stupid simple overdrive mk 4 with lame video

pinkjimiphoton · Post by **pinkjimiphoton** » 03 Dec 2015, 04:51

first the circuit, random stuff i threw together on my breadboard earlier today, starting with my ssod idea.

then a vero, which is verified, built tonite:

i tried this thing with an ass load of transistors... ge, si, npn, even some pnp's.... and just about everything seemed to work to some degree. go figure.

but it's sweet spot is an hfe between about 80 and 140, and as low as 58 to as high as 468 worked well with some transistors, so pretty much anything will work. i reccomend socketing and just trying transistors til it sounds good.

in the video, it's gotta ac176 hfe of 80 in it. i'm playing an epi lp prophecy plus with a 57 classic in the neck, and a burstbucker at the bridge thru an ancient 40 watt 2x12 piggyback shin ei kustom knock off, set clean with a bit of reverb. it's a cool ass amp.

anyways, you may want a master volume. for me, i just turn my guitar up and down. it cleans up really nice like a good fuzz should, and has a nice overdrive charachter. check it out:

ummmmm.... i'll be back with the video, youtube is taking FOREVER. :icon_mrgreen:

ok.... here ya go.... beware. not my most amusing videe but it's short

Nicku777 · Post by **Nicku777** » 05 Jan 2016, 20:02

Hi,
actually it has very nice sound, simple and nice. i want to try and built it and i have question.
1- can i use transistor BC549
2-for the Diode part, i have these " 1N4148 1N4007 1N5819 1N5399 1N5408 1N5822 FR107 FR207 1N4001
3-Capacitor C1, C2, C3, can i use ceramic?
4-What does D2 LED here? is it like light? and it has to be Blue?

thanks

pinkjimiphoton · Post by **pinkjimiphoton** » 05 Jan 2016, 21:26

Nicku777 wrote:Hi,
actually it has very nice sound, simple and nice. i want to try and built it and i have question.
1- can i use transistor BC549
2-for the Diode part, i have these " 1N4148 1N4007 1N5819 1N5399 1N5408 1N5822 FR107 FR207 1N4001
3-Capacitor C1, C2, C3, can i use ceramic?
4-What does D2 LED here? is it like light? and it has to be Blue?

thanks

hi nicku,

i made a couple changes to the circuit, forgot to update with all the holidays and gigs and shit...
bc549 is probably fine, i really liked bc337 i think it was... anything with a gain of 100-500 should do fine.... the higher the gain, the more aggressive the distortion.

for the diodes, use whatever you have. FWIW, i ended up removing them as unnecessary... i would reccomend breadboarding it so you can tune it to taste. i would use the 4148, as they sound pretty much the same as GE diodes in this circuit.

ceramic caps are fine, but as shown the output cap isn't big enough. i pulled the .01 cap out and made it .47 . .01 is more of a treble boost, and about 6db shy of unity gain. the bigger cap should let you easily achieve unity about 12:00 so ya get a bit of boost.

the led can be removed with almost no change to the sound. i had put it in on the breadboard seeking a bit more bite, but have since removed it from the actual circuit. so you can add it or subtract it at will. color doesn't really matter, blue i think has a little higher breakover voltage than some of the other ones. i just used whatever was kicking around on my bench. if you DO use the led, it's more distorted. if you have germanium transistors, you can also reverse bias a germanium diode there (from b to e if memory serves) to help stabilize leakage.

but i tried it with a bunch of uni transistors of si and ge flavors, and a bunch of jfets and mosfets. surprisingly, npn or pnp work (depending on the transistor, leakage if applicable and whether it is forward or reverse biased... some transistors sounded better BACKWARDS, believe it or not.)

so anyways, yeah, use whatcha got my friend. just make that output cap substantially bigger and you should be good to go. nice and touch sensitive, good dynamics from the guitar and reacts good with volume from the guitar..... have fun with it, make it your own, and let us know how ya make out, ok?

peace and blessings to you and yours
pjp

pinkjimiphoton · Post by **pinkjimiphoton** » 05 Jan 2016, 21:29

oh yeah,,,,

if ya want a screaming high gain distortion that's almost uncontrollable but sounds really cool, try a darlington like mpsa13. inSANE. not very stable , but a lot of fun to play with.

Nicku777 · Post by **Nicku777** » 06 Jan 2016, 16:23

Hi PJP

Thanks for your quick answer and details. yes you are right i will make it first on breadboard.
but i loved the sound on the video clip, very tight overdrive.

Best Regards Nick