Amp Shutting Down, need help

Cappy, *maybe* your grounding situation could be the culprit, though since I lack any knowledge regarding Cary's circuits, it might be worth a quick phone call to them for verification.

The only other thing I can think of is that your power cord might be wired backwards (if removable). I assume you've tried swapping it out with one or two other replacements as wiring mistakes do happen whether hi-end or cheap molded variants. Lots of equipment can still operate if reversed, but some circuit designs may take issue.

Also, since you haven't confirmed my question pertaining to your Cary being powered up with *no* input or speakers cables attached, have you tried powering it up with *only* speakers connected (no inputs)? Have you tried swapping speakers and speaker cables - independantly - just for troubleshooting sake (even using cheap speakers and lamp cord)? Note: The amp may not operate without speakers connected, and may trip off as well. See the operation manual for any warnings regarding operation without speakers connected.

Final advice; Be as systematic as possible while troubleshooting, change only one item at a time, and don't *assume* anything. After that, if you're *absolutely* sure every thing's wired correctly (including your AC), and Cary states your grounding configuration doesn't pose an issue, maybe someone else may have additional experience regarding acceptable DC percentages, if present.

In touch,

Thank you again for your suggestions! I am being extremely systematic and it never hurts to hear that over again:)

• I have tried two different power cords, the polarity on both of the power cords is correct
• The outlet polarity is correct. I have tried 4 different circuits in my apartment and the problem still occurs.
• I tried with and without speaker cables including lamp cord.
• It seems that none of my outlets have separate ground wires. I will call Cary today to discuss.
• Remember the unit works perfectly with a 50’ extension cord attached. WHY OH WHY does this work?
• My gut tells me that somehow I am getting dirty (do you love my technical term) electricity which causes the Cary to feedback and trip the 15amp circuit breaker. Remember the circuit breaker trips after 20 second after the unit is powered on.

To be continued……

After talking to many people I was told to attach a 50' extension cord and low and behold it worked.

What does the 50' extension cord add to the equation?

Impedance is the only thing that I can think of.....

The 50' cord increases the total length of the branch circuit feed to the amp.... ????

Was the only thing that was plugged into the end of the 50' cord the Cary amp?

If yes, it is possible the 50' cord/added impedance is some how decoupling the Cary power supply from some other piece of audio equipment that is fed off the same branch circuit the Cary is plugged into. ????

I would like you to do a test.

Unplug all your audio equipment from the dedicated 120V 20 amp branch circuit. You can leave the ICs connected to the Cary amp.

Now plug the Cary Amp directly into the wall receptacle of the 20 amp dedicated circuit. (The Cary is the only thing that is plugged into the duplex receptacle.)

Turn on the amp...... Post back your results.
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I plugged the Cary amp directly into the 20 amp branch circuit; with and without interconnects and with and without speaker cables. Nothing else was plugged in to the branch. The 15amp circuit breaker (which is the on off switch for the amp) blows after 20seconds.

When I attached the 50' extension cord it only goes to the Amp and it works. Nothing else was attached to the extension cord and it worlks when all my other audio gear is plugged in as well.

The 15amp circuit breaker (which is the on off switch for the amp) blows after 20seconds.

Now that is a horse of a different colour!

Primary winding inrush current draw of the power transformer/charging electrolytic power supply caps is causing the circuit breaker on the amp to trip open......

The 50' cord is working like a soft start circuit limiting the inrush current draw to the Cary amp. At least that is what it sounds like to me.

What can you tell me about the 120V 20 amp dedicated branch circuit.
Distance from the electrical panel?
Wire size?
Electrical panel manufacture?

Another test....

Multimeter set to AC volts.
Insert the test probe leads into the unused receptacle of the duplex receptacle. Make note of the voltage reading. Cary plugged into the other recept.

While watching the meter flip the switch on the Cary to the on position. Note the reading/s of the meter.

Does the voltage sag several volts and remain low until the amp's breaker trips open? Voltage reading/s?

OR

Does the voltage sag and then swing higher than the original no load voltage? Voltage reading/s?
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