundings/ grounding on PSU.

Have you by any chance connected the input ground to chassis earth?

also do you have volume control?, I do not believe in any volume control except for high quality stepped volume control.
if its ordinary 16mm pot, has its body been grounded?
also is every wire is twisted properly and no high current / AC wires near input section and signal wiring?



Hi prasi,

Yes i have connected the input ground to chassis - should i connect or not?

There is no volume pot connected

Mains ground is connected to chassis and from chassis wire is connected one end of ground loop breaker and the other end is connected to psu ground
From psu ground one wire is connected to amp ground and one wire goes to speaker ground and signal ground

Please let me know if any thing wrong with wirings

IMG_9431.JPG
 
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