DHD ntx 3107
This amp had some bad primary filter caps.I replace all.
The next problem is the amp will start to distort very early when i start increasing the input signal.Both rail voltage will go from 35 down to about 21v when i start increasing the signal causing the reg voltage to fall down to about 4v.
If i used a current limiter to power the amp it will play good audio if i increase the signal way more than if i had just power it up directly . Any suggestions
PS FETs gate and drain cant remember which is which.
10/dv 10/us
This amp had some bad primary filter caps.I replace all.
The next problem is the amp will start to distort very early when i start increasing the input signal.Both rail voltage will go from 35 down to about 21v when i start increasing the signal causing the reg voltage to fall down to about 4v.
If i used a current limiter to power the amp it will play good audio if i increase the signal way more than if i had just power it up directly . Any suggestions
PS FETs gate and drain cant remember which is which.
10/dv 10/us
Attachments
Repost the waveforms with the scope on DC coupling and the trace aligned to the vertical reference line.
Are you sure that this was gate and drain with both taken on 10v/div?
Are you sure that this was gate and drain with both taken on 10v/div?
Yes the same settings was used for both waveforms.Scope is always set to Dc .
I will recheck it tomorrow.
I will recheck it tomorrow.
The originals were not on DC coupling.
Why do you think that there is a problem with these waveforms?
Why do you think that there is a problem with these waveforms?
The rail voltage remain constant if I bring the voltage down to 12.6v
Anything higher it breaks down.
Anything higher it breaks down.
Does the 12v supply voltage drop when the rail voltage drops?
Does the rail voltage drop if you measure across the output of the rectifiers?
Does the rail voltage drop if you measure across the output of the rectifiers?
Does the rail voltage drop even when the pulse width increases as you drive the amp harder into a load.
Does the pulse width go to a full 50%?
It could be that the regulator isn't responding quickly enough.
It could be that the regulator isn't responding quickly enough.
Above 12.6 volts the rail will drop down about half and the audio is distorted.Amp is not even being driven hard at that time.
Below 13v the amp plays good audio even when driven hard.The rails go down a bit when the bass notes hit it goes back up fast with nothing noticeable in audio.
Below 13v the amp plays good audio even when driven hard.The rails go down a bit when the bass notes hit it goes back up fast with nothing noticeable in audio.