Sorry to cut in...

I'm still using an AL ACS 45.1 ( using for probably 10 years I think ) ...Left & Right speakers no issues, but the subwoofers sometimes no sound and sometimes have sound... then I adjust the line in connectors, again, sometimes got subwoofer sound, most of the time... no sound.. errr.. I dun think anything spoil but probably loose connectors or the low freq volume control faulty or something...

Would you be able to help me repair it... ??

I still like this speakers compared to the newer ones... like everyone says.. the new ones quality very bad la...

Thanks

Sorry for the slow reply...

It is either no subwoofer sound at all or have subwoofer sound, sometimes I hv to play heavy bass sounds to kick the low freq sound in..

these days, totally no subwoofer sound... satellite speakers no issues at all ( of coz sometimes the on / off switch a but malfunction but not an issue ... )

sub volume control... turn to extreme right, middle or extreme left...also no sound.. no cracking sound...

I did change to another working 3.5mm cables.. or plug to other sound source to eliminate the cable issue.. both cables is clean and nice...


When you mentioned solder is dry, what do you mean ? How to check it ? Which parts to check for this ??

Thanks for helping...

Ok, here are the pics on both sides of the board...

I did not smell burnt stuff... most probably loose connections or dry solder..

What do you mean broken trace ??

Nowdays, only stereo sound.... no subwoofer sound at all...

Thanks







This post has been edited by stan001: Aug 15 2010, 02:36 AM

Solution found and confirmed!!!!

Re-soldered the two suggested pins and some of the suspected dry solder and my subwoofer is WORKING again!!!!



No wonder last time when it did not work, I bump the woofer it a bit it works... the big metal piece is the heatsink to that 7370b chip right ???


Thanks a lot man!!!!

I must say this product ACS 45.1 must have made it to the hall of fame for one of the longest serving product for the PC... more than 10 years and still running.... and still users reporting in for it and not shy about it!!!!!


My intermittent subwoofer problem was "fixed" with help from beggarmaster2000 to identifying the dry solder joint on the amp IC.

Still using it for my gaming machine... need low and loud sounds during explosion in games...


Somehow after that fix, even the intermittent power/volume switch problem also went away...

I must say, during that time, to design a speaker to use two buttons press to turn on the speaker was really "cool" .. but my preference is still a regular volume control / potentiometer...

I've open up the satellite speakers casing and find the speakers pretty heavy ...

I guess the two switch/volume buttons does take a lof of wear & tear during the last ten years...


Have anyone tried to mod the ACS 45.1 ( for the fun of it ) to change the power switch and volume control back to a regular on/off switch and potentiometer ?

I'm not sure how they wire it up the power switch / volume control ... I only see a bunch of wires coming from the subwoofer..

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Added on February 18, 2011, 2:00 amI think that companies like Altec , when they make such good quality speakers and sells them so low priced as PC multimedia speakers and it lasts so long, it is just bad for business cos no repeat customer orders... and higher manufacturing costs...

Since they built this "reputation", dunno why they went down the "high profit" paths using cheapo parts and such until everyone thinks Altec is a lousy PC speaker brand... except some higher priced speakers..

If they continue that path, I'm sure I would pay a little more if the speaker can last like 5 years or more... total value for money... like the ACS 45.1



This post has been edited by stan001: Feb 18 2011, 02:00 AM

I open up the satellite speakers, there is just the speaker itself with 2 push buttons for on/off & volume control and wires to left & right speakers..

You case is like my case previously... the subwoofer "sometimes" works and "sometimes" no subwoofer sound at all..

After I took a high resolution pic of the PCB front & back and posted here, bm2000 pointed out to me that the solder joint is broken on the amp chip, probably due to the fact that the chip is on the large heatsink and the large heatsink is being vibrated by the subwoofer for the past 10 years...

Anything being vibrated for long period, surely those solder joint all lose and give u intermitted connections..


Pls post yr picture here, hope bm2000 sharp eyes can help to spot the dry solder joint..

hehe, another fellow hv the same crazy idea like me..

If you open the right speaker, you should be able to identify the L& R signal cable...

The right goes to the speaker and the left is the cable going out to the 3.5mm socket...

The other 3 cables.. I hv not trace them back to the PCB yet..

Do share if you discovered anything...

What board are those ?

They look so cool in red PCB...

