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Experiencing Rowland M925 4-chassis reference amps

My pair (or should I call it my quartet?!) of the new SS Rowland M925 reference mono amps were finally delivered yesterday.... Needless to say, I am excited!

The 430W M925 monoblock amplifier is a hefty affair: The amp is formed by four chassis: two power supply chassis and two audio chassis, amounting to a total weight of 380 Lbs in the four boxes, and 320 Lbs in their birthday suits. Each chassis is double boxed, protected by heavy urethane foam inserts, and then bagged in a heavy cloth sleeve tied with a drawstring.

Each power supply box also contains an accessory carton, featuring a power cord terminated at one end with a 20A IEC connector, a heavy ombilical to carry DC current to the audio chassis, and a skinnier ombelical, which I conjecture carries control signals and may have an additional grounding line. A baggie contains 3 1-inch spherical delrin footers that can be screwed into the divets at the bottom of the SMPS chassis if if you do not use 3rd party spikes/footers. A smaller baggie contains 4 smaller delrin beads... They fit into the dimples milled into the top of each the power supply chassis, and are used to keep top and lower chassy from touching when the two are stacked.

I am using Nordost Titanium Sort Kones instead of factory-provided footers. Each power supply chassis stands on top of 3 divet-centered Kones. The whole thing sits on top of 1.5 inch thick granite slabs, which have been patiently waiting in place for the M925 amps since 2011.

The audio chassis are even heavier... They will get into place in the next few days, one way or another. Rowland recommends the stacking be a two-person job.

In order to break-in both output terminal in each unit, I will connect each amp to my Vienna Die Muzik with a form of shotgun wiring: Aural Symphonics Chrono and Cardas Golden Ref for the time being. The Aural Symphonics speaker wire connects to the single 5-way binding post of the Muzik speaker with bananas; the Cardas Golden Ref connects to the same posts with spades... I have already tested the configuration using other mono amps... Works flawlessly. Of course, I have no idea if M925s benefit from shotgun wiring... This will be part of the discovery fun!

The amps will be fed by the Criterion linestage through Aural Symphonics Chrono B2 XLR ICs.

Power cords will be Aural Symphonics Magic Gem and Ultra Cube XXV, plugged into a dedicated 20A circuit served by Furutech outlets.

According to Jeff Rowland, breaking may be excruciatingly long, because of the oversized input transformers and power supply. I suspect that the process may extend well into the summer months... I will log my periodic observations on this thread.

For sake of completion, here are the amps specs as far as I know them:

Monoblock Power Amplifier OUTPUT POWER: 430 watts @ 8 ohms/850 watts @ 4 ohms
Monoblock Power supply: 2400 W regulated DC SMPS per channel, with Active Power Factor Correction (PFC).
FREQUENCY RESPONSE: 5 Hz - 50 kHz
INPUT IMPEDANCE: 40k ohms
THD + NOISE: 0.004%, 20 Hz- 20 kHz
OVERALL GAIN: Switchable 26/32 dB
Combined AMPLIFIER chassis & POWER SUPPLY chassis WEIGHT: 160.4 lb / 73 kg (per channel)
TOTAL DIMENSIONS (H/W/D): 16.5" x 15.5" x 16.25" (per channel) 419mm x 394mm x 413mm

Saluti, Guido
guidocorona
french_fries
815 posts
 
two things come to mind for me. #1- there are many less-expensive choices to be had that have rave reviews behind them- the Pass XA-100.5 monoblocks come to mind just one good example. #2- as for "reference grade" amps, or price-no-object, there is such a wide range of prices vs performance, and after reading about and hearing a whole bunch of expensive gear over 30 some-odd years,
i do not subscribe to $150,000 as being worth the money under ANY circumstances. Goldmund makes a PREAMP that costs more money than a R-925. And I say "so what?" after a certain point i need to see a faceplate with 18K gold and diamonds a la Rolex to justify spending that kind of money.
My chief problem with Rowland is how much are you spending on the cosmetics (i.e. diamond-etching), however attractive they might be. that goes for useless meters, pretty lights, and other gadgets as well found on other brands.
A friend of mine still has a pair of Pass Aleph 1.2 amps which are, i know, not as good as the present breed of Pass Class-A amps, but you wouldn't be too concerned about it after listening to some Blue-Notes on his system. you would most likely be saying (as i have on many occasions) "play it again, Sam".
Even if you have to have "the best", i would hope that sound and reliability would be the primary criteria to determine the choices made.
fredmiu
4 posts
 
HI Guido

As an early user of M925, your experience has been invaluable to those interested in JF top gears.

I just read some background information that M625/725 are Class AB machines, and M825/925 are Class D. Looks like Mr Rowland has produced a top Class D gear as a successor the previous 3XX series.

As the price tag of 725 seems getting close to 825, how would you describe the difference between the music presentation of 725 and 925?
jon2020's avatar
jon2020
988 posts
 
The 825/925's are Class D? And they sound gorgeous? Sacrebleu!
Ahh, the progress of technology. Hurray for that.
guidocorona OP
4,298 posts
 
"Even if you have to have "the best", i would hope that sound and reliability would be the primary criteria to determine the choices made."

Thank you French_fries for pointing this out. Yes, I choose my gear based on my own subjective perception of extremely high musical/sonic performance, as well as of manufacturer's track record of high reliability. As you know, I am blind. As such, esthetics is for me of secondary relevance only, and not a purchasing criterion per se... It remains however, a charming bonus not to be despised or otherwise shunned out of facile masculine pride.

Bottomline, I judge the tree by its fruits, not by its roots... But I think you heard this paraphrase of Stravinsky's Poetics of Music from me before.

G.
guidocorona OP
4,298 posts
 
Hi Fredmiu, while I loved the M725 monos, the performance of M925 is simply of a totally different caliber. M925 combines a an immersive transparency in its harmonic density, an authority that seems to have a natural right to its existance, rather than forcing itself on the user. Yes, M925 has loads more authority, transparency, and detail than M725.... But not in a sterile manner that means detail for sake of audible acrobatics... It is a presentation that gives you much deeper insight into the music: both from the point of view of the music composition/song, and of the depth of the performance/interpretation.

This is a very long topic... PM me if you would like to chat offline.

Guido
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