Logitech X-230 amplifier - upgrade possibilities?

[Leopard]

Hello everyone,

I recently opened up my Logitech X-230 subwoofer, and it has a built-in amplifier for the satellites and the sub itself, of course. I discovered some "Chang" branded capacitors on the amplifier PCB, and would like to know if they are reliable (probably not ) or if someone has run across blown Changs. I will probably change them sooner or later as soon as I find out for what purpose each cap is. Gotta check what kind of op-amp(s?) it uses so I can find a more high-quality replacement. Will return with pics later.

[tonyynguyen]

Re: Logitech X-230 amplifier - upgrade possibilities?

Looking forward to see how well your modification turns out. As I am also in the same boat as you. Trying to recap and upgrade the opamp on a Creative SBS-340.

[Leopard]

Re: Logitech X-230 amplifier - upgrade possibilities?

Ok, here are the pics.

As you can see, the large cap is a Chang 4700uF 25V one. The smallest caps without vents scattered around the PCB are ChengX branded and the two caps with + vents are Cheng branded. I guess these come from the same vendor, and this is just some sort of cap series naming technique.

The large 14-pin IC is the op-amp with the series marking "TL074CN". At first I though that the 8-pin chip could be it, but decided to check around for it on the Internet and found out that it's just a MOSFET.

Now onto the questions.

- Is there any high-quality suitable replacement available for the TL074CN IC?

- There's a cap by the op-amp, what purpose does it serve? Or what purpose does each cap serve, which ones should I replace with audio-grade or film caps and which ones are for power supply usage and to be replaced with quality brand caps?

[Leopard]

Re: Logitech X-230 amplifier - upgrade possibilities?

Ok - the 8-pin chip is not a MOSFET. I was led to a wrong datasheet.
It has the markings:
4565D
JRC


Now I'm really confused - is this JRC chip like a headphone op-amp or an op-amp for the subwoofer? The 14-pin IC is a quad-channel op-amp, so would that be the one responsible for the stereo speakers, since they both have 2 drivers and 2x2 equals 4. I'm a noob at this section so don't be surprised by these questions.

Anyway, has anyone ordered sample parts from National Semiconductor before? Do they charge money for the samples or just for the shipping?

And the final question - I'm going to replace the large 4700uF Chang cap. Do amplifier circuits require low-ESR or will a generic cap from a quality brand do?

[tonyynguyen]

Re: Logitech X-230 amplifier - upgrade possibilities?

I just ordered the LME49860NA sample opamp from National Semiconductor. If you have a business email address, they will provide free shipping. They gave me next day air with UPS.

[Leopard]

Re: Logitech X-230 amplifier - upgrade possibilities?

I just ordered the LME49860NA sample opamp from National Semiconductor. If you have a business email address, they will provide free shipping. They gave me next day air with UPS.

Nice to hear! I do have an email address which I can use for free shipping. Report back if they charge money for the samples or if they are free

[davmax]

Re: Logitech X-230 amplifier - upgrade possibilities?

Ok - the 8-pin chip is not a MOSFET. I was led to a wrong datasheet.
It has the markings:
4565D
JRC


Now I'm really confused - is this JRC chip like a headphone op-amp or an op-amp for the subwoofer? The 14-pin IC is a quad-channel op-amp, so would that be the one responsible for the stereo speakers, since they both have 2 drivers and 2x2 equals 4. I'm a noob at this section so don't be surprised by these questions.

Anyway, has anyone ordered sample parts from National Semiconductor before? Do they charge money for the samples or just for the shipping?

And the final question - I'm going to replace the large 4700uF Chang cap. Do amplifier circuits require low-ESR or will a generic cap from a quality brand do?

I see the LME49860NA as a great replacement for the 4565D. This is the preamp stage where background noise is important, and distortion on this amp is low. However in terms of distortion the main distorting amp is the TDA7377 if driven above ten watts in bridge connection or 4 watts single ended. So like any amp if driven hard distortion will be evident.

Re 4700uF. Standard electro will do. I suspect that additional non electro caps are used to deal with high frequency ripple at the power amps. It will not hurt to use a low ESR cap.

[tonyynguyen]

Re: Logitech X-230 amplifier - upgrade possibilities?

I decided to recap my Creative SBS340 speakers and upgraded the opamp to the LME49860NA.

[Leopard]

Re: Logitech X-230 amplifier - upgrade possibilities?

I decided to recap my Creative SBS340 speakers and upgraded the opamp to the LME49860NA.