Another ACS 45.1 revived !!!!

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Added on March 1, 2011, 6:17 pmYeah.. no need to put another amp just into a PC speaker amp ... overkill solution..

We wanna mod & hacked it ... not make it into a monster... haha





This post has been edited by stan001: Mar 1 2011, 06:17 PM

A picture tells a thousand words...

Pictures and specs would be good info...

It is just speakers, cables and power supply, shouldn't be too complex to figure it out...

If you are asking for help, pls post some clear pictures of yr circuit board and the 7 pin wire you mentioned..

At times, words can't really explain what you are trying to ask..

Thanks for the insight about AL ... this always happens to really good companies in the wrong hands... wrong decision.. wrong products..

But I think for a PC Multimedia speakers (that what they were called.. but I always hated the word multimedia...totally overused ), 650W could be too high price to pay ... ppl could just jump into some low end hifi stuff... unless it was priced very competitively..

Yeah, last time I also removed the black plastic cover before.. easy to put back..

But actually... why the "hell" the heatsink so damn big one .. is that chip so hot ??

Actually, any idea why are there so so many capacitors for... I tot the circuit is mainly power supply / transformers and the sound chip to amplify the sound with some capacitors to suppress the DC signals and big caps to reverse the power for powerful bass..

What the gun for ?

The 10,000 uF, can use 10 x 1000uF wired in parallel on a perf board instead ? Cheaper mah... hehe

Is the 10,000 uF for power reverse when suddenly needed high power for bass purpose ??

Pls use the multimeter beeper / connectivity tester to check for short circuits...

Just to share this with ACS 45.1 users..

I recently got this WM8501 USB DAC designed by chchyong89
http://forum.lowyat.net/topic/1680516

When I was listening using my Macbook Pro using the USB DAC vs built-in DAC to TA-2020 MKIII amp to my bookshelf speakers...

The sound quality differences was minimal ... can hear a bit better sound quality and also Line Out level...

So just now, I took the USB DAC , plug into my Win7 gaming machine connected to the ACS 45.1 ( built-in soundcard is from the Asus mobo )...

The sound quality differences was like "wow" so much differences...

Playing a .flac instrumental music, besides "line out" output (bypass internal amp), can really hear the music separation and the instruments was more "front"...

Just switch between the built-in soundcard vs the USB DAC from the Sound control panel... since the ACS45.1 have 2 sound input...

Software is foobar2000...

Those ppl that want to improved sound quality should try out this USB DAC..

This post has been edited by stan001: Mar 22 2011, 10:12 PM

I'm saying the PC mobo soundcard/DAC is really lousy compared to MAC soundcard.. hahaha, so the USB DAC will help la..

No angry la... why should I be angry ??

Which "damn" DAC are u referring to ?? U r also confusing me la..

I'm NOT selling it, some forumer design & sell it.. nothing to do with me,I'm just a consumer..

No no.. Mac soundcard is "pretty" good ... hehe

Ohh.. that confusing part... hahaha, glad that I confused you...

Ok... let me clarify... just ignore the "mac/ta-2020/bookshelf part"....

Back to main topics...

Really like to see Tim_HKG moded ACS 45.1 with all the nice pictures...

I think there should be a "balance" in price/$$$ to do the "mod"... since modding is more about learning & self satisfaction instead of the money spend / hours needed to mod the speakers/circuits for them to "sound" better...

To get good quality sound .. too many many things that can be change/modify/improve ...

Source :- use higher quality recording / higher bit rate mp3 or lossless audio ( flac )
Engine :- Soundcard / DAC - use internal built-in soundcard, X-Fi or external USB DAC
Amp :- no changes
Capacitors :- use decent caps but not too expensive
Speakers cable :- use thick/low resistance and low cost cables ( UTP 5E copper is good & cheap )
Speakers - no changes

I feel we just choose the ones that bring the most increase in sound quality with the least cost / most satisfaction...

Those large caps act as "power reserve" that might be needed during those high power bass output... *boom* *boom* *boom*

Read this :-
http://www.ehobbycorner.com/pages/tut_capacitors.html

AC Coupling:
The ability of the capacitor to pass AC signals while blocking DC signals is most often used in audio circuits, in order to allow opamps to work of a single supply potential. (or just to protect against DC inputs, which can be noisy)