Rowland M925 monoblock amplifiers -- Break-in Notes

[GuidoCorona]

Hi Sam, as you might have read elsewhere on WBF, before receiving M925, I have used M725 as my reference amps for about one year, and absolutely love them

Having said that, the M925 constitute a paradigmatic shift in what amplification can do…. In other words, they are in an entirely different league… Even compared to the wonderful M725 monos.

First of all the obvious…. That is the M925’s sheer power, which lets them generate life-sized stage and images… Yes, significantly larger and more solid than M725, with incredible ease and authority. There is a sense of space, air, and depth that comfortably exceeds M725, and any other amp that has been in my system until now. M925 never breaks a sweat on high dynamic transients… It is in that totally effortless…. There is a harmonic coherence and exposure of fine detail that is very highly resolving, but is musical rather than being “hiFiish”…. Because it makes music emotional, and never analytic. In addition, the bass has a depth and musical purity to die for. Neither fat overhang nor thuddy behavior here.

Yet, M925 have only 250 hours of full operation on them, that is about 12.5% of my goal of 2000 hours of break in time. I expect to complete break-in by the end of September… During the summer months, I will not be able to leave the amps all the time, because they tend to get quite toasty in the Texas climate… And no, adding one more air conditioning unit for the music loft is not an option worth discussing with my wife.

Of course, things are not perfect… at this point, there are little issues that fade in and out… Yesterday for example, there was a very faint zing added to the upper harmonics of the harpsichord… But this sounded more curious than annoying…. Very different from the typical harshness found in many new amps. What I find astonishing is that whatever fabulous behavior I hear from M925 at any particular session, it is usually exceeded by what the amps demonstrate after another few days…. Hope this continues, because it is quite exciting!

On a nonmusical note…

* Unlike M725 and M625, which have a mild propensity to emitting audible raspberries -- of a very high-end variety of course -- through the speakers, whenever
Power is cycled on/off, M925 are extremely quiet. When the front-mounted momentary contact switch is operated to turn the amps to full power, I can hear
Only the internal "Klump" from a relay switch, followed after a second or two by an almost inaudible "tick" from the speakers. When the power button is
Operate again to place the amps back on standby, there is no noise at all from the speakers or from the amps.

When the amps were brand new, one could hear also a complex buzz from the chassis, almost like a tiny cicada were trapped inside… That has faded, and now the chassis are almost completely quiet…. I expect the burr to fade into complete inaudibility as breakin proceeds to the endline.

Sam, if you have some specific questions… feel free to ask them here…. Or PM me…. I would love to chat offline.

Best, Guido

 

[samgar]

Hello Guido:

Thanks a million for you up-to-date detailed report. I am very interested in the 925 monos, however first I must be able to jusitfy the cost for the improvement, and then sell my 725's. So far it sounds very exciting and I look forward to hear more about your "test drive".

Thanks again and have a great week-end.

Sincerely,

Sam

 

[GuidoCorona]

Sam and all, yesterday I turned on the system after 24 hours of total power down/disconnection because of concerns of bad weather. After one hour and a half of warmup time, I played the Rachmaninov Symphonic Dances in the version for two pianos… A performance by EMANUEL AX and YEFIM BRONFMAN on SONY redbook, recorded in 1999 in 24-bits.
Several things were remarkable, and already let me confirm that I comfortably prefer the total performance of M925 over every other amp I have had in my system, including my beloved Rowland M725 monos…

• The apparent total coherence and extension of the M925 frequency bandwidth, from the bottom notes to the top octaves, without any perceivable suckouts or fatness/overhangs.
• The fine exposure of harmonic information from the high treble to the lowest bass.
• The vast size/proportions of stage and instrument images, that where completely congruent in the three dimensions with real life grand pianos in a recording studio, with the front of the instrument image approximately coinciding with the front of the speakers, and the left/right edges of the stage merging into the side walls of the room (speakers are 11 feet apart, while the room is 18 feet wide)… This among other things means that M925 is thankfully not a forward sounding amp, but is also far from being recessed.
• Tremendous macro authority and dynamics, perfectly consistent with the illusion of a pair of real life concert grands in the room, from whispering pianissimo (ppp) to fortissimo (fff) without any clipping or other signs of strain.
• Subtlety of microdynamics, which exposes the sudden partial dampening of a piano string when a key is half-lifted and so, lowers the felt damper to graze the string.
• The instant speed of macro and micro transient response at all frequencies. There is no euphonic caramelization of transients, neither there is artificial emphasis of leading edges.
• The sense of emotion and musical immersion…. The listening experience is relaxed…. I sink into the listening couch and enjoy …. I do not feel the need to balance on the edge of the seat ready to bolt with audiophilic anxiety.

