Boss Digital Delay DD-6 mods?

[Joe Hart]

Has anyone done any successful mods on a DD-6? I know it's all surface mount components, but maybe someone has some mods and hints?
-Joe Hart

[sean k]

I have a DD-7 and couldn't think what you'd want to mod with these things. They already have so many possiblilities and are so complex inside it'd be a nightmare circuit bending them. Why not go and get some PT2399's?

[R.G.]

An attack of BUMS?

[petemoore]

  One good glance at the board had me looking at the offboard wiring and components for mods.
  With limited inspiration, and limited room inside.
  I'd considered adding a LP filter on the feedback pot to tame highs build up with repeats.

[Joe Hart]

What is "BUMS"?
-Joe Hart

[Joe Hart]

For mods, I was really mostly interested in cutting some highs on the repeats to make it a little more "vintage" sounding.  I know nothing about delays (schematics-wise), and didn't know if there was a "quick and dirty" mod to achieve this.  Thanks.
-Joe

[Scruffie]

What is "BUMS"?
-Joe Hart

I beleive that would be Blind Urge to Mod Syndrome... Not to steal R.G's Thunder

[petemoore]

  Pumping the feedbacker feature [I forget what it's called] helped some when using it.
 The pedal produces amazing layers of HF's which can quickly become fierce, ability to control them would be nice.
 I'd go [at your own risk of course] for the feedback pot [or anywhere else you can figure], if it's a regular pot..hopefully the FB signal path travels through it, I haven't studied echoes much so I can't assume the feedback amount is a simple ''volume control feeds'' on this one.
 Perhaps this pot has a lug, or some other point in the circuit that can be 'tagged' [soldered to] without mucking up the works. Maybe the wiper? can be simply LP filtered, one well chosen leetle cap to shunt some of the highs to ground.  
 Boss didn't leave much elbow room for a pot>cap to allow that to be adjustable.

[sean k]

On my dd7 it's got the analog setting but then the short delay times are analog as well.

I get what your saying now and I think that it may not be so easy to be able to get into the feedback circuitry to install a lowpass filter but I'm only saying that because I took the bottom plate off my pedal and my brain just stopped. It's so complex in there I didn't even want to know whats going on.

If it were a reasonably simple pedal then you'd think that when going into analog mode there was a lowpass from the out of the delay chip that formed the feedback but my guess is they may have gone straight to digital processing, seeing they also have a reverse and hold modes, so ones ability to cut between circuit blocks may be a thing of the past with these things.

But I'm just speculating and given my brain stopped as soon as I opened up the pedal I really don't want it to start up again.

I don't know how Boss works but in this case you may have what could be termed valuable customer feedbak and it may not hurt to enquire directly to Boss.

I've just opened up again... my God!, I found test point 97 on the bottom 

Given they have so many test points it stands to reason there will be a comprehensive service manual and if you cn get one of those you may be in luck.

[synthmonger]

I found that every digital Boss pedal I cracked open was wired for voltage control. The DD-5 was like this and I can safely assume the rest are.

If you want to add external voltage control you'd have to at least add protection diodes and cv summing op-amps.

Check the pots with a multimeter and you'll find they're all wired as voltage dividers.

[Processaurus]

I found that every digital Boss pedal I cracked open was wired for voltage control. The DD-5 was like this and I can safely assume the rest are.

If you want to add external voltage control you'd have to at least add protection diodes and cv summing op-amps.

Check the pots with a multimeter and you'll find they're all wired as voltage dividers.

Yes, probably the most fun to be had with these pedals is by disconnecting the power supply voltage and piping in your own control voltage to the top of one (or more) of the pots.  They use 0-3.3v for the pot's CV. You can use a blue LED (maybe with a Ge diode in series to get the turn on voltage up to 3.3v) to shunt to ground any over voltages on the input (with a small series resistor to limit current between the input and the LED to ground + top of the pot).

input------/\/\/\/\------------------   
              470Ω         l          l   (Existing pot)                 
                             ▼        <         
  l             Blue LED  T         > ←-------- to processor
  l                            l         <           
  l                            l          l             
  l                          ///       ///     

[petemoore]

  ikk...close the casket already !

[synthmonger]

I found that every digital Boss pedal I cracked open was wired for voltage control. The DD-5 was like this and I can safely assume the rest are.

If you want to add external voltage control you'd have to at least add protection diodes and cv summing op-amps.

Check the pots with a multimeter and you'll find they're all wired as voltage dividers.

Yes, probably the most fun to be had with these pedals is by disconnecting the power supply voltage and piping in your own control voltage to the top of one (or more) of the pots.  They use 0-3.3v for the pot's CV. You can use a blue LED (maybe with a Ge diode in series to get the turn on voltage up to 3.3v) to shunt to ground any over voltages on the input (with a small series resistor to limit current between the input and the LED to ground + top of the pot).

3.3v? I've found they always go to a max of 5V. The rotary pots are about 1.5 volt for every function give or take a few mV. My PS-3 is 5v. I really need to get around to modularizing them...

input------/\/\/\/\------------------   
              470Ω         l          l   (Existing pot)                 
                             ▼        <         
  l             Blue LED  T         > ←-------- to processor
  l                            l         <           
  l                            l          l             
  l                          ///       ///     

[Processaurus]

The DD-6 digital section runs on 3.3v.  So does the PS-5, incidentally. 

I did that mod on a DD-6, it's great.  A little zipper noise if I remember right but nothing that is annoying.