DD-6 Schematic or high cut mod?????

[7XL]

I'm trying to either find the schematic or the instructions on how to do a high cut mod on a Boss DD-6. I have no problem dealing with surface mount components.

I've searched everyplace that I could think of (and some that I didn't) and can't find any info, other than its not like the DD-3/DD-5 mod.

Any help?

[theelectic]

If it's anything like the DD-5, work backwards from the output de-emphasis mixers and you should hit a gain stage where you can adjust the high frequency response.

[7XL]

85 views, 1 reply (not the correct one). That's so nice.

theelectric, it's not like the DD-5, that's about all I can gather from the info that I could find. Thanks for the response.

[Mark Hammer]

The most basic high-cut mod involves locating the repeat/feedback/recirculation pot lugs on the board and determining how exactly the recirculation is done. In some instances/designs, the pot is a basic voltage divider like any volume control. Here, you simply run a cap from the wiper to ground.

In other instances, especially in digital designs, the processing chip may well have a dedicated repeat path built into it, in which case what the pot for recirculation does may be anybody's guess. It might be a simple variable resistor (like one sees in the Princeton Technology chips), but it could just as easily be a control line for a VCA built into the main chip (which would render the repeats a little more immune to picking up digital noise, and give more freedom in where to locate the pot), in which case you're SOL. If it IS something like the Princeton chip, I have successfully implemented hi-cut by taking the fixed resistor in series with the variable one (which sets maximum repeat amplitude), and simply dividing it into two series resistors equalling the same resistance, with a cap running from their junction to ground. I have no idea if that is possible to do on a DD-6 or where exactly that connection would be.

I've been flogging the high-cut mod since the mid-to-late 80's. Unfortunately, when everything started going digital, I kind of lost track of the technology, so now I have no idea what to tell people to do unless it's an analog box.

[7XL]

Thanks Mark.

The DD-6 uses some sort of rotary encoder to control the feedback, so the "typical" high cut mod wont work (I actually have a blown up DD-6 from trying it). I found some info on another site that stated that it has something to do with changing a resistor value, not the "usual" cap to ground.

The second problem being the circuit board itself, its nearly impossible to trace , dual sided, surface mount components and proprietary IC's.

[Mark Hammer]

That's a shame. As wonderful as many digital effects are, one of the things I generally DON'T like about them is the difficulty of modifying them to suit one's tastes or needs.

The Line 6 Echo Park has three tonal settings that can be applied to any of its programs. One is a full bandwidth "digital" settig. A second is a warmer-sounding "analog" setting, and the third is a "tape" setting that introduces progressive degradation of the signal on repeats. It's a great little pedal, but it still doesn't do what I can get my analog units to do.