DOD - FX100 Integrated Tube Overdrive

ddpawel · Post by **ddpawel** » 15 Apr 2011, 20:11

Have you seen the interior of the DOD FX100 and DOD FX101 on americaspedal?

Does anyone have schematics of one of these effects?

I have heard only a few demos, but I think they are interesting. If anyone wants to somehow help those interested in rare pedals, to ask the company DOD (contact topic - "I Want To Be Contacted By Technical Support") a diagram of DOD FX100 Even Harmonic Overdrive (because FX101 is on the same board, but has less elements, so it would be easier to build two). They are usually happy to give the schematics of not produced effects (I've asked for two other schematics to mod my DOD pedals, and I feel that they will not send me more).

Tonetweaker · Post by **Tonetweaker** » 21 Apr 2011, 02:10

I don't have a copy of the schematic... but I do have the pedal itself.

If you're up to the challenge, I'd be happy to post up some close-up gut shots (trace side, perhaps?) and help out with any component values needed.

Cheers...
Steve

Tonetweaker · Post by **Tonetweaker** » 26 Apr 2011, 04:09

Move this one over to "Modern Stompboxes" and mark it as [Traced] please...

Without further adieu...

I can also post up a parts list if anyone's interested.

Cheers...
Steve

Tonetweaker · Post by **Tonetweaker** » 26 Apr 2011, 04:13

I almost forgot... D6 and D7 are MIA on the FX100 board, but I added their locations to the schematic in case anyone wanted to try the FX101 configuration.

andrewkirsanow · Post by **andrewkirsanow** » 26 Apr 2011, 18:35

Hi there, I don't want to sound dumb here, but I was looking at the component side photos on another website of the FX100 and the FX101, and where D7 is removed on the FX100 board, there seems to be a resistor in it's place, looks like 1k. In the diagram here, R51 looks like this same resistor so I assume it is removed if the diodes are present. Also, the gyrator formed by Q7, R47, C17, C19, R27 and R32 is not present on the FX101.

Does anyone have experience with these actual pedals?? I wonder if they sound as good as the reviews suggest?

Thanks
Andy.

Tonetweaker · Post by **Tonetweaker** » 27 Apr 2011, 03:05

andrewkirsanow wrote:Hi there, I don't want to sound dumb here, but I was looking at the component side photos on another website of the FX100 and the FX101, and where D7 is removed on the FX100 board, there seems to be a resistor in it's place, looks like 1k. In the diagram here, R51 looks like this same resistor so I assume it is removed if the diodes are present. Also, the gyrator formed by Q7, R47, C17, C19, R27 and R32 is not present on the FX101.

Does anyone have experience with these actual pedals?? I wonder if they sound as good as the reviews suggest?

Thanks
Andy.

Yep. Good catch, Andy. When I drew in the diode placement, I forgot to add the resistor. I can't recall if it was a 1k though... I'll have to open it back up. Stay tuned.

I don't have any first-hand experience with the FX101, but I own the FX100. I was just playing around with it again tonight, mostly to ensure I didn't break anything when I put it back together.

I like it... it's pretty versatile. Despite the "overdrive" label, it's capable of a nice hard rock distortion when you crank the Drive. The Level provides quite a bit of gain as well.

I also own the Juice Box (FX51)... I like them both, but this one gets far more play time.

Cheers...
Steve

Tonetweaker · Post by **Tonetweaker** » 27 Apr 2011, 03:50

UPDATE: Andy was right on the money. R51 sits in D7's slot on the FX100. It is a 1k resistor.

The schematic I posted above was correct, but I have removed D6 and D7 to avoid confusion (mostly, mine

). Here's the updated version...

Cheers...
Steve

Tonetweaker · Post by **Tonetweaker** » 27 Apr 2011, 04:11

As an added bonus, I found a little more info about the FX101 over at the "America's Pedal" site:

FX101 Grind Rectifying Overdrive

It says that while both effects use the same board, "R27, R32, R47, C17, C19, and Q7 are missing in the FX101." Combined with what we know about D6, D7/R51, we get the following schematic:

The guys at DOD were nice enough to send me a copy of the FX100 schematic, which is where I got the info about D6 and D7 for the redraw, so I'm pretty confident there. I also updated the knob labeling scheme to match the silly names on the FX101, and the component side picture linked on their page agrees with the other component omissions, so I think this is a pretty accurate schematic overall.

There you go, Pawel. Two for the price of one!

Incidentally, from what I've read about the FX101, most seem to like it even better than the FX100. As I mentioned, I think the FX100 is a pretty decent pedal, so it really has me curious about the FX101. Does anyone here have an FX101? If so, it'd be nice to opinions on it.

Cheers...
Steve

Duckman · Post by **Duckman** » 27 Apr 2011, 04:22

Hi Steve

Nice tracing there.
I use your schemo just to make you a question and give the idea a graphical approach (I hope it doesn't bother you)

So, if we eliminate the squared parts and keep the coloured traces, it will be the correct way to make FX100 true bypass?

mictester · Post by **mictester** » 27 Apr 2011, 05:06

Duckman wrote:Hi Steve

Nice tracing there.
I use your schemo just to make you a question and give the idea a graphical approach (I hope it doesn't bother you)

So, if we eliminate the squared parts and keep the coloured traces, it will be the correct way to make FX100 true bypass?

