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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
guidocorona OP
4,298 posts
 
Hi Denon1, I will call the factory next week and will ask about Continuum S2 status. meantime, on pure conjecture, based on the fact that Rowland has selected a new more advanced supplier of power conversion modules for Continuum S2 (Pascal), and that Rowland changes component parts only if warranted by more desirable audible performance or reliability, I suspect that the new S2 is likely to sound sweeter than C500.

CS2 also uses the circuit of the new Capri S2 as linestage (designed in partnership with Holm Acoustics), and is compatible with the new DAC card designed for Capri S2. Continuum S2 will also be compatible with the external PC-1 PFC-based rectifier.

Saluti, Guido
high-desert-audio
18 posts
 
The 825 stereo amp is out and shipping.
guidocorona OP
4,298 posts
 
Hi Denon1, I spoke to the Rowland factory today, the Continuum S2 integrated has not yet started to ship... Will keep you posted.

Guido
guidocorona OP
4,298 posts
 
Hi French-fries, Concerning Model 9 variants versus M825 and M925, I have exchanged a couple of emails with Ron Gaston, proprietor of Black Forest Audio in well, you guessed it... Black Forest (CO), and long time Rowland dealer and friend. Ron has extensive experienced with every Rowland amp since the original M7. Here is what Ron wrote on this subject:

"The Model 8/9 amps are big, rich and earthy in presentation. They are not, however, a match for the 825/925 in soundstage, detail or palpable realism. They seem downright sluggish in comparison. I believe the 625 to be superior in nearly every respect to these older, very great amps."

Ron further explains that Only in the bottom end authority M9 variants can outperform the little M625.

Just in case you asked, Ron's house was not affected by the recent fire... Ron, family, and his gear are doing fine.

Guido
guidocorona OP
4,298 posts
 
Lastly, I have been away for one full week.... Break-in has resumed tonight at the 600 hours mark... The sound has an eary beauty even with the amps stone cold after 9 days completely disconnected from the AC. I listened to a couple movements from Mahler's 4th Symphony conducted by Bernard Heitink... Totally enchanting... Even though from my old NAD FM tuner, the bass was foundational and pitched as clear as a bell.

Guido
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