DOD DFX94 Digital Delay/Sampler

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WhiteWarlock
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DOD DFX94 Digital Delay/Sampler

Post by WhiteWarlock »

Image
This pedal was thrown as be after broke broken during someone performance in the late 90s/early 2000...
Created this thread for attempting troubleshooting it again... plus archiving resources...
either it gets repaired soon or goes on ebay as DOA for parts...
all LEDs light up and stay on(no change) when given power...
no signal... no effect... no functional...
No schematics are at all available anywhere online that can find for this model....
DOD DFX94 seems like somewhat rare pedal...
doing more research...
Last edited by WhiteWarlock on Wed Jan 22, 2020 1:11 pm, edited 3 times in total.
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Re: DOD DFX94 Digital Delay/Sampler

Post by WhiteWarlock »

Archival Info
The DFX94 seems to suffer from being 150 pounds of meat stuffed in 100 pound bag.
[b

Operating Theater: DOD DFX94 Digital Delay / Sampler[/b]

Posted on 2012/01/27 by Doktor Ross Sewage

This was another non-functioning pedal handed to me by my friend Mauz, the DOD DFX94 Digital Delay / Sampler. Ixe2x80x99d gotten pretty cocky after Ixe2x80x99d fixed his DOD FX9, so I took this one on with confidence.

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DOD FX94

When working, the DFX94 was purported to have a spacious maximum of 4 seconds delay along with an xe2x80x9cinfinite repeatxe2x80x9d and a sample function. I had no idea how to get any of these special functions to work as finding a DOD manual online is kind of like trying to find a funny Owen Wilson movie. What I did know was that the normal delay functions wouldnxe2x80x99t power up.

DOD pedals seem to be notorious for switching problems. The way the footswitch works is to momentarily connect a transistor pair to ground, shorting a flip-flop circuit, and then all this other stuff happens that makes the pedal switch on and off (an excellent article on the subject is contained here: http://www.geofex.com/Article_Folders/bosstech.pdf). I test the switching on a pedal that uses this system by shorting it past the switch.

I shorted where the wires connected to the switch; nothing. The switch was fine, so maybe it was a broken wire. I shorted where the wires connected to a plug; nothing. Maybe it was the plug. I shorted the jack of the plug to the PCB; nothing. Finally, I shorted the PCB solder pads themselves and the pedal switched like normal. The culprit was a loose connection with a group of solid leads going to the double-sided PCB.

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DOD FX94 switch

The same problem occurred in a different spot on the DFX9 I had fixed for Mauz before. I heated up the leads real good and gave them a generous amount of solder to soak through both sides of the PCB. The switching problem was solved. The pedal was working again, just like Owen Wilson (unfortunately).

The DFX94 does contain 4 seconds of delay. In my opinion, it sounds fairly warm compared to the popular BOSS digital delays. The repeats died off too quick, though, so I opted to fix that.

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DOD FX94 trim pots

I adjusted the 50k trim pot at location P2, clearly labeled xe2x80x9crepeatxe2x80x9d underneath. When the repeat knob is at maximum the pedal now just keeps going for awhile and eventually starts distorting into some luscious noise. Itxe2x80x99s handy if you wanna clear a room. Or you could put on Wedding Crashers.

The xe2x80x9cinfinite repeatxe2x80x9d function on the mode knob works just like the DFX9. The delay is automatically engaged. Hit the footswitch and that repeat keeps going while the instrument signal plays through, bypassing the effect. This is indicated once the LED on the right lights up. You can now play over the looped phrase.

An addition to the DFX94 is the sample function. Turn the mode knob all the way to the right and you can record a phrase. Both LEDs will be on, but you wonxe2x80x99t hear any delay. When you hit the footswitch, the right LED will dim and the pedal will be recording. When the right LED lights back up, itxe2x80x99s done. The sampling time is controlled by the delay knob for up to 4 seconds. Now switch the mode knob to xe2x80x9ctriggerxe2x80x9d mode. When you hit the footswitch it will play the phrase you recorded while the instrument signal goes through unaffected. Go back to xe2x80x9csamplexe2x80x9d mode, and you can keep recording on top of the original phrase as many times as you want. Switch back to xe2x80x9cinfinite repeatxe2x80x9d mode and the mess will go on forever. Kinda like The Royal Tenenbaums.

