Polk SDA 2b - Amp Review

I just got in a new(to me) amp that is replacing my old amp. I thought I would give a quick review for any one curious or looking for a new amp to pair with their SDAs.

Old Set Up:
Polk SDA 2b(upgraded)
Belles dmc Preamp
Schiit Modi 3 Dac
Adcom GFA 555
Interconnects - Random brands nothing to write home about

The new set up replaces the Adcom with a Odyssey Stratos Stereo Plus. I am in the process of upgrading interconnects with Blue Jean RCA and Custom/diy Speaker cables.

My initial impressions of the Stratos is very positive especially when compared to the Adcom. Don't get me wrong the Adcom was fine but I have always felt that the sound stage while wide was being held back unless played at loud levels. The imaging was always "fuzzy" indistinct and fairly 2d especially with the center image. I always thought the highs mids and bass where fine. I always felt the SDAs where being held back by the adcom.

The Stratos on the other hand improves on the Adcom in every area despite technically having less WPC. It has a VERY clear, transparent and neutral sound. The highs and mids are much clearer and distinct. The bass though, is where there is the most improvement and has more slam to it while also being controlled. The soundstage is frankly astounding and seems to only be limited by the room and recording. With the right recording the SDA's sound stage covers the entire wall of my living room and is very holographic. With the SDAs projecting instruments to the sides and forward of the speakers. I probably will need to widen the gap between the speakers to make instrument placement more even. The imaging is also much more distinct with greater separation. I can distinctly tell where the instruments are especially when compared to the ADCOM. With the adcom you could only tell the general location of an instrument. My only have a couple issues with the stratos is that when idle I'm getting a low level hum. I think that may be a issue the the rca cables I am using which is why I ordered the blue jean cables. The second issue is that the Statos is a very large amp. If you are interested in one keep that in mind. You will not be able to hide it and may not be able to fit it where you have your old amp. On the other hand it doesn't run very hot. Overall the stratos is a great SDA option especially if you can get one for under $1000.

Side Note: I have also had the pleasure of barrowing a Belles 350a. The belles 350a stomped all over the Adcom in all areas. When compared to the Stratos.... well I think that comes down to personal tastes. The Stratos has a little better bass, sound staging, imaging and is definingly more transparent. The Stratos just has this crystal clear sound to it that I enjoy. The Belles 350a while lacking in some areas compared to the Stratos, just sounds ... right. It has a nice warm liquid/musical effortless sound to it that I adore especially with the SDAs. Personally I prefer the belles 350a to the Stratos and may one day switch to it. At the same time the Stratos is a excellent performer with the SDAs and it really does bring out the SDA's ablility to project a sound stage. Again I think it could come down to personal tastes on which is better. I also would not hesitate to recommend the Stratos even at the $1500 brand new price.

Side note 2: Yes I know the adcom is probably being held back by 30 to 40 year old caps. But I'm not convinced that even if recapped, that it would be the equal of the other 2 amps. Not to mention the fact that if I did recap the adcom I would have about just the same amount of money that I bought the Stratos for. With the Adcom still having less resale value.

Comments

  • audioluvr
    audioluvr Posts: 3,708
    Your hum is probably a ground issue. Start by checking that all the screws in the case are tight by backing them off to loose then retightening them. Also check inside as there is often one or two ground screws that connect circuit boards to the case. Finally if that don't work try a 3 prong adapter to eliminate the outlets ground.

    Congrats on the Odyssey. They are very nice and clearly show you watts isn't everything. I'm a HUGE fan of imaging and soundstage accuracy. Though I have the Belles 350 I keep going back to my B&K mono's because I have yet to hear anything (that I can afford) that throws such a wide soundstage even at low level listening.

    As for recapping the Adcom. You'd never get your money back out of it plus I'd agree it probably still wouldn't compete with a Belles or Odyssey. JMHO.
    Cambridge Audio 851N Streamer/DAC
    Belles 21A Pre modded with Mundorf Supreme caps
    B&K M200 Sonata monoblocks refreshed and upgraded
    Belles 350A Reference modded with Mundorf Supreme caps
    Polk SDA 1C's modded / 1000Va Dreadnaught
    Wireworld Silver Eclipse IC's and speaker cables


    There is about a 5% genetic difference between apes and men …but that difference is the difference between throwing your own poo when you are annoyed …and Einstein, Shakespeare and Miss January.

    by Dr. Sardonicus
  • windstriker
    windstriker Posts: 133
    I've done some experimenting and need to do more. I have noticed when I disconnect one of the rca's going from the pre to the amp the hum pretty much goes away. Same if I unplug the pre. So is the issue with the pre or something else? Not sure if it matter but the preamps' power cord is only 2 pronged and does not have a ground prong. Need to find another pre to experiment with. May get a cheapy tube buffer off of amazon.
  • audioluvr
    audioluvr Posts: 3,708
    Does the amp have 2 prongs? Maybe swap in different interconnect cables.
    Cambridge Audio 851N Streamer/DAC
    Belles 21A Pre modded with Mundorf Supreme caps
    B&K M200 Sonata monoblocks refreshed and upgraded
    Belles 350A Reference modded with Mundorf Supreme caps
    Polk SDA 1C's modded / 1000Va Dreadnaught
    Wireworld Silver Eclipse IC's and speaker cables


    There is about a 5% genetic difference between apes and men …but that difference is the difference between throwing your own poo when you are annoyed …and Einstein, Shakespeare and Miss January.

    by Dr. Sardonicus