LOVEPEDAL SUPER SIX STEVIE MOD

[Frank_NH]

I don't know why I'm attracted to these simple circuits but...

The Super 6 is a MOSFET booster with some tone shaping.  If you want to add a tone stack, I would consider scaling the Fender tone stacks shown above to lower the impedance.  At the same time, I would also experiment with adding JFET stage after that to provide some extra boost.  As an example, look at the ROG Peppermill:

http://www.runoffgroove.com/peppermill.html

Maybe the "Stevie Mod" version is an active tone stack placed after the MOSFET booster, and driven by an op amp stage (just speculating).  I may try putting this on a breadboard and seeing what I come up with...

[Frank_NH]

I breadboarded a circuit tonight based off the Super 6 and the original Super Reverb amp topology.  Here's the result (simulated in LTSpice as well).  It uses a scaled tone stack and a 2N5457 JFET gain stage (with red 3mm LED clipping) to simulate the extra preamp gain stage in the amp and power amp.  The filter at the end rolls off some of the high frequencies above 5KHz (similar to the ROG amp sims).  It sounds pretty good with a strat.  Note that, like the amp, the gain comes from the volume control (no 1K gain pot at the source of the MOSFET), and if you want to control the overall level you can tack on a 100K volume pot at the end instead of the fixed resistor.  The LEDs give it that "edge of overdrive" crunch, but it never gets too gainy.  You can push it with another OD (like a tube screamer or Klon) for extra fun.

I haven't produced a vero layout but it should be easy to do.  Let me know if anyone decides to build it and has some questions.

[Frank_NH]

Update - I'm really digging this design on my breadboard and will create a vero layout for it.  I made a few mods and will post a new schematic with the vero.

Of course,  after some thought, I realized that this circuit is really just a modification of the old ROG Peppermill (MOSFET booster into a JFET gain stage) except that it has the Super Reverb tone stack, LED clippers, and some voicing cues from the amp.  You can get some great bluesy tones with the gain (volume) turned up, and the tone controls can help you dial in the sound you want for single coils and humbuckers.  

[music6000]

Cool
      I will watch this space for your Vero layout. Would it have a Master Volume at the end with Lug 2 to Output & Lug 1 to Ground in place of R16  100K Resistor.
 
      Cheers music6000

[Frank_NH]

Yes, I'll put in a Level control (A100K pot), since the "amp" Volume control in this case sets the gain of the signal.  I'm almost done and will check over the layout carefully before posting (and hopefully get is built soon thereafter).

[Frank_NH]

OK.  Here is my slightly modded schematic and unverified layout for the "Super 65".  Hope you like it.  One note - I have a 4.7K drain resistor for the 2N5457, but you can socket this resistor or install a 10K trimmer to adjust the resistance.   Have fun!

[music6000]

So the 4001 is for Polarity protection, the 4739 for Voltage protection, Correct.

[Frank_NH]

Q: So the 4001 is for Polarity protection?

A: Yes, the standard polarity protection diode.

Q: 4739 for Voltage protection?

A: Yes, a 9.1V zener diode to keep the BS170 from getting zapped by a voltage spike.  You can also use a Red LED here if you want (see the ROG Peppermill as an example).

Please note that the vero layout is unverified at this stage.  I plan to build it this weekend.

[MetalRules]

Hi Frank
You can verify your super 65 !
really good clean boost with slight crunchy tone
works great with my strat
Thanks!

[Frank_NH]

Cool!  Thanks for verifying the layout.

If you wanted more crunch, you could use a J201 (with a 50K or 100K trimmer).  You could also use other diodes than the red LEDs, which would reduce the output but enhance the clipping.  I think it's good as it is, as the original intent was to give you that edge-of-breakup tone for an SRV blues vibe.

[MetalRules]

You Are right
its on the edge-of-breakup tone and i really like it !
I Really dont want more gain :)
its sound great as it is
thanks !

[music6000]

Hi
   I built this Circuit and it sounds really Great with Little 59's on Single Coils but barely plays Clean with Little 59's in Humbucker mode.
Tried J201,Way too much Gain, Compressed.
Finished up with Fairchild MPF102, Least amount of Gain of all 3 and it has the most Sustain.
I was getting Slight Pop (Thud) with the 2N5457 when switching pedal On & a slightly larger Pop (Thud)
switching it Off.
That has disappeared since the MPF102 has been installed.

Thankyou Frank NH for your Time & Great Layout.

Cheers music6000

[Frank_NH]

Thanks for the feedback.  The MPF102 is a great choice for the JFET.  You can also play around with the source resistor if you want to reduce the gain (change it from 820 to 470 and adjust the 4.7K drain resistor to taste).

Not sure why the popping was occuring - there is a 2.2M anti-pop resistor at the input.  But if the MPF102 helped that, then that's good to know.

[holm]

Hello


Finally got it boxed, and just wanted to ask; if I wanted to add more bass, would I be looking at increasing C8? or could I do anything else.

In advance thanks
Erik

[Frank_NH]

Hey Erik,

Great looking build! Yeah, try increasing C8 to 100 nF or even 1 uF and see if that works for you.  

[Iago]

Your circuit is actually much more interesting than the actual "Stevie Mod" (which is YAT - Yet Another Timmy clone), Frank.  Think I'll give it a try.

[music6000]

I thought I had posted Pictures back when I built it (16th March 2018).
The knobs are Fender with the Skirt machined off.
The Jewel is Fender replacement.
The white dot markers are a Drill hole with White hook up Insulation pulled through & Cut Flush.
I make all my pedals with my in house Eyelet Board design or with purchased PCB's.
The Board is held in place by 3mm Cap screws with a threaded Hex Nylon Riser.





Cheers music6000

[Iago]

Looks killer. The insides remind me of Menatone's old builds.