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
08-15-12: Sailcappy
I have had it replaced to no avail.

I *thought* I'd read someone mentioning the breaker was replaced, but couldn't confirm yesterday when quickly going back through the posts, so I wasn't 100% sure and am entertaining Ralph's (Atmasphere) concern considering the breaker's accumulative set/trip cycles, *if* it was still the original. Also, based on first-hand experiences, have had to replace numerous "new" components after immediate or delayed faulty operation, especially regarding a device unintended for elevated repetitive mechanical cycling.

Regarding the amp working at other locations (which I've always taken into consideration), Ralph posted some scenario possibilities that may allow a deteriorating breaker to continue functioning, and I agree is possible. Lacking any witness confirmation, or actually being there to assure apple-to-apple testing/comparisons, all we can do is speculate. He is quite knowledgeable, as with Al and Jim. We all come from decades of professional backgrounds in various electronics fields and offer legitimate suggestions based on scenarios and probabilities we've encountered over the years. All of us would *prefer* to be there - armed with appropriate test equipment - able to make better determinations. That's what I do for a living. So, lacking factual data, all one can do is suggest trying different things with hopes of resolvement.

Your updated plan is fine if unwilling to wait for Ken to return and 'scope your AC (the best *practical* option to minimize guessing). If the two devices fail to resolve, either keep or sell them, and take my joking recommendation to neatly coil-stack an appropriately rated ext cord and hide it out of sight behind other equipment, rack/furniture, etc., or package it cosmetically. You're planning to power the Cary from the conditioner, so, will *all* of the electronics be accumulated in one location near the 20 amp outlet? ...On a vertical rack, shelves, table-top, etc. - thus able to hide a majority of a coiled flat or stacked (black) ext cord?

If the Brick Wall works, it's not very WAF either, so how would you address that vs. a "shaped" ext cord, if the BW doesn't work. I can't envision a scenario where the cord couldn't be hidden or repackaged cosmetically, even if the amp is remoted across the room. It still requires a cord that has to plugged *somewhere*, and you plan to feed it from the SR conditioner. Describe your equipment layout if otherwise.

Again, if we *knew* exactly what was wrong (if anything) with your AC, if not equipment related, could better diagnose and recommend specific cures.
Hi frank,

......
If the two devices fail to resolve, either keep or sell them, and take my joking recommendation to neatly coil-stack an appropriately rated ext cord and hide it out of sight behind other equipment, rack/furniture, etc., or package it cosmetically.
Key words here are "appropriately rated ext cord". For the Cary 7.250 amp to perform sonically as it was designed to sound, imo, the minimum wire gauge would be #12awg.

50', times two, of 16ga is staving the amp of needed dynamic power.

A 50' 12/3 cord coil would be fairly bulky in size.

And more importantly with a 12/3 cord, I believe, the magnetic breaker would not hold on active start up and trip open.

>>>>>>>>>>>>>>>>>>>>>>>>>

Sailcappy,

I asked in an earlier post if you have any info on the SR Powercell.
Does the unit have a built in isolation transformer?
If so an isolation transformer will not pass DC offset from the primary winding to the secondary winding....

The SR Powercell could correct a poor power factor problem if it is so designed......

It will not block harmonics, that it unless it has a Mitigating harmonics cancelling type transformer..... And I doubt that it does. The cost of the SR Powercell would have been more than $5K. And I doubt if the unit has any harmonics filters built in.... I would think the specs would say so if it did though.

I also asked you if the SR Powercell has built in surge protection, SPD, for connected loads.

The info would be helpful in solving the Cary amp's problem.

Sailcappy, you mentioned in an earlier post if the Mains power feeding your apartment is the problem the landlord would not help, pay, to clean up the power. Probably true..... But there are things that you can do on your end.

Some remedies would require the permission of the landlord.
The landlord also may require his authorized electrical contractor install any harmonics filters or what ever is needed to solve the problem. No doubt you will bear the cost.

You first would need to hire a Power Quality testing company to verify and find the problem/s.

The problem with the Cary magnetic breaker tripping could be a Canary in a coal mine...... IF,.... the mains power feeding your apartment is of poor quality, from harmonics, the life of your audio equipment could be shortened......

http://www.hammondpowersolutions.com/upload_files/hpsi-ta5.pdf

http://www.fluke.com/fluke/twen/solutions/pq/troubleshooting-power-harmonics.htm

http://www.psihq.com/iread/harmonic.htm

http://www.artechepq.com/assets/files/SinglePhase.pdf

[url]http://www.cpccorp.com/harmonic.htm[/url]
.
Again I can not thank all of you enough for your trouble shooting ideas. No updates to report as of now.

As far as the SR PowerCell is concerned
1. It is not a Surge Protector
2. It does not have a Transformer
3. It does not treat for harmonic distortions.
4. All I can get out of SR is that the unit uses a EM Cell to filter AC.

DC eliminator should be ready by Friday.
I had GBART make me a DC Blocker and plugged it in and it did not solve my problem. I will say that GBART created a beautiful box for me. Really good quality. I highly reccomend him if you have DC Blocking needs. BTW mine is now for sale as I do not have DC issues with my line. Check it out under DYI.

On to the Brick Wall. More info to come.
Sailcappy, what happens if you short the input of the amp? Does it still do it?