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2016 DBX 163X Modifications Condenser Microphones
Old 16th June 2016
  #1
Here for the gear
2016 DBX 163X Modifications

Hello fellow gear slutz and gurus. I seen another thread on a modification for the DBX 163X. I decided to touch up on the same modification but with other modifications included as well. DBX 163X (Hong Kong Version). I know this is old news already but it is new news to myself as I just decided to buy one of these compressors at a steal price. Untouched and original. I was wondering if anyone can help me find anything I may be missing. I have attached a photo which could act as a chart.

Power Supply Unit Modification (PSU)
The Blue circled items on my diagram are the PSU mod that requires removing these caps and replacing them. The caps in position C28 and C29 can be replaced by larger caps upwards of the known 2200uF 35V 105C, the smaller caps in position C30 and C31 should be replaced by caps of 100uF 35v.

Voltage Controlled Amplifier Modification (VCA)
The VCA mod is circled in yellow on my diagram. I replaced the current SIP8 VCA with a THAT2180A VCA. I then remove the R9 and R10 resistors that are next to the VCA circled in yellow.

Operational Amplifier Modification (OPAMP)
The operational amplifiers are DIP8 chips that are circled in orange on my diagram and the board has them labeled as OA(?). I simply replace them with ultra low noise versions. Optional is to add a socket to make swapping them easier. Some of the recommended OPAMPS for the position of OA1 are the NE5532, OPA2132, OPA 2134, OPA2107, LT3158, or the preferable LME49860NA. The OPAMPS that can be swapped in for OA2 are OPA134, OPA602, OPA627, LT1357, or the preferable LME49710NA. I have also read that replacing OA3 and OA4 with an LME49860NA can help considerably, but this is an optional modification.

Capacitor and Resistor Modification
This modification is to ensure durability and stability and I have them circled in Red on my diagram. It may also stop overheating issues that some have reported. Remove position C1 completely, Replace C2 with a ferrite bead. Replace C5 with a 22uF 35V bipolar capacitor. Remove C7 completely. Replace positions C3, C4, C8, C9, C10, C11, C18 & C19 with 0.1uF capacitors. Replace positions C24 & C25 with 0.01uF capacitors.
For the resistors I have them circled in gray on my diagram. Simply replace positions R1 & R5 with 1kΩ metal film resistors. Lastly, replace R16 with a 22Ω metal film resistor and R2 with a 100KΩ metal film resistor.

This should pretty much sum up everything that I have done so far on my DBX 163X. Please if you have anymore information on any of these modifications, inform everyone by sharing on this thread. I have seen bits and pieces all over the place but never a solid thread about these modifications. I hope this helps someone who owns one of these compressors or maybe a different model that can use similar modifications.
Attached Thumbnails
2016 DBX 163X Modifications-dbx-163x-mod-chart.jpg  
Old 13th November 2017
  #2
Gear Addict
 
Zen MD's Avatar
 

Old bump i know. Thinking of doing some but not all mods to a pair of 163x. Thinking about replacing all caps with sanyo os con? I dont think i want to change the op amp but would do a 5532 if anything?
Old 3rd February 2019
  #3
Here for the gear
Upgraded my pair of DBX 163x !!!!
After a lot of reading, looking at schematics, sifting through the "Jim Williams Mod" comments but not finding any exact instructions, I finally settled on a plan of action... here's what I've done with notes:


1. Replace C28 & C29 with 2200uF 35v electrolytic caps

2. Replace C30 & C31 with 100uF 35v electrolytic caps

3. Replace C32 & C33 with 10uF 50v electrolytic caps

4. Replace IC1 with a THAT 2180A (9 bucks on mouser in 2019)

5. Remove trim resistors R9 & R10 from the board. The new VCA is pre-trimmed. (be sure to look for "R9" & "R10" designators on your PCB. There are pictures of this mod out there circling the wrong resistors.)

6. Replace OA1 with an OPA2134PA (5 bucks on mouser). I put in an IC socket first. As usual, check orientation before plugging anything in.


thats it!


There are other mods out there that recommend replacing every op amp, cap, and VCA on the board, which would easily triple the cost of modification. My goal was to smooth out the power supply as much as possible, and spend big on the chips that are amplifying the signal. IC1 is the main VCA (the compressor), and OA1 is the amp that feeds it signal. IC2 is RMS detection, so it is watching the signal but not part of the sound. OA2, 3 and 4 are level set, threshold set and output buffers, which I did not swap.


So far these are sounding AMAZING. Clean, loud, and a lot of color.

Considering whats out there, this $50 mod (for the pair) is really worthwhile.

Etienne
Rithma Music
Old 5th February 2019
  #4
@ rithma :
Little newbie question about the mod:
When you write "Remove trim resistors R9 & R10 from the board", do you mean remove the resistors and leave the trace cut, or solder/connect the trace back together afterwards?
Old 4 weeks ago
  #5
Lives for gear
 
Brian M. Boykin's Avatar
Quote:
Originally Posted by Slutty Professor View Post
@ rithma :
Little newbie question about the mod:
When you write "Remove trim resistors R9 & R10 from the board", do you mean remove the resistors and leave the trace cut, or solder/connect the trace back together afterwards?
I know you posted a while ago but for those who read this later, you remove the resistors and leave them off the PCB or just cut pin 4 off the VCA. The 2150a needed to be externally trimmed and the 2180a is internally trimmed. Pic below shows the pin out configuration and as you can see pin 4 is labeled NC for “no connection.”

I’ve done the mods listed above on both of my 163’s and the improvement is well worth it. My next step is to swap all the carbon film resistors with Dale CMF55 metal films. I’ve done this one channel at a time in my console and it makes a considerable sonic difference.
Attached Thumbnails
2016 DBX 163X Modifications-5d556610-59b0-4a2d-abb9-58ad53daad96.jpg  
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