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Icepower 50ASX2 questions

Discussion in 'New Gear - Values' started by marqueemoon, Mar 26, 2015.

  1. marqueemoon

    marqueemoon Gimme indie rock!

    Messages:
    4,141
    Location:
    Seattle, WA
    Can these be run with a passive attenuator? The input sensitivity seems ok? Not sure what else I should be looking at to answer the question.

    Are there any new commercially available cased power amp versions out there? I e-mailed Dalaudio already. I saw B&K did one but I'd prefer real binding posts.

    Anyone done a head to head with a TPA3116?
     

     

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  2. winters860

    winters860 AK Subscriber Subscriber

    Messages:
    4,192
    Location:
    Dirtbag, Ohio
    I've heard that a buffer or preamp stage can make a world of difference with the 50ASX2.

    I can't say it was a fair comparison, taking place 3-4 months apart, but my own experiences back that up. My buddy brought over a barebones DIY 50ASX25 amp with DACT attenuator, but I thought it sounded a little thin in a shootout with a LM3886 amp, a TK2050 amp, and my Marantz 2220. I thought that the Marantz sounded good, but wasn't the last word in detail. The LM3886 won the day as being the best-balanced. The TK2050 was muscular, but had a hard edge I wouldn't have wanted to live with. Finally, the 50ASX2 amp sounded fine, as flat-sounding as the LM3886, but with unfortunately flat dynamics as well.

    Luckily, I have no such complaints about my recent purchase, a TEAC AI-301DA, which houses the Icepower amp, as well as a preamp stage and DAC.

    I haven't done any kind of head to head competition yet. Since that time, a restored Marantz 2230 bested the garage sale 2220 in every way. Comparing the AI-301DA to the 2230, I like them both. While the Marantz is great in its own way, it has a romantic, warm, kinda smooth presentation. The AI-301DA simply sounds like what it's fed. As a bonus, the onboard DAC smokes the Topping TPD2 DAC I had been using. This is certainly the best Redbook CD solution I've ever had. I've got a TPA3116 black board around here that I'll compare someday, but I'm in no hurry.

    The AI-301DA is TEAC's second 50ASX2 amp, the first being the A-H01. I believe they're pretty similar, but the AI-301DA has a better, DSD-capable hi-res DAC, AptX Bluetooth, and addresses chassis quality concerns with the A-H01.

    The A-H01 is being closed out for $270, but you can find the AI-301DA for $399, and a rebate available on purchases until the end of this month drops the end price to $299. For $300 clams, it's a hell of a lot of amplifier, especially considering that the 50ASX25 will run close to $100 by itself.

    The AI-301 has no trouble driving my 93db/w speakers to room-clearing levels. The sound is fantastic, with tight bass, articulate highs, and maybe just a hint of prominent midrange that adds weight to female voices. Good stuff.

    I've experienced two hiccups with the TEAC, though:

    Nearly every button on the TEAC remote turns my Vizio TV on and off. Since the TV is set to HDMI input and used as a computer monitor 99% of the time, I put a piece of electrical tape over the IR sensor and have been happy ever since.

    Also, my HP laptop running Linux Mint Rebecca reverts to onboard sound when the input selector on the AI-301DA is switched away from 'USB", and has to be pointed to the TEAC via sound settings once the input is switched back. While I may be able to overcome this issue via software, I'd have preferred that the amplifier wasn't designed to cut power to the USB input when other sources were selected.
     
    Last edited: Mar 26, 2015
  3. marqueemoon

    marqueemoon Gimme indie rock!

    Messages:
    4,141
    Location:
    Seattle, WA
    Thanks for all the info on the Teac stuff. They look like smartly put together units. Definitely some features I don't need, but for the price they're giveaways.

    I checked out some reviews though and now I'm wondering if it's what I'm looking for sonically (and if the characteristics mentioned are functions of the Teac front end or the modules themselves).Looking for more air and bass control. Don't really need much help in the midrange.
     
  4. natger

    natger Well-Known Member

    Messages:
    526
  5. natger

    natger Well-Known Member

    Messages:
    526
    The cheaply offered module is a SE (single ended) stereo module. Putting the W401 jumper into W400 position creates a BTL (bridge(d) tied load) mono module. The stereo module needs single ended inputsignal, the BTL mono module needs a + and - signal, a balanced or differential source. So most of times to use the mono BTL one would need to convert signal to balanced first. Stereo SE 4 ohm outputpower would be around 40watt, mono BTL version 4 ohm outputpower up to 170 watt.
     
    ellisr63 likes this.
  6. natger

    natger Well-Known Member

    Messages:
    526
    Critique: Icepower 50asx2 still shows peaking frequencyrespons with higher impedance loads.
    True, it isn't ideal, but far from uncontrolled simple classD ampboards. 50asx2 with open load, no speaker/resistor connected, so infinite high impedance/load, shows +3dB peaking around 100kHz. For comparison a simpler classD ampboard tested on same equipment because it happens to be the Icepower 100AS, an almost standard tpa3251 implementation has a smoothed peak of around +23dB around 60kHz.

    peaking icepower.jpg
     

     

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  7. natger

    natger Well-Known Member

    Messages:
    526
    [​IMG]

    So the little handsoldered volumecontrol/buffer/gainstage is up and running. No additional hiss or noise noticed sofar. My 4R7 resistors on the left were a little larger than footprint I put on pcb, but contact with Vaux wires is now direct, no problem. 50asx2 is more quiet than the tpa ampboards even a little more quiet than pffb tpa3128. Just a temp setup thrown together to test, there is a knob on the little conductive plastic pot, but that blocks view of all handwork and B&O testcd I put there for the picture.
    [​IMG]
     
  8. ellisr63

    ellisr63 Active Member

    Messages:
    106
    Location:
    In the Home Theater
    I have 7 amp modules 2 of the 50w, and 5 of the 125w modules. I would like to have balanced amp modules. From what I am understanding, all I need to do is install a jumper and use a balanced input...is this correct?
     

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