Trouble with DD-5 analog mod

[r080]

I am trying to mod a Boss DD-5 delay for a more analog sound. I have tried putting various sizes of capacitors across different leads of both the feedback and level pots, and none of them seem to do a thing. I just get the same old cold digital repeats.

I do not have a complete DD-5 schematic. The part with the feedback is cut off, so I am just assuming that it is similar to the DD-2 and DD-3.

Is there anything else I should try?

[ayayay!]

What value cap? 

[r080]

I tried .01uF up to about .5uF.

[tommy.genes]

I do not have a complete DD-5 schematic. The part with the feedback is cut off, so I am just assuming that it is similar to the DD-2 and DD-3.

I've seen neither a schematic nor a real DD-5, but from what I've heard/read, the feedback portion of the DD-5 is not the same as the DD-2/3, so the same mod does not work. The DD-2/3 essentially copied an analog delay with feedback path, but substituted a digital delay line in place of the old BBDs. The DD-5 handles feedback in the digital realm from what I understand.

-- T. G. --

[r080]

So the microcontroller just tells the delay chip how many times to play back?

It looks like there is no hope of making the repeats get filtered more each time the play.

I did get filtering to work on the level knob, but obviously only for lower mix settings.

[TheBigMan]

Been a while since I modded one (And since I last posted!), but it DOES work on the DD-5.  From memory it's the effect level pot you use.  However as the DD-5 is a stereo pedal it's a dual gang pot, and only one set of lugs carries the signal in mono mode.

[Fender56]

R080,

You can do this mod on the DD-5 (because I did!!!) and it works well. You can not do it (at least easily) on the DD-6 however.

I am sure that I have the schematics somewhere... I will look tonight at home. It is an easy mod, I will reopen my DD-5 and write down how to do it. Since I don't have a stereo rig, I use the mono/left output unaffected, and the right output modded. So I have both options handy!!!

[Fender56]

Schematics:

http://us.share.geocities.com/glowgloves/dd5.jpg


(For some reasons, link does not work... Copy and paste it in your browser)

[tommy.genes]

Putting a cap on the E.LEVEL knob will make all the repeats darker than the original by equal amounts, but will not make them progressively darker with each repeat. That would require placing an RC filter in the feedback path - and the schematic from Fender56 confirms that the DD-5 doesn't have one! 

In other words, putting a cap on the E.LEVEL knob of the DD-5 is pretty much just like placing a cap on the E.LEVEL pot of the DD-2/3. Putting a cap on the F.BACK knob of the DD-2/3 gives you progressively darker repeats, but there is no equivalent mod to the DD-5. All the other pots of the DD-5 (F.BACK, D.TIME and MODE) are only inputting a variable into IC10 (M37470), which is a microcontroller. No musical signal is passing through these pots.

-- T. G. --