Kijanki, I suspect that the more refined sound of the 312 over the 501 is caused by a reasonably wide variety of technical factors, only one of them being integration of PFC. It is worth pointing out that PFC has now being integrated in the Continuum 500 integrated, which costs about half the 312 and also contains a Capri-like front end and some bulk output capacitance not implemented on 312. What frequently happens with technology is that novel design solutions are first tried in higher end devices, and then are gradually migrated to more attractively priced implementations. G. |
I can confirm that current JRDG amps are fully balanced in the input as well as in the output stages. According to Jeff Rowland, his amps put out an active signal on both positive and negative speaker terminals.
Hi Kijanki, have you considered adding a JRDG PC1 Power Factor Correction unit to feed your 102? I have heard that it is designed to enhance significantly its performance, but have not heard directly from anyone who has tried the PC1 on either 102, 201, or 501. PFC is already built into the Continuum 500 integrated, and the 312 amp. Guido |
Hi Kijanki, I looked for the Capri/102 review by Audioenz but could not find it. . . could you post the URL?
The PC1 is unfortunately not inexpensive, at $1500 list, but some dealers have sometimes offered a demo unit for quite a bit less. One good thing about it is that if you ever upgraded to 201 monos or 501 monos, the PC1 would serve there as well. Guido |
Thank you Kijanki, much appreciated. . . now I remember reading this review a while ago. Can't help thinking that the relative darkness, moderate downward extension, slight imaging problems, and other minor quibbles that Mr. Wong observed may have been caused by less than complete break in of the equipment. Capri is a bear to break in, requiring perhaps 1000 hrs. . . not sure about 102, but I wouldn't be surprised if it required more of the same. G. |
Clio, please keep us posted. . . I'd be curious what you think of Capri once you are around the 1K hrs mark. G. |
Hi Kijanki, has your JRDG 102 stabilized completely after 400 hours mark?
I also have observed some treble sterility -- or at least
lak of ultimate musicality -- in some 'entry level' switching amps such as Flying Molde (by far most evident), Channel Island, JRDG 201, JRDG 501. Conversely, JRDG 312, Spectron Mus 3 SE, and to a great extent NuForce 9, are capable of a very delicate and nuanced treble. I have not heard the 102 myself, so I cannot comment on it directly. I can't comment on phase shift above 20Khz because my technical knowledge is very limited. The solution that JRDG has adopted to addressed the perceived harmonic sterility and somewhat moderate microdynamics of raw ICEpower modules is to feed the 312 and the new Continuum 500 a 385V DC through an internal Power Factor Correction circuit in front of the power supply. I have done comparative a/b/c listening of 201, 501, and 312, and the latter sounds more graceful and musical by miles, with no hint of sterility. The external PC1 unit does the same thing for the 102, 201, and 501. . . but 2 units are apparently recommended for use with the 501 monos.
But now I realize I have at least partially hijacked this thread, as my last couple of posts have nothing to do with single ended operations. . . my apologies. G. |
Hi Karelfd, unfortunately I have not had the opportunity of listening to the Acoustic Reality amps. It is my understanding however, that most switching amps are truly balanced designs. I suspect therefore, that no matter what amp of this type you adopt, you may not be getting their musical best in a single ended configuration. This is purely an educated guess on my part, and if anyone has had any direct experience one way or an other, please post your findings here. |
Hi Kijanki, 501 were introduced prior to 312. Both use ASP100. However 501 monos are relatively basic design, while 312 costs almost 3x the 501s, and is much more sophisticated and, includes integrated PFC among other things. G |
Rafael and Dave, the active PFC circuit of the PC1 is in fact used in series with internal DC2DC transformers of compatible devices to optimize voltage regulation. Unfortunately I am not an electrical engineer and my technical knowledge is limited. G. |
Thank you Rafael, I may have misunderstood. . . As I am not an EE, you will get more precise answers by contacting JRDG directly. G. |
Hi Kijanki, once again, I am not an electrical engineer, so I apologize for my lack of rigor. You are correct the PS of the ASC200 power conversion module is already regulated. Yet, according to the designer and to many users, feeding 102/201/501 devices 385V DC current through an active PFC unit, further increases their musical performance. G. |
