Recording Tricks: Mackie CR-1604 Mixer

Mackie CR-1604 mixer

(original version, not the 1604-VLZ or 1604VLZ-pro unless noted)

  • The main outputs are wired "Ring Hot"; wiring details on the insert jacks; pre/post modifications

The popular original Mackie CR-1604 mixer is everywhere you turn, but few engineers know to watch out for a major wiring issue. The original Mackie 1604's BALANCED (TRS) main outputs are wired "Ring Hot" as follows:

Tip = - (cold)
RING = + (HOT)
Sleeve = Ground

NOTE: The CR-1604 was replaced by the much-improved 1604VLZ, then the VLZ PRO, then more versions, all of which fixed this problem. The VLZ improved almost everything about the mixer, including real direct outputs, inserts on every channel, sweepable EQ, 4 busses, better monitoring control, and cleaner signal-to-noise specs. Then the VLZ PRO version came out which improved the mic preamps again.

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This "ring hot" wiring is completely backwards but thankfully this is the only time I've ever seen this! Therefore, if you use a TRS--> XLR cable to run a mix from the 1604, double check that it is wired correctly for your standard (ie. tip-->pin 2 or 3). A cable wired "tip-->pin 2" would actually be running the hot signal to pin 3 and vice-versa. No matter which device is receiving your mix, check how the cables are wired and be prepared with phase reversal adapters.

Mackie tech support says that changing the jacks' wiring is not an easy modification to make, as the jacks are board-mounted. If you use unbalanced plugs in this jack, it is wired "tip hot," and the output is 6dB lower than the Balanced output.

The 1604's Mono Main Out is similarly capable of either Balanced or Unbalanced output (and the unbalanced signal is also 6dB lower). It combines the Right and Left Main Channels and, according to the manual, "the polarity is reversed" (with respect to the main outs). This means that this output is correctly "tip hot," but is out of phase with the stereo output (meaning the stereo output, if summed to mono, would be out of phase with the mono output.) ...Whew!

The 1604VLZ's mono output is AFTER the main fader. Here's the signal flow: Main insert-->Main fader-->mono out-->main out. (Not sure if this is the same as the original 1604.)


The original CR-1604 with XLR-10 mic pre expander and rotopod

Mackie 1604-VLZ PRO Mixer

Get a deal on the current version of this mixer


The 1604's Mic inputs are wired correctly, pin 2 hot:
Pin 1 = Ground

Pin 2 = + (hot)

Pin 3 = - (cold)

The 1604's Balanced TRS Line inputs (Channels 1-6) are also wired correctly:

Tip = + (hot)

Ring = - (cold)

Sleeve = Ground

To use the 1604's Channel Access (on channels 1-8) as a direct out without signal interruption to the master, insert an unbalanced 1/4" plug to the "first click." This is a POST-Fader, POST-EQ feed, useful for sending channels to a multitrack. If you insert a unbalanced cable all the way, it will interrupt the signal to the main mix bus.

See the Mackie Mixer Applications Guide, 2nd Edition for modifications to make the Channel Access points Pre-EQ/Pre-Fader or Pre-Fader/Post-EQ. This also shows how to make the Aux Sends into Monitor Sends with or without EQ, how to make the Aux Sends ignore Mute/Alt status, and mentions a mod to tie the Solo together on two or more 1604s.

To use the 1604's Channel Access (on channels 1-8) as a send/return patch point, use a TRS cable wired as follows:

Tip = Output (send to external device)

Ring = Input (return from external device)

Sleeve = Ground

By the way, HOSA STP-201 Send/Return cables (TRS--> two unbalanced 1/4" Plugs) are wired so that the Orange plug is the Tip (send) and the Grey plug is the Ring (return).

Mackie Tech Support: 1-800-258-6883
Mackie's download page with manuals for most models