I have a pair of the latest 301´s and also very interested to know how these new 925 amps will sound in comparison.
What I have found out during the years I have owned my 301 is that they are are extremely neutral, but also very sensitive to other equipment and cabling. You can get very different sound from them dependant of the rest of your gear. I think many have underestimated class D products because of this. As I see it the amps in the Rowland 300 series have a tremendous potential but require a lot of the owner to reveal this potential, maybe more than with traditional amps. Maybe that also is one of the reasons of slow adoption of class d amps in the high end market. |
Cappuccino, what design/sonic differences are there in the recent 301 amps vs the original series? I have heard that there some differences, but I do not know what these may be. Guido |
"very sensitive to other equipment and cabling"
Capuccino,
very interesting posting ! ... I think you are right
Power cables can make a huge difference and of course also interconnects. That's also why J.Rowland developped his PFC1
Read what Gary Koh from Genesis says about class D ...
interview:
"
N.D. -I would like a few words about your class D amplification, which is a relatively modern implementation in the high-end audio business – it has been mostly seen in consumer applications. Do you believe that it might even account for the future in amplification?
G.K. -The first working model of a class D amplifier was designed by John Ulrich, it was called «The SWAMP» (SWitch WAve AMPlifier) and was delivered in 1976 by Infinity. One of the founders of Infinity, Arnie Nudell was also the one who founded Genesis. In 1991 Infinity was already using class D amplifiers; we’ve been using class D amplifiers for the past nineteen years!
N.D. -So it is a myth that class D is not adequately developed to serve its purpose…
G.K. -It was not developed adequately. Until a couple of years back, class D amplifiers… I could not sit and listen to, they did not deliver music. Class D was very, very good for bass, which is why Genesis speakers used class D amplifiers since 1991 for the servo-bass part of the system.
My class D amplifier came with a story. I was trying to find a more reliable, a better amplifier for the bass and I reviewed all the available class D amplifiers; all those that were available as modules or as designs. After about two and a half years, I finally settled with the Hypex amplifier module, for the bass. Around that time, I don’t know if you are familiar, but I developed a tube amplifier for Genesis...
N.D. -Yes, I saw that they are sold out!
G.K. -The tube amplifiers are sold out… The tube amplifiers were done for only one reason: They were proof of concept that a cheap amplifier can be used to drive Genesis loudspeakers. You see, the designer of Genesis Loudspeakers, Arnie Nudell, was very famous for making speakers that are very difficult to drive; they had very low impedance, they demanded a lot of current and a lot of dealers said that -at that time the equivalents the 5.3s were like, I think, $14.000- to drive a $14.000 loudspeaker they required a $30.000 amplifier! I told them “no, this just means that the amplifier is not designed properly!”. So, a very famous dealer -I won’t mention his name- looked at me and said “if you think you can, you design an amplifier that’s cheap and can drive these spakers!”. It took me… two years; two years later I brought a pair of the M60 monoblocks to his store, I put them down and said “OK, which preamp do you want to use?”. He picked a preamp, he connected it in, then we connected it to… that was the 5.01 and it drove it perfectly. So he lost his bet; I won my bet… Here was a $4.000 amplifier that drove, at the time, a $14.000 loudspeaker!.. The problem with tubes, though, is that the moment you buy the amplifier, it begins to deteriorate, so I didn’t want to really continue making those. However they were a proof of concept; if I can design it -and I am not a famous amplifier designer- then everybody else can design it! That’s the amplifier, I’ve proven my point that you don’t need an expensive amplifier to drive the Genesis speakers.
N.D. -It was like an etude, a study on the subject.
G.K. -It was a proof of concept, it was a study.
N.D. -Your current class D modules, do you design them or are you still using Hypex?
