Amp/Preamp Asylum: REVIEW: Odyssey Stratos Amplifier (SS) by MarkgM

Model:	Stratos
Category:	Amplifier (SS)
Suggested Retail Price:	$995
Description:	150 watts/channel
Manufacturer URL:	Odyssey
Manufacturer URL:	Odyssey

Review by MarkgM on October 17, 2002 at 02:03:20
IP Address: 208.61.71.229

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I have owned a Denon PMA 2000R integrated amp for about 18 months to 2 years at the time of receiving the Stratos amp, and had some thing I was shopping for.
Now this review might be a bit unorthodox. I am highlighting what I perceive to be significant distinctions between the Denon and Odyssey amplifiers, however; the Odyssey is being listened to with a Nohr ACA 1 preamp, and the Denon, obviously, is using the pre-amp it contains internally. So I think there may be overlap between what advantages one pre offers over another, but I think you'll agree that the differences in the amplifier section are strongly emphasized in the following paragraphs.
I haven't heard the Denon in the past few months at this point, and am recollecting the notes that I mentally jotted down at that time. I remember well the prominent differences between the two.
First off, though, there was the break-in period, and as I recall, for as much as there was break-in in the amplifier there was break-in taking place in me, although as I reviewed the Denon amp on Audio Review a couple of years ago, at that time I reported with affirmation significant break-in of the amp from the time I took it out of the box, so I do believe it's true.
I broke in because the new equipment broke a couple of my CDs. And here I am these months later, and I'd swear to you that I did amongst all things discover more of less quality on those CDs in question, in particular ways. I do think there's break-in going on with the Stratos, but I find myself a bit compromised to say just how much.
So I had the Denon, and I suspected that I could get better control of the drivers in my Fuselier speakers than I was getting with the Denon. I also romanticised the idea of getting more SPL.
Well I have to say that on SPL, the 80 wpc Denon produces as much as any amplifier I've hooked up to this speaker, and I'm also not sure how stable the drivers can hold at higher levels regardless of the amplifier power rating. Whether it's the Denon or the Stratos, I've got around 98 db nominal output, clean, with peaks hitting in the 106-108 db range. The speaker is rated at 87.5. I also have connected another speaker to both of these amplifiers, the NCMS Borealis, rated at 85 db. With those I'm getting 100 db nominal out (clean) using either amplifier. I don't think there's any amp under 200 watts that I can post better clean SPL with, (or it's just too darned difficult to look for small differences at 100 db in my face!)
Here's an extra ditty on wattage and SPL - my two cents and I hope it helps clear the air on my position on the matter. The Denon amp, while rated at only 80 wpc, is also rated at delivering as much as 120 amps of current to the output stage. That is no pushover, even when compared to ampere capacities of amplifiers rated at 200 to 250 watts. And now think of this. A 200 watt amp by the same vendor as a 100 watt amp will only produce a small increase in SPL. So a doubling of wattage only converts into a small increase in SPL. And to further compound my case against the "solutions in a bottle of high wattage ratings" position, try taking an honest look at your speakers and see how much linear SPL they are even capable of creating. Do your drivers by design stay linear to higher amplitudes than what your getting with your 50 or 100 watt amplifer, or whatever it is? I digress...
Now comes the issue of how much power these amplifiers produce when not cranking the volume as much as can be done. So this is just leaving the volume knob alone - sitting there in one place. I have noticed that the lows and the highs are extended farther out with the Fuseliers than with the Denon, or at least that's the audio impression I'm getting. My roomie notes the same thing on this. The low bass feels like it extends deeper, and the high treble feels the same way. The high treble picks up strength. This is also very likely a strong contributor of how I had to chang as a listener (even during the break-in period). I didn't get happy-slapped by the Denon so much this way. But the Denon provides equally as many outright details in the music.
The place where the detail comes forth using the Odyssey is not at that general of a level. In this case, however, there is often a notable improvement in the air around each instrument. It's at a finer level (than a whole detail drop-out), but certainly to a noteworthy degree in this particular area. More information throughout the frequency range.
Tonally, I found them to be equal. I view the Denon as a neutral sounding amp and the Odyssey also this way.
Using a test tone CD I made (all 1/12th octave tones 20 - 20 K), the Odyssey amp really tripped me out. I felt like running a comparison of the frequency response I could measure over the same test environment using the Denon. I had four combinations altogether to do this with: Stratos and Denon with Fuseliers and NCMSs. On the Fuseliers powered by the Stratos, for the first time I caught decent sounding tones in the 21 - 25 Hz range. Using the Denon, Tones under 26 Hz did not sound as "tonal" as they did to some extent breaking apart a bit, really, at just about any volume. It was like a percentage of the tone and it was noticeable. And I think the total combination brought this out, as follows: Difficult load to drive - 8" driver covers 28 Hz to 2 KHz load flatly, and rolls off below, needs a great deal of stability to handle the extreme frequencies. The Borealis' corroborate this, because they produce a nice sounding tone down to 21 Hz even when using the Denon.
This is a godsend for me, and a little story to go with that. I've been struggling with the idea as to whether or not it would be prudent to protect the bottom end of the Fuseliers with some kind of a crossing-over capacitor and crossing them over into a sub at around 30 Hz or in the 30s. I no longer feel a need to protect them in the twenties, or to preserve the power of the main channel amp (whatever it be), and that's quite a relief.
Overall, everything truly flattens out to a finer degree with the Stratos and the Fuseliers. (I didn't spend enough time with the Borealis and the Denon combination to say on this) I have noticed that I can turn the volume down lower, and still get a touch of bass feeling and good 3-d holography at a lower volume level with the Stratos than with the Denon, seems like something like 5 db lower.
The quality of a low bass tone made a radical shift in the direcion of desireable. The Stratos gave low bass tones the ability to slice right though me, whereas with the Denon they didn't get further than thump my chest or rattle my gizzards. It just wasn't slicing. This is much closer a feeling of standing on the sidewalk as the memorial day band marches by!
Well, that's all I can remember from my experiences contrasting the two. I think the Odyssey makes quite significant difference to the Denon. I also think the Nohr pre is just plain cleaner than the Denon pre, but enough trying to sort it all out to that extent. The amplifier section has seen a significant upgrade.

Product Weakness: none as reviewed against the Denon
Product Strengths: Speed, neutral sounding, wide and flat response, fine detail

Associated Equipment for this Review:
Amplifier:	Denon PMA 2000R Integrated amp
Preamplifier (or None if Integrated):	Norh ACA 1
Sources (CDP/Turntable):	Meridian 500/566
Speakers:	Fuselier Basic Eights, NCMS Borealis
Cables/Interconnects:	Transparent M Wave 100s
Music Used (Genre/Selections):	various
Room Size (LxWxH):	15 x 12 x 8
Time Period/Length of Audition:	6 months
Type of Audition/Review:	Product Owner

Product Weakness:	none as reviewed against the Denon
Product Strengths:	Speed, neutral sounding, wide and flat response, fine detail