Kicker 2500.1

[mike49504]

Anyone know what transistors belong here? They were missing when i got the amp in for repair. They are on the driver board

[Perry Babin]

KTB985/2SB985

[mike49504]

Thanks Perry,

Now i just have to wait til the parts come in.

[mike49504]

Perry,

I orderd the irf3205's from future they said they were out of stock but had a cross part for them.

Wondering if they will work?

Thier cross part is STP80NF55-06

[Perry Babin]

It shows that they have nearly 4000 in stock:
INTERNATIONAL RECTIFIER | IRF3205ZPBF | Single N-Channel 55 V 170 W 76 nC Power Mosfet Flange Mount - TO-220AB - Future Electronics

[mike49504]

Is there a good sub for the KTB985/2SB985 ?

[Perry Babin]

I don't see many options for this transistor. If you have 2N6491s, they may work (I've used them in many other amps). You'll have to install them facing the opposite direction due to the reversed pin configuration. You'll need to make sure that the FETs in the power supply run cool at idle. If the power supply is regulated and running at less than full pulse width at idle, you'll need to reduce the power supply voltage to force the pulse width to go to 50%. If the power supply FETs still run cool at idle and the current draw doesn't increase with the lower input voltage, they are likely good subs.

If you use them, apply a small amount of adhesive (Goop or similar) between the transistors. Bonding the transistors together will reduce the stress on the solder connections/circuit board and will prevent the legs from breaking.

[mike49504]

Will the green light come on if the power supply fets are removed?

I wanted to check the gate signal but amp does nothing

[mike49504]

Ok fixed that problem loose connection.

Heres what i have for gate signals wondering if theese look ok?

Scope set at 10us 1volts/div

[Perry Babin]

That looks OK. It will change when the FETs are installed.