Review: Jeff Rowland Continuum 500 Amplifier


Category: Amplifiers

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 http://www.soinc1021.qwestoffice.net/

When I arrived at Soundings the Continuum 500 was driving the very nice DALI Helicon 400 Mk.2 speakers. This 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, "icepick-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 a $8800 or so check to Soundings this Friday.

Dave

Associated gear
Vienna Acoustic Beethoven Baby Grand speakers
Analysis Solo Crystal Oval 8 speaker cable
Pro-ject RM10 turntable
Sumiko Blackbird cartridge
Pioneer Dv-58AV universal player modified by Ric Schultz

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Showing 16 responses by guidocorona

Rafael, I can confirm that Continuum uses switching power supply(s). What I do not know is if it has one PS serving both channels or twin supplies. Continuum also has a PFC circuit capable of delivering 1500W of DC, which is essentially equivalent to 2 PC1 devices.
Thank you Cappuccino, what linestage did you use with the big 301 and 501 monos. . . and how does the sound of C500 compare with the 301 monos + linestage X? Guido
That's really exciting Dave. . . and -- no surprise -- you discovered there is a magic synergy between JRDG electronics and Vienna speakers. . . isn't that uncanny? By the way, do you happen to know what power chord was on the Continuum and what speaker wire was in use?
Does continuum have a 15A or 20A IEC connector?

Saluti, Guido
Hi Dave, I know Jeff Rowland is a great believer in fully balanced systems. . . it is highly likely that your Continuum will sound even better if you feed it a balanced signal from the CDP. Guido
The 312 in my system was not at all new, but had probably not been played for a little spell, and had been shipped in a frigid cargo hold. . . it took perhaps 100 hours to settle down.
If the Continuum has a standby switch on the front plate. . . leave that on at all times as well.
Even if the 312 is left completely on, it does take it a good 40 mins to one full hour of playing to sound its best after having idled overnight.
You are correct Dave, what I wrote concerns the 500 model; furthermore the Continuum 250 does not incorporate a PFC circuit. Guido
In current integrateds Continuum 500 has PFC; 250 does not have PFC but is compatible with PC1. In amps 302, 312, 301 have PFC built in; 201, 501 do not have PFC but are compatible with PC1 through fuse change/repositioning. I recommend 2 PC1 units in 501 for max authority, but JRDG can supply PC1 Y splitter if preferred. Capri pre does not have PFC but is compatible with PC1 without any switches/fuse changes because it has an autosense power supply. I suspect Continuum may also have autosense pS, so PC1 on 2650 may not need any setup.
Hi Dave, not surprised about your reaction to the Soltl perf of Beethoven 9th. . . I heard subtleties and profound understanding of the score in the 2nd movement that I had never heard before. . . now have to find a version of the same on CD or SACD for my collection. . . as for Reiner, I am not usually much taken by his performances/interpretations.
Hi Dave, if the Continuum phono stage can even rouse old Reiner from deep sleep. . . it must be marvellous! Sorry. . . just cannot resist jibing when it comes to ol' Fritz (:)!
Rafael, the answer is yes, current JRDG designs are completely balanced from the input to the output signal; so much so that the output signal of JRDG amps have active positive and negative phases. This is one of the reasons why they tend to have superior control of bass drivers of certain speakers with difficult loads -- e.g. Vienna Acoustics. . . . speaker cones are apparently both pushed then pulled, rather than simply pushed then released.
Because of the built-in Power Factor Correction circuit, it is said that Continuum 500 is much closer to the JRDG 312 power amp than to the sound of the 201 or 501 monoblock amplifiers.
Hi Cappuccino, your findings do not surprise me a bit! have you experimented with PCs on C500? What works, what does not. . . and how? Thanks. Guido
Cappuccino, what speakers do you use with 301s? I have heard that because of low damping factor of 60, 301 work best with relatively sensitive speakers with easy loads, but I have never been able to verify this issue myself. Guido
Thank you Kiwi for the review. How many hrs of playing time did you put on the Continuum before proceeding to critical listening? G.
Kiwi, I suspect you may have been reviewing a device that was not fully broken in. Switching amps do very strange and often unpleasant things to the treble until they have stabilized. . . and stabilization may not occur for about 1000 hrs of playing time. May I also ask how many hours of active warm up you allowed before performing critical listening.
Hi Kiwi, I can confirm that the heat from the C500 is caused by the internal PFC module. It is a 1500W unit from a different manufacturer than the 750W twin units used in the 312. . . and it generates much more heat than the other modules combined. . . your speakers are blameless! G.