Advice on 2 channel amp for SDA 2a

Hello forum...
Currently shopping for a good used amp to power my Polk SDA 2a's.
Could use some advice/knowledge to help my decision. Sadly, I don't have much of a budget. $300 to $350. Right now I am looking at:
Adcom 5500, Carver A 400x, Carver TFM 35, Carver TFM 6BC, NAD 317, Parasound 275 V2.

Most of these are still up for auction so the priced is in flux, but as of now they all fall into my budget. Thanks in advance.
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Comments

  • Smit
    Smit Posts: 31
    Also found a Parasound HCA 1000 for $325.
  • This has been talked about in other threads. Search is your friend. I guess I would offer my opinion that you'd better make sure it is rated for driving a 4 Ohm load and that the 4 Ohm power rating is at least 50% greater than the 8 Ohm. I'd also want to have 2dB of dynamic headroom at 4 Ohms but that might be difficult in your price range.
    George / NJ

    Polk 7B main speakers, std. mods+ (1979, orig owner)
    Martin Logan Dynamo sub w/6ft 14awg Power Cord
    Crown D150 amp
    Logitech Squeezebox Touch Streamer w/EDO applet
    iFi nano iDSD DAC
    iPurifier3
    iDefender w/ iPower PS
    Custom Steve Wilson 1m UPOCC Interconnect
    iFi Mercury 0.5m OFHC continuous cast copper USB cable
    Custom Ribbon Speaker Cables, 5ft long, 4N Copper, 14awg, ultra low inductance
    Custom Vibration Isolation Speaker Stands and Sub Platform
  • In my investigations so far, NAD seems to sort of pull a fast one in their specs. because it seems to me they don't often give a continuous power rating for 4 ohms, yet they will give the "IHF Dynamic Power" ratings for 4 ohms and even 2 ohms. What's up with that?
    George / NJ

    Polk 7B main speakers, std. mods+ (1979, orig owner)
    Martin Logan Dynamo sub w/6ft 14awg Power Cord
    Crown D150 amp
    Logitech Squeezebox Touch Streamer w/EDO applet
    iFi nano iDSD DAC
    iPurifier3
    iDefender w/ iPower PS
    Custom Steve Wilson 1m UPOCC Interconnect
    iFi Mercury 0.5m OFHC continuous cast copper USB cable
    Custom Ribbon Speaker Cables, 5ft long, 4N Copper, 14awg, ultra low inductance
    Custom Vibration Isolation Speaker Stands and Sub Platform
  • pitdogg2
    pitdogg2 Posts: 24,477
    Forget adcom 5500 it is not common ground as far as I know.

    Carver A400, TFM35 and Parasound are you best choice
  • Smit
    Smit Posts: 31
    Gardenstater: Thanks for the reply. I have been searching thru old posts for info. Thought I'd toss out some specific amps and see what all of you said. Thanks for the info.

    Pitdogg2: I had a feeling the Adcom wouldn't work because of the common ground issue. But I wasn't sure. Thanks for the help.
  • You will need to get input from those who have had ears on them, which isn't me. I'm stuck looking for reviews in mags and forums and looking at whatever specs I can find from the mfg..

    That Parasound has a halfway decent dynamic headroom of >1.5
    George / NJ

    Polk 7B main speakers, std. mods+ (1979, orig owner)
    Martin Logan Dynamo sub w/6ft 14awg Power Cord
    Crown D150 amp
    Logitech Squeezebox Touch Streamer w/EDO applet
    iFi nano iDSD DAC
    iPurifier3
    iDefender w/ iPower PS
    Custom Steve Wilson 1m UPOCC Interconnect
    iFi Mercury 0.5m OFHC continuous cast copper USB cable
    Custom Ribbon Speaker Cables, 5ft long, 4N Copper, 14awg, ultra low inductance
    Custom Vibration Isolation Speaker Stands and Sub Platform
  • PSOVLSK
    PSOVLSK Posts: 5,021
    I ran my 1C’s on a TFM-45 with great results. I’m also a fan of Parasound, but no person experience with SDA/Parasound combo.
    Things work out best for those who make the best of the way things work out.-John Wooden
  • invalid
    invalid Posts: 1,271
    Parasound will be your best bet with the sda2A's. The adcom isn't common ground as far as I know.
  • Smit
    Smit Posts: 31
    Thanks all. Watching the Parasound HCA 1000 and the HCA 750. Plus a couple of Carver TFM 35s.
  • Smit
    Smit Posts: 31
    Thanks Butterbean.
    Anyone familiar with a Sonance Sonamp 275 SE 2 channel?
    Found one for $150 on the bay.
    I am unsure if it is a common ground amp. It is bridgeable - does that make it common ground? How exactly do I determine a common ground amp?
  • Smit
    Smit Posts: 31
    P.S. - I am searching for other posts regarding the common ground question.
    I know, I know - the search function is my friend. B)
  • Smit
    Smit Posts: 31
    Okay...been researching common ground posts on the forum here and I can definitely say my head is officially spinning...
    However, the Sonance Sonamp 275 SE does have a "normal" and "bridged" switch.
    I am becoming more convinced this is a common ground amp.
  • Sometimes you can look at the schematic and it will actually show a common ground. Usually they don't and you have to check the actual unit (with an ohm meter) or find someone who has, or contact the mfg..
    George / NJ

