Logitech Z-2300 Remote Control Pod Disassembly

Back in October I purchased a standalone Z-2300 subwoofer on eBay, knowing I could build a DIY remote control pod based on my working Z-2300 set. I disassembled my original remote and deciphered the pinout in a matter of hours. A board was sent off to BatchPCB the next day; two weeks later, I posted this video on YouTube:

Since then, I’ve received dozens of messages from fellow Z-2300 owners, all asking for more information.

Here’s the deal: It would be unethical of me to release the schematic and/or circuit board for public usage, and quite possibly a breach of Logitech’s intellectual property. There are no copyright, trademark, or patent markings on the Z-2300 speaker set or the control pod’s circuit board. However, a Logitech Product Team member at the Logitech message board writes:

The wiring diagram is not a public document.

This is understandable—no company publicly releases schematics for their products, and definitely does not allow for others to profit from the company’s products/services. As an engineer, I wholeheartedly respect that.

What is bothersome is Logitech’s backwards policy on replacement parts. I’ve owned my Z-2300 set since late 2005. The volume control has always exhibited terrible channel balance at low volumes. This is caused by differences in the left and right potentiometer gangs, which are pronounced at the lower and upper thresholds of rotation. Such tolerance errors are common amongst dual-ganged pots. There are two fixes: 1) Replace the potentiometer and hope for less error, or 2) Implement attenuation circuitry at the audio input (series resistors), such that the maximum counter-clockwise position of the potentiometer is avoided. I could’ve fixed this imbalance myself. Instead, it was easier to raise the volume on the pod and decrease volume at the PC. Anyway, I called Logitech’s support line one day to see about the prospect of purchasing a replacement remote control. After explaining the annoyance, I was kindly told that Logitech could send me a completely new Z-2300 set for free. Not even a shipping charge. What?! I was willing to shell out cash for a replacement part, and here they were offering to send me a $200 speaker set on their bill.

It turns out this is how Logitech’s warranty works. Rather than repair a faulty device or send out (or sell) replacement parts, they prefer to give away brand new products. I can see how the cost of labor for repairs could be less than profitable, but surely it would be cheaper to send out small replacement parts rather than entire product sets. The Z-2300’s remote control cannot be worth more than $10 in parts—probably much less considering they’re mass produced. Although fantastic for customer service, this approach to repairs is incredibly wasteful. Logitech is a fantastic company, and I was appreciative of their offer, but I declined. I did not need or want a second Z-2300 set (at the time). I was just nitpicking…

Logitech’s wasteful policy affects products besides their Z-2300. A few eBay sellers offer hand-made audio interface cables for the Z-5500, which bypass its digital remote control. These $5-$10 contraptions sell for ridiculous prices ($45-$80). Considering that there are no replacement parts to be sold, this is a clear case of demand outweighing supply. So, the question is, why on Earth doesn’t Logitech sell replacement parts? It would be profitable!

With all of that said, I would very much like to release the information I have unearthed. From the messages I’ve received, it is clear that plenty of people with out-of-warranty Z-2300’s are interested in purchasing Logitech replacement parts. Several people have lost their control pods during moves; some have dropped or otherwise broken them; some want to tap into the circuitry for unique modifications (often multiple subwoofers…); some, like me, just wanted a better performing volume control.

Since I cannot publicly release my replacement Z-2300 control pod PCB, or even the schematic or pinout, below are pictures taken during the disassembly of the pod:


The PCB silkscreen provides wiring labels for all 9 wires (plus 1 shield “wire”). Of course, you’d have to open the pod up yourself and use a continuity checker to find out which pins of the High Density 15-pin D-Sub connector these wires go to. Lastly, I can verify Logitech’s claim that standard VGA extension cables should not be used with Z-2300’s. The center row of pins for a VGA extension cable are all tied to ground. Logitech uses a single pin in this row for an audio signal. Anyone attempting to extend the interface cable should make sure to use a pin wired 1:1 (that is, pin 1 is wired to pin 1, pin to goes to pin 2, etc., and no pins are tied together).

EDIT (April 27, 2010) – SCHEMATIC RELEASED!

DISCLAIMER: This design is for personal use only. Information is provided without warranty, either expressed or implied. Schematic and information below may contain intellectual property of Logitech.

