Bridging Parasound Amp

BSUfbfan
BSUfbfan Posts: 201
edited March 2006 in 2 Channel Audio
Hey, all

I have (2) Parasound HCA-600's and I am planning on bridging one to each of my new (vintage) SDA-CRS+, however, I am concerned because it lists Mono power at 150 watts continuous at 8 ohms and the Polk SDA's run around 6 Ohms. I know the Parasounds are high-current, but will they handle this 6 ohm load bridged?

I could just run one in stereo, but then I'm only getting 60x2 at 8 ohms.

Thanks.
SDA SRS 2.3
Post edited by BSUfbfan on
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Comments

  • F1nut
    F1nut Posts: 49,711
    edited March 2006
    Do you have the AI-1 interconnect for the CRS+'s?

    Aside from that, I wouldn't recommend it as the amps will see the load as 3 ohms and you know they'll dip lower than that.
    Political Correctness'.........defined

    "A doctrine fostered by a delusional, illogical minority and rabidly promoted by an unscrupulous mainstream media, which holds forth the proposition that it is entirely possible to pick up a t-u-r-d by the clean end."


    President of Club Polk

  • BSUfbfan
    BSUfbfan Posts: 201
    edited March 2006
    F1nut,

    The interconnect is coming with the speakers (just bought them from another Polkie, thanks RSkarvan), And I have now upgraded from Monitor 5b's to SDA finally!!!!!

    Why would the amps see a 3 ohm load? I am not going to parallel the speakers thereby halfing the resistance. Just running the 6 ohm speaker directly to the bridged amp. Does bridging the amp automatically half the impedence of the speaker?

    If so I'll sell my HCA-600 cheap and upgrade to the HCA-1500. Unless of course you (or any CRS+ owners) think that 75 watts of high-current power is enough to drive these sufficiently.

    Thanks

    Mike
    SDA SRS 2.3
  • ohskigod
    ohskigod Posts: 6,500
    edited March 2006
    without the a1 interconnect (might want to snap a pic to be thorough, biamping to each speaker is a big no no. need a common ground amp for SDA without the a1. monoblocks, or seperate bridged amps will not be common ground, hence could be bad. Amps will be seriously Fubared by not making sure.
    Living Room 2 Channel -
    Schiit SYS Passive Pre. Jolida CD player. Songbird streamer. California Audio Labs Sigma II DAC, DIY 300as1/a1 Ice modules Class D amp. LSi15 with MM842 woofer upgrade, Nordost Blue Heaven and Unity interconnects.

    Upstairs 2 Channel Rig -
    Prometheus Ref. TVC passive pre, SAE A-205 Amp, Wiim pro streamer and Topping E50 DAC, California Audio Labs DX1 CD player, Von Schweikert VR3.5 speakers.

    Studio Rig - Scarlett 18i20(Gen3) DAW, Mac Mini, Aiyma A07 Max (BridgedX2), Totem Mites
  • Ferres
    Ferres Posts: 310
    edited March 2006
    Parasounds are not really suited for 'bridging' below 8 ohms. It is not recommended according to John Curl who designed them in the first place.
    Gear: Rotel RC 1082, Rotel RSP 1068 pre/pro, Rotel RMB1077 amp, Cayin CDT 15a CD player, S301 bluray.

    Speakers: Tannoy DC sensys speakers, Paradigm Servo15 Sub, Velo Spl-1500r

    Conditioner: Isotek :D
  • BSUfbfan
    BSUfbfan Posts: 201
    edited March 2006
    Thanks for the info guys. I'll try as-is and just upgrade to a larger 2-channel if the need is there.
    SDA SRS 2.3
  • reeltrouble1
    reeltrouble1 Posts: 9,312
    edited March 2006
    Well, at your own risk you may want to try it. Dont juice it if you do. Make sure you have the AI-1 interconnect indicated above, note this is not the standard connect. I cant remember if they are 6 or 4 ohm. Jesse are you saying the +'s are 4 ohm.

    RT1
  • dorokusai
    dorokusai Posts: 25,573
    edited March 2006
    That's correct, Parasound does not recommend bridging any of the HCA series into a speaker <8ohms. It doesn't mean it can't be done, or won't work, but it's not recommended.

