Hello friends, i have a problem with my zapco sp 3000.1
IT worked fine until 15 days ago
Now it has a "bump" when power off.
Protection and muting relays works fine, both close after a few seconds of power on the amp and open immediately as soon as I turn off the amp.
when the amp shut down I hear a loud bump on the speakers.
Have you got an idea of what I can check?
IT worked fine until 15 days ago
Now it has a "bump" when power off.
Protection and muting relays works fine, both close after a few seconds of power on the amp and open immediately as soon as I turn off the amp.
when the amp shut down I hear a loud bump on the speakers.
Have you got an idea of what I can check?
the bump comes simultaneously with the opening of the relay
I hear the relay and the bump.
I tried to remove the preamp section, I hear a slight tick when relay close and slicht tick when open.
If the amp has the preamp section with preout cable connected, there is a slight bump if the gain is low, with the gain high I have a loud bump.
Input is an Alpine car radio, volume is 1.
If I unplug the preout cable there is no bump, but a slight tick, if I connect the preout cable, I have the bump
I hear the relay and the bump.
I tried to remove the preamp section, I hear a slight tick when relay close and slicht tick when open.
If the amp has the preamp section with preout cable connected, there is a slight bump if the gain is low, with the gain high I have a loud bump.
Input is an Alpine car radio, volume is 1.
If I unplug the preout cable there is no bump, but a slight tick, if I connect the preout cable, I have the bump
No, because I had it in my car, it worked fine until 15 days ago, now I have another zapco sp3000.1 in my car and it has no bump, no problems.
The defective zapco has bump in car with audison bit one, at home with alpine 7944 and 9813
The defective zapco has bump in car with audison bit one, at home with alpine 7944 and 9813
Last edited:
Are you sure that the relay contacts for one of the relays aren't welded closed?
Do the ±15v rails for the preamp section drop at approximately the same rate when the amp shuts down?
Do the ±15v rails for the preamp section drop at approximately the same rate when the amp shuts down?
I changed the relays, I tried its with the tester, I have 0 ohms when amp is on, as soon as it shut down the relay opens.
I tried the contact under the board on the input and output of the relay. Relays opens immediatly.
+ and - 15 volts on preamp section are no longer present as soon as I turn off the amplifier,drop at the same rate
I tried the contact under the board on the input and output of the relay. Relays opens immediatly.
+ and - 15 volts on preamp section are no longer present as soon as I turn off the amplifier,drop at the same rate
Attachments
Last edited:
I've tested the preamp section of another zapco 3000 i have thats works fine.
In my zapco the bump is present with the two preamp sections.
In other zapco there is no bump with both the preamps.
In my zapco the bump is present with the two preamp sections.
In other zapco there is no bump with both the preamps.
Are you saying that you pulled preamp boards out of the other zapco amp and installed them in the noisy amp and the amp still pops?
Do you see a pulse of DC on any of the output filter inductors between the time that remote voltage is applied and the time that the relays engage?
There is 25-30 mv dc but is present with amp in on. When power off it is immediately 0.
At low volume i have 500-600 mv ac in output inductor and in speaker terminal, this voltage is the sound voltage it depends by sound volume.
When amp power off i have a 2 volts AC peak that is the bump.
At low volume i have 500-600 mv ac in output inductor and in speaker terminal, this voltage is the sound voltage it depends by sound volume.
When amp power off i have a 2 volts AC peak that is the bump.
There is 25-30 mv dc but is present with amp in on. When power off it is immediately 0.
At low volume i have 500-600 mv ac in output inductor and in speaker terminal, this voltage is the sound voltage it depends by sound volume.
When amp power off i have a 2 volts AC peak that is the bump.
If amplifier gain is low and souce volume high there is no bump, if amp gain is high and source volume low I have the bump.
If I unplug Rca i have no bump
At low volume i have 500-600 mv ac in output inductor and in speaker terminal, this voltage is the sound voltage it depends by sound volume.
When amp power off i have a 2 volts AC peak that is the bump.
If amplifier gain is low and souce volume high there is no bump, if amp gain is high and source volume low I have the bump.
If I unplug Rca i have no bump
- Status
- Not open for further replies.