Jeff Rowland Model 501 - Help ...

Kijanki,

Thanks a lot for your answer. I asked a friend of mine to test this JR's by putting them near TV and FM radio sets and after I get the message from him, I will also let you know ...

One question more: this carrier signal that you are mentioning, that travels through speaker cables - does it produce any noise in the speaker tweeters ? I have Focal Electra 1027 Be speakers with Berillium tweeter. All cables are Crystal Cable (very well shielded). Speaker cable is Crystal Cable Micro.

Dejanm - As far as I know tweeter has very high impedance at 0.5MHz therefore power delivered will be very low. In addition there should be no intermodulation products because membrane cannot move at these frequencies.

I promised to provide a feedback from a friend who tested these Jeff Rowlands ... so here it is ...

He installed JR Model 501 monos in a system where Primare was a preamp and the speakers are Harbeth. CRT TV was about 20 cm away from monos (they were put one on another) and the FM tuner was somewhere about 80 cm away from these monos. Power cords of these monos were plugged into separate wall mains from the rest of the system.

He could hear a brum on all radio stations (cable network reception) and the picture on some (not all) TV stations was clearly degraded. It is a clear evidence of some, not negligible, radiation from these units.

Therefore I decided not to go after these babies although, as I already mentioned, the offer is really good one. That is pity, because I know that they can produce, with the right speakers, excellent sound reproduction.

I wish to thank to you ALL for your advices and comments ...

The latest Bel Cantos have a filter that keeps out the Class D generated interference.

I'm very skeptical of these results. I have a Rowland Capri preamp and 102 amp stacked next to my Kenwood KT-917 tuner and sitting beneath a Panasonic plasma TV, which hangs on the wall above and behind. The amp is 7 inches from the tuner and about 18 inches from the TV. There is no indication whatsoever of interference or noise. I'm using the Rowland 102 to power a pair of 108 db efficient horns so I'm sure the noise would be obvious if it existed.