    I've bridged the HCA-1500 Mono into SDA1C(6ohm) with no issues, but that was temporary and an experiment. I certainly wouldn't try it with an HCA-600.
    CTC BBQ Amplifier, Sonic Frontiers Line3 Pre-Amplifier and Wadia 581 SACD player. Speakers? Always changing but for now, Mission Argonauts I picked up for $50 bucks, mint.
  • F1nut
    F1nut Posts: 49,711
    edited March 2006
    Does bridging the amp automatically half the impedence of the speaker?

    Yes, the amp sees half of the speakers impedence. As the others have pointed out, it would not be a good idea. The regular interconnect cable is not the AI-1, that was a special cable.
    Political Correctness'.........defined

    "A doctrine fostered by a delusional, illogical minority and rabidly promoted by an unscrupulous mainstream media, which holds forth the proposition that it is entirely possible to pick up a t-u-r-d by the clean end."


    President of Club Polk

  • BSUfbfan
    BSUfbfan Posts: 201
    edited March 2006
    Sorry for the confusion, when I said that I would try "as-is" I meant one HCA-600 running stereo at 70watts x 2 @ 6 ohm.

    I won't take the chance of smoking the parasound. I'll just put em up for auction and buy a bigger one, cause I know the SDA's love the power.

    So the AI-1 cable was a special unit for people that wanted to run (2) mono amps and not have ground problems?

    dorokusai, How do you like the performance of your HCA-1500 with your SDA's? That is the amp I will most likely buy unless I can find a sweet deal on a high-current pro amp.

    Thanks guys.
    SDA SRS 2.3
  • dorokusai
    dorokusai Posts: 25,573
    edited March 2006
    BSU - I had them awhile ago, but have been a Parasound fan for a couple years. It's a really solid amplifier and not uncommon on the used market. I would keep your eyes out for a HCA-1200 MKII(Pre-HCA1500 & Discontinued), HCA-2200 MKII(Discontinued) or HCA-3500(Discontinued)
    CTC BBQ Amplifier, Sonic Frontiers Line3 Pre-Amplifier and Wadia 581 SACD player. Speakers? Always changing but for now, Mission Argonauts I picked up for $50 bucks, mint.
  • BSUfbfan
    BSUfbfan Posts: 201
    edited March 2006
    dorokusai wrote:
    I would keep your eyes out for a HCA-1200 MKII(Pre-HCA1500 & Discontinued), HCA-2200 MKII(Discontinued) or HCA-3500(Discontinued)

    Thanks for the info!!! I'll do just that.
    SDA SRS 2.3
  • steveinaz
    steveinaz Posts: 19,521
    edited March 2006
    Positive reviews on the HCA-1500A are all over the web. I have one and like it very much, though they do need plenty of ventilation room. 7" minimum over the top, 4" per side; and an enclosed rack is not recommended. These "ventilation specs" are accurate, mine would thermally shutdown after about 45 minutes until I gave it 7" of space up top. After that, no problems.

    Click my sig and see how it's situated now (the "system" pic), this works really well as air circulates easily in this rack---much better than my old rack (the HCA pic).
    Source: Bluesound Node 2i - Preamp/DAC: Benchmark DAC2 DX - Amp: Parasound Halo A21 - Speakers: MartinLogan Motion 60XTi - Shop Rig: Yamaha A-S501 Integrated - Shop Spkrs: Elac Debut 2.0 B5.2
  • BSUfbfan
    BSUfbfan Posts: 201
    edited March 2006
    Steve,

    Nice pic's. The cabinet looks really good, and appears to have plenty of room for a BIG widescreen HDTV set!!:)
    SDA SRS 2.3
  • F1nut
    F1nut Posts: 49,711
    edited March 2006
    So the AI-1 cable was a special unit for people that wanted to run (2) mono amps and not have ground problems?

    Yes, that and any non-common ground amp, dual mono amp or mono blocks. I see you bought Ron's CRS+'s. His use the blade/blade cable and the AI-1 only works with the pin/blade cable. You might still be able to use mono blocks (not bridged amps) by connecting the negative outputs on the amps with a heavy gauge wire, but you would need to check with the manufacturer first.
    Political Correctness'.........defined

    "A doctrine fostered by a delusional, illogical minority and rabidly promoted by an unscrupulous mainstream media, which holds forth the proposition that it is entirely possible to pick up a t-u-r-d by the clean end."


