Parasound Halo A23 Stereo Amplifier Review

Discussion in 'Power Amps' started by purr1n, Jan 18, 2017.

  1. ohhgourami

    ohhgourami Friend

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    I'll have to find a way to let you try my Anthem MCA 20 which I'm using to drive my ESL panels. Luckily, it's relatively light at 30ish pounds. I have yet to compare to my 302e but it has been decent so far.
     
  2. Rex Aeterna

    Rex Aeterna Friend

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    most professional theater stuff from my experience are made with extremely high standards and actually sound very good. him using the excuse of it being a ht crowd thing is kinda an insult. but, anyhoo, i think something like my crown xti 4002 is a much better deal at 1k than the parasound(i paid 1k for my crown brand new). yea it has features on it that most people will never use and is only made for balance operation having xlr outputs/inputs but, it actually sounds good and has power for days. the beast i think has 32 t-03 metal die outputs and uses plenty of beefy mosfets as well by the power supply. the crown xti 4002 is still class a/b amp but, uses a very strange topology. i had no issues testing and driving 1ohm nominal loads on it for hours before. it is very stable amp.
     
  3. msommers

    msommers High on Epipens

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    Was this the Halo Integrated or A23?
     
  4. purr1n

    purr1n Desire for betterer is endless.

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    A23. The 2 is for 2 channel. 3 means it's for deaf home threatre people.
     
  5. msommers

    msommers High on Epipens

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    My mistake. I didn't realize Halo was a whole line-up they had, thought just the one model.

    Either way, it's rather unfortunate. I had read such high praise on many forums about their Halo Integrated. I'm really enjoying my Hegel. Another brand that doesn't get much attention, but excellent build, is a Canadian maker called Magnum Dynalab.
     
  6. Mr.Sneis

    Mr.Sneis Friend

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    Not sure if I should be ashamed about this but my 2 channels stereos are not all that fancy but I do like 'em good enough and use them on the daily. Yamaha cr 1020 recapped by myself. Kyocera a710 currently original. I have used both as power amps fed with a pre and my only real complaints are not so perfect noise floor.

    Never having a true/high end separates situation though, maybe I just don't know what I am missing.

    I also did not get a bargain on either amp, basically ebay pricing even though they were locally sourced.
     
    Last edited: Jan 19, 2017
  7. Vansen

    Vansen Gear Master (retiring)

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    Hell, I have a Yamaha A-S801 that I picked up new for $600. If someone's serious about reviewing it, I'd consider loaning it out. At $600, I don't have many complaints on it for my uses.
     
  8. ultrabike

    ultrabike Measurbator - Admin

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    The reason I always wondered about it is that the A-S1000 is a "Floating Balanced Power Amplifier" which based on the description seems to mean that it follows a Ragnarok-like circlotron topology. I don't know for sure, but I think the A-S801 follows a more conventional topology.

    However, the A-S1000 does not seem to come with balanced inputs. The A-S2000 does, but I think that retails for $2k.

    (EDIT: The A-S2000 also describes a "Headphone amp with fully discrete configuration", which seems to imply they have a dedicated headphone output of some sort... and feet "insulators" pads which hopefully are made of sorbothane. There's proly better amps out there anyway.)
     
    Last edited: Jan 19, 2017
  9. Poleepkwa

    Poleepkwa Friend

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    The Hypex amps might be a good alternative in this pricerange to the Parasound - still not as cheap as the PRO amps though (no fans though).
     
  10. Hrodulf

    Hrodulf Prohibited from acting as an MOT until year 2050

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    Older Sony ES series and higher end Marantz aren't bad. Not the last word in resolution, but doesn't offend much as well.

    Oh, and whenever you re buying used power amps, be sure to tighten output transistor mounting screws. Otherwise a very interesting failure mode might occur.
     
  11. ButtUglyJeff

    ButtUglyJeff Stunningly beautiful IRL

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    I would like to hear impressions of anything Yamaha too. Oh if you could get your hands on the CA-2010, but I bet that's still well above $1k mark used...
     
