Anyone Have A Maxon OD-9 Schematic?

[turbolx5oh]

I'm looking for a Maxon OD-9 Schematic. Google search comes up with a OD-808 but no OD-9. Anyone know where I can get the schematic for this box?

[Mark Hammer]

It's a new box, right? Why would you expect a schematic to be floating around?

[turbolx5oh]

It's a new box, right? Why would you expect a schematic to be floating around?

OD-9 has been out a while.

I personally don't expect anything from the internet. That way I'm never disappointed and usually my expectations for schematic floatage are usually even lower if I can't find it on Google.

[Mark Hammer]

Fair enough (though "new" for me means out for a couple of years, not necessarily a recent NAMM display). Okay, well then next question is: Is this request for repair, mod, intellectual curiosity, or cloning purposes?

I don't have the schematic, but may be able to assist in two of those areas listed.

[turbolx5oh]

Fair enough (though "new" for me means out for a couple of years, not necessarily a recent NAMM display). Okay, well then next question is: Is this request for repair, mod, intellectual curiosity, or cloning purposes?

I don't have the schematic, but may be able to assist in two of those areas listed.

I have one and when I opened it up to see how few components are on the circuit board, I got curious. Looks to be a VERY simple single opamp tubescreamer layout. One thing though, the box just has too much of a mid hump for me. I personally don't want to modify mine because I can get good money for it on ebay if I decide to sell it. I'd like to make a clone to futz with. I've already got all of the parts to make one I'm sure.

[Mark Hammer]

Overdrives of that nature are a bit like macaroni and cheese; everybody has their own "recipe" even though they all have the same basic ingredients. If you want/expect to sell it, then I suggest you take a peek at either the BYOC projects or those at the Generalguitargadgets or Tonepad sites, for usable low-cost replacement clones. There is simply no end to the sorts of mods one can apply that provide custom tone-tailoring, including various ways to reduce the perceived midrange hump. Many of those will be available at the diy stompbox forum. Trust me, that particular topic is one of the more well-trodden paths in the world.

[turbolx5oh]

Overdrives of that nature are a bit like macaroni and cheese; everybody has their own "recipe" even though they all have the same basic ingredients. If you want/expect to sell it, then I suggest you take a peek at either the BYOC projects or those at the Generalguitargadgets or Tonepad sites, for usable low-cost replacement clones. There is simply no end to the sorts of mods one can apply that provide custom tone-tailoring, including various ways to reduce the perceived midrange hump. Many of those will be available at the diy stompbox forum. Trust me, that particular topic is one of the more well-trodden paths in the world.

Oh, I agree but my guitar teacher has said I can't make one that sounds like the OD-9 after I described how simple it was. As far as BYOC is concerned, I've got a Shredder and a Screamer and the Screamer doesn't have the mid hump of a OD-9 and I think the OD-9 only has one clipping diode. But my Screamer already sounds good enough for me and I really don't want to tweak it. I'll just keep doing a periodic search for the schematic until one pops up some where.

[Sock Puppet]

http://www.dirk-hendrik.com/ibanez.html#Overdrive OD-9

According to Dirk, the "OD-9 is electronically a full twin of the orange OD-850 Overdrive"

HTH

S.

[turbolx5oh]

http://www.dirk-hendrik.com/ibanez.html#Overdrive OD-9

According to Dirk, the "OD-9 is electronically a full twin of the orange OD-850 Overdrive"

HTH

S.

In that page he is talking about a vintage OD-9. The schematic for the OD-850 doesn't have an opamp in it and the Maxon OD-9 does. Besides the circuit board for that OD-850 looks way more complicated that my Maxon OD-9 (see attachements). Good find on that site though. Some cool info.

[Mark Hammer]

Well, assuming Dirk is right (and he has shown good judgment in my experience for the years I've known him), the OD-9 is a Big Muff Pi with a slightly different tone control and electronic switching (and the input and output buffers that implies).

BMPs have undergoone a surfeit of tweaks over the years, and people swear by this issue, that one, or the other one. I've built a handful, following the very same schematic and they all come out different-sounding, so I am in no position to say "Build this one, and you will recreate the tone you like".

The PCB picture you post indicates that what you have is fundamental different from the basic 4-transistor BMP circuit. Instead, what it suggests is that the OD-9 is actually a different circuit. Maxon made an interesting overdrive before the TS-808 which essentially reversed the order of the clipping stage and tone-control stage, such that the tone pot adjusted the quality of what was driving the clipping stage. I suspect that is what the OD-9 is.

[turbolx5oh]

Well, assuming Dirk is right (and he has shown good judgment in my experience for the years I've known him), the OD-9 is a Big Muff Pi with a slightly different tone control and electronic switching (and the input and output buffers that implies).

BMPs have undergoone a surfeit of tweaks over the years, and people swear by this issue, that one, or the other one. I've built a handful, following the very same schematic and they all come out different-sounding, so I am in no position to say "Build this one, and you will recreate the tone you like".

The PCB picture you post indicates that what you have is fundamental different from the basic 4-transistor BMP circuit. Instead, what it suggests is that the OD-9 is actually a different circuit. Maxon made an interesting overdrive before the TS-808 which essentially reversed the order of the clipping stage and tone-control stage, such that the tone pot adjusted the quality of what was driving the clipping stage. I suspect that is what the OD-9 is.

Yea you're probably right. It looks super simple to make.

[Mark Hammer]

try this schematic out: http://www.freeinfosociety.com/elect...banezod855.pdf

If you compare it to the TS-808/TS-9, you'll see that it's essentially the same thing, except the tone contro stage comes first. Never actually heard one myself, but I've engaged in enough comparisons of pre-clip vs post-clip EQ to know it should make a difference.

A second difference is that where the "normal" TS-9/808 has the diodes in the feedback path of the op-amp, the 855 has them going to ground. I won't go into the reasons here, but it produces a different quality of distortion and dynamics. In essence, the 855 is a Distortion+ or DOD250 with a tone stage preceding the clipping stage.