the Lemon Drop and Jelly Roll by Lumpy's Tone Shop

[mordechai]

These circuits sound SO good, and from the gut shots they look fairly simple.  Anybody have any info on components, or schematics, behind these two pedals?  I'm attaching links to the website for each:

http://www.lumpystoneshop.com/lemondrop.htm

http://www.lumpystoneshop.com/jellyroll.htm

[Meanderthal]

 Jelly Roll:

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

[Meanderthal]

Lemon Drop:

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

Replace 8k2 resistor with a pot to get a 'tone' knob.

[mordechai]

So the Lemon Drop and Jelly Roll are strongly inspired by or are nearly identical to these ROG circuits?

[Meanderthal]

 The eighteen and jelly roll look identical. Parts values may vary some, but even the perf layout is identical.

The Lemon drop appears to be a variation of the peppermill, and I may be wrong about the tone control now that I look closer. But, it's a peppermill with tone control. Again, parts value may vary, but probably not very much.

The ROG circuits DO sound great...

[Meanderthal]

Haha, almost identical layouts, there are differences(still comparing). Pretty close though... Safe to say based on.

[Lumpys Tone Shop]

If I have some spare time this week or during the weekend I'll draw up the schematics.  Neither circuit is based on the ROG circuits, it puzzles me it's even being suggested.  The tube to FET which I learned from ROG many years ago definitely inspired the Jelly Roll, but it's not based on any of their designs. 

The Jelly Roll uses the typical tube to FET process applied to an unknown model Supro (single end 6973).  If it's similar to any ROG circuit it would be the Supreaux but the only similarity would be the fact it uses 3 FETs and only has a similar output stage.  The first two gain stages are quite different, much closer to a the peramp of a 1624T Supro. The tone control is directly after the first stage and is closer to the tone control you'd find in a Thunderbolt.  It's not even remotely close to the Eighteen. You might want to look a little closer before using the word "identical" 

The Lemon Drop uses a similar idea as the Peppermill to push a JFET into overdrive, but it does it differently and I didn't get the idea from the Peppermill either.  If the idea of overdriving a JFET is unique to ROG, then I guess I'm guilty.  The input stage on the Lemon Drop is a BJT, not a MOSFET.  It's practically the same as the 7 Series input stage simply biased for 9V.  Transistor is a BC108B rather than BC107s used in the amp.  As simple as that sounds, it's what makes the pedal sound the way it does.  The JFET is a 2N5457, similar stage setup as the Peppermill, but that is so basic anyone could come up with that...  The tone control is set up like a range control on a Rangemaster copy.  There were 2 custom versions that were built with the 7 series tone stack.  The original prototype was a little more complex utilizing more features of the 7 series preamp but it never quite got the sounds of the amp.

Nothing mind blowing design wise, just building off basic building blocks, not another pedal.

[azrael]

Oh yeah, the BJT is pretty obvious from the gutshots. You can see the metal can.

Thanks for weighing in Lumpy, very cool of you to be this open about it.

[nocentelli]

If I have some spare time this week or during the weekend I'll draw up the schematics. 

That would be great! The Lemon Drop sounds fantastic, very nice Page-ish tones.

[Meanderthal]

 Haha, so I was wrong...

If one were to start with the circuits I mentioned, and tweak, one could easily wind up with the circuits you describe.  Fet gain stages(based on tube amp circuits), or mix n match ... I sure wasn't THAT far off, now was I?...

And, as you can see, I DID say not identical as I noticed differences. 

Not trying to cut down your work or offend. In fact the build quality looks great!

[Meanderthal]

 Not all metal cans are bjt. Just as not all metal cans are germanium or even vintage. Google mosfet to-39.

[mordechai]

I just ordered a Lemon Drop pedal and look forward to recording with it soon.  But in the interim -- what is it about the BC108B that is so appropriate for the Lemon Drop's tone?  How is it being used as a gain stage, and how would it differ from, say, a 2n5088 or something like a BC182 or BC183?

[azrael]

Not all metal cans are bjt. Just as not all metal cans are germanium or even vintage. Google mosfet to-39.

Fair enough, but the style and sizing made me think BC109 or something when I initially saw it. Just how I looked at it.

[Meanderthal]

 Yeah, metal can is just a package. It's what's in it that makes all the difference. To be fair, it's not like I see lots of mosfets that look like that, but I might want to try one sometime just to see if there's any mojo in it. A lot of nice things come in that package...