  12. Hrodulf

    Hrodulf Prohibited from acting as an MOT until year 2050

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    I'm guessing that quality power amping is less of an issue stateside. Here in EU for quality power my go-to choice would be DIY. Always.
     
  13. Big D Design

    Big D Design RIP 2021

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    Just thought I would mention the Vincent Audio SP-331 $1,395. Someone has the same Martin Logan ESLs as I do and swears by it. He also has some other speaker set that goes even lower than the 1.6 ohms that the ML ESLs do. This guy has thrown some pretty good competition into the mix and couldn't dethrone the Vincent. The only thing about Vincent Audio is the they are designed in Germany, but manufactured in China. Supposedly they are a subsidy of Thorens. They have soldered in tubes, but there is a repair facility in Michigan that is very reliable. This would be an amplifier that would be good to test. The highs are not real upfront on the amp, from what I hear due to the tubes. But the delivery of the music is is supposedly in the high end category. They have a Class A model of this called the SP-331MK but it's $2,400. A thousand more for Class A may be worth it, but most of us don't have the extra coin to ever do anything but buy one used or dream about it.
     
  14. Aklegal

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    Seriously I would try Odyssey next - either the Khartago or the Stratos, IF we are still sticking with in-production models.

    Skip the Emotiva crap - I have owned a bunch of those for home theater and I would sub them into my main system while I was in between amps. I have never heard the A23 but I bet it would give me the same feeling as the few two channel Emotivas I have owned. They are ONLY good for HT.

    An out of production amp I would check for is the Marsh A400s. I owned one 8 years ago but I sold it because it couldn't drive the 4 ohm Tyler Acoustics speakers I had at that time. Not really the fault of the amp because those speakers drop well below 4 ohms over certain frequencies. Even with that issue the amp still sounded great. It would probably sound amazing with higher efficiency or 8 ohm load speakers. You can probably get one for anywhere between $450 to $800.
     
    Last edited: Jan 24, 2017
  15. msommers

    msommers High on Epipens

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  16. auri

    auri Facebook Friend

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    Funny story, even within the context of gaming mice (and their "7.1" headsets etc) Razer is notoriously crap. Decent industrial design, but chintzy at best build quality.

    I picked up a Parasound HCA750A off ebay for $150 to replace a Crown D75 for my nearfields. I thought it was an improvement, and I'm hoping a Vidar will be an improvement over it. It'll make a good sub amp one day :D
     
  17. murphythecat

    murphythecat GRU-powered uniformed trumpkin

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    the best performance you can get for under 1k SS is to go vintage. ive asked personally the main designer at ifi audio and diy guru, thorsten loesch what he'd choose for best udner 1k amp, his answer was either build a LM3875 gainclone which I did and sounds amazing or:
    "For 1K I'd probably look for some of the late 80's early 90's
    Japanese integrated a bit below "flagship" level (flagships are
    overengineered and often do not sound as good as simpler mid-level units, with
    very simple circuitry. There are good example from many brands, to me Denon, Luxman,
    Onkyo and Sony stand out. But make sure to get the right models."


    or go vintage...
    Sony ta 707/888/777 ES, Luxman L-510/530, Denon PMA1560 models are full high end machine and if restored will compete with Acuphase or Luxman of today.

    Thorsten Loesch, the main designer at ifi audio also told me this:
    "An example of a really great Amp is Sony's TA-F707/808ES and relatives (Sony reprised the key parts of this design as late the mid oughties in the TA-F-777ES are pure-bred high-end machines. In "Source Direct" Mode you have just the Volume control and the actual Amp. In the 707/808 you get J-Fet input, Mosfet Voltage Amp and Mosfet Output stages, kind of like the very latest amplifiers Nelson Pass peddles on Diyaudio and not miles off how I would do it, if I did this kind of gear. Except Sony did it in '87...

