hi all
I have this boss PF1800 class AB amplifier. Found no damage on outputs or power supply but just resistors across speaker terminals burnt. I think they are 4.7ohms. I have 5.6ohms in stock. Can I use this instead and what will be the reason they got burn in the first place. The 104j caps are good found no short. Is there anything that I need to focus on?
I have this boss PF1800 class AB amplifier. Found no damage on outputs or power supply but just resistors across speaker terminals burnt. I think they are 4.7ohms. I have 5.6ohms in stock. Can I use this instead and what will be the reason they got burn in the first place. The 104j caps are good found no short. Is there anything that I need to focus on?
Attachments
If it's your amp, you can use whatever you'd like. If it's a repair that you'll charge for, I'd use the original value.
These are generally damaged by abuse (common) or when the amp oscillates (rare).
These are generally damaged by abuse (common) or when the amp oscillates (rare).
Are you sure they are across the speaker terminals and not in series with the capacitors? If they are in series with the capacitors, they are a Zobel network to counteract the rising impedance of the speakers at high frequencies. I would guess that the amplifier was oscillating badly to burn these out. When did they burn out? Was music playing? Were speakers connected? Does the amplifier still work? Sorry, so many questions
Brian
Brian