    President of Club Polk

  • I-SIG
    I-SIG Posts: 2,238
    edited March 2006
    BSUfbfan wrote:
    Steve,

    Nice pic's. The cabinet looks really good, and appears to have plenty of room for a BIG widescreen HDTV set!!:)

    I got a 2200 and I'm trying to talk Steve into getting a plasma! I think he's set on the DLP though. :)

    Wes
    Link: http://polkarmy.com/forums

    Panasonic TH-42PHD8UK 42" HDTV | Polk Audio SDA-SRS's (w/RDO's & Vampire Posts) + SVS PC+ 25-31 | AudioQuest Granite (mids) + BWA Silver (highs) | Cary Audio CAD-200 | Signal Cable Silver Resolution XLR's | Wyred 4 Sound STP/SE Pre | Signal Cable Silver Resolution XLR's | Cambridge Audio azur 840C--Wadia 170i + iPod jammed w/ lossless audio--Oppo 970 | Pure|AV PF31d
  • BSUfbfan
    BSUfbfan Posts: 201
    edited March 2006
    F1nut wrote:
    I see you bought Ron's CRS+'s. His use the blade/blade cable and the AI-1 only works with the pin/blade cable. You might still be able to use mono blocks (not bridged amps) by connecting the negative outputs on the amps with a heavy gauge wire, but you would need to check with the manufacturer first.

    Wow, now i'm really confused. I thought the original SDA-CRS had the blade/blade cable and the 2nd gen. CRS+ had the pin/blade. Oh well, i'm learning guys.

    I-Sig, how do you like the performance of that 2200 on your SRS's? I'm currently on the prowl for that or the 1500.

    Thanks.

    Mike
    SDA SRS 2.3
  • dorokusai
    dorokusai Posts: 25,573
    edited March 2006
    3G's of CRS per the SDA Bible.

    CRS(84-86) - BB
    CRS+(86-87) - BB
    CRS+(87-90) - PB
    CTC BBQ Amplifier, Sonic Frontiers Line3 Pre-Amplifier and Wadia 581 SACD player. Speakers? Always changing but for now, Mission Argonauts I picked up for $50 bucks, mint.
  • Ferres
    Ferres Posts: 310
    edited March 2006
    The parasound HCA 2200II is a great amp. It's a dual toroidal type, bi-wirable with balance and unbalanced inputs. The HCA-1500 is not in the same league.
    :P
    Gear: Rotel RC 1082, Rotel RSP 1068 pre/pro, Rotel RMB1077 amp, Cayin CDT 15a CD player, S301 bluray.

    Speakers: Tannoy DC sensys speakers, Paradigm Servo15 Sub, Velo Spl-1500r

    Conditioner: Isotek :D
  • I-SIG
    I-SIG Posts: 2,238
    edited March 2006
    BSUfbfan wrote:
    I-Sig, how do you like the performance of that 2200 on your SRS's? I'm currently on the prowl for that or the 1500.

    Thanks.

    Mike

    Mike,

    It's got some serious juice. I really love it. The difference between it and the Carver I used to have until it blew are very noticeable. Lots of control over the bass, smooth and open mids. The highs seem to be good, but I'll be able to tell better when I can afford to replace the tweeters. I've had 110dB peaks watching movies. Not too shabby. The only thing about playing that loud is I think I need more SVS. :(

    Wes
    Link: http://polkarmy.com/forums

    Panasonic TH-42PHD8UK 42" HDTV | Polk Audio SDA-SRS's (w/RDO's & Vampire Posts) + SVS PC+ 25-31 | AudioQuest Granite (mids) + BWA Silver (highs) | Cary Audio CAD-200 | Signal Cable Silver Resolution XLR's | Wyred 4 Sound STP/SE Pre | Signal Cable Silver Resolution XLR's | Cambridge Audio azur 840C--Wadia 170i + iPod jammed w/ lossless audio--Oppo 970 | Pure|AV PF31d
  • dorokusai
    dorokusai Posts: 25,573
    edited March 2006
    Ferres wrote:
    The parasound HCA 2200II is a great amp. It's a dual toroidal type, bi-wirable with balance and unbalanced inputs. The HCA-1500 is not in the same league.
    :P