Good job! Did you notice any major improvement in sound? And did National charge for the samples (not shipping, the samples themselves)?

[tonyynguyen]

Re: Logitech X-230 amplifier - upgrade possibilities?

Good job! Did you notice any major improvement in sound? And did National charge for the samples (not shipping, the samples themselves)?

The audio is cleaner then before. There use to be clipping coming from the speakers at high volume before, and now its completely gone. I have the amp powering 2 Yamaha bookshelf speakers.

Nope, National didn't charge me anything for the samples. I believe as long you have a business email (something not @yahoo/gmail etc), then National would even ship it for free.

[Leopard]

Re: Logitech X-230 amplifier - upgrade possibilities?

Oh very yes!
I received my samples today (3x LME49860NA and 3x LME49740NA) and replaced the 4565D. Didn't replace the TL074CN yet, since it took forever to desolder even the 8-pin op-amp... So I'll replace the 14-pin TL074CN with the LME49740NA during the weekend when I have more spare time.

Results as of now:
- High volumes improved by a very noticeable amount. Audio is much cleaner just like tonyynguen said.
- Bass control improved a lot. The subwoofer gives off a more "thump" sound instead of "whomph".
- Overall midrange quality got much better, overdriven guitars much nicer and vocalists' sounds do not drown into the bass anymore.
- I also noticed superior audio transparency over the 4565D.

I'll have to wait more so the new op-amp burns in before giving final judgements. But for now, the improvement is surprisingly large!

I'll post back when I replace the TL074CN during weekend. Maybe I should replace the input filter caps aswell - there are two very small ventless caps by the input area.

P.S. The LME49740NA is a suitable replacement for the TL074CN, right?

[Leopard]

Re: Logitech X-230 amplifier - upgrade possibilities?

Ok - I replaced the TN074CL without success. While desoldering the IC, two of the fourteen contact pads came off. No surprise, the thing doesn't work properly anymore. At first it would not produce any sound - only some buzz. Now that I soldered jumper wires in, the satellites work but the subwoofer just gives off noise. I'll now try to clean the solder joint area with isopropyl alcohol and resolder bad-looking joints if I find any. I'll post back if I get positive results later today...

[Leopard]

Re: Logitech X-230 amplifier - upgrade possibilities?



SUCCESS!

There was a third contact pad which had gone bad. A third jumper wire and everything works a-ok now!

[zandrax]

Re: Logitech X-230 amplifier - upgrade possibilities?

Hooray

Zandrax

[feistydragon]

Re: Logitech X-230 amplifier - upgrade possibilities?

SUCCESS!

There was a third contact pad which had gone bad. A third jumper wire and everything works a-ok now!

ihello guys, i'm new to this forum. i decided also to makean upgrade to my x230 and started by changing the caps with better quality electrolytics and also mkt. i also changed the np's into the satelites and also the variable resistor for the woofer control instead of 10KΩ i puted 20KΩ. the sound was much clearer and also the woofer control is beter. reading your conversations i decided to change also the opamp and the quadamp. did you order it from the states or uk? coud you tell me where from please, because here in greece the cost is about 30euro for the 2 ic's

[Leopard]

Re: Logitech X-230 amplifier - upgrade possibilities?

ihello guys, i'm new to this forum. i decided also to makean upgrade to my x230 and started by changing the caps with better quality electrolytics and also mkt. i also changed the np's into the satelites and also the variable resistor for the woofer control instead of 10KΩ i puted 20KΩ. the sound was much clearer and also the woofer control is beter. reading your conversations i decided to change also the opamp and the quadamp. did you order it from the states or uk? coud you tell me where from please, because here in greece the cost is about 30euro for the 2 ic's

I ordered samples from National Semiconductor. The samples are free and they provide free shipment if you have a "business" e-mail adress. (Not hotmail, gmail, yahoo etc.)

[feistydragon]

Re: Logitech X-230 amplifier - upgrade possibilities?

oh, ok many thanx

[feistydragon]

Re: Logitech X-230 amplifier - upgrade possibilities?

excuse me but one last question. i understand the buisness email, but must i have an electronics shop, or they will send it to any buisness email?

[tonyynguyen]

Re: Logitech X-230 amplifier - upgrade possibilities?

No its not required that you actually own a business. As long as the email domain isn't one of the free service type.

[feistydragon]

Re: Logitech X-230 amplifier - upgrade possibilities?

hello guys, i ordered through a business email of a friend samles of lme49740na and lme49860na and they denied, saying that they cannot process my order and i should be adressed to national in germany! do you have any idea what to do?