NOTE: By last evening, the amps had been operated a total of approximately 257 hours at full power, with another 60 hours on standby with the input stages being fed FM interstation hash at moderate volume.

Guido

 

[GuidoCorona]

A minor milestone... I have just clocked 302 hours of playing time, and an additional 60 hours of low power ops. I decided to check again the Christiane Jaccottet recording of Bach's Well Tempered Klavier... Disk 2 of 4, to be specific....

The trace burr or overpressure in the high treble region of the harmonics that I reported around the 250 hours mark has disappeared completely. If I did not know better, I would be tempted to say that the amps have reached maturity, as the sound of the harpsichord was magnificent and musically involving... But I know I should expect even further opening up... probably intermixed by a few more episodes of minor "bad attitude".

Saluti, Guido

 

[marty]

I'm enjoying your description of the 925 break-in process. My experience with the 501 is that a month is about the right time for full-break in. Have no idea why Rowlands take this long. I might have to do with his specific type of power supply? Could it be transformers? Who knows. But indeed his amps appear to become truly beautiful sounding at their best at about a month of regular use.

 

[GuidoCorona]

Hi marty, the power supply subsystem of M925 is indeed quite a hefty affair... I heard it is 1200W PFC rectifier + 2400W DC per side... Then there are the Lundahl input transformers.... According to Jeff rowland, they supersized pro-audio devices... He suggested that they take a very long time (value unspecified) to break-in... Hence his suggestion to feed a signal with the amps on standby part of the time. I suspect that lots of power regulators, ceramic boards, and other parts contribute to slow break-in.

I have had the amps in my system for about three weeks, with a 2/3 power/downtime cycle... This far the breaking in and fleshing out of the amps seems to be continuing steadily... We'll see if the pattern changes in the next couple of weeks.

Saluti, Guido

 

[GuidoCorona]

All, today, at approximately 430 hours of playing time plus 60 hours of low-level operations, the M925 amps are showing signs of musical grandness as well as of some… residual break-in growing pains.

The Dvorak 9th Symphony 2nd movement under Bernstein and the Israel Philharmonic is magnificent: size and clarity of staging, imaging, speed and fullness of macro transients, authority…. The lower brass fanfares are not only powerful and harmonically complex, but are heard inserted into the living context of the 3D stage, rather than a musical object without spatial references… I know I said this before, but the reality is that these effects keep growing in perceived size, complexity, and sheer emotional impact.

The massed upper and mid strings are not only textured and sweet, but resolve into the bowings of the individual fiddles and violas. The flutes have an ethereal beauty, while the English horn keeps enhancing the multilayered earthiness to its melancholic sound. The chamber-like section toward the end of the movement is assuming delicacy, detail, harmonic richness, and a filigreed transparency that are enchanting....

However, we may have a little temporary break-in tantrum… The mid bass has lost a bit of power and resolution, while manifesting some signs of wooliness... I can hear the anomaly in the introduction of the Dvorak sextet with double bass, in the plucked electric bass of Diana Krall’s Temptation, and in a slight uncertainty of the string bass line of Dvorak’s 9th, particularly the plucked sections... The bass anomaly can also be heard in a certain lack of vicerality in the midbass of Bach's toccata, adagio and Fugue in C minor performed by Wolfgang Rubsam on Naxos redbook. Interestingly, the minor emotional disorder does not affect the deep bass: the lowest bass notes in the adagio movement remain visceral, pitched, and harmonically textured.

I will log my next report at the end of the month, close to the 600 hours mark.

