Jeff Rowland


I recently replaced my Parasound A21 with a JR M525. It has taken my system to new levels: soundstaging, spacing between instruments, tonality, and a natural midrange. The M525 is the first amp I've ever owned that presents a 3 dimensional soundstage. All that being said, now I wonder what improvements going from the M525 to the JR S2 integrated or bridged M525s will yield? Is it a night and day difference? Are bridged M525 better than the S2? My system: Aerial 7Ts, PS Audio DirectStream DAC, Bryston BDP-2, and all Wireworld Silver 7 cables.
ricred1
ricrd...no saracasim intended....I love Wireworld stuff..use it myself. I have also used Rowland (know Jeff peronally). Excellent company....I always look up to Mr. Rowland.. (He's very, very tall :)
I remember the 7T's though very good speakers didn't have the bass that I thought it would have, by looking at the speaker. Have you thought of adding a sub?? A powered sub would make the main speaker sound better too.
Ricred, what can often be a very major contributor to lack of bass impact is the acoustic effect of the rear wall (the wall behind the listening position). I can't tell from your system description photos what that distance is, but under typical indoor environmental conditions rear wall reflections will produce a suckout (i.e., a lack of bass) centered at a frequency in Hz of about 282 divided by the distance in feet between the listener's head and that wall.

So if you were say five feet from that wall, there would be a suckout centered at about 282/5 = 56 Hz. In my experience that effect can often be MUCH more significant than differences in bass performance between most electronic components.

Good luck as you proceed. Regards,
-- Al
03-07-15: Kijanki
Ricred1, I stated 22% loudness increase, but it would be true for 2x loudness. I forgot that bridging doubles the output voltage, thus quadruples the power. In such case you can count on (substantial) 49% loudness increase. Speaker's minimum impedance remains the problem.

L=k^(1/3.5) where L=loudness, k=ratio of power.

L=4^(1/3.5)=1.49
Kijanki, that's not true over the entire amp power range, correct? it will be true for a small power output range until the amp runs into its max current capability. So, we'll see a 4X the power just for that small power output range.

when the amp output voltage doubles so does the current. So, you have 2X voltage & 2X the current & an increased heat dissipation (& maybe even amplifier catastrophic destruction).
Or, am i thinking of this incorrectly? Thanks.
always look up to Mr. Rowland.. (He's very, very tall :)
indeed he is. I met him at the 2013 RMAF - on Sat he was running the demos himself in the afternoon (had the 525 amp driving the Raidho stand mounts which were crazy priced). I'm tall but no comparison to Jeff Rowland himself....