I posted what appears below on another forum and also wanted to post here to see what opinions on this you all might have. I recently read a review of the Musical Fidelity M8 equipment that Jacob Heilbrun reviewed for AS back in September. He made a statement in that review that now has me concerned. Jacob reports that the M8700 monobloc runs in a bridged design that should cause some concern, or pause at the very least, of connecting a sub such as an REL to it. Apparently the risk of a ground problem in this configuration could cause something (or everything) to go up in smoke. My Musical Fidelity 550K's also operate in a bridged design and Jacob's statement now has me worried. What I wrote elsewhere is copied below in its entirety:
In my 2 channel audio system I am running a Jolida 502 BRC Tube Integrated Amp into a pair of Musical Fidelity 550k Superchargers. The 550K's then power a pair of Magnepan 1.7's. Recently, and through the gracious support of Definitive Technology, I have repaired my SuperCube III and am looking to add it to this audio setup. (As a temporary test run as I ultimately have my sights set on and REL T5.)
Now to digress a moment. When I first got the Maggies, I did not own the 550K's. Trying to drive the 4 ohm Maggies with the 65 watt Jolida wasn't getting it done for me, so after much deliberation and scouring the used market, I finally secured a mint pair of the 550K's to introduce into the system. (Yes, they are miracle workers, but that's for another thread).
I originally had the Maggies tapped to the 4 ohm speaker taps on the back of the Jolida because, well, they are 4 ohm speakers. But since I am wiring the SuperCube high level through the Jolida speaker taps also, I became concerned about tapping the SuperCube to the 4 ohm taps. In the end I decided to re-tap everything to the 8 Ohm taps under the theory that it really wouldn't matter since the Jolida sees the 550K's as a low impedance input that the Jolida can easily drive. In short, the 550K's are supposed to make the Jolida work about 10 times less than it normally would to drive the Maggies.
I ran the system about 30 to 40 percent power for about 20 minutes and everything seemed to work very well. The SuperCube is working and really rounding out the lower mid to low range very nicely. My question is: Am I running the risk of damaging something long term? I've been to the Musical Fidelity website which has proved futile to find any info on their legacy products like the 550K's.
Any members of the forum with more of a technical background that can chime in on how the relationships between resistance and impedance interact in a system such is I have described here would be very much appreciated.
Thanks!
I should note that in my setup the 550K's and the SuperCube III share only the speaker taps on the back of the Jolida. The sub is not connected directly to either of the 550K's. Is that a potential problem though?
In my 2 channel audio system I am running a Jolida 502 BRC Tube Integrated Amp into a pair of Musical Fidelity 550k Superchargers. The 550K's then power a pair of Magnepan 1.7's. Recently, and through the gracious support of Definitive Technology, I have repaired my SuperCube III and am looking to add it to this audio setup. (As a temporary test run as I ultimately have my sights set on and REL T5.)
Now to digress a moment. When I first got the Maggies, I did not own the 550K's. Trying to drive the 4 ohm Maggies with the 65 watt Jolida wasn't getting it done for me, so after much deliberation and scouring the used market, I finally secured a mint pair of the 550K's to introduce into the system. (Yes, they are miracle workers, but that's for another thread).
I originally had the Maggies tapped to the 4 ohm speaker taps on the back of the Jolida because, well, they are 4 ohm speakers. But since I am wiring the SuperCube high level through the Jolida speaker taps also, I became concerned about tapping the SuperCube to the 4 ohm taps. In the end I decided to re-tap everything to the 8 Ohm taps under the theory that it really wouldn't matter since the Jolida sees the 550K's as a low impedance input that the Jolida can easily drive. In short, the 550K's are supposed to make the Jolida work about 10 times less than it normally would to drive the Maggies.
I ran the system about 30 to 40 percent power for about 20 minutes and everything seemed to work very well. The SuperCube is working and really rounding out the lower mid to low range very nicely. My question is: Am I running the risk of damaging something long term? I've been to the Musical Fidelity website which has proved futile to find any info on their legacy products like the 550K's.
Any members of the forum with more of a technical background that can chime in on how the relationships between resistance and impedance interact in a system such is I have described here would be very much appreciated.
Thanks!
I should note that in my setup the 550K's and the SuperCube III share only the speaker taps on the back of the Jolida. The sub is not connected directly to either of the 550K's. Is that a potential problem though?
. You may want to try and contact Sumiko regarding your question....I would be interested to see what they respond. In the meantime, i would be VERY careful with hooking up a powered sub to your amp....probably NOT something to do unless one knows the protocol.
