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Re: Quad 405 without current limiting?

Posted by MarcelvdG@Haarlem105.nl (A) on March 14, 2003 at 03:09:43

In Reply to: Re: Quad 405 without current limiting? posted by RBrezins on March 9, 2003 at 12:26:36:

If the two 1kohm feedback resistors are burned, I'd recommend checking the output transistors, DC protection triacs and DC feedback loop electrolytic capacitor before turning on power! I know from experience that failure of the output transistors can damage the feedback resistors, triacs and DC feedback loop electrolytic capacitor (the 100uF one, called C2 if I remember correctly).

Switching on the amplifier with disabled current limiting and without an op-amp in the socket can also cause the destruction of all the devices mentioned above.

By the way, if you don't like electrolytics, possible modifications of the DC feedback loop can be found at the audio circuit:

www.audiocircuit.com/9121-solidsamplifier-circuit/ Commercial/Quad-QUA/9121CMQUA-MOD-405-MG.htm

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