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dcstep
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Jeff Rowland Design Group Continuum 500 Integrated Amplifier

Preliminary, limited review --
I haven't even taken delivery of my Continuum 500 integrated amplifier yet, but I got to listen for 3-hours this afternoon to help with the decision to put down $8,800 to take it home.

My dealer is Soundings, South of Denver, Colorado, owned and operated by Rod Tomson with the very able assistance of this very knowledgeable crew. See the Soundings site at www.soinc1021.qwestoffice.net/

When I arrived at Soundings the Continuum 500 was driving the very nice DALI Helicon 400 Mk.2 speakers. These are very nice speakers that received a positive review from Michael Fremer in Stereophile recently.

I listened to several cuts from the following CDs:
"Strike A Deep Chord" on Justice Records
"Cannon Reloaded" on Concord
"Breakfast on the Morning Tram" by Stacey Kent on Concord
"Famous Blue Raincoat" by Jennifer Warnes on Shout
"Don't Take Your Time" by Erin Bode on MaxJazz

I started off really worried when I played "Mercy, Mercy, Mercy" from the Cannonball Adderley tribute album, Cannon Reloaded. The bass was indistinct, with few overtones and just showing a one-note quality. The bass on this cut is Marcus Miller playing some really tasty electric bass, with lots of energy and pop. It was lacking all those.

After that I pulled out the Jennifer Warnes CD and played the "If It Be Your Will" cut which has extensive, low, bass synthesizer. On the DALIs it lacked definition and detail. I just sounded like a low sine wave being switched on and off, with no character.

Listening to the DALIs with several vocals, with more typical, higher bass and things were pretty good, with great imaging, rich midrange and high-end details.

When I expressed my concerns to Soundings' Mark Krekeler he suggested that we put the Vienna Acoustic Beethoven Baby Grands into the system. There was immediate nirvana. Now Marcus Miller's bass was rich with overtones and details. The synth on the Warnes CD now had texture and detail, not just sine waves.

Now I could really listen the amp and not be drawn to focusing on what I wasn't hearing in the particular speakers attached.

Several cuts on the "Strike a Deep Chord" were very revealing. The richness of Odetta's voice has absolutely powerful. The chest and head were clearly revealed. Most striking was Clarence "Gatemouth" Brown's which features extreme dynamics, from almost silent to huge sections of bass, guitar, vocal, horns and drums. The quiet was almost totally black.

The highs had no extra edge. I was really surprised by this, given the low hours on the amp. Clarence plays with a piercing tone on "The Drifter". (We guitar players call this tone, "ice pick-in-the-eye" bright). Well it was all there, but not ugly. I didn't detect any of the usual "new equipment needs burn-in syndrome" so if this things gets better with time I'll be VERY, VERY pleased.

That's all for now. I need to get it into my own system, in my own room, burn it in for a few hundred more hours, then spend three or four several hour sessions to get more conclusive. I'll hang onto the Conrad Johnson CA200 long enough to do some meaningful comparisons. (Watch for a great deal on A'gon in the not too distant future).

Here's the bottom line, I loved the Continuum 500 enough that I'll be taking an $8800 or so check to Soundings this Friday.

Oops, I almost forgot to mention cosmetics. JRDG is known for their beautiful chassis and this is no different. In one word, it's "stunning". I'm getting the natural finish chassis which as a

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Re: Jeff Rowland Design Group Continuum 500 Integrated Amplifier

Nice, Dave. I'll look forward to your detailed take on the Rowland amp (and the Cardas cabled AKG701). But $8800! That's a lot of coins... on Dali Helikons: I auditioned them, too, when I was shopping for speakers but they didn't do much for me. It was one of those things that I knew within a minute that they weren't meant for me.

dcstep
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Re: Jeff Rowland Design Group Continuum 500 Integrated Amplifier

The AKGs should be in this weekend. I'm hoping that was a worthwhile upgrade.

Yeah, $8800 ain't cheap, but when you consider that there's SOTA power conditioning, a pre-amp that compares to units costing as much as the whole thing and 1000 watts into 4 ohms, then it looks like a deal. It's much less expensive than buying JRDG Capri preamp and a 312 stereo amp. Still, no for everyone's budget, I understand.

I'm really surprised that I liked the DALIs so much when I first heard them a few weeks ago. Yesterday they left me cold and the bass was really unacceptable in a $7000+ pair of speakers. Their low cutoff was just very poorly done.

