How to buy a used amp/what to look for

payneinthe
payneinthe Posts: 63
edited April 2014 in Electronics
When buying a used amp off CL, what should I be looking for to make sure it's in good condition?
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7.1: LSIc, LSI-9 L/R, F/X1000 SL/SR, RM101 BL/BR, PSW 650 SW
Onkyo TX-929
Parasound HCA-1206

2-channel: Parasound P5, Odyssey Kismet, Vandersteen 3A Signature, Pro-Ject Debut Carbon
Post edited by payneinthe on
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  • ZLTFUL
    ZLTFUL Posts: 5,650
    edited April 2014
    That it works. :lol:

    Seriously though, listen for hum from the speakers and chassis itself. If the seller is OK with it, ask them to pop the cover so that you can make a visual inspection for leaky/bulging capacitors and burnt resistors.
    "Some people find it easier to be conceited rather than correct."

    "Unwad those panties and have a good time man. We're all here to help each other, no matter how it might appear." DSkip
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  • rooftop59
    rooftop59 Posts: 8,121
    edited April 2014
    I would spend at least an hour with it, turn it off and on several times. Unplug and plug in all the cables several times to check for loose connections. Also take a rat shack SPL meter and measure to make sure the outputs are putting out the same volume. This is why I actually prefer to make these kinds of purchases either on this forum or on ebay, because on ebay you have a 45 day inspection period, and you can by a squaretrade warranty. Nothing like that on craigslist...
    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
    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     Harmon Kardon HK3490; Bluesounds Node N130; Polk RT25i; ACI Titan Subwoofer
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  • Polkie2009
    Polkie2009 Posts: 3,834
    edited April 2014
    rooftop59 wrote: »
    I would spend at least an hour with it, turn it off and on several times. Unplug and plug in all the cables several times to check for loose connections. Also take a rat shack SPL meter and measure to make sure the outputs are putting out the same volume. This is why I actually prefer to make these kinds of purchases either on this forum or on ebay, because on ebay you have a 45 day inspection period, and you can by a squaretrade warranty. Nothing like that on craigslist...
    These are all great ideas, but the few times I've bought sound equipment off of CL, most buyers just weren't too keen on me turning the item on and off, unplugging and plugging back in all the connections and opening the hood etc.I always got the impression they didn't want a stranger hanging out for an hour seeing if anything is wrong with the component . I guess the great thing about buying from someone here at Club Polk in the flea market is that ,if__ something is truly wrong with the item sold(which is pretty rare), it will get straightened out.
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  • rooftop59
    rooftop59 Posts: 8,121
    edited April 2014
    Polkie2009 wrote: »
    I guess the great thing about buying from someone here at Club Polk in the flea market is that ,if__ something is truly wrong with the item sold(which is pretty rare), it will get straightened out.

    Absolutely agree. Therefore I think the best suggestion to the OP is to be patient (easier said than done I know) and stick around and get to know folks a bit. A good deal is bound to come up in the FM over the summer, so the best advice is to wait for that, or go fleabay as I said...
    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
    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     Harmon Kardon HK3490; Bluesounds Node N130; Polk RT25i; ACI Titan Subwoofer
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  • F1nut
    F1nut Posts: 50,566
    edited April 2014
    I would never buy used audio gear off CL. Here and Audiogon, eBay if a had to.
    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

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  • badchad
    badchad Posts: 348
    edited April 2014
    I've usually just listened with a brief demo. If it works, I'm good. I've never been keen on hanging out and listening for an extended demo and/or opening equipment to inspect it. I've bought "new" in box speakers off CL and just picked them up without demoing. I'm pretty risk tolerant with CL though. I take my chances.
    Polk Fronts: RTi A7's
    Polk Center: CSi A6
    Polk Surrounds: FXi A6's
    Polk Rear Surround: RTi4
    Sub: HSU VTF-3 (MK1)
    AVR: Yamaha RX-A2010
    B&K Reference 200.7
    TV: Sharp LC-70LE847U
    Oppo BDP-103
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  • skrol
    skrol Posts: 3,378
    edited April 2014
    I would say the first thing is a visual inspection of the exterior to see if there are signs of abuse (spills, busted knobs, busted connectors, etc.).

    Second, turn it on and measure the DC offset at the speaker terminals.

    If it is ok then hook up some speakers and listen for hum or other anomalous noises.

    Then play some music through it and monitor temperature gradients across the heat sinks.


    I looked at a Hafler amp once (CL listing) and saved my speakers (yes, I brought my own) because I checked the DC offset before connecting.

    Stan
    Stan

    Main 2ch:
    Polk LSi15 (DB840 upgrade), Parasound: P/LD-1100, HCA-1000A; Denon: DVD-2910, DRM-800A; Benchmark DAC1, Monster HTS3600-MKII, Grado SR-225i; Technics SL-J2, Parasound PPH-100.

    HT:
    Marantz SR7010, Polk: RTA11TL (RDO198-1, XO and Damping Upgrades), S4, CS250, PSW110 , Marantz UD5005, Pioneer PL-530, Panasonic TC-P42S60

    Other stuff:
    Denon: DRA-835R, AVR-888, DCD-660, DRM-700A, DRR-780; Polk: S8, Monitor 5A, 5B, TSi100, RM7, PSW10 (DXi104 upgrade); Pioneer: CT-6R; Onkyo CP-1046F; Ortofon OM5E, Marantz: PM5004, CD5004, CDR-615; Parasound C/PT-600, HCA-800ii, Sony CDP-650ESD, Technics SA 5070, B&W DM601
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