Sunday, 29 January 2012

Devi Ever Karaoke Party

A quicky for you Devi fans.  This is actually a really good sounding overdrive for such a low parts count.  I did a layout for this previously based on a guessed schematic but this is the corrected versions from Devi's schematic.



31 comments:

  1. How does this work? It seems like a lot of distortion from only one transistor. Granted, there is a whole lot I don't know about electronics.

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  2. Yes there is a lot more gain than you would expect out of a single transistor effect, but it does use the MPSA18 transistor which the datasheet lists as having a hfe of between 500 and 1500. If the transistors are measured and handpicked to be at the upper end of that spec, then I suppose it could explain it.

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  3. Hi,

    I've made this up and I'm not getting anywhere near the amount of distortion that the YouTube demo displays?

    It sounds like I'm plugged into a home hifi.. you that dry, brittle broken sound? would having the transistor in the wrong way be a possibility?

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  4. I seem to be making a habit of answering my own questions l0l

    This is exactly what it sounds like with my strat too...
    God bloody awful (in my humble opinion)

    http://www.youtube.com/watch?v=1guWt6gkwYE

    So it seems this is normal... sorry ;-|

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  5. I thought it sounded pretty good on the proguitarshop demo, particularly with humbuckers, I haven't tried it myself yet though. It's certainly not going to be a high gain monster with a single trannie though.

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  6. I totally agree, The proguitarshop demo was what swayed me to build it... but with my set up Strat & Jackson into a Blackstar tube .... it sounds nothing like that :( It sounds exactly like the demo I posted though...

    It reminded me of the sound I got when I got my first guitar but couldn't afford an amp so I plugged into a intergrated stereo amp.

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  7. Guys guys....

    Devi's own demo sounds just perfect. I have this circuit waiting to be boxed. And i'm going to do it next.. (High hopes for ZW44 trumped this from the que... :))

    I thought to myself why build semi-boring basic stuff, when you can build something as awesome as Devi's fuzzes/stortions. Granted, these aren't the boxes for your base tone, but something that is just amazing to have when you're recording.

    Actually i think it's pretty weird that someone else's demo sounds so different than the original demo from the manufacturer..

    I was just wondering why this hasn't been tagged as verified?
    +m

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  8. I built two and they both sound shit. It's hard to get the circuit wrong and I've gone over it a few times. The output is low and almost no drive. I have to crank both volume and drive all the way to get a fuzzy sound. Any ideas?

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    1. The only thing that I did differently is the 3M3 because I don't have one. I wired a 2m2 and a 1m in series to get a 3.2M. Is that too far off to have such a great effect on the whole thing?

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  9. i built one of these last night. IMO, they're okay, and nothing to write home about, but they are as about as simple to build as it gets. i'm now using an MPSA13 (darlington) in mine to get a little more gain/fuzz than the MPSA18.

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    1. I agree John, although it works pretty well as a dirty boost on the gain channel.. worth a try.

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    2. yeah, i could see that, but to me, after building so many other 'higher end' ones, it just didn't deserve its own box, footswitch and jacks, so i ended up building a Sonic Titan for the enclosure, and added a three way toggle to go from stock, to slightly boosted bass, to a full low end. and i like the ST, ALOT more.

      here's a pic of it:

      http://johnkvintageguitars.homestead.com/Effects/Fuzz-ODs/SonicTitan/Super_Titan_-SuperSonic-01.jpg

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    3. Looks great ;o) ... I'm a big fan of the Titan.. Definitely one of the best drives around.. really nice mid honk to it too... Might try the bass mod switch too

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    4. Thanks for the pic John, and for the Pinnacle. Did you use the stock Titan layout or with the modified tone control?

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    5. i used the stock tone control (and i like it) but i did add a three way bass boost switch for the front end since the pedal cuts bass and adds mids.

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  10. Just to add to the reviews here, mine sounds awful too, i was hoping for something like the PGS demo but it was nothing like it.

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  11. Hellow. I am always looking forward to your report.
    I think that direction of MPSA18 is opposite.
    Please check it.

    Datasheet
    http://www.redrok.com/NPN_MPSA18_45V_100mA_0.625W_Hfe400_TO-92.pdf

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  12. the diagram of the transistor might be backwards but the EBC labeling is correct, since the emitter goes to ground.

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  13. the EBC labeling is correct.OK thanks.

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  14. im pretty new to this and i want to know what kind of pots i need to use for this. It's my first pedal.

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    1. 16mm base is cheap and good. Check out these:
      http://www.taydaelectronics.com/potentiometer-variable-resistors/rotary-potentiometer/linear/100k-ohm-linear-taper-potentiometer-with-solder-lugs.html
      and
      http://www.taydaelectronics.com/potentiometer-variable-resistors/rotary-potentiometer/logarithmic/100k-ohm-logarithmic-taper-potentiometer-with-solder-lugs.html

      There will be a text on the pots - A100K means it's log, and B100K means it's linear.
      +m

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  15. Built it a couple of weeks ago, and here is the pic:

    http://www.facebook.com/photo.php?fbid=208016372672697&set=a.208016339339367.48072.100003930063241&type=1&theater

    Cheers!

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  16. Just built this and though it sound great with both singlecoil and humbucker guitars I keep getting a bit of hum. I sliced between all tracks, there are no shorts. Sounds like I'm grounding somewhere. Maybe replace the filtering cap? Should I go bigger or smaller? There's 100uF in there now, should I go with 200 or rather with 50. Tiny brain still doesn't quite get what happens inside them elcos.

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    1. Are you trying it with a battery or a wall wart? Does the hum appear on both? If not, then the issue could be with the filter cap... You could try any value for it. Start with 47µ...
      +m

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    2. tnx Miro. Using a battery. I'll try an adapter first, then check back in.

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    3. Solved. Bit of an 'oops' moment. Checked everything on the board. Sliced between strip again, no change. Hooked up adapter, no change. Took the lead out the OUT jack, ground wire just ripped out. Bad solder joint? Resoldered, hum is gone.
      ...oops...

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  17. How could I replace the control pot with a spdt switch to have just 2 Gain settings?
    I want one setting full on and one setting at about half.

    Should only take me a switch and a resistor, right?

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  18. Got this working all right. Managed to fit it to 1590A:
    http://blackoutelectronics.com/gallery/Blackout%20Singstar.JPG

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  19. HAI...SAYA ORKES KERONCONG GANDARWA DARI KOTA SOLO INDONESAI. BISAKAH BANTU SAYA BERI SKEMA EFEK GITAR DISTORSI UNTUK SAYA MASUKAN KE GITAR AKUSTIK. TERIMA KASIH BANTUANYA.

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  20. There's a 2 tranny version of this out there on the interwebs... wierd!
    http://infernalindustries.blogspot.ca/

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