Use for old Adcom amp?

Discussion in 'Archived Threads 2001-2004' started by Dean_M, Feb 14, 2002.

  1. Dean_M

    Dean_M Second Unit

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    I recently bought a Denon 3802 to replace the antique Adcom GFA-555 amp that I had, and I'd like to find a way to get some use out of the old beast rather than try to sell it.
    At 200WPC stereo, 600W bridged, would it make a suitable amp for driving a subwoofer like one of the SVS units if I were to use it in the bridged mode? Any other suggestions for getting some use out of the Adcom would also be appreciated. Although, I should point out that my girlfriend, who has grown tired of me babbling on and on about AV equipment in the past few months, has already made one suggestion. However, I don't think it would work well and it would make sitting or walking very uncomfortable.[​IMG]
    Also, any suggestions for an amp that would be a good match for the 3802? I'm thinking of using the Denon as a preamp.
    Dean
     
  2. John Tompkins

    John Tompkins Supporting Actor

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    Dean, if it were me I would use the denon 3802 as a pre and run your front speakers on the Adcom. Then at some point you can add an Adcom 3 channel amp for center and rears. You can pick up a 3 channel Adcom for a pretty good price.

    Also You can drive 2 subs with it, But I'm not sure if you would want to bridge the adcom to run a 4 ohm speaker.
     
  3. Mark Hayenga

    Mark Hayenga Supporting Actor

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    Yes! It would make a fantastic sub amp. I'm currently using a 555mkII in stereo to run my two DIY Adire Tempest based subwoofers. Just remember that the SVS' are 4 ohms (if I remember correctly) and the 600w bridged rating for the Adcom is into 8 ohms (if it's like my 555ii). On mine the manual recommends getting a fan-retrofitted top plate for the amp that can be installed by a service technician if you're going to bridge it into 4 ohms. I've bridged mine into 4 ohms before without the fan without problem, but it is best to be cautious. Best plan would be to either get a single subwoofer with dual 8 or 4 ohm voice coils and run each channel to its own coil, or get two 4 ohm subs (SVS', etc) and run them in stereo. Or put them in series and then bridge, or however things work best in your setup.
     
  4. Dean_M

    Dean_M Second Unit

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    Thanks for the input guys. I'm new to this stuff and even more of a fossil than the Adcom is, so I appreciate the help. The fronts that are scheduled to be delivered tomorrow are Infinity IL60's which are rated for up to a 175W amp. Wouldn't the Adcom be a bit of a mismatch at 200WPC, or is it not enough to make a difference?

    I didn't realize that the SVS units are 4 Ohm, and my room (15'x15'x9') is a little small for two stand alone SW's I would think. Especially, since the IL60's also come with 500W amp'ed SW's.

    Any recommendations for a good dual coil 8 Ohm SW?

    Dean
     
  5. SeanMcV

    SeanMcV Auditioning

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    I purchased an SVS 20-39cs last fall, and I'm currently driving it with one channel of my old Adcom 555 II. Works like a champ. The 555 II was rated by Adcom at 325 W/Ch into 4 ohms, which is more than enough power to drive my SVS. Using just the single channel, I managed to bottom the sub out while watching Jurassic Park III, so the output capabilities of the amp aren't the limiting factor in my system.
    I did check with Adcom tech support about running the amp bridged into a 4 ohm load, however, just to satisfy my curiosity, and was told it would not be a problem. I don't recall the exact output number they quoted for a 4 ohm load, but they did give me one, and it was somewhere in the vicinity of 900 W. If you're looking into one of the new SVS cs+ series subs, which have greater output capabilites than my cs, the bridged amp might be worth experimenting with. Or, as suggested above, the two channel amp does seem to call out for a second sub. So far I've shown great restraint and not given in to temptation, but it hasn't been easy. [​IMG]
     
  6. Justin Lane

    Justin Lane Cinematographer

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    If you want to run two SVS off this sub, you could always put them in parallel effectively giving the amp an 8 ohm load when bridged. This kind of limits the tweaking possible having two subs run off one channel, but it is always an option.

    J
     
  7. Dean_M

    Dean_M Second Unit

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    I got the specs on my amp from Adcom and it puts out 325WPC at 4 Ohms in stereo mode, which should be more than enough for my needs. I'm thinking of getting the 20-39CS+ and running it off one channel for the time being. This will be followed by much whining, wimpering, and the performance of unspeakable acts on my part in hopes of getting a second SW to match. Who needs dignity and a sense of self worth when there are upgrades at stake. [​IMG]
    Thanks again for the help.
    Dean
     
  8. Kevin P

    Kevin P Screenwriter

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    With two subs I wouldn't bother bridging the amp, just run one sub per channel.
    900 watts into a SVS is huge overkill--the CS is rated up to 300W and the CS+ up to 500W. The subs will bottom out if you push too much power through them, if your home theater doesn't implode first. [​IMG] Just use one channel of the amp if you get one sub, the 325W into 4 ohms will be plenty. SVS subs are very efficient.
    KJP
     
  9. Jason Watson

    Jason Watson Stunt Coordinator

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    __________________________________________________ ________

    "The fronts that are scheduled to be delivered tomorrow are Infinity IL60's which are rated for up to a 175W amp. Wouldn't the Adcom be a bit of a mismatch at 200WPC, or is it not enough to make a difference?"

    __________________________________________________ ________

    Dean,

    You will have no mismatch here at all. You could double the amplifier power and probably never have a problem. I am pushing 750 watts into my fronts(rated at 250 watts IIRC)and have had no problems at all.

    Jason
     
  10. ThomasR

    ThomasR Auditioning

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    I use an original Adcomm 555 amp to power my VMPS Large Subwoofer, 1 channel for each active driver. It works just great as a subwoofer amp.
     
  11. Jim Thompson

    Jim Thompson Agent

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    Justin

    Putting the SVSs with a4 ohm each in parallel will halve

    the impedance not double it.
     

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