Tweet
Every so many years, our rehearsal studio/rental gear complex Maintenance man brings me his aging Macike DFX12 mixer, with the usual complaints of it behaving intermittently. This time I got railroaded into this repair which is another topic all together, but the result is rendering service in lieu of payment for something ridiculous.
Powered it up, plugged the Mixer XLR Outputs into my Symetrix SX204 Headphone Amp, Sourced it with pink noise thru my HP 353A Xfmr Output/Step Attenuator box (GREAT Interface box for thsoe who don't know it!!), and patched it in, beginning with Ch 1.
The DFX12 is a 12 Ch mic/line mixer....2 Mic/Stereo Line input channels, lower gain, and 2 stereo Line Input channels. Has a 5 band stereo Graphic EQ and an effects unit built in. Typical lots-of-features small footprint Mackie Mixer.
Their Mic Ch Gain pot has traditionally been a weak spot in all of their mixers....1604VLZ series mixers on down. This DFX12 uses a 5k reverse log pot, whereas the 1604VLZ series use a 10k version, same mechanics.
6mm D-shaft. Mackie's P/N for this Reverse Log Pot is 5KZY 130-030-02 (or just 130-030-02). It appears to now be obsolete.
In the past, I've kept them alive by removing them from the PCB, then carefully prying them open and cleaning/lubricating them, then reassembling them, Fresh ones would be a good thing to have, but thus far, I haven't found any new ones. I did see them listed under Reverb, being sourced over in Europe, and other source, also over in Europe.
The other part that's now very dodgy is the Graphic EQ In/Out switch. It's a 4PDT push-button switch...their P/N 500-036-00. They use two of these in the system. The Main/Aux switch, rarely used, sounds fine. The EQ In/Out switch appears to have been the main culprit of the mixer's not having a Right Ch, and that channels Right Master Fader being blamed for the whole thing. Our maintenance man doesn't know his mixer, so re-education is always required.
That switch is also no longer available. Taking one of those apart......thank you NO. I'd swap the switch with the Main/Aux switch, but it still leaves that gamey switch in the path. Maybe removing the switch and hard-soldering the EQ IN Circuit would solve it. If I just bridged the switch contacts IN, pressing the switch to bypass....trouble.
Anyone know of sources for these 5k Rev Lot Pots and the 4PDT push button switches?
Main Service Manual.pdf
DFX 12 Main PCB Assembly Schematics (055-396-01).pdf
DFX 12 Parts List (part #0000090-90, Rev A07, August 2006).pdf
Powered it up, plugged the Mixer XLR Outputs into my Symetrix SX204 Headphone Amp, Sourced it with pink noise thru my HP 353A Xfmr Output/Step Attenuator box (GREAT Interface box for thsoe who don't know it!!), and patched it in, beginning with Ch 1.
The DFX12 is a 12 Ch mic/line mixer....2 Mic/Stereo Line input channels, lower gain, and 2 stereo Line Input channels. Has a 5 band stereo Graphic EQ and an effects unit built in. Typical lots-of-features small footprint Mackie Mixer.
Their Mic Ch Gain pot has traditionally been a weak spot in all of their mixers....1604VLZ series mixers on down. This DFX12 uses a 5k reverse log pot, whereas the 1604VLZ series use a 10k version, same mechanics.
6mm D-shaft. Mackie's P/N for this Reverse Log Pot is 5KZY 130-030-02 (or just 130-030-02). It appears to now be obsolete.
In the past, I've kept them alive by removing them from the PCB, then carefully prying them open and cleaning/lubricating them, then reassembling them, Fresh ones would be a good thing to have, but thus far, I haven't found any new ones. I did see them listed under Reverb, being sourced over in Europe, and other source, also over in Europe.
The other part that's now very dodgy is the Graphic EQ In/Out switch. It's a 4PDT push-button switch...their P/N 500-036-00. They use two of these in the system. The Main/Aux switch, rarely used, sounds fine. The EQ In/Out switch appears to have been the main culprit of the mixer's not having a Right Ch, and that channels Right Master Fader being blamed for the whole thing. Our maintenance man doesn't know his mixer, so re-education is always required.
That switch is also no longer available. Taking one of those apart......thank you NO. I'd swap the switch with the Main/Aux switch, but it still leaves that gamey switch in the path. Maybe removing the switch and hard-soldering the EQ IN Circuit would solve it. If I just bridged the switch contacts IN, pressing the switch to bypass....trouble.
Anyone know of sources for these 5k Rev Lot Pots and the 4PDT push button switches?
Main Service Manual.pdf
DFX 12 Main PCB Assembly Schematics (055-396-01).pdf
DFX 12 Parts List (part #0000090-90, Rev A07, August 2006).pdf
Attached Files
Comment