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NLG Members who host their own Repair Logs of Various Games. => NLG Users Repair Log's => Topic started by: lindam1 on November 26, 2011, 05:17:31 PM



Title: s2000 poor/sharp sound... Warning
Post by: lindam1 on November 26, 2011, 05:17:31 PM
I have been reading MANY posts about putting 47 ohm resistors in line with speakers to improve sound quality. This is something that I would not recommend. An amp. is built to the same specs as the speakers it will drive (4ohm, 8 ohm, & even 16 ohm) whenever you add resistance to that line you risk a high probability of overloading and overheating the output chip causing it to fail. In the posts everyone said not to use 1/4 watt resistors as they will burn up. the reason they burn up is that they cause to much impedance is the audio circuit. unless IGT has built a VERY robust amp. I would avoid this based on my Knowledge and experience or you may be buying a new amp PCB or replacing the chip.


Title: Re: s2000 poor/sharp sound... Warning
Post by: stayouttadabunker on November 26, 2011, 09:05:03 PM
Would you have any other suggestions to improve the sound quality of the S2000 sound set-up?
It seems from your post that you have some good knowledge on audio and maybe you could share some of that with us to have these machines produce better sound?

My machine, for example, is and has always been just a bit too loud in my opinion, even on it's lowest volume setting of "1".
Without a decibel meter on hand, I cannot tell you for sure exactly what the volume difference is between "1" and "2",  but in a home environment - I find that the volume setting
at even the "2" setting, to be extremely loud.

BTW
I have had the 47ohm resistors placed on the three white speaker wires of my machine
for about 2 years now and I haven't noticed any difference whether or not any IC components on the amplifier circuit board is burning out or not.

I look forward to your thoughts on the subject of sound amplification for this machine.
There have been very many posts on this subject but I do not believe there has been any answer better than replacing the 502a, and 502b, 502d ( there was no 502c version to my knowledge)  MPU's with a 504a or 502b version.
From what I understand about this S2000 sound phenomenon, there were no revisions done to the sound amp - only to the MPU's.
I may be wrong on this but I think the 504b revised MPU board was the version
with the sound fix by IGT?  :128-


Title: Re: s2000 poor/sharp sound... Warning
Post by: lindam1 on November 27, 2011, 01:46:54 AM
I think that IGT builds there amps to take alot of abuse, but the quality of sound is definitely a poor design. This may sound silly, but an easy work around for the tinny sound in the upper speakers is a cotton ball between the speaker and grill, or a heavy piece of material on the outside over the grill. the mod. mentioned is most likely the real fix but many folks can't work on this stuff at the board level and replace soldered parts.


Title: Re: s2000 poor/sharp sound... Warning
Post by: channelmaniac on November 27, 2011, 01:47:26 AM
You can safely go up in resistance and not overheat the IC driving the speaker. If you go lower it will cause the IC to source/sink more current and will overheat and possibly burn out the IC.

The reason 1/4 watt resistors might burn up is not impedance... it's raw power. The resistor is rated to dissipate 1/4 watt in heat. Too much current flowing through it will cause the resistor to create too much heat which will burn it out/up. Remember Ohm's Law when inserting resistors.


Title: Re: s2000 poor/sharp sound... Warning
Post by: brichter on November 27, 2011, 03:45:07 AM
I think that IGT builds there amps to take alot of abuse, but the quality of sound is definitely a poor design. This may sound silly, but an easy work around for the tinny sound in the upper speakers is a cotton ball between the speaker and grill, or a heavy piece of material on the outside over the grill. the mod. mentioned is most likely the real fix but many folks can't work on this stuff at the board level and replace soldered parts.

I've not heard of anyone complaining about a "tinny" sound from the speakers, just the annoying hum when the reels are spinning.


Title: Re: s2000 poor/sharp sound... Warning
Post by: lindam1 on November 27, 2011, 10:18:16 AM
In that case, I have totally misunderstood the problem everybody's having. mine sends you out of the room in the bonus round cause the sound is so high pitched, Extreme sharp treble. Maybe my sound PCB in the upper cabinet is bad.