    By the '90's the japanese majors abandoned the serious HiFi market and focused on other fields, the golden decade is about 1979 to 1989, when they poured huge amounts of money into audio R&D. The Speakers and Amplifiers from this era, if high enough in the model range were uniformly excellent and remain often undervalued."

    but still, im surprised by the Parasound performance. Did you let it burn in for at least 200 hours?
    if not, this is why it sounds this bad. period.
     
  18. murphythecat

    murphythecat GRU-powered uniformed trumpkin

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    look at the schematic. you want lateral mosfet output:

    "Bipolar output Transistors and vertical Mosfets (Hexfets etc.) are all
    extremely temperature dependent in certain parameter.

    Tubes and LateralMosfets are not temperature dependent or in a way
    that stabilises the operation.

    Class AB works well as long as the output devices work stable with
    temperature, so tubes and LateralMosfets. It does not work well with
    Bipolar transistors or Mosfets, unless the whole output stage can be
    made from a single piece of silicon (chipamp).

    If the prior conditions are not met severe thermal distortion accrues,
    worse with more junctions in the output stage though vertical mosfets
    are even worse than a tripple follower bipolar output stage.

    I have never seen this subject addressed much after a few japanese
    papers in the 80's, it seems like everyone decided because there was
    no easy cure for the problem the best way to deal with the problem was
    to ignore it.

    If well implemented a Class A Bipolar or Mosfet Amplifier operates at
    very stable temperature (as long as 95% of all music is in Class A,
    some Class AB for high peaks is okay).

    As LateralMosfet Amplifiers are rare (the Output Devices actually
    cost real money - why use them if D. Self says "they measure 10 times
    worse than bipolars"), not only on DIYA and most of the options
    presented ain't great either...

    There are also some other measures that can improve the front-end
    inherent linearity and improve the Class AB output stage,all of which
    are applied in the LM3875/86. Degenerating the input stage, input
    stage current mirror and the voltage amplification stage improves
    linearity a great deal, as does the consequent application of buffers
    in front of each stage. Few discrete amplifiers apply these excellent
    ideas and even fewer integrated chips do, they usually aim to
    maximisenegative feedback at low frequencies, which is mostly
    pointless.

    So I stick to my guns. All else being equal, if the power is enough,
    go gainclone, LITERAL gainclone, that is copied from the Gaincard,
    which uses LM3875. No other chipamp's (except the LM3886). Few
    discrete I can think of stand a chance to match this."
     
    Last edited: Jan 29, 2017
  19. purr1n

    purr1n Desire for betterer is endless.

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  20. haris javed

    haris javed New

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    I am sorry, but I agree with this reviewer. I bought this a,p pretty cheap. It was 385$ + 48$ shipping USD (My unit has some cosmetic defects) . My unit is about 3 years old (silver) and used. I am not too happy with the sound. My previous setup is a 2.1 channel setup. Audio From PC > IFI micro DSD > Emotiva TA-100 > (SVS ultra bookshelf speakers, and SVS sb-12 nsd) with this setup was very musical with large sound stage

    Next I added the A23 to the mix, and things got weird - It added weird high end sparkle (not in good way), the sound stage also decreased quite a bit. The bass became tighter, but it feels that the music is no longer synced, but everything is getting played separately. I do have a Parasound HCA 3500 amp, and when I connected that unit with my speakers, the weird harshness went away, and the music was enjoyable again. (same room, listening distance, repeated the same song about 45 times)

    Back to Emotiva TA-100 VS Parasound A23, it is a conundrum. The Emo has less power 50W @ 8ohms VS 125W @ 8 ohms, but Emo is just more musical to me (so is the HCA 3500). This sounds like an Amplifier made for movies, and I think it will do well in that section. Any suggestions to improve the sound? I am not a believer in super expensive cables (went to school for EE, and ended up with a masters in applied physics) - I have a decent understanding of circuits, amps, electronics but some things discussed in audio are above my head. I just use simple blue jeans low capacitance RCA cables, and blue jeans speaker cables - my cables runs are short (RCA 1 feet, and 7feet for speaker cables)

    thank you
    Haris
     

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