Dave

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Re: Jeff Rowland Design Group Continuum 500 Integrated Amplifier

Here are a few other little minor notes:

The power switch is on the back and hard to reach when it's on a high shelf in my equipment armoire, but that's no problem since it's intended to be left on. (At least I think that's the intention. I'll ask Jeff when I tour the factory in May).

When turned off it needs some time to settle back in when you turn it on again. Of course, it was off when I picked it up at Soundings. I rushed home and hooked it up within thirty-minutes of it being turned off. At first it was a little unfocused. Timbres were fine, but it just seemed slightly confused in a timing domain or something. Anyway, it locked in after about thirty to forty-five minutes of play and then got really sweet.

The total hours are now in the 100 to 150 range. Mark of Soundings picked it up at the end of last week and, per my request, played it constantly from then until I picked it up. Like I said earlier in the thread, it's already much better than the Conrad Johnson it replaced, which has several hundred hours on it (approaching 1000, I'm guessing).

The guys at Soundings are a little surprised, saying that their past experience tells them that most JRDG amps need closer to 1000 hours to sound thier best. Perhaps the Power Factor Correction built into the Continuum is speeding that along.

One last thing, as an early adopter I'm doing without a manual right now. No big problem and I'm sure that'll be rectified shortly; however, I thought that I should mention it.

Dave

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Re: Jeff Rowland Design Group Continuum 500 Integrated Amplifier

BTW, I put in 8-hours of listening today, 5 of which were focused and loud as the cuts played would dictate. I have no fatigue at all.

I swapped out the stock power cord for Coincident Speaker Technologies CST-PC. The difference was very small. When I've put the CST on other pieces it yielded a dramatic improvment, so I'm thinking that the Continuum's internal Power Control Factor processing must reduce sensitivity to upstream improvements. The swap took 15-minutes because the amp is high in an equipment armoire, so that may have reduced my ability to hear a change, if any. Perhaps I should have waited a week or two to make the switch so that I settled into the Rowland more.

Oh, one more revelation; this amp is incredibly quiet. After listening at around the 85dB range I turned off the universal player and put my ear to the tweeter. It was absolutely silent. When I turned the attenuator all the way up to 99.5 (that's the step reading, the dBs would actually be higher if I ever listened at that level. Most digital sources are yielding around 85dB with the attenuator set at 70-75) I could hear a slight hiss. This is very, very quiet.

Listening to a few recordings with very quiet passages, like the very dynamic Reference Recordings "Crown Imperial" CD, the quietness give a greater sense of dynamic and clarity to the quiet voices.

Dave

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Re: Jeff Rowland Design Group Continuum 500 Integrated Amplifier


Quote:
I swapped out the stock power cord for Coincident Speaker Technologies CST-PC. The difference was very small. When I've put the CST on other pieces it yielded a dramatic improvment, so I'm thinking that the Continuum's internal Power Control Factor processing must reduce sensitivity to upstream improvements.


Interesting observation.

I bet you are correct. A robust, well-regulated power supply is a wonderous thing.

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Re: Jeff Rowland Design Group Continuum 500 Integrated Amplifier

dc: thanks for keeping us up to date on your experience with these great amps. many of us aspire to have a real premium amp like that so it is great to hear that you are totally happy with them. keep on reporting.

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Re: Jeff Rowland Design Group Continuum 500 Integrated Amplifier

Dave, love your report on different equipments you acquire. How would you rate it vs. the Concerto, presuming that you'd auditioned the Concerto before? Also does the Continuum run in Class A? Sounds like you got yourself a classy amp, if you prefer it to the excellent Conrad Johnson you used to own!

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Re: Jeff Rowland Design Group Continuum 500 Integrated Amplifier


Quote:
Dave, love your report on different equipments you acquire. How would you rate it vs. the Concerto, presuming that you'd auditioned the Concerto before? Also does the Continuum run in Class A? Sounds like you got yourself a classy amp, if you prefer it to the excellent Conrad Johnson you used to own!

A few months back, I came very close to buying a Concerto instead of the CJ, but I got one of those deals that "I couldn't refuse" on a very lightly used CJ. (About half price).

I heard the Concerto in Sounding's system and it was very nice. It's more like two 201s while the Continuum is more like two 501s plus the Power Factor Correction. (Or, comparable to a 312, but with a Capri built in). The Carpi pre-amp has recently received rave reviews and it's the basis for the Continuum pre section.

