Hi
Somebody brought this amp to me saying that it is totally dead. Upon checking I realise that it is using a "ICEpower 125AX2" module, a class D power amp combined with the SMPS. I injected a signal directly to the power amp and it is working. There is no power to the preamp board. There is a 3 wire cable coming from the module to the preamp board and it connects to the 7915 and 7815 fixed regulators. There is totally no voltage on these wires. I guess if I can provide the +15 and -15 volts to the preamp, then the amp will work. I cannot source the schematic for the module, only the preamp schematic can be downloaded (attached). The module is a smd board and looks very complicated to me. Instead I was thinking about providing a separate +15vand -15v just for the preamp. Will this work and will it cause any interference to the SMPS. Please advice.
Thanks
Somebody brought this amp to me saying that it is totally dead. Upon checking I realise that it is using a "ICEpower 125AX2" module, a class D power amp combined with the SMPS. I injected a signal directly to the power amp and it is working. There is no power to the preamp board. There is a 3 wire cable coming from the module to the preamp board and it connects to the 7915 and 7815 fixed regulators. There is totally no voltage on these wires. I guess if I can provide the +15 and -15 volts to the preamp, then the amp will work. I cannot source the schematic for the module, only the preamp schematic can be downloaded (attached). The module is a smd board and looks very complicated to me. Instead I was thinking about providing a separate +15vand -15v just for the preamp. Will this work and will it cause any interference to the SMPS. Please advice.
Thanks
Hi, if the power supply +15 -15 have disappeared ... the preamp may have a problem.
you can try with a separate power supply, as you thought
you can try with a separate power supply, as you thought
Maybe the regulators or preamp itself are shorted, so they pull down the ICE module built-in +/-25V auxiliary power supply.
I would disconnect all wires leaving that ICE connector and check for +/-25V present straight at the connector.
If not present, yes, any external+/-15V supply will/should feed that Preamp.
Just in case add 10 to 47 ohm 1/4 w resistors in series with each rail, to act as current limiters or fuses IF the preamp is shorted.
I would disconnect all wires leaving that ICE connector and check for +/-25V present straight at the connector.
If not present, yes, any external+/-15V supply will/should feed that Preamp.
Just in case add 10 to 47 ohm 1/4 w resistors in series with each rail, to act as current limiters or fuses IF the preamp is shorted.
