UK Vintage Radio Repair and Restoration Discussion Forum - View Single Post - HMV Stereomaster 2419 left channel output help

paulsherwin · 1st Oct 2020, 9:01 am

No, you don't need to go back before the power amp stage. There's no DC path to these earlier transistors so they should be fine. You should be able to treat the power amp as a discrete subsystem.

The 2SC1129s (if that's what they are) seem to be being used to set the bias for the output pair. It's not clear why the designers decided to do things that way.

Be careful about leadout differences when subbing transistors.

1st Oct 2020, 9:01 am	#14
paulsherwin Moderator Join Date: Jun 2003 Location: Oxford, UK Posts: 27,947	Re: HMV Stereomaster 2419 left channel output help No, you don't need to go back before the power amp stage. There's no DC path to these earlier transistors so they should be fine. You should be able to treat the power amp as a discrete subsystem. The 2SC1129s (if that's what they are) seem to be being used to set the bias for the output pair. It's not clear why the designers decided to do things that way. Be careful about leadout differences when subbing transistors.