    Not in the same league? Because of inputs? You must have started smoking crack recently.
    CTC BBQ Amplifier, Sonic Frontiers Line3 Pre-Amplifier and Wadia 581 SACD player. Speakers? Always changing but for now, Mission Argonauts I picked up for $50 bucks, mint.
  • steveinaz
    steveinaz Posts: 19,521
    edited March 2006
    BSUfbfan wrote:
    Steve,

    Nice pic's. The cabinet looks really good, and appears to have plenty of room for a BIG widescreen HDTV set!!:)

    Oh yes, that's definitely in the cards this year, probably a 50" DLP, but still deciding on make/model. Also going to be getting a Marantz DV-7600 DVD/CDP.

    Wes, you ready for a heck of a deal on a CEC transport? (we'll talk, you NEED this transport).
    Source: Bluesound Node 2i - Preamp/DAC: Benchmark DAC2 DX - Amp: Parasound Halo A21 - Speakers: MartinLogan Motion 60XTi - Shop Rig: Yamaha A-S501 Integrated - Shop Spkrs: Elac Debut 2.0 B5.2
  • steveinaz
    steveinaz Posts: 19,521
    edited March 2006
    Ferres wrote:
    The parasound HCA 2200II is a great amp. It's a dual toroidal type, bi-wirable with balance and unbalanced inputs. The HCA-1500 is not in the same league.
    :P

    Yeah, you're off on that call. Where did you get this info? What amp is there, that isn't bi-wireable? The HCA1500 does lack balanced inputs, but since my pre doesn't have balanced out, it's a moot point. Aside from shear power output, how does the 2200 outclass the 1500?
    Source: Bluesound Node 2i - Preamp/DAC: Benchmark DAC2 DX - Amp: Parasound Halo A21 - Speakers: MartinLogan Motion 60XTi - Shop Rig: Yamaha A-S501 Integrated - Shop Spkrs: Elac Debut 2.0 B5.2
  • dorokusai
    dorokusai Posts: 25,573
    edited March 2006
    It uses a stacked toroid, so it being dual toroid means nothing. It was John Curls first revision, and Parasound let him walk on water with the design.

    Almost every Parasound design since John Curl joined has been a dual mono design, to include the HCA1500. As far as componentry, they are both outfitted with high end goodies, and Class A capable.

    The series are unrelated in another respect because they are totally different model years. The later line increased in models, which caused a shift in marketing and features. The HCA-3500 included the XLR and was the TOTL for both series.
    CTC BBQ Amplifier, Sonic Frontiers Line3 Pre-Amplifier and Wadia 581 SACD player. Speakers? Always changing but for now, Mission Argonauts I picked up for $50 bucks, mint.
  • Ferres
    Ferres Posts: 310
    edited March 2006
    Would you consider the Rotel RB-1080 in the same class as the Rotel RB-1090?

    True, they are not of the same year model but by just one generation. The build/performance of the 2200II is more closer to the 3500 with a little less watts. The 1500's would be more in par with the 1200II's.

    If you can say the HCA 1500 is substantially superior to the HCA 1200II, then I would agree with you. I have to use 2 HCA 1200II's(monoblock config) to get close to the performance of the 2200II yet I still feel the 2200II is a little more revealing. :)
    Gear: Rotel RC 1082, Rotel RSP 1068 pre/pro, Rotel RMB1077 amp, Cayin CDT 15a CD player, S301 bluray.

    Speakers: Tannoy DC sensys speakers, Paradigm Servo15 Sub, Velo Spl-1500r

    Conditioner: Isotek :D
  • steveinaz
    steveinaz Posts: 19,521
    edited March 2006
    I'm saying that the statement of the HCA-1500A not being in the same league as an HCA-2200II is strictly an opinion that is unsubstantiated. The build quality, componentry, and topology certainly don't support this view, nor do the plethora of rave reviews for the HCA-1500.
    Source: Bluesound Node 2i - Preamp/DAC: Benchmark DAC2 DX - Amp: Parasound Halo A21 - Speakers: MartinLogan Motion 60XTi - Shop Rig: Yamaha A-S501 Integrated - Shop Spkrs: Elac Debut 2.0 B5.2
  • Ferres
    Ferres Posts: 310
    edited March 2006
    The 2200II got raves aswell during it's time. I'm sure the 1500 is an excellent amp for it's class in par if not better than the 1200II's.