Someone by the name of “HxCxK” independently uncovered and released a rendition of the Z-2300 schematic last month. Since he has let the cat out of the bag, below is what I originally found:

Miscellaneous schematic notes:

  • Resistor R108 omitted (serves to buffer supply rail into standby pin; not critical)
  • Potentiometers not measured (10k parts are common and work well in this circuit)
  • Capacitors C100, C101 are optional. Someone with more free time may wish to investigate the frequency response with and without these parts.

Principles of Operation:

  1. A stereo audio signal comes in through the green 3.5mm connector.
  2. Signal passes through the remote’s main volume potentiometer for attenuation.
  3. Signal is then fed down to the subwoofer enclosure for pre-amplification.
  4. The pre-amplifier(s) distribute the audio into two places:
    a) To the left and right satellite amplifier (and subsequently to the 2 speakers)
    b) Back up to the remote.
  5. Inside the remote, the signal is split again:
    a) To the headphone jack
    b) To the subwoofer potentiometer (where it is combined to mono at this point)
  6. Output from the subwoofer potentiometer finally gets fed back into the enclosure and last, into the subwoofer amplifier.

D-15 Connector Pinout:

Pin PCB Name Description
1 SLINE Subwoofer Line Input
2 (unused)
3 SGND Signal/Audio Ground
4 PGND Power Ground
5 STDBY Standby, Active Low
6 RL Right Line Input
7 (unused)
8 (unused)
9 (unused)
10 (unused)
11 RHP Right Headphone Output
12 LL Left Line Input
13 LHP Left Headphone Output
14 (unused)
15 VREG 15V Supply Rail

See images above for connector numbering. Those who wish to quickly test their Z-2300 can ignore most of this. The Z-2300 switches on when Pin 5 is connected to Pin 15. Then, apply audio signals as follows:

Pin 12: Left Input
Pin 6: Right Input
Pin 1: Subwoofer Input
Pin 3: Audio Ground

Printed Circuit Board:

The board can be purchased from BatchPCB in unassembled form. This is entirely non-profit. As such, NO SUPPORT IS PROVIDED. You are on your own.


Top View of Board


Top Copper Layer


Bottom Copper Layer

Parts List:

Reference Part Description Part # Qty
J1 STX-3100-3C 806-STX-3100-3C 1
J2 STX-3100-9N 806-STX-3100-9C 1
R102, R103 2.85k resistor 271-2.87K-RC 2
R105 3.62k resistor 271-3.6K-RC 1
R104 4k resistor 271-4.02K-RC 1
R107 10.2k resistor 271-10.2K-RC 1
R100, R101 33 resistor 271-33-RC 2
R106 591 resistor 271-590-RC 1
U2 Alps RK0971221Z0 (10k, Volume) 688-RK0971221Z05 1
J3 ICD15S13E6GV00LF ICD15S13E6GV00LF 1
U3 Alps RK09712200MC (10k, 15mm) 688-RK09712200MC 1
LED1 3mm LED 1
C100, C101 0.01uF Multilayer Ceramic Capacitor C324C103K5R5TA 2
[Cable] Male to Female, HD, 15-pin D-Sub AE1380-ND 1

Edit (12/18/2010):

iNeedFixin.com” href=”http://www.ineedfixin.com”>purchased from an independent builder.

228 Replies to “Logitech Z-2300 Remote Control Pod Disassembly

  1. Hello Jseaber:

    Thanks for your knowledge page and effort !

    And would you please kindly tell me how to do with the black cable on the position on WA1? thanks !62e0ee18-2870-44eb-85bc-a3326b9bd02b.png

  2. Thank you very much for this post. I worn out three control pods now. I even bought a whole speaker set just for the control pod, because it was cheaper than buying the replacement pod as advertised on eBay. Anyways, I figured I’d try to fix one myself, this post is pretty helpfull. Although I cannot read schematics properly, I think I can solder parts on a PCB board.

    Having that said, I think the link to BatchPCB is dead. Is there another way of getting the PCB? Maybe share the source files, so we can choose a firm to order the PCB from?

    Hope you can help me out. Thanks in advance!

  3. Thanks for all the info! My control pod started having issues recently after years and years of use. Fortunately my problem was a short in the audio input line. Rather than replace the line I installed an auxiliary input port. It’s working great!
    I’m sure others have already done this but I hadn’t seen any yet.

    view?usp=drivesdk

  4. Hey,

    My plan is to add a remote power switch whilst still using the original controller.

