Orange Graphic MKII "Stompbox Adaptation" Schematic Inside. Happy Kwanzaa!

[Bucksears]

DOH!!
Nelson, sorry man, I was supposed to start working on this PCB. I'll get off my butt and get to it this wkd!

- Buck

[ragtime8922]

Hm, i've been lurking at all the schems of the oranges (heh), and i think i spotted an error here...

The capacitor connected to the bass pot has been marked 0,22uF, while i have seen a schem or two with that value, i suspect it should have been 0,022uF (22nF).

I've tried all the variations of the orange tonestack in the duncan TSC and that one with the 220nF next to the bass pot makes bass response unusable...

Other major differences between different orange tonstacks are in that highmid determing capacitor, usually 1500pF or 330pF, the larger valued one lets more highmids...

This is just my logic, i'm not trying to say anything bad about your design, but i have some limited expirience with this type of tonestack and this value really gives some wierd graphs...

If you consider how nice treble and/or mid  boosters contribute to tone AND how, historically, large ammounts of low end in a pedal produce mud then the response displayed in that graph isn't bad at all. However, ideally, that graph wouldn't be the result when both knobs are dimed.

[MartyMart]

I think that you are correct, many other similar tonestacks use that 22n ( 0.022uf) cap
value too.
220n seems WAY too large here.

Marty.

[Branimir]

To ragtime:

I was thinking at the "original" preamp schematic (tube one) cap value error, that was simply copied to this stompbox design...



cheers!

ps: i would be much interested in building this circuit just to try it with my diy Orange only thing i would consider doing is omitting the tonestack, or putting somekind of one knob control, since i don't think that it would be wise to have same bass/treble setups on both the pedal and the real thing I know a lot of the mojo in this circuit is right there in the tone shaping, and all of the distortion comes after the tonestack so throwing out the tonestack would introduce distortion to the freqeucies that usually are supressed in the orange... Of course, amp's tonestack would take care of that part, but the dirt has been done.. heh...

[mydementia]

Hey guys.
Any progress on a PCB layout for this one?  I've thoroughly enjoyed the Dr. Boogey and JCM800 JFET emus and, for some strange reason, can't seem to get enough...

Thanks.
Mike

[nelson]

I used it as the preamp for a 6 w stereo guitar amp layout.

It doesnt have the speaker roll off filter on the output but this is easy to tack on (check out output section of ROG marshall emu).


http://cordova.asap.um.maine.edu/~raymondj/imagehost/stereoamp.pdf

you can find the layout in there.

you could also replace the 2 470R resistors with a 1K pot if you want the original boost pot (make it footswitchable).

[MartyMart]

Hey nelson, how's it going ?
I've just started the Citrus and will complete it in the morning .... a question :
The Bass pot to Treble pot connection, do the 2200pf and 0.022uf caps both connect
to lug 2 and the 100k to lug 2 on treble pot ?
And I'm 99% sure that should be a 0.022 NOT a 0.22 cap ... !

Thanks,

Marty.

[joelap]

Bump.  Any progress on this box?  Thinking about perfing one up, wondering if anyone's done a layout yet or has clips?

[MartyMart]

Search for "Citrus Graphic"
There's a complete vero layout and notes on value changes.
Bass Tone cap is a 0.022uf
Bypass caps are all 0.068uf's not 0.68uf's

It's a cracking little amp sim !

MM.

[audioguy]

Has anyone made a PCB of this yet???

Thanks!