G.K. -I still use Hypex, but I heavily modify the Hypex modules. The reason is that if you listen to a lot of class D amplifiers, they don’t have what I call the “soul” and the emotion of music. You know, you don’t feel that the singer sings of a lost love or you don’t feel that the singer is actually in love with you and she’s singing to you. The problem I solved -after actually discovering that it wasn’t a problem of the module- was the problem of the power supply. I designed a power supply that works perfectly with the class D module, to deliver that soul and emotion.
N.D. -Is it a linear power supply or a switching one?
G.K. -It is a linear power supply… I couldn’t make a switching power supply work; I tried.
N.D. -I know it is quite a bit of a challenge, but, if anyone can do it, I believe it’s you.
G.K. -Thank you!" |
Guidocorona,
I believe it is the same difference as for the stereo amps, I mean the old 302 against the current 312. I have not heard the old 301 monos or the 302 stereo amp so I can not comment on the difference myself, but those who have say the new model is quite a bit better. |
Cappuccino, in that case the more recent 301 batches must be quite special. . . as much as I found the original 302 lacking, I am still in love with the 312. But I'm looking forward to hearing the newest 925 in my own system. . . probably Q2 or Q3. We'll see what the newest design does for living. G. |
Cappuccino, Not sure if I or someone else has asked you this, but have you any knowledge of the comparitive performance between your 301 mono's and the 312 that Guido & I both have being run by the Criterion. Also, have you tried or already own the Criterion? Aloha, David. |
Kawika,
unfortunately I have no experience with the Criterion. I have Burmester frontend with the 069 cd and 077 pre, both in the reference line. I just love what these products did with my system so I must admit I am leaning more towards getting a full Burmester system than getting the Criterion. I had the 301 amps before I invested in the Burmester gear. If cost wasn´t an issue I would get the huge 909 monos from Burmester, but I would like to know the Rowland 925´s performance and if they maybe could be a better alternative. |
As I have the Model 312 for only 1 year, I can keep it until the review of the future 825.
But I think I known what is the difference from the old 301 and the 302 for the new Class D devices.
Once I read, always in Audiogon forum, there was a PROJECT MISTAKE in the early serie 300 and in others Class D devices, like the 501. And Jeff Rowland projected a little device to use externally together with those amplifiers.
I think it's true, because I found a store, in Dinamarc or Finland, that sells Jeff Rowlands devices on line and they have a observation that you need to buy that little device to use together with the amp to improve the sound and THEY STILL have the price for it as well.
At the same time, they say that the Model 312 has this little device already INSIDE the amp's gabinet.
Because of this I bought the 312 with confidance. |
Braz, the 'device' is a power rectifier based on a technology called Active Power factor Correction (PFC), followed by a bank of capacitors for filtering furter the DC before the actual switch mode power supply. As far as I know, the technology is used only by JRDG and by Chapter Audio. I suspect it is a significant factor in the 300 series sweetness of sound. The new amps are apparently also using active PFC and SMPS, although the core of the amps is not class D, but class A/B. Guido |
I should be the envy of all of you. I use a Capri preamp, a 102 amp and a PC-1. I find that I am quite happy with equipment at this level and do not have to spend thirty, forty, or fifty thousand dollars to be temporarily satisfied. It is my sincere wish that all of you are able in time to find a plateau where you are comfortable.
The use of good horn speakers has helped me to reach my plateau. |
Macro. . . I am glad that your case of audiophrenia is milder than most. . . may I ask you about PC-1. . . how has it affected 102 and Capri? I did prefer Capri without PC-1. G. |
Guido -
One of my symptoms is contentment. When I received my Rowland gear (all at once), I just hooked it all up and left it that way. I have never compared anything since. That will be two years in April.
To be honest, I have entertained thoughts many times of replacing those pieces but I like their size, looks and ergonomics so much that I an unable to mess with it.
I did read your comments about using Capri sans PC-1 and told myself I should try it but til now inertia has stood in my way. Maybe tomorrow. |
I also have a 501 that I use for my center channel. It improved a lot when I got the PC-1, but was still definately behind my 301´s.
