Is there a transistor with the same specs as this one?

[chipper]

It's by motorola MTP75N05HD I think? I couldn't find this exact part all they gave me was data sheets. Is there a similar replacement?

Here's a link for the data sheet (it's not spam!)
MTP75N05HD pdf, MTP75N05HD description, MTP75N05HD datasheets, MTP75N05HD view ::: ALLDATASHEET :::

[Perry Babin]

If it's being used in the power supply of a Rockford amp, you can use the IRF3205 as a sub. If the gate resistors are greater than 51 ohms, replace them with 47 ohm resistors.

[chipper]

Originally Posted by Perry Babin

If it's being used in the power supply of a Rockford amp, you can use the IRF3205 as a sub. If the gate resistors are greater than 51 ohms, replace them with 47 ohm resistors.

Yeah Punch 225 all the driver transistors may be good according to my multi meter. But I'm missing a small surface mount resistor for the pwr supply fet.

I have a question? How much power can you expect from these type of amplifiers? Drivin at 4 ohms bridged. I heard around 690 watts?

[Perry Babin]

Which resistor?

I wouldn't expect more than ~450 watts. If someone got 600+ watts out of it, they were probably trying to calculate the power output by measuring the voltage across a speaker load instead of a dummy load, which isn't accurate.

[chipper]

Originally Posted by Perry Babin

Which resistor?

I wouldn't expect more than ~450 watts. If someone got 600+ watts out of it, they were probably trying to calculate the power output by measuring the voltage across a speaker load instead of a dummy load, which isn't accurate.

It's a very small surface mount resistor. I think it's connected to the gate of the pwr supply fet. I also have a question? What if there is no gate resistor in place and you apply power to the amp? What is the operation result? Anything fry up?

[Perry Babin]

If there is no gate resistor (gate not connected to anything), the FETs are likely to fail.

The gate resistor is a 68 ohm.

[chipper]

Originally Posted by Perry Babin

If there is no gate resistor (gate not connected to anything), the FETs are likely to fail.

The gate resistor is a 68 ohm.

I think that's what may have caused the new fets to fail funny how the fets with the missing gate resistor failed when I applied power to it including remote voltage. I really hope I can get it to work.

[Perry Babin]

Replace the blown FETs and gate resistors. Before applying power, connect only remote and ground. Measure the DC voltage on the gate leg of each power supply FET and post the voltages you read.

[chipper]

Originally Posted by Perry Babin

Replace the blown FETs and gate resistors. Before applying power, connect only remote and ground. Measure the DC voltage on the gate leg of each power supply FET and post the voltages you read.

They were IRFZ44's that I put in that failed. I'll get the results in a bit.