Different Op-Amp Characteristics?

Discussion in 'Effects, Pedals, Strings & Things' started by PitchShifter, Oct 18, 2008.

  1. PitchShifter

    PitchShifter Member

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    I've discovered that I have a dark sounding amp (darker than the Pod I've been using to record demos in the bedroom anyway).

    So I tried switching the op-amp in one of my OD pedals for the first time using an alternate one to see how it would change the character of the sound.
    I'd like to try a few more options but aren't sure where to start.
    I've searched through the forum but most of the info on op-amps is rather vague, "I tried type XXX and that worked for me" type of stuff.

    Is there are a good summary available of the characteristics of the more common types used in OD pedals?
     
  2. Craftmatic

    Craftmatic Member

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    From a another thread:

    "TL072ACN CLEANER WITH A JFET INPUT
    RC4559 DARKER MORE DRIVE
    TL062 VERY CLEAN
    TL082CP BRIGHTEST
    LM1458 MOST BASS RESPONSE BIG AMP SOUND
    LM833 COOL KINDA GRINDY
    JRC4558 COMPRESSED
    TSH22IN "STEVE'O CHIP.. REAL HOT CHEWY"
     
  3. PitchShifter

    PitchShifter Member

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  4. BluesHarp

    BluesHarp Member

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    The Lm1458 rocks in a Timmy!
     
  5. Craftmatic

    Craftmatic Member

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    How about an LM1558 in an Eternity?
     
  6. gratay

    gratay Member

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    I tried a few different ones in my MI Audio Blues boy deluxe and the one I like the most is the
    Burr Brown OPA 2604 ..Its very smooth, quite transparent and warm
     
  7. IvIark

    IvIark Member

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    I tried a few in an MI Audio BBD too and decided that I liked most of them more than the stock JRC4558, the only one that didn't sound at least as good to me was the LM1458 which was a bit fizzy (and I wasn't expecting that).

    The ones I preferred to the stock chip were an RC4558P, LF353N, NE5532 and TL072 and have a few more to try which I'll do soon. My favourite was the NE5532 which worked fantastic with the BBD and my amps. The opamp that gave the most obvious change of the pedal's character was the TL072 which sounded much more raw. In fact it gave a very convincing impression of an OCD.

    If you want more indepth info on opamps, look for a TI publication called "Opamps for everyone" of the "Handbook of Operational Amplifier Applications". I think they're freely downloadable.

    The actual schematics of many of the popular opamps vary considerably. Just look at the JRC4558:

    [​IMG]

    Compared to the NE5532 I mentioned above:

    [​IMG]

    Sometimes you just need trial and error to see what sounds good.
     
  8. BluesHarp

    BluesHarp Member

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    Wow.. theres more going on in there than most pedals.
     
  9. AshyLarry

    AshyLarry Member

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    I like the OPA2132 when I had it in the Pure Drive, bright and clean. At high gain it got slightly fuzzy, very slight. The pure drives boost stage used a jrc4558d that made it really fuzzy.
     
  10. jstone

    jstone Member

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    True...:)
     
  11. PitchShifter

    PitchShifter Member

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    I found a couple of good reviews of the various op-amps and have ordered about a dozen different models to try out.
    Presently, both my Timmy and my LTD are using non-stock versions, so it will be good to cycle them through and see how the character sounds throuhg my amp.
     
  12. mibu

    mibu Member

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    I'm also a big OPA2604 fan...
     
  13. BluesHarp

    BluesHarp Member

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    The Burr Brown? ( BB2604 ) Its one of the best driving opamps.... yea I agree. I would have it in my Timmy if I decided to use it for a medium/low or higher gain pedal. Im using the Timmy as a boost or a fat eq pedal so the Lm1458 gives it that smooth warm and less of a sharp high.

    I took the tlo72 out of a mk1 silverkiss and put that 2604 in and its on my bass board.


     
  14. gratay

    gratay Member

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    Thats interesting... I have been fiddling around at home with my BBD and although I really like the OPA2604, I have the TL072 in there at the moment...I'm going to do a gig with it because I think the brightness of the TL really suits stacking with other pedals.
    If I was just using it by itself I'd probably go back to the OPA...
    To sum it up I think like the TL more for rhythym playing and the OPA for a solo sound I guess?
     
  15. StompBoxBlues

    StompBoxBlues Member

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    I think there are too many variables as to bias and circuitry around the op-amps to have a concrete THIS op-amp = darker, THAT op-amp = trebly...etc.

    I'm just guessing, but depending on the values of the other components, the design, there may be some characteristics that are common, but I'd bet that there are just as many exceptions where a generally dark op-amp would sound bright, etc. It's all interaction.
     
  16. jaxonmills

    jaxonmills Member

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    What op-amp should I try in my Timmy? I'm using it as a solo boost w/ asymmetrical clipping.
     
  17. jaxonmills

    jaxonmills Member

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    To answer my own question, I put a LM1458 chip in my Timmy. I like it! In asymmetrical clipping mode, it functions like my Keeley SD-1, but much more transparent and tweakable. So +1 for the LM1458.
     
    Last edited: Oct 28, 2008
  18. Brad J

    Brad J Member

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    I've recently found op-amps to differ wildly between manufacturers, case in point:

    I recently built a Son of Screamer, had a few opamps laying around, threw in the first I came across, an odd branded RC4558P (still not sure what it is).
    Great sound right off the bat, the OD I've been wanting for a long time. Tried the other well liked opamps, LM1458, TL072ACN but they didn't sound anywhere near as warm or transparent.

    So I order a TI RC4558P, to replace the no namer one that I have in there, put it in and it's colder, brittle and unresponsive, back in goes the budget opamp, bingo!

    It's really well worth trying different manuf. opamps of the same type, they really are'nt all the same.
     

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