But believe me, it improved even more when I later on connected the PC-1 to my Burmester 948 which is powered by a Nordost Odin power cord!! Now I think the 501 are almost in the same league as my 301´s - got to throw in another pair of Odins I think! BTW, I think someone mentioned audiophrenia in this thread... |
Yes, Audiophrenia being the most virulent known form of audiophilia nervosa. See:
http://positive-feedback.com/Issue46/audiophrenia.htm |
Hi Guido,
Can you describe the volume control technology used for the Criterion?
I currently own the Synergy IIi - the volume control design is based on the CS3310 IC. Rowland were careful in their design to maximise the performance from this now IC.
So I am curious if Rowland has moved on to newer technology?
BTW, I really enjoy the Synergy, but hoping to upgrade in the future.
Thanks in advance.
Regards
Mark |
I also have a 501 that I use for my center channel. It improved a lot when I got the PC-1, but was still definately behind my 301´s.
...
But believe me, it improved even more when I later on connected the PC-1 to my Burmester 948 which is powered by a Nordost Odin power cord!! Now I think the 501 are almost in the same league as my 301´s
sorry I don't understand ??? |
Ok, let me explain more in detail. This is how my 501 amp for the center channel gets it power:
Wall outlet -> Nordost Odin power cord -> Burmester 948 AC conditioner -> Nordost Brahma power cord -> Rowland PC-1 -> T+A custom built power cord -> Rowland 501.
The main reason why I have the Odin cord from wall to the Burmester 948 AC condition is because I also have my two channel front end gear connected to it. So get me right, I did not buy the Odin with the purpose to use it with the 501! That us just a bonus the way I have set it up.
I have not connected my 301´s to the 948 of two reasons; the 948 has not enough capacity for that I think and also I have two dedicated AC lines for my 301´s. The power cords I have for the 301´s (Wireworld Gold Electra) unfortunately are not in the same league as Nordost Odin. That is the reason I said that the performance from my 501 are almost in the same league as my 301´s and why I also think I need two more Odins (for mye 301´s).
Hope this helped. |
Mark, here is what I know about the control knob on Criterion.. . .
The knob first of all has 2 distinct ways of operating. . .
turning the knob adjusts volume for primary and secondary zones, right to left balance, input offsets, output offsets, menu scroll.
Pressing the volume knob utilizes the knob as a selector for entering menu mode and activating a selection.
I do not know what chip/module the volume control is based on, (it may be an HP part but I am not sure(, but it is an optically encoded system, therefore the knob can be rotated continuously clockwise and counterclockwise without ever reaching a stop position. When Criterion is turned on, volume is always at 0dB. The volume is speed sensitive: turning the knob slowly or pressing single taps on the remote control volume buttons changes volume in 0.5dB increments. . . rotating the volume control faster or holding down remote volume buttons changes volume in 1.5dB increments. . . the loudness range is 0dB to 99.5dB. Per my notes, precision/stability is said to be within 0.01dB. Furthermore, the volume control is said to cause the audio bandwidth to remain unrestricted at all gain levels, without the volume becoming a bandpass filter at low SPLs. Also when using the volume to change offset values, balance, and volume for secondary zone, the volume knob remains velocity sensitive.
It is my understanding that the volume control does not act on the audio section directly. . . The volume control is in the control chassis.. . it communicates with a microprocessor controller in the same chassis. . . when a volume change is requested, the microprocessor awakens a communication bus. . . sends appropriate control codes to the audio circuit in the audio chassis that alters the gain of the OPA1632, then powers down the data bus until new controls are required. So the controller is always offline, unless it is needed to change a preamplification parameter. . . and the change takes place in a fraction of a second.
From an experience point of view the volume control is extremely quiet. it turns with a little less friction than on Capri. I can hear very soft volume change clicks only when rotating the knob quickly beyond the 93dB mark on the display. . . which is something that I do only if no music is playing. The background noise is essentially completely quiet up to the top of the gain scale.