    Polk 7B main speakers, std. mods+ (1979, orig owner)
    Martin Logan Dynamo sub w/6ft 14awg Power Cord
    Crown D150 amp
    Logitech Squeezebox Touch Streamer w/EDO applet
    iFi nano iDSD DAC
    iPurifier3
    iDefender w/ iPower PS
    Custom Steve Wilson 1m UPOCC Interconnect
    iFi Mercury 0.5m OFHC continuous cast copper USB cable
    Custom Ribbon Speaker Cables, 5ft long, 4N Copper, 14awg, ultra low inductance
    Custom Vibration Isolation Speaker Stands and Sub Platform
  • invalid
    invalid Posts: 1,271
    I believe it is common ground if the bridged switch is in the stereo or normal position, if in the bridged position the ground is floating.
  • Not so sure bout this one. Perhaps others will weigh in for you. B&K ST2140. Little light on the 4Ohm continuous power rating (185 vs 140 for 8Ohm) and dynamic headroom is 1.4dB

    https://www.ebay.com/itm/B-K-Amplifier-ST-2140/383957441637?hash=item5965a59c65:g:gbUAAOSwgAFgKwd6
    George / NJ

    Polk 7B main speakers, std. mods+ (1979, orig owner)
    Martin Logan Dynamo sub w/6ft 14awg Power Cord
    Crown D150 amp
    Logitech Squeezebox Touch Streamer w/EDO applet
    iFi nano iDSD DAC
    iPurifier3
    iDefender w/ iPower PS
    Custom Steve Wilson 1m UPOCC Interconnect
    iFi Mercury 0.5m OFHC continuous cast copper USB cable
    Custom Ribbon Speaker Cables, 5ft long, 4N Copper, 14awg, ultra low inductance
    Custom Vibration Isolation Speaker Stands and Sub Platform
  • Smit
    Smit Posts: 31
    That B&K 4420 is sweet! But a bit north of my budget.
    Thanks for the replies.
  • This is also a bit north and there is lots of bidding. McCormack DNA 0.5, 100 wpc 8 ohms, 200 wpc 4 ohms !!

    https://www.ebay.com/itm/McCormack-DNA-0-5-DELUXE-2-channel-amplifier-EXCELLENT-condition/393146407628?hash=item5b895a1acc:g:icYAAOSwiAdgMxI1
    George / NJ

    Polk 7B main speakers, std. mods+ (1979, orig owner)
    Martin Logan Dynamo sub w/6ft 14awg Power Cord
    Crown D150 amp
    Logitech Squeezebox Touch Streamer w/EDO applet
    iFi nano iDSD DAC
    iPurifier3
    iDefender w/ iPower PS
    Custom Steve Wilson 1m UPOCC Interconnect
    iFi Mercury 0.5m OFHC continuous cast copper USB cable
    Custom Ribbon Speaker Cables, 5ft long, 4N Copper, 14awg, ultra low inductance
    Custom Vibration Isolation Speaker Stands and Sub Platform
  • F1nut
    F1nut Posts: 49,708
    Smit wrote: »
    Okay...been researching common ground posts on the forum here and I can definitely say my head is officially spinning...
    However, the Sonance Sonamp 275 SE does have a "normal" and "bridged" switch.
    I am becoming more convinced this is a common ground amp.
    filterThe Sonance Sonamp 275 SE stereo power amplifier is intended to drive a pair of speakers in a remote room of a multiroom audio system.

