Jeff Rowland Design Group
Take your pick, these designers below they will have something. But for your speakers, I’m told they closely follow the impedance and negative phase angle of the PL300’s, and these speakers are not a very demanding load. worst is 4ohms from 70hz to 200hz. Even mosfet will do.(Pass) https://www.stereophile.com/images/1016MA300fig1.jpg But I have a feeling this is a loaded question, to which you won’t be convinced, no matter who says what. These designers are to me are still at the pinnacle of hi end amp design, and still use linear amps and linear power supplies for their "flagship amps". Flemming E. Rasmussen Gryphon Dan D’agostino Krell and D’agostino. Nelson Pass Pass Labs PassDiy, Threshold John Curl, Halo and other hiend old school Parrasounds Jeff Rowland Design Group non class-d old school Mark Levinson non Class-d ect ect. Cheers George |
George, It isn't a loaded question, but you are correct that I'll never be convinced by what people say for a couple of reasons. For one I honestly think so many people make comments about components that they never actually heard. Secondly, there are no absolutes in audio, only preferences; therefore it isn't what someone says, it's what our ears hear that makes the difference. I don't think what I have is the best, not even close. I set a price range for what I want to spend on each component and try to evaluate it in my own system. If I end-up preferring something else, I have no problem saying I prefer something else. |
It isn’t a loaded question, but you are correct that I’ll never be convinced by what people say for a couple of reasons.OK, if it wasn’t loaded, you ask for my opinion on what would be good, I gave you the designers on where to look, I think your capable to choose a Linear amp with linear power supply from one of these designers, that would easily out perform the 652’s for sound quality. The 625 S2 could have been much more if they used linear power supply instead of smp. Independent bench tests carried out: " The 1-watt signal-to-noise ratios measured by Newport Test Labs fell quite a bit short of JRDG’s specification of 95dB, with the lab reporting figures of 80dB unweighted and 88dB A-weighted referenced to one watt. I suspect that the signal-to-noise measurement could have been tainted by very high frequency noise generated by the 625 S2’s switch-mode power supply" Cheers George |
Measurements : Dan D’Agostino Momentum monoblock power amplifier The unweighted, wideband signal/noise ratio, ref. 2.83V into 8 ohms and taken with the input shorted, was a good 77.2dB, this improving to 78.1dB when the measurement was restricted to the audioband. Switching an A-weighting filter into circuit improved the S/N ratio to 81.65dB.Read more at https://www.stereophile.com/content/dan-dagostino-momentum-monoblock-power-amplifier-measurements#7q... Dan D’Agostino Progression Mono monoblock power amplifier Measured with the input shorted to ground, the Progression offered a wideband, unweighted signal/noise ratio of 57.5dB, ref. 1W into 8 ohms. This was primarily due to the presence of noise with a center frequency of 923kHz. Concerned that the amplifier was picking up some RF interference that was being demodulated, I turned off all the CFC and LED lights in my test lab, but the noise persisted. The ratio improved to 80.1dB when the measurement bandwidth was restricted to 22Hz–22kHz, and to 87dB when the reading was A-weighted. Parasound Halo JC 1 monoblock power amplifier The JC 1’s unweighted, wideband signal/noise ratio (ref. 1W into 8 ohms) was good at 73.3dB, this improving to 87.8dB when the figure was A-weighted. Pass Laboratories XA200.8 monoblock power amplifier The unweighted, wideband signal/noise ratio, ref. 1W into 8 ohms and taken with the input shorted to ground, was an excellent 83dB. This improved to 88.2dB when the measurement bandwidth was restricted to the audioband—and was even better, at 92.1dB, when the measurement was A-weighted. Jeff Rowland design 625 s2 stereo Power Amplifier the lab reporting figures of 80dB unweighted and 88dB A-weighted referenced to one watt. Look like the Jeff Rowland S/N ratio is better than Dan D’Agostino and Parasound |
