I am repairing this NAD2220 for a friend that has blown 2N3055/MJ2955 in both channels a some drivers. I read posts about putting a low value 2W resistor inline with each emitter for stability.
I was wondering if this was really necessary and if so how to physically do this with T04 transistors (they are on PCBs not point wired).
The arrows mark the outputs on the schematic and the pencils mark the emitters on one channel.
Thanks
I was wondering if this was really necessary and if so how to physically do this with T04 transistors (they are on PCBs not point wired).
The arrows mark the outputs on the schematic and the pencils mark the emitters on one channel.
Thanks
Attachments
They are not needed when fitting 2N3055 and MJ2955 transistors. Any other transistors will affect the quality of the audio produced and possibly become unstable.
The quiescent current is set by removing the link and then is replaced after adjustment.
The temperature is monitored to keep the Vbe of the output transistors constant with regard to the quiescent current. (Q410 ... the Vbe reduces as the temperature rises).
There is no need for any other components.
The quiescent current is set by removing the link and then is replaced after adjustment.
The temperature is monitored to keep the Vbe of the output transistors constant with regard to the quiescent current. (Q410 ... the Vbe reduces as the temperature rises).
There is no need for any other components.