    Ummm.....no thanks.
    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

  • invalid
    invalid Posts: 1,271
    You should just save up a few hundred more $ and get something that's going to work well with the sda2A's and last a while. Something like the b&k that's for sale on this forum. At the price range you are in you might be able to get an adcom gfa 555 but it will probably blow up being they are 30 years old. I blew up mine twice, so I got something better.
  • geppy1
    geppy1 Posts: 3,071
    I would like to point out the 2140 is solid amp Has no problem driving 2.3s and various Mirage and even Infinity RS 2.5s One of my two favorite B&K amps
  • Smit
    Smit Posts: 31
    Yea, I think I need to save a few more $$$ to get the proper amp rather than settle. Thanks again for the tips.
  • audioluvr
    audioluvr Posts: 5,420
    edited February 2021
    Any of these would be a good amp for driving your SDA's. If you can pick one up for a good price that the PO guarantees it won't be DOA go for it.

    Edit: As all these are older units you might want to know a really good electronics tech locally as older electronics fail. it's just a matter of time and they degrade with time. Some equipment is worth refreshing. Some not so. An amp that cost $1,000 30+ years ago that costs $500+ for a refresh could be a good option or a total waste of money depending on if you love the sound it brings to your system or if it has a cult following that makes it a worthwhile investment. This hobby is not for the faint of heart. ;)
    Gustard X26 Pro DAC
    Belles 21A Pre modded with Mundorf Supreme caps
    B&K M200 Sonata monoblocks refreshed and upgraded
    Polk SDA 1C's modded / 1000Va Dreadnaught
    Wireworld Silver Eclipse IC's and speaker cables
    Harman Kardon T65C w/Grado Gold. (Don't laugh. It sounds great!)


    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
  • Reviews on that NAD are good but their specifications still puzzle me. Not sure if you'd call it arrogance or what you'd call it. Same continuous and clipping power ratings into 8 and 4 Ohms. Dynamic only 25% higher at 4 vs 8.

    wrggl3fc6xwt.jpg
    George / NJ

    Polk 7B main speakers, std. mods+ (1979, orig owner)
    Martin Logan Dynamo sub w/6ft 14awg Power Cord
    Crown D150 amp
    Logitech Squeezebox Touch Streamer w/EDO applet
    iFi nano iDSD DAC
    iPurifier3
    iDefender w/ iPower PS
    Custom Steve Wilson 1m UPOCC Interconnect
    iFi Mercury 0.5m OFHC continuous cast copper USB cable
    Custom Ribbon Speaker Cables, 5ft long, 4N Copper, 14awg, ultra low inductance
    Custom Vibration Isolation Speaker Stands and Sub Platform
  • rooftop59
    rooftop59 Posts: 7,952
    edited February 2021
    Smit wrote: »

    That parasound is overpriced, and if you’re going for one get the “1000A” as it has more power (125 v 100) and other improvements. The 1000 is NOT 125 wpc.

    The B&K is not from an experienced seller and has almost no pics. Avoid it...
    Living Room 2.2: Usher BE-718 "tiny dancers"; Dual DIY Dayton audio RSS210HF-4 Subs with Dayton SPA-250 amps; Arcam SA30; Musical Fidelity A308; Sony UBP-x1000es; Squeezebox Touch with Bolder Power Supply
    Game Room 5.1.4:
    Denon AVR-X4200w; Sony UBP-x700; Definitive Technology Power Monitor 900 mains, CLR-3000 center, StudioMonitor 350 surrounds, ProMonitor 800 atmos x4; Sub - Monoprice Monolith 15in THX Ultra

    Bedroom 2.1
    Cambridge Azur 551r; Polk RT25i; ACI Titan Subwoofer
  • Smit
    Smit Posts: 31
    Thanks guys.

    I think I've read posts here on the forum about concerns with NAD's specs being a bit "broad" and not specific. Will do more investigating....

    And I think I'll cool my jets on the Parasound and B&K on ebay.
    I understand they are great brands/products - but maybe these specific amps are to be passed on.

    There are a couple of Carver TFM42s that are still at auction for a few days, I'll see where the price goes and think about it.

    Appreciate the advice.
  • Why......whadidya hear? That Parasound HCA 1000 has 1.5+dB dynamic headroom and 60% better continuous power into 4 Ohm vs 8.
    George / NJ

    Polk 7B main speakers, std. mods+ (1979, orig owner)
    Martin Logan Dynamo sub w/6ft 14awg Power Cord
    Crown D150 amp
    Logitech Squeezebox Touch Streamer w/EDO applet
    iFi nano iDSD DAC
    iPurifier3
    iDefender w/ iPower PS
    Custom Steve Wilson 1m UPOCC Interconnect
    iFi Mercury 0.5m OFHC continuous cast copper USB cable
    Custom Ribbon Speaker Cables, 5ft long, 4N Copper, 14awg, ultra low inductance
    Custom Vibration Isolation Speaker Stands and Sub Platform