I wanted both all the power I could get, the Capri-like pre and the PFC. I heard the dramatic impact of raising power when I listened to the DALI 400s with four different amps. The more powerful amps weren't better because they played louder, but because they controlled the woofers much, much better. IMHO, once you get into floor standing speakers with multiple woofers, damping becomes very important. It's easy to hear it with certain speakers. (Like DALIs and Vienna Acoustics).

My VA Beethoven Baby Grands probably would be fine with the Concerto's power, but I wanted the upward mobility of the higher power. (I plan to move into a larger space in 2009 and want to be able to upgrade my speakers without needing to upgrade electronics).

Anyone considering a Concerto should still put it high on their list, but I'd only pay around $3500. At that price it's a wonderful bargain. My CJ CA200 will sell in that range also, making it a great bargain. I'd love for it to go to someone here at Stereophile.

Ok, let's see if you can take this, the Continuum and all current JRDG power amp products, operates in Class D. Its core is the IcePower design, but it's been giantly enhanced by Rowland. All readers should now that there are a lot of naysayers, that dismiss Class D out of hand, saying it's inferior to tubes or SS in Class A or AB. I listen with my ears rather than my eyes and say that these Rowland Class D designs sound better than many other "big names" like Krell and Mark Levinson, at least IMHO. (Flames are welcome if anyone feels compelled, although I can't defend my position other than to say that's what I hear).

Beside the great sonic performances, some advantages of Class D are compact size, cool operation, less harsh clipping than typical SS designs, etc.

Dave

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Re: Jeff Rowland Design Group Continuum 500 Integrated Amplifier

You're welcome Tom and I'll try to keep it up.

Dave

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Re: Jeff Rowland Design Group Continuum 500 Integrated Amplifier

Here's more that came up in the midst of a "Class D" thread over at the Asylum. Because of the Class D "controversy, I thought I'd repeat it here:

Vic said:
"I'm interested in your personal evolution leading up to the Continuum. Is this your first switching amp? If not, can you describe your impressions of PFC technology compared to other switching amplifiers you've experienced? How many hours do you have on the JRDG?"

Good questions Vic. In case you missed it, in another thread I review my Continuum.

Here's my entire "serious" amplifier experience which starts in 1967, with a tube Scott amp. I forget the model, but it was around 30 watts, driving Jensen speakers with a Garrard TT. That was followed by a Sansui (100 watts) that drove the Jensens until they were replaced in 1974 by DCM Time Windows. In the early 1980s I moved to Byston 1B/2B amp/pre power driving Celestion SL-600s.

Last summer I replaced the Celestions with Vienna Acoustic Beethoven Baby Grands and added a Pro-ject RM10 TT with a Sumiko Blackbird cartridge. Last winter the Brystons were replaced with a Conrad Johnson CA200. My ancillary system is a Woo Audio WA6 single-ended headphone amp, driving AKG 701s with Cardas cable and Audio Technica WA5000, plus a couple of Ulitmate Ears IEMs. I've got an upgraded rectifier tube in the Woo, GZ34 Holland if I recall correctly.

The Scott, Sansui, Bryston and CJ were all Class AB. The Woo is Class A. Oh, the other important part of my front end is a Pioneer Elite AV-58DV universal player, with full mods by Ric Schultz, which is very sweet digital, particularly with SACD and DVD-A.

As a side note, I'm a jazz guitarist for fun and I've been using Class D amps by Acoustic Image since the late 1990s. I also use a Class A tube Alessandro guitar amp and own a couple of SS Class AB guitar amps.

My Continuum has around 200-hours.

The PFC technology is not instead of switch mode power, it's more like conditioning the AC power. Actually, more than conditioning, it converts AC to DC for both stabilization and elimination of 60-cycle noise elements.

Since the PFC is internal to the Continuum I can't do any with/without analysis; however, over at Audiogon.com Guido Corona (user name Guidocorona) has put a Rowland PC-1 PFC unit in front of Rowlands Capri pre-amp with very pleasing results. I've also heard of others putting the PC-1 in front of the 501 monoblocks is a large leap foward, bringing those units up to the top of the line 312 amplifier.

I'm astounded by the quietness of the Continuum. Guido and my dealer tell me that the PFC is a big part of that.

Hope that helps. I'm not anti-tube or anti-Class A or anti-Class AB. I've listened to most of the "big names" including Krell, Mark Levinson. The Woo is actually a "high-end" single-ended, Class A headphone amplifier, particularly with the upgraded rectifier. Oh, my phono-pre is a Pro-ject "Tube Box SE", but it's likely to be replaced by the Rowland phono card for my Continuum, eliminating one more potential source of 60-cycle noise.