    The 2200II is a different class more in the level of the 3500 when it comes to overall performance. I'm not sure if it's the dual toroids or something else but I know the 2200II out classes my 1200II. I hear an immidiate difference when I switch amps. The tightness and detail is very noticable as soon as the music starts playing.

    Based on specs the 1500 is only a little different from the 1200II so this is my basis for that 'league' opinion. :)
    Gear: Rotel RC 1082, Rotel RSP 1068 pre/pro, Rotel RMB1077 amp, Cayin CDT 15a CD player, S301 bluray.

    Speakers: Tannoy DC sensys speakers, Paradigm Servo15 Sub, Velo Spl-1500r

    Conditioner: Isotek :D
  • BSUfbfan
    BSUfbfan Posts: 201
    edited March 2006
    I decided yesterday to just go buy a new Parasound amp at the local Hi-Fi shop, but thank god I did some research after all of your recommendations the last few days. I asked to see a spec. sheet and was honestly shocked. The new amp line from Parasound is called the "New Classic" and looks similar to the good ol' stuff, but the biggest amp is called the 2250 and is rated at 250 watts a channel at 8 ohms. The problem is, it's peak current per channel is only 45 amps, which is the same as the HCA-1000 even though the 1000 is only rated at 125 watts per channel at 8 ohms.

    To do a real comparison I looked at the specs I had with me on two of the comparable (wattage wise) older Parasounds: the HCA 1500 (205 watts per channel) and the HCA 1200II (205 watts per channel) and these bad-boys have 60 and 57 amps of peak current per channel respectively.

    It appears from the brochure that Parasound did this to make the amp "run cooler", but that has to work out to a huge drop in over-all power and sound quality (at least at high volumes). The amp was still fairly expensive, probably due to all of the new features like an auto turn-on circuit, impedence switch and worst of all an A-B speaker switch (WTF!:confused: ). Why they would put that on a "audiophile amplifier" is beyond me.

    The funny thing is that the website says they came out with this line to "improve and refresh the classics". Hmmmmmmm.

    I'd like to hear your feedback on this, cause it appears I will be looking for an older HCA-1500, HCA-1200II, or (if lucky) an HCA-2200II.

    Thanks.
    SDA SRS 2.3
  • unc2701
    unc2701 Posts: 3,587
    edited March 2006
    Wait a sec??? They have an impedence switch? That's not a good sign at all on a SS amp.
    Gallo Ref 3.1 : Bryston 4b SST : Musical fidelity CD Pre : VPI HW-19
    Gallo Ref AV, Frankengallo Ref 3, LC60i : Bryston 9b SST : Meridian 565
    Jordan JX92s : MF X-T100 : Xray v8
    Backburner:Krell KAV-300i
  • BSUfbfan
    BSUfbfan Posts: 201
    edited March 2006
    Yes. switch it one way for 2-3 ohms, and the other way for 4-8 ohms. The website says its so you can run a "long string of house music speakers". Appears that they have clearly shifted the 2-channel sound quality amps over to Halo, and are using the "NC" series for custom install.

    I just hate the fancy looks of the Halo stuff, but I guess looks don't matter, right?
    SDA SRS 2.3
  • unc2701
    unc2701 Posts: 3,587
    edited March 2006
    Ok, that's not as bad as I thought. If the had a 4 ohm vs 8 ohm switch, that'd just be sad. Still, it does sound like it's geared for whole-house distribution, given the 2 ohm switch, auto-on and A-B switching.
    Gallo Ref 3.1 : Bryston 4b SST : Musical fidelity CD Pre : VPI HW-19
    Gallo Ref AV, Frankengallo Ref 3, LC60i : Bryston 9b SST : Meridian 565
    Jordan JX92s : MF X-T100 : Xray v8
    Backburner:Krell KAV-300i