    This would allow me to use a small 5v relay, powered by the USB port on my amp so when the amp is off so is the power on the sub.

    I thought about just using STDBY and VREG directly, but R108 will take a shed load of current. I wonder if it would be as simple as removing R108 and adding a switch between STDBY and VREG as I originally thought?

    Any idea what the best way would be? The switch that’s in there just now has 6 pins so that’s no use for my single throw single pole relay. Any thoughts appreciated!

    Thanks again for your reverse engineering.

    1. Oh and plan B is just to use the relay to switch the mains input to the unit but would prefer a low voltage alternitive 🙂

    2. Hi Nathan – Interesting idea. Sorry, it’s been years since I tinkered with this circuit. Briefly revisting the schematic, I imagine you could drive a low current relay coil from a USB port, with the contact (switch) replacing `POT_SW` in the Z-2300 pod. Or even better, wire the contact inline with `POT_SW`. You’ll have to get creative lifting the potentiometer switch pin(s). Totally possible.

      1. What I ended up doing was plan B – using a 5V relay across the main switch in the rear of the unit directly. This has the advantage of completely cutting power so no quiescent current at all. Now when my AV reciever is off the sub is completely off. Result! It’s handy having multiple USB ports in the reciever so not compromising anything else.

  5. The problem I have is the sub woofer stopped working, I believe I found the problem in the fact that the potentiometer that controls the base was reading as an open circuit so I have attempted to replace it.. My first attempt at soldering and electronics so learning fast… but damaged the copper connectors taking out the old one. I have attempted to reconnect it back up as per where it connects and seems to align with schematic. However I have no idea where the second gang of potentiometer pins connect to and I still have no base (sub woofer).

    Please help

    https://drive.google.com/file/d/1kkOiZNwzi9v4lZd2Tj25LMCQjtNINoyEfg/view?usp=sharing

  6. I picked up the sub only at a thrift store hoping that I could hook it up to my 5.1 stereo receiver. Is there a way to get an LFE (single RCA) input into this system without having to procure a remote?

    Thanks

    1. By that, I mean, can I cut two of the four leads from the RCA input from the circuit board and solder that (An LFE input) into the subwoofer inputs to the sub amp and get it to work? Which wires to which pins (on the primary PCB pin out).

  7. hola jseaber , mira tengo una sola duda porque hay 2 capas de cobre una superior y otra inferior y una cada una tiene algunas pistas como diferente algo asi

    1. hello jseaber, look I have one doubt because there are 2 layers of copper one upper and one lower and one each has some clues as different something like that

  8. For whom it may concern,
    Please note that the resistors in the bass control section are all 1% resistors and their values are absolutely critical, in particular R106 which sets the level of bass signal fed back to the main unit. It MUST be 590 ohm, substituting for a higher or lower value E12 resistor will mess with the balance between high and low output.
    I suspect logitech did this to make it even harder to go out and make your own control pod.
    SO, to make an accurate controlpod which sounds exactly like the original one, use 1% resistors as follows:
    R102/R103 = 2K87 1% metalfilm
    R104 = 4K02 1% metalfilm
    R105 = 3K65 1% metalfilm
    R106 = 590 ohm 1% metalfilm

    These are all E96 series precision resistors which might be a pain to procure. They are however the exact same values logitech used.
    The rest of it isn’t critical, the series led resistor is for a blue led, you might want to use a higher value for red/green ones.

    In my z-2300’s, I have 4 of them, i modified the bassunit so the 2 pots are next to the 15 pin connector. I drilled 2 holes for the pots, wired them directly to the corresponding pins on the 15 pin conn. and converted the rca outputs to inputs so you can plug in a simple rca cable. Be sure to apply generous amounts of glue/gunk to avoid hissing through its holes. There’s a lot of pressure inside the enclosure when really playing loud.
    The speaker outputs in my units are now Speakon terminals mounted in the mdf enclosure next to the amp baseplate.
    The modification is not that hard, although the pots are a pain to fit between the pcb and the rca terminal. Also you will need a steady hand to solder the wires directly to the 15 pins on the main pcb.
    The big advantage of this mod is that you will never have to fiddle with a control pod again, my z-2300’s are basically mini-PA systems, using any medium power 8 ohm speakers found at thriftshops. I prefer JBl control 1’s by the way, they sound excellent on a Z-2300 sub and can handle the power easily.

    Happy Hacking,
    DrZ.

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