directed d2400

[Perry Babin]

With only the 640s in the circuit, it is likely producing DC which is causing it to go into protection. With no outputs, it may power up normally.

[mike49504]

with no outputs in the amp it powers up fine.

If i put 9640 and 640's in the amp it draws excessive current .

I checked the outputs all test good.

From all of the dircted amps ive worked on this one is the one from hell.

All the other directed amps ive worked on the 9640's were closet to the power supply fets then the 640's were near the rca jacks.

it seems like all pads are connected together in this amp for some reason.

Any thoughts?

[Perry Babin]

Which pads are connected together?

[mike49504]

i was getting strange readings between the pads i switched batteries in my meter now its measuring right.


With no outputs in the amp it powers up and idles fine.

On the output pads the reading i get are

1 banks of outputs

Leg1: -68.2
Leg2:0
Leg3:- 71.3

2nd bank

Leg1:72.1
Leg2:0
Leg3 70.1

So that appears to look good.

As soon as i put the outputs back in it it draws excessive current.

So Do you know what they are using for the drivers for the outputs?

[mike49504]

Ok the 2 drivers circled are defective.

They are marked.

DK QY

AG QQ

Is there a good sub for theese??

[Perry Babin]

See if the 2SA1797 and the 2SC4672 appear to be the same transistors.

[mike49504]

Im just wondering i have some other transistors that are new but i lost the packaging on them to tell me what they are.

they are marked
DY
209

CY
209

Wondering if theese will work in this amp or not??

[Perry Babin]

The SMD Code Book

Use this page to find the part numbers. Compare the dimensions in the datasheet to the device to confirm that they are the correct parts.