BOSS DR55 MODIFIED AND MIDIFIED by DenDer

DenDer · December 05, 2008, 10:07:02 PM

Quote from: nochtanseenspecht on December 05, 2008, 08:18:23 PM
here you have a new karma
hee but congratulations you found the problem !

btw; NEVER put recharchable batteries in your dr55
mine nearly died from that..but the reason i don't know

Thnx David

But why is that with rechargeable batteries? BTW i only use normal penlites in my Dr55.

nochtanseenspecht · December 07, 2008, 07:54:39 PM

cannot tell you... i tried it once with regular nicad penlites, it worked fine for 20 minutes, then it started to distord
and stopped. i feld it got very warm, checked the batterys, and saw that the whole batterycompartiment melted
away, also the nicads half melted... later, with a new compartment and alkaline penlites it worked again.. pfew!
maybe someone else knows the reason for this ? better not try it

Gordonjcp · December 07, 2008, 08:54:16 PM

Bizarre. Possibly one of the nicads was faulty or incorrectly fitted, but I can't see any other reason why it would do that. You didn't have a power supply connected at the same time, did you?

nochtanseenspecht · December 08, 2008, 07:35:26 PM

yeah bizarre, no adapter connected, and the polarity was good, it worked for 20 minutes.
i tought first, 4 nicads can only deliver 4.8 volts instead of 6, but on the other hand, old alkalines don't
deliver 6 v either... i guess i will never know what happened
but sometimes small machines have an explicit warning not to use them with rechargable batteries,
maybe thats what happens then
anyway, the dr55 uses extremely little power( as long as you take out the jack when not in use)
so it run long long time on 4 penlites

DenDer · December 15, 2008, 04:29:45 PM

That's strange if i put in 4 alkaline batteries i get somewhere between 6V and 6.14V.......

nochtanseenspecht · December 15, 2008, 07:56:41 PM

that's normal voltage for 4 fresh penlites

DenDer · December 15, 2008, 10:21:48 PM

Maybe that was the problem with the rechargeable ones. That the mA was to high so the Dr55 couldn't get rid of it and burned your battery holder.....just a thought........

nochtanseenspecht · December 16, 2008, 12:07:23 AM

mja.. who knows. but it was a scary moment, alone with the dr in the dark

DenDer · December 18, 2008, 12:29:30 PM

So i made a little schem of the midi sync on vero board.

Actually IC 2 can move one hole to the right to give room for the resistor thats in the STOP line to the DR55 but keep in mind that everything on the right of IC 2 has to move one hole to the right to.

In the normal schematics, from Ben Riggs, he uses an onboard DPDT switch but i substituted it with an out board DPST switch for easy switching of the midi direction (send or receive).

At the moment i'm modifying another DR55 for a client so i'll post some pics of how i made the case and some pics of the midi sync board.

DenDer · December 19, 2008, 10:53:11 AM

I discovered a strange mistake in the PCB foil prints of the DR55. I wanted to apply the HH mod, so connecting the RS triggerline to the "off" point of the HH switch. As you can see in the picture, which i cut out of the PCB foil schem, there are 3 points on this switch. Namely "off", 1/8, 1/16. The most right points are for the 1/16 and the two solderpoints of the switch are connected underneath the switch. The same counts for the 1/8 solder points. But strangly enough for the "off" solder points they are not connected on the PCB foil schem but they are on the real PCB.

Gordonjcp · December 19, 2008, 10:55:48 AM

It's probably just a slightly different version of the PCB. The switch is double-pole, so in this case it doesn't really matter if the pins are wired in pairs because we're only using one pole.

DenDer · December 19, 2008, 10:58:54 AM

That was what i was thinking to but i thought i'll shared it anyways just to avoid some confusion for others. I've got my own Dr55 which is the same as the one i'm modding for someone. Another difference between the two Dr's that i have here is that mine has solid green caps and the other has slightly transparent ones......

DenDer · December 21, 2008, 12:25:09 PM

As promised a pic of the midi sync on veroboard and a pic of the case in progress....

btw people keep on contacting me about the schems...please go to my webpage for further info.

DenDer · January 17, 2009, 05:25:07 PM

So a little update on the midi kit struggle that i'm having.....when i installed the kit the midi part wouldn't work....i've mailed my sss of with Ben Riggs and he helped me in every way that he could but my kit kept on firing the 1st step......that was no good....
So i contacted the guy who burned my pics again and he build the kit on some breadboard and hung a scope on it. But the pic wasn't transferring midi to pulses so something was wrong with the pic. That was for me a great relieve since i had gone over my vero a million times but i couldn't find a mistake. I even asked someone else to check my work and he couldn't find a mistake either. Comparing my vero with the schems.

So what's the problem. Pic 12F629 and 12F675 have an internal clock. And if you burn the pics, the burner erases the pics first, before he burned the hex into them. But with this erasing the internal clock is also erased, therefor he couldn't make anything out of the midi commando's he was receiving. So all the pics now need some new callibration.....
I'm just very happy that we found the problem.

So if you're going to burn the hex into the pic just don't erase it first, that will keep on the callibration of the clock inside the pic......on this site there is some more info on this subject.

http://picprojects.org.uk/projects/recal/index.htm