I have a couple of older crown K1 amplifiers that are used to drive some JBL woofers in a home stereo. I measured the DC voltage offsets on the outputs and they measured between 100-150mv. I am not getting any warnings or errors during use. I called up a local crown technician at a service facility to see if the offset can be easily adjusted. He told me that there is no DC offset adjustment for this type of amplifier.
The spec states the offset should be +- 10mv. The crown technician told me to just use the amplifiers. He said the DC offset should not drift much over time and should be a nonfactor in operation on how I am using them. I know that class a/b amps should have an offset less than 50mv. I am not using the amps for any high frequency drivers. Any comments on DC offset on these amps or should I stop using them.
Thank you for any input.
Regards,
gwho
The spec states the offset should be +- 10mv. The crown technician told me to just use the amplifiers. He said the DC offset should not drift much over time and should be a nonfactor in operation on how I am using them. I know that class a/b amps should have an offset less than 50mv. I am not using the amps for any high frequency drivers. Any comments on DC offset on these amps or should I stop using them.
Thank you for any input.
Regards,
gwho
Looking for a Crown K1 amplifier, I kept getting photos of a 2x350W rather flat rack-mount type amplifier. Is that the one?
Looking at photos of the inside, I get the impression it is a class D amplifier?
I see two options: The simple is to use non-polarized low ESR capacitors in series with the speakers. The more complicated is to figure out how to insert a DC-compensation in the input of the amplifier.
Not using them would be a pity.
Looking at photos of the inside, I get the impression it is a class D amplifier?
I see two options: The simple is to use non-polarized low ESR capacitors in series with the speakers. The more complicated is to figure out how to insert a DC-compensation in the input of the amplifier.
Not using them would be a pity.
150mV is nothing to worry about. If you had a couple of volts, that would be different. IC206 looks at the offset and when it is too great, shuts the class D section down.
Faux French,
Thank you for the response. I will consider the series capacitor to block DC voltage to the speaker.
Regards,
gwho
Thank you for the response. I will consider the series capacitor to block DC voltage to the speaker.
Regards,
gwho
Jon Snell,
I did not know about the DC offset shut off. I guess I can live with the offset then. Do you know at what voltage the offset shuts off at? I assume it is a low enough voltage where the speaker will not get harmed.
fyi, I did speak to another crown Tech. He said in these amps the offset may be due to bad capacitors on one or several of the boards. The boards would have to be pulled and the capacitors tested and replaced.
Regards,
gwho
I did not know about the DC offset shut off. I guess I can live with the offset then. Do you know at what voltage the offset shuts off at? I assume it is a low enough voltage where the speaker will not get harmed.
fyi, I did speak to another crown Tech. He said in these amps the offset may be due to bad capacitors on one or several of the boards. The boards would have to be pulled and the capacitors tested and replaced.
Regards,
gwho
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