DD3 Signal took a vacation... come back please!

[delbowski]

i must be mr. delay question this week... but i'm hoping this question is an easy one.  i modded a friends dd3 to have a high cut toggle and put an effects insert where the direct out jack used to be.  i've done this to my dd3 already and it worked like it should on my pedal. 

i'm not getting any signal to my amp in bypass mode, and when i turn the pedal on it doesn't pass the original note but all the delays come through loud and clear.  when i put a pedal into the insert there is still no original note, but all the delays now have whatever effect is connected to the delay. 

i'm guessing that all my jacks are wired right or else i wouldn't be getting any signal at all, but what is stopping the original from getting through?  i'm hoping that i'm not overlooking the obvious, but i can't see this being as hard as i'm finding it to be! 

thanks for any help,
del

[p1_ind]

On the DD2 and older DD3 the Direct Out jack is a stereo jack.  There is a switching circuit in the pedal that works with the direct out jack so that when a mono plug is put into the jack it grounds the ring to the sleeve and cuts the direct signal from the Mono (normal) output jack so that you only get the delayed signal out of the Mono out and only direct signal to the Direct out jack.

I hope that helps.  I know there are schematics online of the DD2 and older DD3.

Adam

[delbowski]

thanks Adam, for the help...

i think the way i wired it up wouldn't make a difference though. 

i put a nc trs jack in place of the direct out jack and totally removed the wires that the direct out jack had connected to them (two wires from direct jack to board).  i did this on my other pedal and there was no problem.
i took the lead from the feedback to the tip of the trs, jumped it to the nc ring lug and then took the lead from the board to the other ring lug. 
i took the ground from the switch to the sleeve of the trs and then jumped that to the sleeve of the input jack (the trs jack i'm using has no metal that makes contact with the enclosure).
i'm pretty sure i wired it all up correctly, so there still is a stereo jack where the direct jack used to be, and it doesn't work even without anything plugged into the nc trs.  like i said before, i'm getting no original signal, but delays are coming through and no signal in bypass.  any more advice??  thanks a lot... you guys are great.

del

[p1_ind]

The direct signal is turned off and on at Q5.  Check both drain and source on Q5 with an audio probe for the direct signal.  If you have direct signal on only one side then check the voltage at the gate pin of Q5 to see if the Q7 switching transistor is turning it off.  If you always want direct signal at the normal mono output you could just remove Q5 and jumper the drain and source pins.  I have had poor solders in the Q7 and Q5 areas cause no direct signal on a DD3.

Adam

[delbowski]

thanks for the information!  i'll try it out and let you know the results... really appreciate it

del

[chokeyou]

which reminds me, I yanked the board out of a DD3 and disconnected most of the jack wires. I've tried to get it back together off of schems with no luck 

can anybody take some pictures (detailed) of the wire connections? theres a lot of same colored wire so if you could give me the location of the other end that would be amazing. I'm willing to paypal somebody a couple of bucks for the trouble!

if you feel like it, post the pics here or email me at tylerromo at gmail dot com

[delbowski]

The direct signal is turned off and on at Q5.  Check both drain and source on Q5 with an audio probe for the direct signal. 

i checked either side of Q5 and get the direct signal on both sides, but still nothing coming through in the end.  if i jumpered the outside pins of Q5 like you suggested, will i get both the direct and delayed signal like i'm looking for?  is it maybe a problem that i totally removed the leads that were originally going from the board to the direct out jack?  also, the pcb and layout looks exactly like my other dd3 that has no problems... how could i tell if the one is an older version? 

thanks so much... i really appreciate it!

del

[p1_ind]

The older model uses a DIP style delay IC.  The newer version uses a surface mount digital IC.
If you have signal on both sides of Q5 jumpering it won't help.
If it is the older model check Pin 2 of IC1 (M5218L) at this point the direct and delayed signal are mixed.  If there is no direct signal there then there is a broken trace or lifted pad or something between Q5 and IC1.

[delbowski]

thanks a ton p1_ind... you are being a HUGE help!  i've got that same chip (M5218L) and tested at point 2.  no direct signal, just delays.  i checked it on my working pedal and it's all there.  i got a schematic for it and i'm gonna see if i can't find something between Q5 and IC1 like you mentioned.  thanks a lot, i'll post how it goes.  really appreciate it!

del

[delbowski]

i tried to use the schematic to follow the traces between Q5 and pin 2, but the schematic i found is WAY different than what i have.  here is the one i found:

http://www.8bitsindgenug.net/boss_dd2.png

this is the only working link to a dd3 schematic i could find in the searching i did, and while it says that Q5 goes to pin 2 of IC1, on my pedal Q5 and IC1 are about as far apart as physically possible; on total opposite sides of the pcb.  even he components that the schematic says are connected to or are in the signal path of Q5 are not anywhere close either.  does anyone have a schematic of the Boss DD3A board?  this seems to be a dead end from the searches i've done... anyone have any experience with this?  i could really use the help!  thanks a lot...

del

[delbowski]

anybody out there know where i could find a schem for the DD3A board??  i've looked high and low and have come up short (that sounds like a corny joke)... 

thanks

del