Pre-amp for Rowland Model 102

Guido, I don't have Capri. Furman made it cleaner. They claim large peak current available (large capacitor behind large inductor) but it did not improve dynamics (other than removing bass resonances). Furman made big difference on my previous digital (DLP) TV, making colors more clean and saturated. I know it doesn't sound plausible in digital domain but removing jitter can do it. One thing that made huge difference was speaker cable (Acoustic Zen Satori) that enhanced lower midrange (Cello, male voice chestiness etc.) where 102 seemed to be a little thin. In addition it has this "silky" quality (but I'm rather new to high end cables).

Guidocorona,

"It bested my ARC REF 3 in harmonic development, control of treble intermodulation in complex passages (think of multipart violins)"

In reference to your quote above, how do you define harmonic development and treble IM? Are they something you listen for or measure?

ZD, I only "measure" things with my ears, thus I apologize in advance for the unscientific and somewhat subjective nature of the following....

On the subject of treble intermodulation.... Frequently, on multipart string music, you may notice that there is a range of chorded notes, approximately in the 3rd treble octave, that have the habit of sounding rather harsh, distorted, and metallic. What I always look for is ways to make those notes sound like "music", without resorting to filtering effects.

On the subject of harmonic development.... if you listen carefully to piano music for example, you may hear the fundamental frequency, but also a set of harmonic frequencies that rise, sustain, and decay on their own terms.... this complex and evolving harmonic resonance is what gives an instrument some of its individual richness, or.... palpability.

My experience is that a PFC-based DC front end for an autoranging SMPS can increase an amplifier's ability to expose the complex behavior of independently decaying harmonics, and control a fair amount of treble harshness, without ever being perceived as a band-pass filter.

For example, integrated PFC rectification is one of the main differences between the class-D Rowland M501 monoblocks and the class-D M312 stereo.... Yes I know, there are other factors involved, such as higher quality transformer coupling etc... but.... M501 is a fun amp with a lot of power that sounds a little "matter of fact", while M312 sounds much more musical and emotional.... M312 Was my very favorite power amp prior to my adoption of the Rowland M725 monos, which while being based on class A/B design, are still fed by a PFC-based DC front end. Back to M501, the monoblocks can be front ended by a PC-1 PFC-based rectifier on each... Owners that have used M501 in such configuration claim that they rival the overall musicality of M312.

Warning, unlike Furman Elite, PC-1 transforms 120V AC into a 220V DC current... So do not feed it into any device unless the target component has an autoranging power supply, or it has been switched to 240V operations, lest.... you will be regaled by a cute puff of blue smoke and a slagged component.

Guido

Guido, PC1 converts 110VAC to 175VDC and 240VAC to 385VDC according to Jeff Rowland info:

http://jeffrowlandgroup.com/kb/questions.php?questionid=191

Most of the gear won't work with DC voltage at all because of transformer.

Guidocorona,

Thanks for the answer. No need to apologize for being unscientific, this isn't a classroom. Just to clarify, your description of treble IM, to me, sounds like its a matter of getting timbre correct. Not an easy thing to do but its extremely important.

Feds,

The above comments make me think what it is that I like about my Rowland 112. When I first got it, I definitely thought it was rolled off in the HF's. The more time I spent with the amp, however, made me change my opinion. All the information is there. Cymbals sound like cymbals and not like you took a piece of metal dropped it on a hard floor. I'm pretty sure I was mistaking the amp being rolled off, when it was just doing a very good job of making the HF's sound like what they are supposed to be, instead of noise. The amp does have some flaws, though. Thats why I was curious about your 102.