PPI pc1400

[mike49504]

Wondering on this amp if legs 1 and 3 are connected together on the ouputs (tip35c and 36c)

The guy who owns this amp powerd it up with a load on the outputs with the bottom cover off and toasted all 12 power supply fets the drivers and the gate resistors.

I checked the outputs all seem to test fine out of the board but legs 1 and 3 are showing they are connected together on the pads So wondering if this is normal for this amp or do i need to do more checking

[mike49504]

Ok disreguard the post amp is up and running perfect.

[mike49504]

I repaired this amp and it was working perfectly. The guy went to competition yesterday and ran the amp at a 1 ohm load and blew it up again.

He asked if the amp could have some mod's done to it.

So im wondering is there a mod i can do to this amp to make it run at a 1ohm load??

Also they are using irfz44's in the power supply Is there a good upgrade to theese or should i stick with the 44's?

The outputs are tip 35 and 36's In my opinion theese are good outputs so i wouldnt do any mod's to them.

This amp currently accepts 8 guage power and ground wires. Im thinking to mod it so it will accept 4 guage power and ground Will this improve anything or is it a waste of time?

[Perry Babin]

You should avoid situations like this. There's no way to make it reliable into 1 ohm. If you make the power supply more durable, the outputs will fail. If you made those hold up (not likely without reducing the rail voltage), the transformer would likely fail.

[mike49504]

Ok ill leave it original Wondering will the Z44's or the Z44n's work better in this amp or doesnt it make a difference

[Perry Babin]

I wouldn't expect it to make a difference. I was told by an IR employee that the larger die of the Z44 makes it better at handling transient surges in current but under normal operating conditions, there isn't likely to be a difference.

[mike49504]

Perry,

DO you know what they are using for the drivers for the outputs??

Also i found a transistor marked J 108 P718C Which measures 5.6 ohms between legs 1 and 2 the other one measures 20 ohms between legs 1 and 2 and theese are out of circuit. Defective?

[1moreamp]

Originally Posted by mike49504

Perry,

DO you know what they are using for the drivers for the outputs??

Also i found a transistor marked J 108 P718C Which measures 5.6 ohms between legs 1 and 2 the other one measures 20 ohms between legs 1 and 2 and theese are out of circuit. Defective?

J108 are j fet mute transistors and they will read like this. I would only worry about these if the muting circuitry is faulty Mike. I just did a 1800 < same as the 1400 > last week so the info is fresh...

Drivers to the outputs are 2SC2344 and its match as i recall, if I understand your question correctly..... Hope this helps some....

[Perry Babin]

You recall correctly. 2SA1011 and 2SC2344.
http://datasheet.octopart.com/2SA101...eet-101366.pdf

The J108s will typically read 5-8 ohms. if one reads 20 ohms out of the circuit, it could be defective.

[mike49504]

Well im gonna have to check the drivers again I had a few shorted outputs and a blown power supply. Took all of the outputs out and its reading shorted from pads 1 to 3 on the outputs