DOD - FX51 Juice Box  [schematic]

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DOD - FX51 Juice Box

Postby alteredsounds » 01 Jan 2009, 12:36

Image

Great sounding box from the old DOD FX range, if anyone's interested I'll do values and the trace side
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Re: DOD FX51 - Juice Box

Postby puppiesonacid » 01 Jan 2009, 16:25

yeah im interested. post away.
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Re: DOD FX51 - Juice Box

Postby PurplePeopleEater » 01 Jan 2009, 17:49

Definitely - the Juice Box is one of my favorites. Great sounding OD. IIRC, it's basically the Bad Monkey with more EQ.
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Re: DOD FX51 - Juice Box

Postby alteredsounds » 01 Jan 2009, 22:41

cool, i'll get to work on it, was looking at maybe reversing the Zoom Ultrafuzz too if there's interest, cant see if its been done
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Re: DOD FX51 - Juice Box

Postby Entrant_21 » 02 Jan 2009, 03:24

Hey definately trace it, sounds like a great pedal!
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Re: DOD - FX51 ( Juice Box )

Postby Cups » 06 Oct 2009, 00:49

I own one. I really like it. Been looking for a schematic since forever.
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Re: DOD - FX51 ( Juice Box )

Postby blanik » 06 Oct 2009, 03:47

there's two 4558 and one 4007UBE, is the 4007 just used for the switching or is used for clipping??
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Re: DOD - FX51 ( Juice Box )

Postby Dirk_Hendrik » 06 Oct 2009, 17:59

Antiparallel diodes bottom left. Assume clipping.
4007 in a DOD? assume bypass switching.

Love it when manufacturers stick to a working topology.

and yes please, give us all. Tracing shouldn't be that difficult. :mrgreen:
Sorry. Plain out of planes.

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Re: DOD - FX51 ( Juice Box )

Postby borislavgajic » 06 Oct 2009, 18:10

Dirk_Hendrik wrote:
and yes please, give us all. Tracing shouldn't be that difficult. :mrgreen:



why not :mrgreen: ?
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Re: DOD - FX51 ( Juice Box )

Postby himister » 06 Oct 2009, 21:58

+1 Count me in Boris. :applause:
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Re: DOD - FX51 ( Juice Box )  [schematic]

Postby nexion777 » 27 Jun 2010, 03:24

Here the schematic (I hope is right).

http://www.diystompboxes.com/smfforum/i ... ic=80440.0

But... Can we have a gutshot for the track side? :blackeye
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Re: DOD - FX51 ( Juice Box )

Postby Bernardduur » 27 Apr 2015, 20:04

I've bought a broken one for dirt cheap........

And I must say the problems with this unit is as many others have descrived in the online fora. It is bright, the controls have sometimes little to change and the overal sound (with a clean amp) is pretty clangy / overly bright. When combined with an already OD'ing amp it works pretty well...........

So I wanted to see what I could change.

The pedal's brightness is part due to the design and part due to the chosen values of the potmeters. All potmeters in this unit are 100k lin and that doesn't work that well for some paramters. The gain (called 'juice') doens't do anything on the first 50%, then suddenly all nice gain structures can be made. Same with the treble (called 'Tang') that does not function between 20 -100%; only the first 20% really change the treble from down and bassy to high and shrill. Time for a change!

I added a 100k resistor parallel to the gain potmeter. Now I can dial in a lot of gain sounds much better.
I added a 1u cap to the 0.22u cap on the opamps feedback loop to get some more lows in the higher gained settings. Works pretty well!!
I added a 47k and a 10k to the treble potmeter (between the lugs); with these changes it now functions from 0 - 75% perfectly!

This made the unit already great, but I wanted more! There is one gyrator for the lows (approx 106.3Hz / Q=1.47) that is tied to a potmeter so the lows can be dialed in. Another gyrator (approx 876.6Hz / Q=1.21) is set to max. I added another 100k lin potmeter to the unit to dial in the mids. This function really makes the pedal shine! In the lower mids setting it becomes a transparant drive pedal, on the higher mids setting it really cuts through the mix (tubescreamer like). Nice!!


One last thing I noticed is the 'clean interference loop' (Q5 - R21) that I put on a switch. I was expecting it to behave like a clean blend and making the pedal sounds fuller and more broad. But I was surprised to find out that switching this circuit in made the sound only worse. It lowers the output and makes the mids stand out more (a more focussed or edgy sound). Switching this circuit off really opened up the pedal and make it more broad sounding with nice lows and highs.

I dunno why this behaves like this. I can only guess a phase interference to make these sounds. I'm glad that I made it switchable!!
'No more....... loud music.......'
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