Why is there this obsession with removing electronic switching? The people who designed this pedal really knew what they were doing! The electronic switching will be entirely silent, whereas mechanical switching will almost certainly "pop"!

Duckman · Post by **Duckman** » 27 Apr 2011, 06:05

Yes, you're 100% right, but I want to use less parts, and, see if I guess well, despite the fact of learn something new.
So, what you think? Squared components are all related to the switching section or not? I'm sure you can help.

andrewkirsanow · Post by **andrewkirsanow** » 27 Apr 2011, 07:17

Hey Steve, thanks for checking out my rantings, I'm loving the schematics. Thanks very much for taking the time to draw it out! I've had a strange liking for DOD pedals ever since I owned one of the American Metal pedals in the early 90s. I just have to build this one though!

Thanks again
Andy.

Ice-9 · Post by **Ice-9** » 27 Apr 2011, 08:53

Duckman wrote:Hi Steve

Nice tracing there.
I use your schemo just to make you a question and give the idea a graphical approach (I hope it doesn't bother you)

So, if we eliminate the squared parts and keep the coloured traces, it will be the correct way to make FX100 true bypass?

No not exactly. To make this true bypass you are correct in removing all the components you have boxed. The first purple trace need removing altogether but leave the second purple trace, then a 3pdt switch needs wired in at the jacks to make it true bypass, your example takes the input from after the buffer.
Hope this helps.

Dirk_Hendrik · Post by **Dirk_Hendrik** » 27 Apr 2011, 16:13

Thanks Steve!

Duckman · Post by **Duckman** » 27 Apr 2011, 19:31

Ice-9 wrote:No not exactly. To make this true bypass you are correct in removing all the components you have boxed. The first purple trace need removing altogether but leave the second purple trace, then a 3pdt switch needs wired in at the jacks to make it true bypass, your example takes the input from after the buffer.
Hope this helps.

Thanks, Ice! I got it.

Now I'm curious to see the opposite side: if I want to convert a true bypass to a super silent switching mode.
The DOD switching section looks interesting, but I'll do a search before.

mictester · Post by **mictester** » 27 Apr 2011, 19:37

Duckman wrote:
Ice-9 wrote:No not exactly. To make this true bypass you are correct in removing all the components you have boxed. The first purple trace need removing altogether but leave the second purple trace, then a 3pdt switch needs wired in at the jacks to make it true bypass, your example takes the input from after the buffer.
Hope this helps.
Thanks, Ice! I got it.

Now I'm curious to see the opposite side: if I want to convert a true bypass to a super silent switching mode.
The DOD switching section looks interesting, but I'll do a search before.

There is an easier (and more reliable) way - use a 4013 for the bistable and a 4066 for the audio routing. It's really easy, and allows the use of cheap momentary switches. The two ICs, their associated components and the switch cost less than a GOOD QUALITY latching footswitch!

Steven_M · Post by **Steven_M** » 27 Apr 2011, 19:49

mictester wrote:
Duckman wrote:
Ice-9 wrote:No not exactly. To make this true bypass you are correct in removing all the components you have boxed. The first purple trace need removing altogether but leave the second purple trace, then a 3pdt switch needs wired in at the jacks to make it true bypass, your example takes the input from after the buffer.
Hope this helps.
Thanks, Ice! I got it.

Now I'm curious to see the opposite side: if I want to convert a true bypass to a super silent switching mode.
The DOD switching section looks interesting, but I'll do a search before.
There is an easier (and more reliable) way - use a 4013 for the bistable and a 4066 for the audio routing. It's really easy, and allows the use of cheap momentary switches. The two ICs, their associated components and the switch cost less than a GOOD QUALITY latching footswitch!

But take considerably longer to design the layout for, and solder in place. I'm all in favor of electronic switching, but 3pdts are much more convenient. Money I have, time, I do not! For mass manufacturing though, you are of course right.

Duckman · Post by **Duckman** » 27 Apr 2011, 19:52

Ok, I retraced it to get a clean version (if Steve still agree)

If some moderator delete the previous one with purple traces, we can save some space

Duckman · Post by **Duckman** » 27 Apr 2011, 20:01

mictester wrote:There is an easier (and more reliable) way - use a 4013 for the bistable and a 4066 for the audio routing. It's really easy, and allows the use of cheap momentary switches. The two ICs, their associated components and the switch cost less than a GOOD QUALITY latching footswitch!

Steven_M wrote:But take considerably longer to design the layout for, and solder in place. I'm all in favor of electronic switching, but 3pdts are much more convenient. Money I have, time, I do not! For mass manufacturing though, you are of course right.

Yeah, all this points must be considerated. My question now: imagine you got your mini board with you switching section on it and now its time to insert in your TBP'ed pedal... will be correct place you input miniboard after you input buffer and your output miniboard before your output buffer?

celadine · Post by **celadine** » 28 Apr 2011, 03:13

Soulsonic's Hunny Bunny is similar to the core of this pedal - check it out for modding ideas:

https://www.freestompboxes.org/viewtopic.php?f=13&t=4027

DOD - FX100 Integrated Tube Overdrive [schematic]