Soul Sonic - Hunny Bunny, sweet overdrive

Greg · Post by **Greg** » 11 Jan 2009, 22:45

Any pedal with a "honey" control has got to rock !

Nice circuit soulsonic.. thanks. Looking forward to hearing some clips.

JimiB · Post by **JimiB** » 13 Jan 2009, 05:10

Very cool! I am going to devote my time and energy here instead of the silly RE the HB thread.

soulsonic · Post by **soulsonic** » 13 Jan 2009, 06:39

I'm building up my show-off unit right now... just waiting for the lacquer to dry, then, into the oven it goes!

JimiB · Post by **JimiB** » 13 Jan 2009, 21:00

allright allright showoff!

Where's this layout you were talkin about -

soulsonic · Post by **soulsonic** » 14 Jan 2009, 00:41

It turned out nice!

Here's the guts...

And as promised, here is the layout for those guts...
members/soulsonic/Layouts/HunnyBunnyPCB.pdf
members/soulsonic/Layouts/HunnyBunnyLayout.pdf

Cheers!

Sound clips coming soon-ish....

And, yes, I will most likely start selling these. It sounds wonderful and I think it would really appeal folks who want a natural overdrive with lots of feel. It's very responsive to dynamics - especially at low gain settings. It's one of those boxes where you can get a bunch of different tones just by playing with the volume knob and using good dynamic control. Actually does remind me alot of those things they say the Honey Bee does.

Since, I'm going to be selling these.... I don't want to see anyone selling one using my board design. The board artwork is my legal property and I hereby give you permission to use it to build one for yourself or your friend, but I absolutely forbid anyone from using it for commercial purposes.

gus · Post by **gus** » 14 Jan 2009, 01:22

Nice.

I built a circuit like that about 96 with the DC offset of the opamp as the biasing for the enhancement mode N channel MOSFET. In my build I used a power mosfet. It is good to see circuits like this. About time someone saw the DC output of a opamp as a way to bias an enhancement mode MOSFET 3 to 4 vdc is a good starting point. I have a few other ones I have not shared in public forums.

Something fun to try is to offset the bias up or down by adjusting one of the 100ks for the opamp. Clip the opamp with an offset and change the operating point of the MOSFET. You don't have to be 1/2 the supply.

Something I like to do is to use a power mosfet with 1,000 or more pf gate cap and adjust the series resistor into the gate for a lowpass filter after a opamp or other gain stages. OR a Power mosfet and SE transformer in the drain leg OR............

Have fun

soulsonic · Post by **soulsonic** » 14 Jan 2009, 03:14

Thanks for the insights, Gus! I'm glad this is being noticed. I will definitely experiment further and see what other flavors I can come up with. It's certainly a versatile building block.
I got the initial inspiration of an opamp driving a transistor from that old Angry Beard III circuit, and then in a thread somewhere (I think it was the "Boutique MOSFET Madness" thread) someone mentioned that you could use the bias voltage from an opamp to possibly bias a MOSFET; so, I drew up a basic concept, gave it a whirl, and started getting cool sounds almost immediately.

JimiB · Post by **JimiB** » 14 Jan 2009, 03:40

Awesome thanks! Will build and report back.

RnFR · Post by **RnFR** » 14 Jan 2009, 04:19

looks great SS! so whats up with that emitter config? am i right about the gain filtering? just trying to understand it a bit better. seems like a cool way to adjust a gain stage- especially something like this where you are driving a single transistor.

soulsonic · Post by **soulsonic** » 14 Jan 2009, 06:38

"Honey" controls the amount of degenerative feedback in the MOSFET stage. The 470nF/330R combination does the same thing but only for higher frequencies (~1kHz+); so, as the "Honey" is turned up, so does the low-frequency gain. You get more bottom as well as more overall drive as a result; it gives you alot of ability to adjust both the amount and character of the distortion produced by the MOSFET. Between the Gain and Honey controls, there are many different color combinations possible.

RnFR · Post by **RnFR** » 14 Jan 2009, 06:58

very cool, i'll have to try to incorporate some of that into my designs.

WhiteKeyHole · Post by **WhiteKeyHole** » 15 Jan 2009, 02:50

Sounds pretty great, good job.

I didn't use exact parts, I was anxious to hear it so I used whatever I had laying around (OPA277 and IRFM014). "Honey" seems pretty subtle, but yeah, stays true to the name. Cool.

WhiteKeyHole · Post by **WhiteKeyHole** » 15 Jan 2009, 03:39

"Honey" isn't actually subtle, it's just that most the change happens in the last twenty percent of the rotation. Pretty unsubtle, actually.

soulsonic · Post by **soulsonic** » 15 Jan 2009, 04:19

Yeah, you might want to try different tapers for the Honey control... it is pretty subtle in the middle of the range, but yeah, comparing all the way down to all the way up is like two completely different stompboxes.

Does it get a nice crunch? Mine starts out crunchy, and as you dial the controls up it starts turning into more of a distortion. Has it got a nice tube-y vibe to it?

WhiteKeyHole · Post by **WhiteKeyHole** » 15 Jan 2009, 04:37

Yeah, definitely like two different boxes, that bass comes in like thunder. I think a 2K pot would be just as effective.

Yep, nice crunch. It does get into distortion territory with the gain up, some chugga-chugga. Tube-y vibe for sure.

nooneknows · Post by **nooneknows** » 15 Jan 2009, 10:27

Wow, I've just breadboard it and it sounds amazing! With my strat on my el84 Peavey c30 it's like having a new 'Plexi channel'.
Very dynamic with the picking and the guitar volume level, it goes from almost clean to full Hendrixy scream with a turn of the knob.
Mine is a bit trebly, maybe too much, I double checked the circuit and it seems correct, has yours this enphasis on the high side?

Thank you!!!!

WhiteKeyHole · Post by **WhiteKeyHole** » 15 Jan 2009, 11:46

Yeah, mine needed the treble tamed a bit.

Desdog · Post by **Desdog** » 15 Jan 2009, 13:47

WhiteKeyHole wrote:Sounds pretty great, good job.
I didn't use exact parts, I was anxious to hear it so I used whatever I had laying around (OPA277 and IRFM014). "Honey" seems pretty subtle, but yeah, stays true to the name. Cool.

Soulsonic, thanks man.
I also had no LM301 on hand, built and put in 741 opamp and didn't get above unity gain.
Then I checked the voltages on the BS170 and measured 9.10V - 4.58V - 0.25V on the transistor pins left to right facing the writing. So I reversed the mosfet

and now I'm getting the trebly distortion sounds everyones is talking about, but also the BBC, radio Moscow and radiola Italia...

So now D=2.80V G=4.5V and S=3.08

opamp voltages are
1= 0V 8= 0V
2= 4.57V 7= 9.10V
3= 4.47V 6= 4,57V
4= 0V 5= 0V

Will try some other opamp later, but what going on with my mosfet?

nooneknows · Post by **nooneknows** » 16 Jan 2009, 21:32

Desdog, a ground loop? some layout problem with wires too long? a ground connecion not tight?

Anyway, what about putting a cap across the volume pot to filter out some of the highs? the trebly part of the sounds is really too much prominent in mine. I have to try it, this pedal is intriguing and it sounds wonderful.

soulsonic · Post by **soulsonic** » 16 Jan 2009, 22:16

You could also try increasing the size of the compensation cap to roll off more highs.