Saluti, Guido

 

[GuidoCorona]

I have been asked to comment once more on audible differences between M725 monos and M925. Admittedly, my M725s are wonderful amps, but what I heard yesterday evening on M925 at the 576 hour mark, is simply not possible on M725. I had turned on my old NAD tuner and listen to Film Focus on KMFA Austin...
This week’s program is dedicated to "travelling to the Moon" or something to that effect.... The track "The launch" -- by James Horner I believe – from the 1995 film "Apollo 13" blew my mind for the intimate depth and power of the bass.... Not a bloated swelling thing, but a tidal depth at the very bottom of the audible range.... Something that the triple 9" bass drivers of the Muzik speakers were transmitting to my chest and feet perhaps more than to my ears. The entire image: orchestra (partially synthetic) and synthetic bass – no string instrument goes that deep, occupied a solid continuum from beyond the left wall to beyond the right wall. Mesmerizing is perhaps the best way to describe it... Sure, there was authority and all of that, but.... An authority that just "exists" without the need of questioning its right to be... An authority that works for the music material without attracting attention to itself.... Just allowing the material to flow in a totally integrated way, because.... It is in the nature of music to achieve that... And in the nature of the amps to deliver the effortless magic.

I realize that this is rambling and all, but I do not have a better way to express it. Today I might play once again my usual test tracks... But I have a strong hunch that the bass malaise that I reported last week has happily gone away.

 

[samgar]

Hello Guido:

You latest article as well as the prior ones, are very convincing that the 925's out perform the 725's. I would expect that to be the case. Most of you reviewing is on the instrumental side. How about female voices? Do you hear alot of breath and natural tone and no edge? The 725's are superb in that regard, so I would expect the 925's to excell in that area as well. Just wanted to hear your thoughts.

Thanks,

Sam

 

[GuidoCorona]

Hi Sam, you are right, I have not talked too much about vocals... My bad. For evaluating vocals, I use Diana Krall in Temptation, Nora Jones in Sinking Soon, and several cuts from an April Music sampler which covers male baritone, classical alto, and a female vocalist on Cohen's Aleluia with flugelhorn accompaniment.

Yesterday, I was listening to most of the material listed above, when my wife -- the one who can be cheerily dismissive of my audiophilic efforts -- all of a sudden commented on the sheer beauty of the alto voice, and of the young vocalist on Alleluia... Yes, Kral, Jones, and modern vocalists have body and breathiness if their voice has those characteristics... Classical singers like soprano, altos, etc... usually have no breathiness, for the simple fact that breathiness is trained out of them. As for hard sibilants and etched plosives, there were not such annoying artifacts... Voices were open, expressive, and wonderfully articulated in their diction.

Having said this, M925 is evenly revealing, and does not act as a filter or an equalizer... This means that it does not attempt to mask problems elsewhere in the signal chain. If there is an anomaly elsewhere in the system, the anomaly will become manifest in spades.., with all the distorting artifacts that go with it. It is very important for example, that all associated wiring and cords in the chain do not shift balance towards any particular portion of the spectrum, and do not cause overpressure in vocalization, excesses in leading edges, or intermodulating artifacts in multipart treble.... You will hhear any defects.

I am currently using a complete loom of Aural symphonics wires with excellent results. See my review on PFO:
http://www.positive-feedback.com/Issue67/aural_symphonics.htm

The only exception is a length of Cardas Golden Ref speaker wires used for biwiring the Muzik speakers.

I will soon edit this post with more details about my vocal test tracks... And I will fix spellings as well. G.

 

[clab]

The only exception is a length of Cardas Golden Ref speaker wires used for biwiring the Muzik speakers.

Dear Guido

I am a little bit surprised that you use Cardas Golden Ref, don't you think that you loose definition / resolution with these cables ?

Speaking about female voice test track, Verdi's aria "d'amor sull'ali rosee " from Trovatore with Levine / Millo (Sony Classical) is a fantastic test ... also for the tweeters ;-)

nice to read your posts

Saluti

 

[GuidoCorona]

Clab, it is quite possible that Cardas Golden Ref might alter resolution of the system in one way or another. I addeded them because I have had a hunch that M925 may benefit from biwiring, and Cardas olden Ref are today my only 2nd set available.

In about one week I will conduct some tests with/without Golden Refs as 2nd wires, and will report results.

