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

Showing 10 responses by french_fries

This is so reminiscent of the introduction of the Model 9's so many years ago, with a choice of battery or A/C power supply boxes. The mere thought of having a pair of those huge amplifiers with the adjoining connections was enough to make most people (with the $35,000 in cash of course) wish they had a much bigger room to place them in. If i couldn't get my mind around what those might have sounded like in their last and best iteration, now i have an even greater disconnect with the sonic envelope the 925's can produce. And to have to wait for months for them to reach their full potential is just crazy- just put on the 1812 Overture for a couple of days straight! Just kidding of course, but i would hope they would sound quite good after a long weekend playing music "regardless" . At any rate, i am very happy for you and you should have a great time with them.
forgive me for being so ill-informed, but i still don't know what power-factor-correction IS, and what the benefits of having it ARE. How does it differ from schemes used in past amplifiers to "purify" the incoming electrical source?
(Just kidding around), but at FIRST you expressed concern that voices sounded steely while the amps were breaking in, and NOW your concern is that due to the improvement in transparency that the amps produce, voices sound flawed due to the limitations of the singer(s). Perhaps a downgrade in the future would be something to consider if this becomes increasingly bothersome...
i have a related problem with my system, in that very beautifully-recorded cd's (like some Pentatone sacds, Channel Classics, and some others) put an alarming number of OTHER cds, both redbook AND hi-rez, in a very distant 2nd category of sound quality. This dichotomy of "very good" versus "eh" recorded music must not guide my hand as i decide what pieces i want to listen to, and yet- clearly there are a great deal of better recordings being produced today. You just have to be extremely picky when filling your shopping "cart".
It can make the difference between 6/10 sound and 9/10 music.
Interesting that Elliottyeh mentioned battery powered Rowland amps. I heard thru the dealer that the amps had no "guts" on battery power and therefore speakers with greater power demands were not a good match. so i am curious as to whether the M-9tihc (high-current) amps could even operate properly with battery power supplies.
So little has ever been written about the Model 9's, but they were
extremely exotic as well as expensive for their time- I also remember the ML-33's at 400 pounds/each. or the Krell Master Reference amps- 1000W each.
A steinway piano might have weighed a bit more, but not by much.
BUT I imagine with a refreshed
set of caps and other critical parts, the M-9's might still blow most of us away even in 2013. I am not saying the 925's are not everything Jeff wants to achieve at this point, but as in the case of the new Pass XS line as well as any other 4-box arrays, you are talking about a LOT of hardware to power your speakers.
perhaps when the Rowland 825 stereo amp (two-box) comes out that might
be a little more practical - and shares the same level of technology with the 925's. As to when you might see the 825 "on the shelf", that's another chapter yet to be written. Plus every extra "box" of 6061 aircraft aluminum adds a lot of money to the cost of the final product.
Hi Guido, regarding your "beloved" NAD tuner, i am in the market for a tuner but
i don't know if i should spend $150, $1500, or $3500. You seem to be happy as long as the device brings in stations fairly well with as little fuss as possible (i.e. oscilloscopes and other cute add-ons). OTOH Magnum Dynalab makes really great tuners- who wouldn't want an MD-109 if they could win it in a local drawing..? I have a good classical station with a strong signal and very little noise from nearby broadcasts, Plus two stations with good jazz programming.
any thoughts while you listen to your $100 tuner through your $60K amplifiers?
Mr. G, maybe i misunderstood, but you said you were listening to Mahler through the tuner...? and you stated you enjoyed the experience. But anyway,
i am trying to figure out if a Sansui tuner would be sufficient, or do i need a truly great component (and spend 3X as much)?
Hi G., I just wanted to pipe in here with still another vote for my Mark Levinson #53 amplifiers which have not been well regarded due to certain factors that i won't expand upon here. this is simply to say that in reading through your increasing enjoyment of the 925's, i have come to similar emotional connections to many of my cd's. Just yesterday i listened to a female vocalist album that put me in a mental state of lying in a warm bath melting away, so sweet was her voice. I couldn't have faulted some nuance or detail in that state of bliss even if i had wanted to, but when the piece was over i was disappointed that it couldn't have contained (many) more tracks.
I am just glad the audiophile BS hasn't ruined my ability to get off like i used to do back when i listened to dorm room stereos.
Hi Mr. G, the dealer never gave me any power cords with my amps (!) I know!
anyway, i obtained the best PS Audio power cord they make, along with some
very well made but inexpensive cords and (of course!) a PS audio wall outlet
(for good luck i guess...). long story short, the sound coming out of my speakers are in "balance" already. they don't "shout" at me or bite my ears off,
which is not always easy when you turn up the volume.
but the GOOD NEWS is that, even with a ton of detail being presented along with the music, the artistry comes shining through as well. I was afraid at one point i had "overdone it" with all the upgrading i have done. OR maybe some elements were still breaking in, as you have suggested. i am just really pleased it all worked out.
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.