Green Citrus (for Orange Lovers)

[johnk]

silasmoon wrote

So forgive my multitude of questions, but still pretty new to this. On the original vero you posted with the LED on the board and the LED+ coming off - how does the offboard wiring work? I've always just attached the LED to the 3PDT with a resistor to power.

if it's not on the board, just wire it your usual way.

[johnk]

mine's done!

[silasmoon]

Wow looks awesome! Would love to hear a clip of the new vs. old if you still have both. Thanks again for all the help - super excited about this build!

[johnk]

silasmoon wrote

Wow looks awesome! Would love to hear a clip of the new vs. old if you still have both. Thanks again for all the help - super excited about this build!

I don't still have both but IMO, the new one blows away the other one. it still can get the same tones as clyen's, but it's a lot more versatile and variable without the flubby low end and much more control of the treble.

[Surgeon]

I built your last layout John and it works fine. Thanks!

[silasmoon]

Having a bit of trouble with this after assembling it. I made a post over on DIYStompbox for troubleshooting. Essentially bypass works, but otherwise it makes no sound. I didn't have J201's on hand so I just used four 2N5457's instead.

I tried to bias as best I could (need a larger array of resistors) but here are my readings:

Q1:
G - 0.0
S - .9
D - 5.2

Q2:
G - 0.0
S - .95
D - 5.0

Q3:
G - 0.0
S - 1.5
D - 2.4

Q4:
G - 0.0
S - .7
D - 6.8

[silasmoon]

Just an update - looks like the hole before treble-3 wasn't needed in the first vero. I bridged it and it seems to be working now. Although it doesn't add much dirt (might be the transistors and biasing though). Thoughts?

[boratto]

I suggest you try the last John´s modded V2.
http://guitar-fx-layouts.42897.x6.nabble.com/file/n11668/001-GreenCitrusMKII-modded.png

[Surgeon]

And here's mine...







To silasmoon: make sure your jfets are adequately biased... seems obvious I know but too low or high resistance to drain can make the circuit completely mute. Just a suggestion...

[boratto]

Masterpiece! What vero version did you used?

[silasmoon]

Okay cool - I will give it a shot. Probably will build this again with the new vero and salvage my transistors. Did you have any issues with using trimpots instead of socketed resistors?

[johnk]

with socketed resistors, I usually start with a 10k-12k and raise or lower the value from there to get the drains to read between 4.5-5V., since for me, trimmers usually add noise to the circuit.

[Surgeon]

Boratto:

Thanks, nowhere near as nice as John's work but it's not bad.

I built John's last vero (the one titled "modified"). Great sounding. Still dark but it's the nature of the amp it tries to emulate so it's all good.

About the bias: I used 10k for the mmbf5457 and 24k and 27k for the mmbfj201... they all are between 4.5 and 5v with this.

[cylens]

Here's mine, I will build a few of those, I'm testing an added FAC control, choosing caps, right now:

[boratto]

Guys, these photos you all published, are pure inspiration for me. Technology + Art, plus excepcional care on the vero build. These little things cames as fresh air, to remember how many good things, we the humans can make flow from our minds, hearts and hands.

[Crusty_Fuzz]

Sup guys! Here my version. And demo with this fuzzy monster http://youtu.be/70ZIdAQDDpY 

[boratto]

Sounds a meanie one!
A lot of feedback, but i thing this is what asking for! Build mine very soon.

[Crusty_Fuzz]

Hey guys. What you think if run this circuit with 18V (through voltage doubler for example)?

[glasspak73]

On Q1 there is a cut between the 22k and 47Ufcap,the 22k is connected from source to ground but the 47Uf cap isn't connected to Q1 Source.Or do i have the wrong schematic?

[Frank_NH]

There isn't a cut.  The 47 uF cap is connected from the source of the JFET to ground and bypasses the 2.2K source resistor for high frequency AC signals (well, high frequency here is 1.5 Hz!).  What this does is to increase the gain of the JFET for AC signals, usually by a factor of 2 or more.  The 2.2K resistor sets the DC bias.

In my opinion 47 uF is way too large for the bypass cap.  It makes these circuits too bassy and flubby/farty.  If you want to tighten up the sound (i.e. reduce bass frequency gain), simply eliminate or at least reduce these caps.  In the present case, I would start at 100 nF and increase to taste.