New Esoteric P02 D02

To Guido,

I know this forum is not about the Rowland and amplifiers, but how does 625 sound compared to the previous Rowland amps with conventional power supply ?
I am asking because it is using Switching Mode Power Supply and Soulution has an upgrade for 700 mono blocks converting the conventional power supply to SMPS. Some people say SMPS may sound bass heavy with softer top, some others say mid band and treble may sound less natural due to some ultra sonic noise involved, etc. It is a very useful and cost/space effective technology that was around some time but it was not that popular before in high end. It looks like it is 2013/14's trend with some brands like Burmester, Rowland, Soulution to use it with conventional amp stages. So what are your findings ?
I also apologize from the forum and Eli for side tracking it.

Hi Pharma, what you heard about SMPS is... All correct. In olden days, SMPS had been born as inexpensive, efficient, and compact replacements for conventional supplies... Without too much concern about performance. Rapid evolution has set in... Today, things are very different... SMPS can be very complex, sophisticated, and heavy.... And convey a sound that can be exquisitely refined, and is often subtly unique to the particular taste of the designer. I am confident that if Solution is now offering an SMPS option to their amps, they do it only because they have obtained an audible enhancement over what they had obtained with their more traditional supplies.

the regulated SMPS in the current generation of Rowland amps, which are often fed by a PFC rectifier, are as sweet as the old toroidal/linear supplies that Rowland used in the 1980 and 1990s on M1 through M9. However, the new SMPS are a lot nimbler and quieter than the old supplies, hence they deliver greater musical resolution, broader and more linear frequency extension, quieter background, and better defined macro/micro transients.

Rowland uses SMPS in the complete product lineup only because, within each price category, he prefers their sound over traditional supplies.

M625 is a fabulous stereo amp within its approx $14K price category. Never the less, the amp and its SMPS is merely the 4th down in the current Rowland amplifier lineup... From the top:

1. M925 4-chassis monos, $58K.
2. M825 2-chassis stereo (sibling of M925; convertable to mono ops with switch in back) $32K
3. M725 monos $29K.
4. M625 stereo. $14K.

I have owned M7 Mk.4, M312, M625, M725, and now have M925. The performance progression from the first to the last is simply staggering. And a good part of the difference is due to the progressive sophistication of their power input sections.... PFC and rectification, DC SMPS, 4-pole capacitor buffering, and regulation. Within the current Rowland production, M925 and M825 would be congruent with the caliber of your system.

If you are interested in more detail, the M925 section of the Rowland Knowledge Base has several technical entries that deal with the power input section of the amp:

http://jeffrowlandgroup.com/kb/categories.php?categoryid=212

Guido

Hi Guido,

Thank you for excellent info. Looks like there will be more high end brands adopting SMPS to be used with conventional amp. stages.
The SMPS upgraded 700 delivers 600w in 8ohms, and 1200w in 4 ohms continuously versus the regular 700 that delivers 430/860w. Also the THD and IM is lower on the upgraded one.
Thanks again.

Hi Pharma... I'll drink to that!

Guido

Hi Guys, Its been awhile! Just checking in on your thoughts.... I have a chance to buy a pair of Acrolink 6300s, not the new series II, they are the originals. I wonder if I should pass on them, and go for the newest ones!

Let me know what you think!

Eelii, how are the PCs?