I need boss dd3 schematic

[Fp-www.Tonepad.com]

Please!

fp
fp@tonepad.com

[zeta55]

Check your mail.

[Fp-www.Tonepad.com]

I haven't received it yet. Can you email it again?

Thanks!
Fp

[zeta55]

Sent.

[Maneco]

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

[Fp-www.Tonepad.com]

Thanks, I got the email.

Thanks Maneco, but that schematic doesn't match the pedal I have here.

The board says "BOSS DD-3A". Does anybody have this schematic?

Fp

[Fp-www.Tonepad.com]

btt

[Fp-www.Tonepad.com]

I'm going to keep bumping this one to the top...

I really need this schematic!!

Fp

[Fp-www.Tonepad.com]

btt

[Dirk_Hendrik]

Thanks, I got the email.

Thanks Maneco, but that schematic doesn't match the pedal I have here.

The board says "BOSS DD-3A". Does anybody have this schematic?

Fp

Are the differences that big? I had DD2's and DD3's which had the same board. I cannot imagine that you have something so entirely different all of a sudden that the schem that you have now is 100% worthless?
What's the prob with your DD?

[Fp-www.Tonepad.com]

The circuit blocks are similar, but the controller IC is very different.

The DD2/3 schematic only helps very little

Fp

[bioark]

please i need ...please
the board number is dd3 a

[O]

Hate to piggyback, but I'm going to be needing one soon.

thanks in advance...

-Oscar

[Paul Marossy]

I don't suppose Roland would give you one if you requested it, would they?
Just a thought.  

[cd]

Bringing up this old post since I could use the schem as well, and Roland/BOSS has been a brick wall (so far).

The new/re-issue DD-3 is very different from the old DD-2/3 - the schem floating around for the original is maybe 50-75% the same.  I haven't traced out the newer one (3A board) yet, and I'm not going to but so far the differences/puzzling things to me are:

- only one DRAM chip - MB81464-10, which I looked up as a 4x64k DRAM chip (the original had three 4164 DRAM chips.)  Is the single 4x64k DRAM made up of four 64k chips (for a total of 256k) whereas the original had three (for a total of 192k)?
- different microcontroller - no surprise there
- the 4066 - is this used as an A/D, D/A converter??  I thought it was a CMOS switch?
- the oscillator still uses a 74HC00, but at first glance, it's wired completely differently (different range?)  
- JRC311D chip - voltage comparator - haven't figured out what this is for yet

[Dirk_Hendrik]

The DA is used for AD conversion (with a 12 bit R2R resistor ladder) using the SAR principle (for more info, google). The 4066 is used to switch the sample and holds.

[cd]

Thanks for the pointers, Dirk!  Found a good site with A>D explanations:

http://scitec.uwichill.edu.bb/cmp/online/el21c/lesson11.html

[dpresley58]

I don't suppose Roland would give you one if you requested it, would they?
Just a thought.  

"Give"...? Nope, but they probably -will- send you one.... I just got a copy of the PSM schem from them. Of course, it took three weeks and $25 bucks...

[Fret Wire]

For Service Manuals:
1-(323) 890-3700 ext. 2289

Some ship immediately, some (older models) have to be printed up. 2-3 week wait on reprints. Your credit card is charged as they ship.

[cd]

FYI, I had time to trace through some of the circuit in my newer DD-3 (from '93 or so, AKA the one that does NOT match up with the widely available schematic), here are some of the more interesting findings:

- uses an MN51010RBA controller chip - don't bother Googling it, there's no datasheet
- there is 74HC00 which works as VCO in the DD-2/3.  In the new DD-3, there is also a 74HC00, but it doesn't work as an oscillator - in the new DD-3, that chip is setup as a flip-flop in place of the BA634 in the old DD-2/3, which acts as a mute circuit (confused yet?).  The 74HC00 in the new pedal connects to the same regions/places as the old BA634.
- which leads me to believe, the delay time is still voltage controlled, but instead of the delay time knob working the 74HC00 (like in the DD-2/3) in the new DD-3 the delay time knob goes directly into the MN51010RBA controller chip - so there must be a VCO built into the controller chip... right?
- read through this entire thread for other info, the DRAM config is different too, there's a single 4x64k DRAM instead of three individual chips

That's about it, the actual signal path looks similar, I didn't bother to trace the whole thing out (so DO NOT ask me for a schematic - there's a # to call for one right above this post) but the compander is still there, works the same way with the same pre/post filtering, mixer, etc.

I'm going to try to dink with the VCO to get more delay time... am I right in thinking that I have to SLOW down the controller chip to do this?  i.e. the controller works more slowly so it refreshes slower which means more time?  Of course there's the danger of going too slow, which means not refreshing at all...

More reports as the experiments continue.