At some point, I may examine alternatives to Cardas Golden Refs.

Saluti, G.

 

[DaveyF]

Guido, I recently changed to Nordost Frey with my Rowland Model 8. WOW, the Model 8 LOVES the Nordost cables. They are so much faster and more revealing than my old Highwire cables, which had replaced my.....Cardas Golden cables, LOL.
Bi-wired Nordost is superb. A double run would be even better ( a little pricey, but). Nordost and Rowland...GREAT synergy IMHO. BTW, the Nordost room at Newport was demo'ing with Jeff's gear. A model 625 if I am not mistaken.They were showing the new Valhalla 2; which if in the budget, should be on your VERY short list. Fantastic cable!

 

[GuidoCorona]

Hi DaveyF, apologies for the delay... I have been away all last week. Nordost wires together with Cardas Clear and Clear Beyond are some of Jeff Rowland's favorites... They are all on my radar, together with Shunyata, Hidiamond, and the rather wonderful Aural Symphonics that I am using now.

Break-in has resumed Monday night at the 600 hours mark... The sound had 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.

Several people have asked me about audible differences between M925/M825 and the venerable Rowland Model 9 series. Since I have never listened to M9 variants, and my answers have been up to now purely conjectural, I have reached out to Ron Gaston, proprietor of Black Forest Audio in well, you guessed it... Black Forest (CO), and long time Rowland dealer as well as Jeff’s personal friend. Ron has extensive experienced with every Rowland amp since the original M7. Here is what Ron wrote to me just a few days ago on M8 and M9 versus M825, M925, and... M625:

"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 [even] 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 do outperform the little M625.

Just in case you asked, Ron's house was not affected by the recent wildfire... Ron, family, and his beloved collection of audio gear are doing just fine.

More listening and reporting during the coming weekend!

Saluti, Guido

 

[DaveyF]

Hi DaveyF, apologies for the delay... I have been away all last week. Nordost wires together with Cardas Clear and Clear Beyond are some of Jeff Rowland's favorites... They are all on my radar, together with Shunyata, Hidiamond, and the rather wonderful Aural Symphonics that I am using now.

Break-in has resumed Monday night at the 600 hours mark... The sound had 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.

Several people have asked me about audible differences between M925/M825 and the venerable Rowland Model 9 series. Since I have never listened to M9 variants, and my answers have been up to now purely conjectural, I have reached out to Ron Gaston, proprietor of Black Forest Audio in well, you guessed it... Black Forest (CO), and long time Rowland dealer as well as Jeff’s personal friend. Ron has extensive experienced with every Rowland amp since the original M7. Here is what Ron wrote to me just a few days ago on M8 and M9 versus M825, M925, and... M625:

"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 [even] 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 do outperform the little M625.

Just in case you asked, Ron's house was not affected by the recent wildfire... Ron, family, and his beloved collection of audio gear are doing just fine.

More listening and reporting during the coming weekend!

Saluti, Guido

Guido, that description of the older models is IMHO a little odd. I'm totally confused by anyone calling an amp's representation of a musical signal as: earthy ( this isn't a wine, LOL)
I have heard the new 625 amp on many occasions now, while it is a fine amp, I do NOT think that it is more palpable or 'fast' than either the model 8 or the model 9. ( Any variant ).
I have not heard the new 825/925 so cannot comment on those amps, BUT I can say that the 625 would not get me to trade my model 8. Not even close, IMO.
One other thought, I suspect Ron never heard the older amps with a 'fast' cable like Nordost. If one has never heard what Nordost can do with the older models...then I can see how
one could feel that these older amps are a little slow compared to today's models. My amp never showed what it could do with Cardas...and even when I changed to the Silver Highwire
( which was more open and a little faster than Cardas) one could possibly say that the amp sounded a little 'sluggish", particularly when compared to what it can do with today's Nordost.

 

[GuidoCorona]

Of course, you are right DaveyF, M8 and M9 may be classic vintage amps, but vintage wines they are certainly not… On the other hand, many cherished things are oft metaphorically called “earthy”, including the sound of my old beloved golden-mellow M7 monos.

I am confident that their agility makes Nordost Odins wonderfully synergistic with classic Rowland products, and I even conjecture that Odins would have made amazing music together with my old powerful and earthy darlings in their day.