After taking care of the insides, I did a bit of work on the outside of the pedal. First I replaced the missing knobs with some Ixe2x80x99d salvaged. I wanted to make sure they didnxe2x80x99t go missing again.

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DOD FX94 knobs

VERY carefully I expanded the slots of the knurled pots. This xe2x80x9cpig ironxe2x80x9d is an extremely cheap metal. It will break, so this should be done with the utmost care. Do not overdo it or youxe2x80x99ll have a broken pot. Do it just right and your knobs will be as snug as You, Me and Dupree.

The battery cover for this little guy was missing. As if youxe2x80x99d want to run a digital delay on batteries. Itxe2x80x99s sucking 32mA on average and will suck life out of batteries quicker than The Darjeeling Limited can suck the life out of a theater. Curiously, it uses less power than its little brother, the DFX9. I still opted to close off the battery compartment rather than have a loose 9V battery snap flying about. I cut a small piece of plexi-glass and fit it into the battery compartment.

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DOD FX94 battery cover

more info on the DFX94: http://www.americaspedal.net/dfx94/
http://www.doktorsewage.com/operating-t ... y-sampler/
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Re: DOD DFX94 Digital Delay/Sampler

Post by WhiteWarlock »



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Re: DOD DFX94 Digital Delay/Sampler

Post by WhiteWarlock »

HOW TO USE THE DFX-94 FOR LOOPING:

Most delay functions are pretty self-explanatory, so I'll
assume you mean how to use it for sampling, and then
triggering the sample during performance.

Here we go (with the manual in front of me):

1. Select the SAMPLE position on the RANGE/MODE switch.
In this mode the BYPASS fotswitch becomes the SAMPLE
footswitch only.

2. Adjust the amount of delay time you want with the
DELAY control.

3. When you're ready to sample, tap the footswitch.
The INFINITE REPEAT/SAMPLE LED light will go *OUT*.
The unit is *now* sampling whatever you play into it.
The LED comes back *ON* when the sample record time is
done. (If you're plaing along at home, the unit is
finished sampling what ever you played into it).

4. Select the TRIGGER position on the RANGE/MODE switch. In
this mode the BYPASS footswitch becomes the SAMPLE
TRIGGER footswitch only. The unit is now ready for
triggering.

5. Whenever you want to TRIGGER the playback of
your recorded sample sound, tap the footswitch.

With practice (trial and lots of error), by putting
the unit into and out of SAMPLE RECORD for one cycle,
you can layer more lines onto the previously sampled
sound (after a while though, quality deteriorates).

After recording a sampled sound, you can also turn the
RANGE/MODE switch to INFINITE REPEAT and play back a
repeating loop (the whole point, right?) of your
recorded sample.
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Re: DOD DFX94 Digital Delay/Sampler

Post by WhiteWarlock »

DOD DFX94

Delay pedal and analog sample from 250 ms to 4 sec. (And 6 if you change a trim pot inside)


4 knobs:

Level Level repeating sound in the mix.
Repeat repetition rate
Delay Time of Delay
Range / mode selection section of time or mode (sampler, infinite repeat, trigger)

Power 9-volt mini jack
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Re: DOD DFX94 Digital Delay/Sampler

Post by timdrage »

those are fun :) I found one in the street once, fixed the battery clip and tweaked an internal pot and it worked fine for a while, stopped for some reason tho and I sold it in a lot of dead pedals ha
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Re: DOD DFX94 Digital Delay/Sampler

Post by WhiteWarlock »

the mode pot is broken/cracked... potentiometer is drying now... superglue...
seriously doubt that is the only problem... both lights come on and stay on soon as it gets power...
no signal at all... hasn't been functional since the 90s...
it may end up on ebay soon & will just use the PDS1002.... DL4... or one of the Time Machines...
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