Logitech Z 2300 Controller

[DarkStarZN]

I apologise for resurrecting such an old thread. I've built a controller to the same specs as what HxCxK has on that circuit diagram, however I'm running into a few issues.

Bass control doesn't seem to be working

There is a constant humming/buzzing on the subwoofer (Something isn't earthed properly and I think it's from the AC line). It gets louder when I touch the (insulated) SLINE (pin 1) wire.

The only one thing I haven't done is ground Pin 3 to the actual chassis of the subwoofer.

I've also compared it to jseaber's diagram and I've noticed a massive difference in the resistor values. How much of a difference does this make, I'm wondering?

Any help would be greatly appreciated.

 

[20pyro00]

Hello DarkStarZN! I dont know if i can help you any more, but i write nevertheless
I saw this thread a few days ago. I bought the Logitech Z 2300 Subwoofer+Satelite Speakers from a secondhandshop for only 2€!!!! But unfortuanatly it hasnt the Controller. So i looked up and found this Thread here. I build everything the same as HxCxK´s diagram. After that, i noticed also a lot of humming and buzzing. The Basscontrol also worked not properly(couldn´t made the Bass completely silent). So i started to make some changes:

Also i connected Pin6+Pin3 and Pin12+Pin3 with each a 270 Ohm resistor. And it is important to use a shielded cable(Improoved the humming a lot). So now i have a working, good Soundsystem with a lot of Bass for only 2€
Thanks alot for the schematic HxCxK

Tobi

(Sorry if my english is not the best, im from Germany)

 

[timmo11]

Hi 20pyro00

Thanks for posting this

What is the point of your mod of the 2x 270 Ohm resistors across the L + R inputs. To reduce hum?

and now for my bad German just to return the favour

Zum welchen Zweck hast Du die 2x 270 Ohm Wiederstande über die L + R Eingänge? Gegen Brummen?

THanks

TIm

 

[20pyro00]

Hi Tim,
Yes, they reduce humming a lot. And the audio is still pretty loud.

Tobi

 

[timmo11]

Ok thanks so much for this.
I am reviving a Z4 subwoofer, I will be adapting all of the above information for that.

Another Favour
Could you tell me the power rating of the potentiometers you used?


also:

Re the discussion of 5K vs 10K, linear vs logarithmic

here is an image from another blog where someone took apart a Z323 to repurpose the amp to power something else...

On this unit the subwoofer control pot is on the main board inside the speaker. To my eyes it's clearly 5K B (ie LINEAR)
[ his whole story is here: https://pcbisolation.com/blog/logitech-z340/ ]

Pretty clearly though you and other people here have a had good results with 10K.

 

[timmo11]

OK for anyone else reading....

Have tracked down specs for the existing pots on the boards as per the circuit diagram above

The input volume pot is shown as a dual-gang APLS RK097122Z0 - I think it is meant to end Z05 and specs are here [registration required but no fee]

https://www.globalspec.com/specsearch/partspecs?partId={C0C01B95-6F15-45F5-A531-B63477BE4063}&comp=995&vid=139751&srchwebhitid=1718470111&srchitem=28&sqid=28897249

Max Resistance 10k Ohm
Operating voltage 50V AC

Again by my reckoning

P = V²/R = 2500/10000 = 0.25W


The sub pot is an ALPS RK09712200FS - specs here as explained above

https://www.globalspec.com/SpecSearch/PartSpecs?partId={938F29C9-72AD-46A8-8A8A-52677AFC2F3B}&vid=139751&comp=995

Max resistance 5K Ohm
Max voltage 50V AC

By my reckoning this means the max power P = V²/R = 2500/5000 = 0.5W

The elimination of R104 4K means that using a 10K pot the total resistance gained can be the same, however you can drive the sub harder I guess by aloowing the lower limit across the pot to be zero instead of 4K

Replacing them:

Unless you want to order 700+ of these, there is no way to substitute the exact same ones.

Bourns seem to make much the same ones.

Tim

 

[rjenkinsgb]

Sources for your pots, at one-off:

The RK097122Z0
https://uk.rs-online.com/web/p/potentiometers/7293521/
;
And the obsolete RK09712200FS; a 50K version but that may be OK depending on the circuit; or if only one gang is used you could parallel the two gangs to give 25K.
**broken link removed**

 

[Cristi90]

Hi everybody, does anyone build a z2300 remote control pod and I can buy it from him ? I don't know nothing about electronics, printed circuit board and anything else, my control pod just Got broken and I can't use my logitech z2300 anymore. Since the control pod is to much expensive I was tough at a build one but I can't do it by myself. Thanks