DOD - FX22 Vibro Thang [schematic]
- modman
- a d m i n
Information
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Board index » Circuit Analysis » Modern Stompbox Effects (1975 - ...)
Most of this generation DODs have schematics all over the internet ...
Board index » Circuit Analysis » Modern Stompbox Effects (1975 - ...)
Most of this generation DODs have schematics all over the internet ...
Please, support freestompboxes.org on Patreon for just 1 pcb per year! Or donate directly through PayPal
- devastator
- Cap Cooler
....it appears that the 6mm switch has been replaced,possibly wrongly oriented-remove it and turn it 90 degrees and solder it back on...I've repaired this replacement error several times for diy friends that don't understand the internal connections of this switch..........dr
- ddpawel
- Breadboard Brother
DOD - FX22 Vibro Thang GUTS - no schema yet?
Why not let someone write to the DOD Technical Support? I asked them about the schematics of DOD Big Fat Distortion in order to modify my DOD Grunge, and within 24 hours they helped.
The simplest solutions are the best.
Why not let someone write to the DOD Technical Support? I asked them about the schematics of DOD Big Fat Distortion in order to modify my DOD Grunge, and within 24 hours they helped.
The simplest solutions are the best.
- ddpawel
- Breadboard Brother
Schematic of LFO section:
LFO goes to 1 and 18 pins of the first LM13600 and 1 pin of the second LM13600. DROP goes to 18 pin of second one.
Soon I will send phase stages.
LFO goes to 1 and 18 pins of the first LM13600 and 1 pin of the second LM13600. DROP goes to 18 pin of second one.
Soon I will send phase stages.
- devastator
- Cap Cooler
You have this pedal in your hands ?
glad to see it being traced !
Thanks!
glad to see it being traced !
Thanks!
- Professor SourTone
- Solder Soldier
Its a nice pedal - lots of action for low £...
- devastator
- Cap Cooler
Hello there !
May I use this thread to expose my issue ?
Just received my 2nd FX22 ... Yes iI do love those pedal for Rhodes and electric keyboards ...
I've modified the 1st one in order to activate the speed (rpm's) with a volume pedal ... it works really nice!
Now on the second one the rpm's when at max is not fast as my first one (75%) ...
what could do this ? the pot seems fine as when I bypass it it is the same.
The IC (JRC 2904D) ?
Thanks very much
G
May I use this thread to expose my issue ?
Just received my 2nd FX22 ... Yes iI do love those pedal for Rhodes and electric keyboards ...
I've modified the 1st one in order to activate the speed (rpm's) with a volume pedal ... it works really nice!
Now on the second one the rpm's when at max is not fast as my first one (75%) ...
what could do this ? the pot seems fine as when I bypass it it is the same.
The IC (JRC 2904D) ?
Thanks very much
G
- Dirk_Hendrik
- Old Solderhand
Information
Hard to tell unless you explain a little more about how you modified your FX22's.
But no. It's not the IC. Why do you even think that?
But no. It's not the IC. Why do you even think that?
Thanks fior answering !
No my modified one works perfectly independantly of the mod.
The problem is the new one on wich the speed doesn't go as fast as on my first one.
By reading the diagram kindly post by DoctorSound I can 't really see what could be the culprit ...
RPMS controls the speed .... DROP the depth.
No my modified one works perfectly independantly of the mod.
The problem is the new one on wich the speed doesn't go as fast as on my first one.
By reading the diagram kindly post by DoctorSound I can 't really see what could be the culprit ...
RPMS controls the speed .... DROP the depth.
Received that from DOD :
It might be that the taper of the pot is off spec, even if it reads the resistance values correct on a meter.
Regards,
Bill Clayton
Technical Customer Service
Harman Signal Processing
Seems to me a strange answer as when I hardwired bypassed the pot it doesn't change anything to the problem.
It might be that the taper of the pot is off spec, even if it reads the resistance values correct on a meter.
Regards,
Bill Clayton
Technical Customer Service
Harman Signal Processing
Seems to me a strange answer as when I hardwired bypassed the pot it doesn't change anything to the problem.
- GodSaveMetal
- Resistor Ronker
- mictester
- Old Solderhand
Information
What nonsense from DOD!! It's the tolerance of C25 - most electrolytic capacitors have a wide tolerance - often as much as 20%! Your 4µ7 could be as low as 3µ7 or as high as 5µ6. If it's higher in value, the oscillator will run more slowly....trubac wrote:Thanks fior answering !
No my modified one works perfectly independantly of the mod.
The problem is the new one on wich the speed doesn't go as fast as on my first one.
By reading the diagram kindly post by DoctorSound I can 't really see what could be the culprit ...
RPMS controls the speed .... DROP the depth.
[ Image ]
"Why is it humming?" "Because it doesn't know the words!"
I've just managed to shunt the bypass network on my FX22.
It was a frustrating attempt at first, but after studying the schematics, I remembered something from my studies of passive crossovers in speaker networks, which was;
when you need a non polarized capacitor and you have none, wire up the negatives of two half value capacitors together, et voila, a non polarized cap is made.
In studying the schematic, I learned C12 & C13 on the input side of the effect block of the circuit, and C11 & C19 on the output side of the effect block of the circuit
are wired in such a way, with a J201 in between the capacitor pairs. The Source of each J201 are tied to an RC network to ground, Q2 & Q6 in between the capacitor pairs, and Q3 in the bypass loop. The switch button inverts which J201 Source to ground when activating the 4007A inverter IC network.
