Capcom Inpress (Q Sound), CPS 1.5 Popping sounds , CPS2 Work

[Battlesmurf]

I have a Capcom impress. Over the years, I've replaced a chassis and (if memory serves) the power supply, but not 100% of that- might be misremembering.

I have used CPS2 things in there just fine. Stereo jack plugged in to the QSound Amp, RCA plugs to the boards, sounds great, works great.

I recently tried CPS1.5 (Punisher, Slam Masters, Cadillacs/Dinos) via the same method, no luck. All are original boards, all have been resurrected from the same person. I can get sound if I only plug in the white RCA plug (the one that has a ground wire in with it), but the second I try to plug in the Red/Right cable, I get a "thump_thump_thump_" sound from the speakers.

I need a fresh set of opinions on this, please

Thoughts?

[Artemio]

I had that issue and ground loop noise with cps III.

I fixed it by changing the amplifier:

http://forum.killercabs.com/viewtopic.php?t=8875


It seems that in Japan these were issued with a 18 volt transformer, and in the usa they were fed 12 volts instead. That seems to be the source of these issues with non cps2 capcom hardware.

[tobeder]

Hi, Artemio. I'm having the same issue with CPS III in my Capcom Impress. Seems that the link that you posted in the reply doesn't work anymore. How do you replaced the amplifier? or if you know if there is an alternative to this issue. Thanks in advance.