Let me know if you need more information. . . but this is all I know up to now. Guido |
|
Thank you Guido re the description of the volume control. The Synergy is similiar in that it also uses a optical encoder under microprocessor control. I am curious about what electronic circuit (whether chip or discrete) is used to implement the volume control. Cheers Mark |
mark, Criterion uses large scale integration for its optical volume encoder, rather than discrete components. The dynamic range of the Criterion circuit is expected to be much wider than in previous JRDG preamplifiers, including that of various versions of Synergy and Coherence. I am not sure about the part number / manufacturer of the volume encoder module. |
All, it looks like our Criterion and related products thread is back in business after a brief abscence caused -- no doubt -- by a minor quantum fluctuation in the probabilistic Landscape that powers the Multiverse. My thanks to all that contributed to the cloning of the appropriate superstrings that allowed the threads return.
Regards, G. |
Guido, It looks like the Corus production is 4 mos out. Is that your understanding? |
|
Husk, I'll know more about Corus product availability in the next couple of weeks. . . but the prediction of 4 months out for Corus does not match anything I have heard this far from JRDG. Claude, Erick Lichte seems to be correct about Model 925 pricing, but pessimistic about product availability. . . His crypto-reference to audio jewelry is very cute. G.
|
some more pictures http://www.flickr.com/photos/metropolismusic/4261312831/ |
Found more pics of the new JRDG gear at:
http://positive-feedback.com/Issue47/ces104.htm
G. |
Nice pictures of CES Guido. Thanks for the link! I took my Criterion up to a friends over the weekend for a listen in his system. (Wadia 922/931 fed by 781i, Rowland 312 into Aerial 20t MKII via Silent source cables everywhere. The room was fully treated, but on wood upper floor.) The first listen was obviosly direct digital to amp for about 5-7 cuts. Then swapped after pre had been on for about 6 hrs for a listen. Upper mid to beyond took on a more solid feel not a thickening at all. The background stayed pitch black. Bass got just a tiny bit more authority, but the biggest effect was two fold. First the overal sound took on a sort of Majestic feeling. Yes, hard to explain but I think the bit of extra dynamics and sensity of the upper end gave it this feeling. Second was when huge and/or very loud uber dynamic swings were fed thru the stream, the pre kept it all together without even the time to sigh about the load! Now, I must tell you, if you haven't already figured it out, that the floors and walls were VERY active by now and feeding back from this energy. Yes the 312 can provide, but it needs unrestricted wall juice and needs to stay away from it's upper output limit due to the hardness and tendancy to start falling apart just before the thermal overload protection kicks in. We were listening that loud!I've said it before that the 312 is not the last word in low freq extention and dynamic cpability. Having heard it pushed hard in this system I still feel the same. It has tremendous transparency, and the imaging is spectacular. Look, it's not a pair of 200 lb mono's! It's a 65 lb stereo amp, that poud for pound kicks ass. It's not cheap, but it does more than most any amp I know in its price range. Sorry, got sidetracked and off subject. Just wanted to address some of the 312 amp comments on this and other threads I'm on. Anyway, going back to the Citerion...Taking it out of the chain was imeaditealy noticed. It was like "Hey, where did the majesty go?" There's probably a better pre out there, but at what price and will it be unaltering of the signal? |
In my loudspeakers the low frequency of my 312 is hair-raising.
I still have one stereo GamuT D200 MKIII. As we known Gamut is a wonderfull device. At least more or less, I guess.
Side by side, in my set up, I gave C to GamuT and A+ to the 312 in the low frequency region.
So I think it's very good. |
David, I do admit freely that there are a lot of amps with greater authority than 312. My old Rowland 7M monoblocks for example, had comfortably greater authority than 312. . . after all, 312 peaks at 40 amps for a fraction of a second, while the old 7Ms peak at 50 Amps continuous. Having said that, I really would love for you to visit my system and bring your Wadia player along for the ride. . . I am not at all experiencing shiness in the bass region, on the contrary. My room is relatively dampened. It may be a matter of different speakers, CDp, and cabling. . . or simply different personal preferences. And while I do listen to music at relatively high volume, I probably never get 312 to near clipping situations.
