I also wonder why the TS is considering replacing the resistor, although I do not see the two red bands that I would expect to see on a 22 ohm device. If it has overheated so that the second color band changed from red to black, then there is another problem upstream some place, or possibly the series capacitor has become short circuited. If the amplifier has developed a high frequency oscillation that resistor will certainly get very hot. So I suggest connecting an AC voltmeter across the speaker output connection with no signal applied and check for an output. An oscillation would be far above the audio range and could not be heard, but they certainly can do a lot of damage.The resistor looks fine. Why do you want to replace it?
Yep, so it's going to change the colors, particularly to black. We don't have a complete view of the circuit to tell it's use.To me it looks like the resistor has been overheated a bit.
It doesn't look all that badly scorched - I'd try measuring it and see if its near a standard value, even if it isn't.....I would say 22 ohms 1W resistor, looking at the drawing of the others the way it's marked.
It's a Zobel Network resistor.
The resistor is burned but the amp still working with a click noise. That is the only part burned.I also wonder why the TS is considering replacing the resistor, although I do not see the two red bands that I would expect to see on a 22 ohm device. If it has overheated so that the second color band changed from red to black, then there is another problem upstream some place, or possibly the series capacitor has become short circuited. If the amplifier has developed a high frequency oscillation that resistor will certainly get very hot. So I suggest connecting an AC voltmeter across the speaker output connection with no signal applied and check for an output. An oscillation would be far above the audio range and could not be heard, but they certainly can do a lot of damage.
Not many mono amplifiers about these days - isn't there "the other channel" to compare notes from?If I put a 20 ohm resistor will be fine?
The resistor may look scorched but it isn't that bad.If I put a 20 ohm resistor will be fine?
See post 11, apparently the resistor is failed.The resistor may look scorched but it isn't that bad.
Change C73 first.
by Aaron Carman
by Aaron Carman
by Aaron Carman
by Jake Hertz