Dual Op-amps

Discussion in 'DIY Discussion' started by K-Bear, Feb 9, 2006.

  1. K-Bear

    leo

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    Theres nothing wrong in disagreeing mate, Its good to share idea's and opinions even if we don't agree with everything:)
    Its just that some op-amps like Op27's etc don't like DC on the inputs so with the TDA1541 we have to be careful, some nulling circuits in these old multibit cdp's are not very effective.
    We do at least need a photo and maybe he's only willing to change the op-amps, either way I'm sure this unit can be improved fairly simple
     
    leo, Feb 15, 2006
    #21
  2. K-Bear

    zanash

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    spot on.... if we get a pic or too things can move on !
     
    zanash, Feb 16, 2006
    #22
  3. K-Bear

    K-Bear

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    Op27's and the TDA1541 happily co-exist in the Arcam A5.

    I could try the NETAudio NOS board; works very well in the AA5, not sure of compatibility with the 955, but since the same chipsets are involved, should work.

    I much preferred OP27's to OPA 604's in another player, hence reasoned I might get an improvement by replacing the 2604's with something else.

    Another possibility for the o/p is to install a good film cap wired from the <+> directly to the sockets, thus bypassing the mute circuits.

    The stock power cable certainly looks uninspiring; shielded is the way to go, yes?
     
    K-Bear, Feb 16, 2006
    #23
  4. K-Bear

    zanash

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    Good grief ...have you not got rid ? if they are transistors just snip them off the pcb. **** warning ....make certain you know which they are first !!!*****
     
    zanash, Feb 16, 2006
    #24
  5. K-Bear

    zanash

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    well not just any shielded cable !

    You got to pick a decent one !
     
    zanash, Feb 16, 2006
    #25
  6. K-Bear

    leo

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    The Arcam A5 has a nice nulling circuit, the Op27 for the I/V is hard to beat in this unit, they also work fairly good for the output op-amps too
    BTW there is two caps in the nulling, C8/108 which are certainly worth replacing with a good low esr type like a Panasonic FC;)
    If you use the A5+ I would not bother with the NETAudio Nos board TBH , doing the simple no cost NOS mod would give you almost as good results, if its the standard A5 then the NETAudio Nos board may be worth trying because the clock in the standard A5 is not as good as the A5+.
    Any cdp will respond very well to a good mains cable, I'm sure Zanash can sort you out with a nice one
     
    leo, Feb 16, 2006
    #26
  7. K-Bear

    leo

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    Just trying to find you a schematic for the Rotel but no luck yet:(
     
    leo, Feb 16, 2006
    #27
  8. K-Bear

    zanash

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    I had a quick hunt with no luck
     
    zanash, Feb 17, 2006
    #28
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