I found your observations about Criterion sound extremely a propos. . . 'majestic' is definitely one of its sonic attributes. . . . and it is rather unflappable even when it yields very high dynamic swings.
I found that 312 is very sensitive to power cords. . . including what it does in the bass region. This far, some of the very deepest and cleanest bass has been with Shunyata King Cobra power cords, and Furutech High Performance ICs and speaker wires. I have further found that good power distribution also contributes to a tuneful, deep, and linear bass performance. |
Guido, Did you get a delivery date on the Corus yet? |
No, I have no delivery date on Corus yet. I will check again this week. Guido |
Love the one you're with. Corus anticipation could be a lengthy process. And it will only lead to the next anticipation. This thing is like climbing an endless stairway. It's just a series of plateaus that you die anticipating....... |
Yes How true Guido. I died a Thousand times waiting for the Criterion. (2 years!)It is better than I though it would EVER be. I would actually go as far as saying it is irreproachable ! Yes Virginia, it is THAT good. The only other pre amp I've ever heard that comes close (but with lots less air aruond instruments, and less definition in the nether regions) is the Gryphon Sonata Allegro. |
have you compared it to FM Acoustics or Viola ? |
Or Burmester 077 which I use with mye 301´s? |
I have not had the opportunity of performing a side-by-side comparison with Burmester, Viola, or FM Acoustic. Any of these would make for a very interesting analitical review project. G. |
oh yes! ...
but strangely these kind of tests seem to be very difficult to realize in our hobby
imagine calling three diferent dealers and telling them about the exercice ... |
I personally have never heard FM acoustics preamp ...
I know the Criterion and the Viola Cadenza (the cheapest preamp from Viola) but heard in diferent rooms on other systems ...
I was very impressed by the 3 D precision of the Viola ... but how would have it performed in the same system in direct comparison with the Criterion ???
This is exactly what I would love to know ;-) |
any new updates on the corus? |
Hi Kclone, I will buzz the factory on Monday and will post what I hear from them. Guido |
Kclone, I have just checked with the factory, and Corus has not been released yet. I'll keep monitoring periodically. G. |
I just got off the phone with Kelly @ JRDG. Corus is without a certain launch date as yet. Parts supply is one holdup. Anticipate no more than 90 days till launch but sourcing is the variable. |
|
Yes, Guido, SOURCING. None of the parts in a Rowland product are manufactured in house, although many are dedicated designs made to Rowland spec. They can't complete a product until all of the sources fill their orders.
My kingdom for a horse.....
In any case, the Corus chorus should resume before summer. New list is $12,200. |
Macro, did you mean. . .
My kingdom for a 'source'..... (grins)
But yes, JRDG parts and subassemblies are manufactured mostly by military contractors. Only final assembly is performed in house. |
All, here is a correction to information I have posted earlier, repeatedly. . . and ever incorrectly. . . apologies, my bad:
The upcoming Model 625 will be a stereo amp, NOT a monoblock implementation. It will apparently be the companion piece for the equally upcoming Corus pre.
As for various specs and availability, I have no further information. G. |
I try my Gamut 200w power amplifier in biamp driving the high frequency of both loudspeakers and the Model 312 driving the low frequency of both loudspeakers.
Before, when I put only low frequency sound (zero high frequency), the 312 had a much better definition.
I think if you have a combination with the future JRDG 625 stereo power amplifier with its 300w drinvig the high and the 312 driving the low it will be the PERFECT MATCH. Something like a audiopholic haven.
Anyone knowns what will be the 625's Maximum Power Consumption?
The 312 has 2000 watts.
Thanks. |
Hi Braz, Final Model 625 power ratings and related tech specs have not been published yet. We are all still waiting. Guido |
Brazcole, you should be careful if you plan using different amps on your speakers top and bottom. I know it can be done successfully, but it certainly isn´t easy. |