Best regards,
Dave

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Re: Jeff Rowland Design Group Continuum 500 Integrated Amplifier

Next Monday I'll run down to Colorado Springs to have Rowland install his phono card in my Continuum 500. I'll add an initial report on its sound after a few hours and follow up after I get more extensive hours on the phono section.

Dave

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Re: Jeff Rowland Design Group Continuum 500 Integrated Amplifier

I drove down to Colorado Springs today to have Jeff install the phono stage modules in my Continuum 500. Installing the phono circuits took about 10-minutes but I ended up spending all day with Jeff. He's quite the philosopher and we took turns going off on deep tangents, from the madness of crowds to the Marfa lights.

One of the highlights of the trip for me was seeing inside my own Continuum and marveling at the incredible quality. Most of you know, but for those that don't, the chassis is made out of high quality billet aluminum to tolerances of .003". When I asked about the percentage cost of the chassis vs. total construction cost, Jeff launched to a discussion of how hard it to say because of all the time saved in assembly because the holes always line up, attachment points are machined into the chassis, etc., etc..

Here's an interesting detail, the Continuum is the first (or one of the first) Rowland products to receive a curved faceplate. The faceplate still has the same distinctive machine work ("turning", but way more refined than that), but with a curved front that is more accentuated. Well, the really interesting detail is that each button must be a different length to look "just right". So Jeff went from one button to six buttons in order to achieve the clean, balanced look that he wanted to maintain.

Jeff's has a curved faceplate for the 300-series. I saw the first shipment and oh man, they're stunning. It's an easy replacement for the stock plate. Jeff's costs is "hundreds" and he's working out the retail price.

You may expect a review of the phono stage, but it's way too early. I've only listened to one side of Ella. I can say it's first rate and superior to the Pro-ject Tube Box SE that it replaced. The noise level is vanishingly low, like all the stages of the Continuum and the balance seems very neutral and clean, but I need to listen a wider variety of music over a longer period of time. Also, the stage needs burn-in.

As to the Continuum itself, I think it did move into new territor this weekend. It passed 200-hours. Previously I was totally enjoying my SACDs, DVD-As and vinyl, but I was getting tired listening to certain CDs. My Pioneer AV-58DV universal player only has about 300-hours on it since modification by Ric Shultz. I was beginning to think that the CD function wasn't benefiting as much as the hi-rez digital. Well, this weekend I listened to about 8-hours of CDs with no strain at all.

I think it was mainly due to the amp getting better. It had been on constantly for a week. There's little clear cut that I can point to, other than that EVERYTHING seemed better, more transparent, more open, even less stressed.

Poor digital still shows up as poor digital with the Continuum. Remember those Telarc LPs for the late '70s, with Cleveland and Atlanta orchestras. They were recorded with early digital 16-bit technology. Well, I could hardly stand them. Early RCA analog tape-based LPs still sound glorious in comparison.

So, the Continuum is incredibly revealing, yet incredibly transparent, incredibly quiet and easy to listen to for hours and hours IF and only if, you sources are very good and don't add any harshness.

When I was putting the Continuum back into the system after bringing it back from Rowland's shop, I put the Conrad Johnson CA200 control amp into the system for about 30-minutes. Maybe the CJ needed more warm up time, but both amps were cool before I did this final swap. The highs on the CJ seem slightly harder and more brittle in comparison to the Continuum. I put the Continuum back in the system and started right where I left off yesterday, nice and smooth. I'm afraid that the CJ may have needed another hour or two sweeten up, but when I'd used it in my system it was on standby when not in use and needed only a few minutes to start sounding good. Maybe because it had been disconnected for two weeks it wasn't at its best.

I'm going to make no more comparisons to the CJ. It's a fine amp, but the Continuum is the amp for my old age.

Dave

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Re: Jeff Rowland Design Group Continuum 500 Integrated Amplifier

Wonderful fun!

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Re: Jeff Rowland Design Group Continuum 500 Integrated Amplifier


Quote:
Here's an interesting detail, the Continuum is the first (or one of the first) Rowland products to receive a curved faceplate. The faceplate still has the same distinctive machine work ("turning", but way more refined than that), but with a curved front that is more accentuated. Well, the really interesting detail is that each button must be a different length to look "just right". So Jeff went from one button to six buttons in order to achieve the clean, balanced look that he wanted to maintain

Dave, that baby seems so brand new it

dcstep
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Re: Jeff Rowland Design Group Continuum 500 Integrated Amplifier

Ok RG, at least by the weekend I'll try to get some pictures. Mean time, here's a page with a picture to hold you over:
http://www.htforum.com/vb/showthread.php?t=49927&page=3

Dave

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Re: Jeff Rowland Design Group Continuum 500 Integrated Amplifier

OMG, I got the bill for the phono cards and it blew my mind... $355!! It cost $200 less than the Pro-ject Tube Box that it replaced.

