Has anyone tried these stunning new CPT power cord?

@calander, I was told that all of the current 1800's are now series wired and a larger gauge wire is being used. This was done when Walter took over the company.

@hasmarto By any chance did you have the REL subwoofer that is listed in your system description connected to the 255se at speaker-level? And if so were you connecting the ground (black) wire from the sub to a negative output terminal of the amp?

If so, since the balanced amp has a full amplitude signal on its negative output terminal I’m guessing that the damage might have resulted from the combination of supplying the amp with balanced power via the 1800 and the fact that the full amplitude signal on one of the amp’s negative output terminals would have been connected to AC safety ground via some presumably low impedance in the sub. I can’t fully explain that, but that’s my hunch if the sub was connected as I’ve described.

Good luck. Regards,

-- Al

Hi Al,

Thanks for your response. The Bat was on the mids/highs, and my new Audio Analogue Donizetti was on the bass, just a regular connection, no active crossovers.

 The plan was to get a tube pre for the AA, until that  I did that “bi-amping” out of curiosity, I asked both amp manufacturers and the cable manufacturer, and they said if I like the sound then it’s ok. I failed to mention that I have a sub.

About the sub - it was connected to the big AA amp, positives on the amp’s speaker posts positive and negative to the preamp ground. On the sub its speakon cable was on the balanced out, but my tech knowledge stops right there. What do you think?

@hasmarto

I see that your Donizetti amplifier is the Anniversary Edition, which is described as being fully balanced. So you were correct in not connecting the sub’s ground wire to a negative output terminal of the amp. However the manual for the sub indicates that its balanced input is single-channel, and when a single sub is connected to differential/balanced outputs of a stereo amp the unbalanced input of the sub should be used, with the connections to the amp and preamp being made as you have done. (Or alternatively, with the sub’s ground wire connected to a chassis screw on the amp).


By using the balanced input of the sub in that arrangement the sub would be responding to the difference between the amp’s left and right channel outputs, rather than to their sum as it should be. Which would adversely affect sonics, but I don’t think would cause any damage.


I presume, though, that the AA amp was not being powered via the 1800, and I’m guessing that the sub was not being powered via the 1800 either. While the BAT amp and the rest of the system was being powered via the 1800, and the ground of the sub was connected to the preamp. I’m not sure if the net result of such an arrangement might have been conducive to the BAT being damaged, but having complex ground paths between the components in combination with balanced power being supplied to part but not all of the system, with the system including a sub and two fully balanced amps, suggests to me that it is possible.


If I am correct in assuming, though, that neither the AA amp nor the sub was being powered by the 1800, while the preamp, the BAT amp, and the front end of the system were being powered by the 1800, I’m thinking that connecting the sub’s ground wire to a chassis screw on the AA amp might have been a safer approach than connecting it to the preamp. (As I mentioned, the sub’s manual mentions both alternatives for connecting the ground wire when connecting to a stereo amp having balanced outputs). Although there are a few amp designs for which the result might be a hum problem if the connection is made to a chassis screw.


Regards,

-- Al

Thanks for your detailed response, Al.

You are right - neither the sub nor the AA were connected to the 1800.

First thing for me at this point is to repair the Bat.

What could be damaged in it in your opinion?