Does anyone know the difference between the STK4151, 4151-II, 4151-V chips?  Looking at the schematics between a beomaster 4500 and beocenter 9500, they seem identical in pinout and parameters.

I need to replace a MK-V but only have a MK-II.  

Want to make sure before I solder one in.

Thanks. 

They are normally backwards compatible in that you will be able to substitute a Mk II with a Mk V. There are probably minor differences, maybe temperature related issues fixed or safety circuits updated as the versions appear. I don't think it will hurt anything to try mouinting a Mk II but the Mk V is fairly inexpensive, so why not get the correct one ?

Martin

Because I have a MK-II in a drawer??

I checked my beomaster 4500 today while re-gluing the glass.  It is supposed to have the old chip but has a MK-V as well.  

Guess I'll just order one and be done with it then.

Marc 

The MK V has lower distortion than the MK II, they are interchangable otherwise.

Thanks!  I figured they were, but wanted to be absolutely certain.  In the meantime, I DID locate a MK-V chip and replaced it.

My 9500 is back to it's former wonderful self.

My next project is to replace the opamps and caps in the audio path.  ESR on the small caps is getting pretty high.

Still, for it's age I have no complaints.