I actually think the price is fair, because the little cars are about the size of the last joint of my little finger. Obviously they're well designed and takes advantage of the infrastructure of the Continuum, but it really only two little cards. I guess my point is, ask a couple of other high-end makers how much it'd cost to add a phono section to one of their pre-amps or integrated amp.

A further thought or two about the phono "section." The background is total quietness. The tonal balance is perfectly neutral. I've got some RCA LPs of the CSO with Reiner and SACDs of the same performances. Well, the cartridge/phono-stage has the same balance as the the SACD.

With new studio style recordings, like Diana Krall, Nora Jones, Herbie Hancock, I can listen deeper into the vocals, hearing more nuance. There's no stress and listening is great. Detail, clarity, dynamics, bass are all there in abundance and proper balance.

Gee, I can't wait 'til it's burned in.

Dave

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Rowland Continuum 500 Runs a Little Warm

Here's another follow-up. The top of my C500 is hot to the touch. You can hold your hand on it, but it gets uncomfortable after a few seconds. When we visited his shop in Colorado Springs (see JRDG Tour) I guessed that the temp was 130-degrees and asked Jeff if this was an issue. He said it's not where close to a problem. He said that the C500 runs hotter than the C250, because the PFC units in the 500 generate some heat.

Today I actually measured the warmth at 120-degrees with the armoire door closed.

Lots of ICEpower units are cool to the touch and I've heard stories of one or two Continuum 500 owners being concerned about the heat, so I wanted to discuss this issue here.

Dave

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JRDG Web Site Updated

Jeff Rowland has finally updated its web site with a page dedicated to the new Continuum 250 and 500. Here it is:
jeffrowland.com/Continuum.htm
And here are some specs:

* * * *

Specs: 250 Version / 500 Version
Output Power, Continuous RMS watts, both channels driven 250 watts @ 8 ohms / 500 watts @ 8 ohms per channel /
500 watts @ 8 ohms / 1000 watts @ 4 ohms per channel
Frequency Response 5 Hz

tom collins
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Re: JRDG Web Site Updated

its been a while since you posted anything about how the unit is breaking in. do you think it is complete? has there been any change in the sound? are you still happy with your choice? just being nosy.

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Re: JRDG Web Site Updated


Quote:
its been a while since you posted anything about how the unit is breaking in. do you think it is complete? has there been any change in the sound? are you still happy with your choice? just being nosy.

Not nosy at all. If a guy posts he has to expect questions, right?

It improved a ton in the first 50-hours, getting rid of a slight glare on the very top. At 150-hours the top got sweeter by a small increment and it's been steady from there. If you turn it off for any reason, then it needs an hour or so to settle back in. (I hardly ever turn it off).

Guido Corona and I talk a lot about JRDG. He just moved from a ARC REf3 to the Capri pre-amp. The Continuum shares the Capri's circuit. Guido feels that the JRDG's latest offerings remove the last bit of euphonic color from the midrange. Unfortunately, many audiophiles don't want to lose that coloration, small as it is.

Guido reports a couple of people buying the Capri and being instantly dissappointed because it didn't give them the "kick" they'd become used to. OTOH, my experience has been the opposite personally and also with those that I know have gotten either the Capri or the Continuum. They're enjoying the transparency, dynamics, lack of stress and pureness in approach. Any of the current JRDG components will ruthlessly reveal problems with CDPs, ICs and cables, but they'll reward good selections here.

I've mentioned it before, but the phono stage for the Continuum and Capri is exceptional. It's put some highly respected phono stages outbound on the UPS truck.

Dave

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Re: JRDG Web Site Updated

Hi Dave,

Was just curious to hear whether you considered the Boulder 865 when you chose the Continuum, or indeed whether you have ever heard one and could offer any reflections on how they compare. I see that Soundings don't carry Boulder but presumably they have some retail representation in their home state.

I always thought Rowland electronics had a slightly "tubey" sound but as you point out above that may be a thing of the past; I haven't heard any of their recent stuff. Don't know if anyone is selling Rowland here, I certainly haven't seen them at any shows.

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