Danelectro Nifty Fifty Mod help (pots)

Discussion in 'Amps/Cabs Tech Corner: Amplifier, Cab & Speakers' started by ruger9, Apr 9, 2015.

  1. ruger9

    ruger9 Supporting Member

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    Didn't get many hits in the regular amp forum, so I'll try here (it's probably the more appropriate forum for the question anyway)...

    I stumbled across a couple of vids of this amp, and they surprised me how good the amp sounded... started looking up reviews, and these little solid state amps get raves. Just got one off eBay... and I am impressed....

    Really digging it ... with one exception:

    The "Sweet/Dirty" control, which is just a gain/preamp control, gets REALLY dirty REALLY fast... like, I can't even use it above about 10:00-10:30 because it sounds like a fuzz box. AND it dumps a TON of high end into the signal. Up until that point tho, it sounds great.

    Without getting too crazy with mods- because I've been down this road many times before- I'm looking to tame that a little.... here are my ideas, I'd love to get some input:

    1) the gain pot is a B100K. Replace with an audio taper for a more gradual increase in the gain, at least in the first 2/3 of the rotation.

    2) reduce the value of the pot to 50K or even 25K (or even 10K?), in an effort to reduce the high end getting through

    OR.... would a "bright cap" across that pot work? A bright cap bleeds highs to ground as the pot is turned up, right?

    What do you think?
     
  2. donnyjaguar

    donnyjaguar Member

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  3. ruger9

    ruger9 Supporting Member

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    I've never seen nor found a schematic for this amp online. I've got a pic tho... the gain pot and the 2 LED clippers and the 2 opamps..... (in this pic, which is not my amp, the LED clippers were swapped out for diodes, and the 2-TLO72s were removed, replaced with sockets and different opamps.... but the stock amps has 2-TLO72s and 2 LEDs.)


    [​IMG]
     
  4. ruger9

    ruger9 Supporting Member

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    on another forum, someone suggesting bridging the 2 LEDs with a cap to "get rid of some of the high end nastiness"???

    Also, instead of replacing the pot, adding a resistor to ground to (sort of) transform it into an audio taper?
     
  5. ruger9

    ruger9 Supporting Member

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    Well, no action here.... lucky I found someone over on TDPRI that could lend a hand....

    Going to first try running a cap in parallel with the LEDs, which is supposed to get rid of some of the "high end nastiness", found that on AMZ-FX, I think....

    Other option would include using a resistor to change the taper of the pot to make it more gradual, and trying a "dark cap" to ground on that pot....
     
  6. thesteve

    thesteve Member

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    I don't have one of these amps and have nothing to offer in terms of help, but I'd love to find out what the final result sounds like as you go through your mods.
     
  7. TimmyP

    TimmyP Member

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    A cap solution will effect the signal all the time. I expect that you need to cap to do more as the gain is increased. If you can make it fit, try a dual pot, with the second adding in a 'cut cap' (think AC30, but not necessarily in the same place in the circuit). Although even by experimenting with pot values, you might never get it to work as desired.
     
  8. ruger9

    ruger9 Supporting Member

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    Even with the gain pot turned to zero?


    I tried a few different cap values, starting with a 100pf and up to 470pf, it had zero effect. So i tried (3) 470pf in parallel..... zero effect. I'm going to bump it up to .1uf to see if I'm even barking up the right tree.....

    I have decided to not attempt a pot change... these things are so delicate, and every time the amp is taken apart/reassembled I feel like you're just inviting havoc. This amp was not made to be worked on.... and even tho I only paid $80 for it, I don't want to risk breaking it, 'cause I really dig it.

    There's a very good chance I'll just leave it alone and never use the gain control.... it sounds fantastic using the vol only, even cranked.
     

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