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Amp Shutting Down, need help

I have a Cary 7.250 brand new amp that shuts down after 20 seconds in my NYC apartment. I have sent the unit back to Cary where it tests fine. I have tried the unit at my friend’s apartment and his place of work and it works fine. The unit is 100% in working order. After talking to many people I was told to attach a 50' extension cord and low and behold it worked.

The good news is that I have a dedicated 20amp circuit to this outlet. My voltage reads 118 volts and Cary said that is not a problem as the unit will work between 90 and 130 volts. I have tested for voltage on the negative lead to ground and there is no stray voltage. I have also tried the unit on other outlets in the apartment and the same problem occurs.

My mono blocks and all other components work just fine. So I’d love to hear suggestions as to how to get rid of this 50’ extension cord?

Thanks in advance.
sailcappy
slikric3000
638 posts
 
A line conditioner, my Classe' CA400 will not run off the crap that comes out of my wall either in my apartment.
joeabrams
132 posts
 
What speaker cable are you using? Many solid state amps will not respond well to high capacitance speaker cable -- some will go into "protection" mode, as yours is doing. Speaking very generally, many flat cables and many skinny/round cables are high capacitance.
sailcappy OP
57 posts
 
Great idea's.
1. Synergistic Research Powercell 10se MKII and the Cary will not work if it plugged into it or not.

2. The Cary will not work if it has all the speaker and interconnects attached or even if all the cables are not attached. As a matter of reference all of my interconnects and speaker cables are Crystal Cable Micro's.

3. I am using a 20 amp Maestro outlet.

Any other thoughts?
metro04
222 posts
 
Hi 'Cappy.

Just to confirm; you're stating that the Cary still shuts down after 20 seconds without *any* cables connected except the power cord? If so, please bare with me with the following request:

Can you please re-confirm that your wall outlet(s) are wired and grounded correctly. You stated you're getting 118 volts between the HOT (smaller slot) and NEUTRAL (larger slot), and no stray voltage between the NEUTRAL and GROUND. Assuming your smaller slot is wired HOT, measure the voltage between it and the GROUND. If your apartment is wired correctly within the breaker box, you should read the same 118 volts as well since the NEUTRAL and GROUND should be connected together within the breaker box in most areas (I believe). *Some* equipment topologies require a properly polarized and grounded source to operate, hence, not to assume all is right even though other equipment designs will operate.

Please advise,
sailcappy OP
57 posts
 
Metro04 - First off thank you very much for your insight. I had my friend who is knowledgeable about power test the lines and he confirmed that the polarity is correct vs. the small and large slots. He also noted that none of my outlets in my apartment are wired to ground it seems the ground is left to the junction boxes alone.

Where to go from here?
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