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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I don't remember seeing an XLR on the back of my modded Pioneer universal player, but I'll look again. Right now I'm using a Pro-ject Tube Box SE phono-pre for vinyl, but Rod and I started talking about trying Jeff's phono card in the Continuum, which I will do before too long.

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.

Guido, how many hours did it take your 312 to settle in? That's got PFC also, doesn't it?

Oh Guido, you asked a question, when I heard it in Soundings it was with the stock power cord and that's what I'm using right now.

Crap, I forgot to look at the IEC connector, but give the weight of the supplied cord, I'm thinking that it's 20A. I'll try to remember to double-check this p.m.

Dave
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.
Interesting. There's no standby mode on the Continuum, so it's staying all the way on, all the time.

I sat down today and started serious listening with no wait. I'll pay closer attention tomorrow, to see how it changes over the first hour. I didn't notice a change, but I was playing a wide variety of music. Tomorrow I'll try the same piece.

Dave
Hello Dave,
Thank you for the nice review. Can you tell me if this amp uses convetnional or switching power supplies. I know it uses power correction - I think you mentioned it somewhere.
My congratulations !!!!!
Thanks
Rafael
Switch-mode I think, consistant with the rest of Jeff's product line. See:
http://www.jeffrowland.com/Technology/SwitchMode.htm

Unfortunately, I have no direct literature to support it; however, his use of switch-mode in his other products, the high power, compact size and cool running make me think it's also switch-mode.

Dave