Alpine MRP-M860

[S Merlington]

This amp is using TIP41C and TIP42C as the outputs ..

They were removed from the board before I got the amp ..

Does the Tip42C connect to the positive or negative rail ?

 

[Perry Babin]

Does the collector or the emitter connect to the rail?

 

[S Merlington]

The collecter is connected to the negative rail.

And for the other output the collecter is connected to the positive rail .

 

[Perry Babin]

When the collectors are connected to the rail, the NPN transistor connects to the positive rail. The PNP to the negative rail.

 

[S Merlington]

I've gotten this amp back 2 times now ..

The outputs are TIP41C/42C this amp works perfect on the bench but only Works for about 2 days in a car and it blows the outputs again ..

Wondering what am I missing here ?

 

[Perry Babin]

Defect in the vehicle that caused the original failure has not been repaired?

Bias not holding?

Where did you get the TIP transistors?

 

[S Merlington]

I got the the TIP parts from a store near me ..

Those blew so I used new ones I got from digikey ..

Both batches blew ..

I will check the bias

 

[S Merlington]

everything is checking ok ..

Can i swap out the outputs from TIP41/42C to 2N6488/6491 for testing ?

 

[Perry Babin]

Is MRP-M860 the correct model number?

 

[S Merlington]

Yes

 

[Perry Babin]

I can't find anything on it. You may be able to use them but the bias probably won't track properly with them.

 

[S Merlington]

I used Tip35/36C in place of the Tip41/42C and this amp has beem playing at high volume on the bench for 45 mins now bias still checks fine ..

I will let you know the outcome when its back in the car..