[milpai]

Hi All,
Was wondering if any one has compared the Stratos Monos VS Parasound A21. I am looking for a amp with high sensitivity (<= 1.5V) and input impedance of > 20 kOhms. This will be used with Promitheus Ref C-Core TVC and Marantz CD player (2.2V) to power up a pair of Quad 21L speakers (88dB, 6 Ohms).
I initially thought about Kismet Monos, but they seem to be waaaaay out of budget. Forgot to check with Klaus on the price of Kismet stereo. What is the input sensitivity of Stratos Monos? Do they have the characteristics of NAD amp (my current one)? I love NAD sound to Rotel - so that should be a good preference reference.
Thanks

[Eduardo AAVM]

You should spend some time and read latest review.

5 years ago or so, a mexican magazine ran a review on a Stratos Plus, still the green boar version, well I guess the reviewer trying to find if Odyssey was really as good as many claim chose for speakers a pair of "easy to drive" Apogees with an even lower sensitivity than your Quads, and a minimum impedance of 2 Ohms.

So I think you can go and grab a superb Odyssey amplifier, honestly I think Parasound has nothing to do against it. You can go diferent ways: a pair of Khartago Monos (each is practically at the same level the reviewed Stratos Plus is) a Stratos Stereo Extreme is also an excellent performer, I like it very much. And before the Kismets you can also think about Stratos Monos or Stratos Mono Extremes.

[milpai]

You should spend some time and read latest review.

5 years ago or so, a mexican magazine ran a review on a Stratos Plus, still the green boar version, well I guess the reviewer trying to find if Odyssey was really as good as many claim chose for speakers a pair of "easy to drive" Apogees with an even lower sensitivity than your Quads, and a minimum impedance of 2 Ohms.

So I think you can go and grab a superb Odyssey amplifier, honestly I think Parasound has nothing to do against it. You can go diferent ways: a pair of Khartago Monos (each is practically at the same level the reviewed Stratos Plus is) a Stratos Stereo Extreme is also an excellent performer, I like it very much. And before the Kismets you can also think about Stratos Monos or Stratos Mono Extremes.

Eduardo,
Do you know the sensitivity on the Stratos Monos and the Extreme monos? I believe the input sensitivity of the amp matters when matching with a TVC.

[klaus@odyssey]

Again,  as I wrote you,  the amps match beautiful  with the TVC,  but please,  don't try to mention the amps with NAD  or Rotel in the same breath........

As for the Parasound,  I'll a/b them any day of the week.

[Oystein]

I agree that in general NAD and Rotel are in a different leage compared to Odyssey.
I replaced my NAD 317 integrated for a Khartago Plus and the difference is huge in every way possible.
On the other hand I purchased a NAD C162 pre-amp new for really cheap (on sale because NAD replaced it with the C165) and the C162 can hold its own combined with the Khartago.
It is discrete Class A design and for approx 1500 EUR total I have a killer set that is hard to beat at this price point.

BTW: the C162 is also listed as a top buy in the TAS 2009 Editor's Choise Award FWIW ...

[milpai]

Again,  as I wrote you,  the amps match beautiful  with the TVC,  but please,  don't try to mention the amps with NAD  or Rotel in the same breath........

As for the Parasound,  I'll a/b them any day of the week.

Klaus, when I mentioned the NAD amp, I meant the slight warmth of that amp. I was not trying to compare NAD with Odyssey. But trust me - once you bypass the preamp in my NAD, it is an altogether different amp. The moment I introduced the TVC in my system, I was zapped by presentation the NAD was giving me. Though I am quite happy with the NAD, I want to go higher in the chain. Isn't that what we all do?

For the TVC to work in a system, the sensitivity of the power amp is very important compared to impedance. I have heard good things about Parasound A21 and Odyssey Stratos Monos. The Parasound's sensitivity of 1V seems to match my TVC's requirement. The Parasound also has a hefty 250Watts along with a 60amp current rating. The Quads start singing with high power/current amps. I checked Odyssey's site but could not find any sensitivity info.

Klaus, I am trying to get as much information as possible, from various sources (users/forums/owners). Once I finalize this, I will call you. I don't feel there is any point by calling you before I finalize my requirements and preparing a list of questions.

Finally, I believe that forum users are the best judge of products rather than a mag. That is how I ended with my Promitheus Ref C-Core TVC. I did quite a lot of email interactions with the users and concluded what I needed. And you see, the users are ALWAYS right!! 

[AnalogDog]

Manual that came with my Stratos monoblocs says in the input impedance is 10Kohm; believe they are currently closer to 20kohm. Input sensitivity not specified, but I'm betting it's around what you require. Check with Klaus, as the specs do change. I suspect these amps sound best with a tubed preamp with a very stiff power supply and low output impedance.That's what I've got paired with mine, and the sound is marvelous. Evidently Klaus agrees, witness his Candela linestage, and his new Kismet tubed phono and line stages.

[trebejo]

There's way too much speculating on what is a simple, straightforward spec. What is the amp's gain? That is not a hard question to answer.

For the TVC, you should look for 30db or greater, I think.

Recommendations to get a different pre-amp miss the point, entirely. A potential purchaser should know, beforehand, whether the amp has a chance to work with his current setup. There are other amps out there, including plenty that will work with a TVC!

[jmck407]

There's way too much speculating on what is a simple, straightforward spec. What is the amp's gain? That is not a hard question to answer.

For the TVC, you should look for 30db or greater, I think.

Recommendations to get a different pre-amp miss the point, entirely. A potential purchaser should know, beforehand, whether the amp has a chance to work with his current setup. There are other amps out there, including plenty that will work with a TVC!

This is the closest I have found to what the gain of the mono extremes are, http://www.audiocircle.com/index.php?topic=3275.msg27024#msg27024, but can't find anything directly from Klaus, although he does respond to Mike, and does not refute his numbers...so if not dead on accurate, they are most likely pretty close.

I have this combination, and have been trying to figure out exactly how the two interact.  From reading, many people seem to think matching input sensitivity of an  amp to output voltage of a pre, is one of the most important things to look for when choosing an amp for a pre or vice versa, but I have seen a few mention it is not that critical if the gain of the amp is enough.   Milpai posted a great breakdown of how the tvc works, and I ran some calculations for the tvc with mono extremes, based on his response in this thread  http://www.audiocircle.com/index.php?topic=71162.0 

If these numbers are correct the tvc will never quite reach the point of maximum gain when matched with the mono extremes, and this could explain why I can't get ear shattering levels with this combination.  Having stated that, for most all music the combination works extremely well in my 2 channel setup....really outstanding presentation with most music.    I still would like to get some kind of verification, on the input sensitivity, and maybe understand more why a high gain amp (like over 30db recommended by trebejo) makes input sensitivity matching less important.  My guess would be that with a high gain amp, you reach a level that is considered "loud enough" without reaching the peak gain of the amp, thus getting to the input sensitivity of said amp is not all that critical for most tracks.