I am looking forward to the opportunity of test-driving Odins in my rig, although I hold the nagging suspicion that I might find recent Shunyata wires and Cardas Clear variants more congruent with my goldilockian fondness for the most recent, and in my opinion highest yet, evolutionary plateau of the Rowland thinking.

G.

 

[samgar]

Hello Guido:

I hope you are doing well, as it has been a while since you added up-dates on this forum.

I just received my 925's and say I am quite impressed with them right out of the box. It is thrilling to know that they will be getting better as they break in. Compared to the 725's, I hear a bigger sound stage and better separation of instruments. It also is apparent that the bass has more punch with no bloat. I feel that the 925's like most of Rowland amps will be a real masterpiece.

I think my next venture will be to compare my EMM LAB DAC2X to the Rowland Aeris Dac. Have you had the chance to listen to the Aeris yet, and if so, what's your opinion?

I hope you are still enjoying your 925's as well.

Wishing you the best.

Sam

 

[GuidoCorona]

Sam and all, my apologies for the long absence from updating you on M925 progress. Today at 1,780 hours of operations per my Excel break-in tracker, progress has been steadily significant since the 600 hours mark discussed earlier in this thread. I use the term “steadily significant” on purpose, because I am not sure that the progressive refinement of this amazing amplifier has abated yet.

Reality is that, starting about the 700 hours mark, I have been tempted several times to declare the amplifier fully “broken-in”… After all, when one perceives no constriction anywhere, frequency and harmonic coverage is a linearly sculptured affair throughout the spectrum, treble intermodulation of multi-part violas and violins has vanished, your mind freely zooms in and out of musical detail, Authority as well as micro/macro dynamics have established such a “right” to exist that you do not even perceive them as isolated factors in the musical whole… And most of all, you simply get lost in the music without reservations… Well, you would thing the creature is just about ready and stabilized.

Yet, things have continued to refine until now…. Perhaps we could claim that by the 1,100-hour mark the amp is 100% broken in… I would have assigned this milestone to the 1,000 hours mark, except that at about 1050 hours I experienced the very last performance oscillation, where M925 showed a slight “warmishment” for just 4 to 6 hours, after which things have returned to normality without further flexions.

To my surprise, all audible parameters have continue to refine after this point, leaving me quite befuddled about how much immersive music the whole rig, starting from Rowland Criterion and ending with the Vienna Muzik speakers, is increasingly able to extract from my old Esoteric X-01 player. Will things continue to evolve even further? I have no idea yet... But will let you know.

if anyone were starting to wonder if the last couple of months of silence meant that perhaps yours truly were having second thoughts, falling out of love, or succumbing to the pangs of obsessive second guessing, or simply getting a little case of audiophilic wandering eye (or is it wandering ear?)…

Nothing could be further from reality… Rest assured that Rowland M925 has firmly established itself as my absolute reference amplifier by far.

As for Aeris, I would love to get one in my system, but have no firm plans yet.

Saluti, G.

 

[GuidoCorona]

All, I have received the list of RMAF suites at the Tech Centers Marriott in Denver where we will be able to listen to Rowland amps coming Friday 11th through Sunday 13th:

The M825 stereo amp, Aeris DAC, and the Capri Series 2 preamp will be playing in suite 8032 with Joseph Audio speakers and Cardas Clear wires.

M825 and Aeris will also be heard with Lawrence Audio in Tower Room 1122.

The Continuum S2 integrated will be making music in public for the first time in Tower 2001 (the Rowland suite), together with Aeris… If I remember things correctly, they may be using Cardas Clear and Clear Beyond wires, and Raidho speakers.

Other Rowland products will be mostly on static display in room 2000 and 2001: including M925 monos, M725 monos, M625 stereo, M525 bridgeable, Corus linestage, and Capri S2 pre.

Yes, I will attend starting Friday.

Saluti, Guido

 

[Mrdean]

Guido, please give a serious listen to the Aeris DAC. I am convinced that this DAC is unlike anything else digital. It should take about 3 seconds to hear how it sounds unlike all the other contenders for best DAC, with most of them costing at least twice as much.
Your friend, Matt