crown d150 output transistors

[markp]

Does anyone know what the output transistor for a Crown D150 is? It is labeled "C7064-6".

 

[djk]

epitaxial 2N3773, use a MJ15024

 

[markp]

Anyone have the schematic for a D-150?

 

[SY]

I do. If I can get my scanner working tonight, I'll post it. What's your serial number? There are several versions.

I've also got bad output transistors in my D150. Given the cost of replacement, I'm tempted to just gut the thing, drop the supply by a few volts, and rebuild it with 3886s.

 

[markp]

My serial number is 65896. The MJ15024s worked as a sub so far but there is more in this amp that needs help so the schematic is a must.

 

[SY]

OK, I'll see what I can do this evening. If it doesn't work, do you have a fax number? (don't post it, use the eamil button to send it to me)

 

[djk]

One of the more common failures in the D150 and DC300 is the voltage doubler on the positive rail. The cap goes open and/or the diode shorts.

Replace both.

This supply feeds a stereo pair of constant current sources, TO-92 plastic case with an 'S' shaped heatsink.

Replace both.

Now check the ±10V supply for the opamp, just pair of zeners and resistors off the main rails.

Don't forget to replace the cap in the feedback loop to ground (D150 only).