Well, the part I was dreading.. The phone call in the Behringer's service center. I was answered by a human in less than a minute who ask me what I was looking for and transfered me over to someone else. I spoke with this nice young lady who asked me what I had and what I needed for it. I told her I had a DDX3216 and I needed the Anaout01 board:
She typed away on her computer and asked me to hold for a moment. Not more than a minute later, she came back and said that they didnt have any more brand new parts, but they had another mixer, returned to the factory with a dead CPU board and they could take the Anaout01 board from that one and send it to me. They asked me for my address and said it should be heading my way in the next day or so. No charge. This was my only experience calling into behringer and I have to say I was quite pleased, but I digress. Im getting a replacement out board.
Now for the ugly.
They really LOVE the hot glue at the Behringer factory. I mean its everywhere.. In fine strands, slatherd on ribbon cables, I mean.. it really was ugly. On the connectors, I used an Ice cube wrapped in a paper towel to get it cold and used a pair of needle nose to pull the glue off in 1 piece most of the time. For the more delicate things, I used my soldering iron to heat it up (just got it close enough to melt it) and used a cotton swab to coax the glue into an area where I dont have to be so delicate to get the glue off the board. It took a while but I eventually got most of what I needed to get off the parts.
Now on to the other good stuff:
The Analog In board:
If you havent read the block diagram for this thing, look it over carefully before doing anything. I dont have a schematic to work from so Im going from what that says, and what I know of circuit design. When it comes right down to it, its pretty simple. Take you generic Mic pre schematic (such as the one for the INA217) make a couple of modifications to the circuit and you have whats on this board. The OPAMPS in this thing are the much viled NJM4580L. In a SIP configuration no less. Theres 1 dual opamp per 2 channels. There are 4 electrolytics in the signal path per channel and 1 that the phantom power goes through. .
The A/D Converter board: (the AKM AD convters are on the flipside of the board. These are the parts Im going to mod though. )
The rotary encoder control board: Note the missing encoder on channel 4. Had a Mic fall right on that knob and busted the shaft. I never made a difference in the channel only becase I could still use the knobs under the LCD to control whatever the encoder would but since I have it in pieces anyway... Might as well fix it.
and lastly, the underside of the front cover. I had no need to remove the pirmary control surfaces from their mounts so I didnt. Only the Encoder board needed to come off and as luck would have it, it was the first card on the stack.
Heres inside the case. It contains the shielded power supply, the CPU board, (Its an AMD CPU if you're wondering), the DSP board for the effects and the rails for the expansion cards.
So on to the modding:
Initially, Im just going to test to see what the difference will be with the change in components beforing throwing down a lot of money on doing the whole mixer so,
On the Anain01 board:
The list of parts to be replaced.
The opamp that runs Micpre 1,2
The 2 opamps that drive line in channels 15 and 16
and all the capacitors in the signal path of those channels.
On the Anain02 board
the 2 opamps on the first 2 channel that drive the line ins the AD converters as well as their related signal path caps.
On the Ctrl11 board:
just replace the rotary encoder with one that doesnt have a broken shaft.
On the Anaout01 board:
The 3 opamps that drive the Control Room outs, the 3 opamps that drive the Main outs and the related signal path caps.
Bringing the total of 11 OPA2228s. The total for this would be well over 50 if I was doing to whole thing so better to hear what the difference will be at around $50 in parts rather than the $200 or so it will cost to get parts fo the whole thing. Plus, by only doing these components, I have a means of comparing the modified to the unmodified and can make some samples.
Ill keep updating as things progress.