The Effect bypass bypass (or "always on") was accomplished by desoldering the negative side of C12 & C13, lifting it from the PCB and jumpering them with a length of wire.
For the output side I did the same thing to C11 & C19.
The Input & Output remain as originally wired and the TRS input functions to activate the battery snap B+ just as before.
The switch still functions to change the inverter (4007A) as before, but with the bypass shunt in place, merely deactivates/activates the indicator LED, having no audible effect on the sound output.
Your FX22 will now be ready to wire in your favorite True Bypass method: 3PDT, OptoCoupler, or Relay.
As soon as I have an idea about a better input and output circuit than the stock J201 input and 2N5088 output devices, I will post my findings.
(I just wish this pedal was still under warranty so I could add one more to the burn pile)
It was a frustrating attempt at first, but after studying the schematics, I remembered something from my studies of passive crossovers in speaker networks, which was;
when you need a non polarized capacitor and you have none, wire up the negatives of two half value capacitors together, et voila, a non polarized cap is made.
In studying the schematic, I learned C12 & C13 on the input side of the effect block of the circuit, and C11 & C19 on the output side of the effect block of the circuit
are wired in such a way, with a J201 in between the capacitor pairs. The Source of each J201 are tied to an RC network to ground, Q2 & Q6 in between the capacitor pairs, and Q3 in the bypass loop. The switch button inverts which J201 Source to ground when activating the 4007A inverter IC network.
The Effect bypass bypass (or "always on") was accomplished by desoldering the negative side of C12 & C13, lifting it from the PCB and jumpering them with a length of wire.
For the output side I did the same thing to C11 & C19.
The Input & Output remain as originally wired and the TRS input functions to activate the battery snap B+ just as before.
The switch still functions to change the inverter (4007A) as before, but with the bypass shunt in place, merely deactivates/activates the indicator LED, having no audible effect on the sound output.
Your FX22 will now be ready to wire in your favorite True Bypass method: 3PDT, OptoCoupler, or Relay.
As soon as I have an idea about a better input and output circuit than the stock J201 input and 2N5088 output devices, I will post my findings.
(I just wish this pedal was still under warranty so I could add one more to the burn pile)
- czech-one-2
- Breadboard Brother
Thats awesome! I've got a vibrothang incoming so I may try that! Anybody know how to hook up a flashing rate led?B_Y_O_Bass wrote:I've just managed to shunt the bypass network on my FX22.
It was a frustrating attempt at first, but after studying the schematics, I remembered something from my studies of passive crossovers in speaker networks, which was;
when you need a non polarized capacitor and you have none, wire up the negatives of two half value capacitors together, et voila, a non polarized cap is made.
In studying the schematic, I learned C12 & C13 on the input side of the effect block of the circuit, and C11 & C19 on the output side of the effect block of the circuit
are wired in such a way, with a J201 in between the capacitor pairs. The Source of each J201 are tied to an RC network to ground, Q2 & Q6 in between the capacitor pairs, and Q3 in the bypass loop. The switch button inverts which J201 Source to ground when activating the 4007A inverter IC network.
The Effect bypass bypass (or "always on") was accomplished by desoldering the negative side of C12 & C13, lifting it from the PCB and jumpering them with a length of wire.
For the output side I did the same thing to C11 & C19.
The Input & Output remain as originally wired and the TRS input functions to activate the battery snap B+ just as before.
The switch still functions to change the inverter (4007A) as before, but with the bypass shunt in place, merely deactivates/activates the indicator LED, having no audible effect on the sound output.
Your FX22 will now be ready to wire in your favorite True Bypass method: 3PDT, OptoCoupler, or Relay.
As soon as I have an idea about a better input and output circuit than the stock J201 input and 2N5088 output devices, I will post my findings.
(I just wish this pedal was still under warranty so I could add one more to the burn pile)
- deltafred
- Opamp Operator
Slight correction, you need 2 capacitors of twice the value you require not half.B_Y_O_Bass wrote:when you need a non polarized capacitor and you have none, wire up the negatives of two half value capacitors together, et voila, a non polarized cap is made.
Politics is the art of so plucking the goose as to obtain the most feathers with the least squawking. - R.G. 2011
Jeez, she's an ugly bastard, she makes my socks hurt. I hope it's no ones missus here. - Ice-9 2012
Jeez, she's an ugly bastard, she makes my socks hurt. I hope it's no ones missus here. - Ice-9 2012
- Blitz Krieg
- Breadboard Brother
viewtopic.php?f=7&t=20594&start=20#p257508
287m wrote:no, two 1 uF polarized (+-) wired in series like +--+ , still 1uFBlitz Krieg wrote:^^^^ 2 uf?
normally, you right.grrrunge wrote:No! Capacitances in series adds up like resistances do in parallel. 2*1µF in series would effectively give you 0.5µF.287m wrote:hey Miles
You can make a quick and dirty 1u nonpolar wannabe capacitor by tying together the negatives of 2 1u electro
then solder positive leg to board
To get 1µF you'll need two 2µF caps in series
normal elco actually conduct in the reverse direction, two 1uF polarized act like they each have a diode in parallel with them that conducts when the voltage is backwards for that one cap.