CONTEST Buddy's Summer Contest - 1 Knob? No Prob!

[HamishR]

Well I just built my Paternity pedal but I'm having trouble getting my pics onto the computer. It actually sounds really cool! Once you dial in the trimmers it makes a cool clean or dirty boost. I'm quite chuffed!

If I can get the pics loaded I'll post 'em ASAP.

 

[Chuck D. Bones]

Aren't you a professional photographer?

 

[Chuck D. Bones]

Here's another one.
FYI: I'm not competing, I'm chumming the waters...

A variation on the RangeMaster. The GAIN knob varies the gain, but only in the mid and treble regions. With GAIN at zero it's a Clean Boost, with GAIN dimed it's a Treble Boost, and it's continuously variable in between. I'm not usually a fan of this biasing scheme, but it works well here.

To wit:

Q1 must be high HFE. BC549C and BC109C might work. R3, C1 and Q1's voltage gain set the high-pass freq. With GAIN and Level Trim at zero, the gain is close to unity. Q1-C runs around +5.4V on mine.

You can power it with +18V for more gain & headroom.

 

[HamishR]

Well yes, I am a professional photographer. Pretty much semi-retired now though. As in the work isn't coming in so much any more!

Anyway I've fired up the ol' computer which will actually connect to my iPhone (no fancy cameras for this stuff thank you very much) so here are not only pics of the Paternity 1-knob but another I had just recently rediscovered.

First the Paternity 1K:

 

[HamishR]

And here are some pics of another one-knob boost, the Lula Boost. It's a Tchula without diodes and no gain control. The only knob is a volume. The Tchula has a great tone but starts above unity. As a largely clean boost this has such a cool tone to it - very classic and usable, and can go from nothing to a decent boost. Works best into an already dirty sound. It has a low noise floor for what it is and I am really enjoying it with both my Gretsch and Les Paul.

 

[HamishR]

Back onto my newer computer to load the schematic for Lula.

And a Vero layout if anyone is interested. It will take all of 5 minutes to build! It could easily be made smaller but I like to space it out a bit for a 1590B. And yes I know it says 14x7 and it's actually 13x7.

 

[Nostradoomus]

Took me 15 minutes because I had to teepee some values

 

[Nostradoomus]

also @HamishR R4 and R5 differ from schematic to layout.

 

[HamishR]

also @HamishR R4 and R5 differ from schematic to layout.

Woops! R5 is meant to be 820R! Sorry about that!

(EDIT) Fixed!

 

[Silver Blues]

Those are impossibly clean vero builds, kudos.

 

[HamishR]

aw shucks....

I just like neat. It makes all my mistakes easier to find.

 

[Chuck D. Bones]

My final entry: The Knight & Day v2.1. Based on the Knight Kit Fuzz, I removed the FUZZ pot and added a FAT switch. C1-C3 throttle the bass coming in. Very responsive to guitar knobs & picking. without the LED, current consumption is quite low. This could be built into a guitar.

 

[bean]

These are all looking very tasty!

 

[BuddytheReow]

As mentioned previously, the contest has been extended until July 31st. Only 2 weeks left. Let's see what you got!

 

[t1redhands]

I've had a bunch of these LM3900 chips hanging around (StompBoxParts sale, anyone else?) and while I plan on making some old-school synths one day, I wondered how it would work in a distortion/fuzz application. I put this Big Muff-style schematic together and fiddled with the capacitor values, ending up with something similar to the Jordan Creator. The amplifier stages are pulled from the LM3900 datasheet as I couldn't find an existing distortion pedal to pilfer be inspired by. And of course, once I put this together I discovered the Hagerman Metal pedal which is basically the same as this without clipping diodes and different component values. It's a really neat fuzz-stortion, not very Muff-like. I think I'm starting to understand how these Norton op-amps work... maybe.

https://soundcloud.com/palmettopedals%2Fone-knob-lm3900-distortion

 

[Chuck D. Bones]

Wow! A blast from the past. I remember when these first came out. Not your usual opamp, that's 4 sure. Well done.

Even more bottom-end than a Muff, eh?

Now I need to scrounge thru my stash and see if I have any...

 

[BuddytheReow]

Interesting @t1redhands . Forgive me for asking, but what does this portion of your circuit do? I am making the assumption that C4/R11 and R10/C5 are high/low pass filters to attenuate the highs/lows. What about R13 and R13? Are they simply to attenuate the signal going into the last stage?

I don't think I have a LM3900 lying around to test this....

 

[t1redhands]

Interesting @t1redhands . Forgive me for asking, but what does this portion of your circuit do? I am making the assumption that C4/R11 and R10/C5 are high/low pass filters to attenuate the highs/lows. What about R13 and R13? Are they simply to attenuate the signal going into the last stage?

I don't think I have a LM3900 lying around to test this....

It's a Big Muff tone control with R11/12 acting like a pot set in the middle position. There's probably a more elegant, efficient way to do this, but I was testing out different values using a tone pot and found that it sounded the best in the middle position. I suspect it would work just as well with the high-pass and low-pass in series.

 

[Chuck D. Bones]

I suspect it would work just as well with the high-pass and low-pass in series.

It would not. As drawn above, we get a -4dB scoop at 1.4KHz. In series (low-pass first), we get a very broad bandpass centered at 1.2KHz.

 

[t1redhands]

It would not. As drawn above, we get a -4dB scoop at 1.4KHz. In series (low-pass first), we get a very broad bandpass centered at 1.2KHz.

Womp womp, of course.
I like this fixed mid scoop so much that I might play around with the recovery stage to see if I can get a tone control in there, maybe an active low-pass. Not for this contest, though.