Hi,
I have a sound issue with this game (pls check my wiring shema).
In the past, I had only a mono speaker connected to the main Tocos 500ohm vol. pot and to jamma L/10 and it worked fine, now this configuration gives me issue with SH3, but every other games works, includes stereos like CPS2.
i) there's a volume pot on the pcb right? )start simple)
ii) Almost certainly you're just killing the signal - afaik the sound amplitude on some cave boards is very weak and essentially not amplified (it probably technically is, but very lowly so).
Many times people are worried about too strong a pre-amplified sound killing their amp / speakers/tv but *assuming the sound works on your board at all* my bet is that the sound is just being killed off by you're attenuation up front.
Try getting a cheap speaker and wiring it up directly to grnd + 10... check the sound works ... you're probably then fine to just skip your high low attenuation circuit with this cave board.
It's ok for me to skip the Hi-Low, but where should I connect the audio wires coming from the jamma loom?
With a mono speaker there is only two wires: one to L, the other one to 10, but in the case of some stereo speakers I have four wires.
Last edited by erzane on Wed Jul 31, 2019 11:25 pm, edited 2 times in total.
"high-low level converter" - is this just a pile of resistors? I see this kind of setup a lot to get "line level" audio out of a PCB. While the actual Vpp may be at an appropriate level, a common issue is that the negative side of the balanced JAMMA audio output gets tied to ground, and a lot of current flows there inappropriately.
Proper isolation is necessary, and in some cases I expect the former configuration can damage amplifiers on JAMMA boards. A cheap ground loop isolator should have a transformer in it to isolate levels, and would be a good thing to run inline before going to an external amplifier. Perhaps this sort of situation has damaged the CV1000's amp? Or, it is possible that the scenario is the opposite, and without a load on the speaker lines, there is little to no voltage present between the two pins. Rolling Thunder behaves this way, at least - it needs the low impedance speaker load.
Hi-Low converter have two restistors: Line Out = 10K/25w; Line In = 1K/25w.
On the following shema, Hi-low is now skipped. Amp is also skipped (since SH3 don't have built-in RCA like CPS2, a shame), so the only way seems to be the classic way I guess, but in this case I have 2x right (+/-) and 2x left (+/-). How should I handle this?
The Hi-Low I built:
My audio setting:
HEY added some external stereo speakers on their E2 with SH3 cave PCBs:
How did they manage it Maybe are they using a converter like Capcom or Sega?
Last edited by erzane on Thu Aug 01, 2019 11:10 am, edited 1 time in total.
A cheap ground loop isolator has the isolating transformer that I would recommend for any externally driven setup. It is also possible that the amplifier in use there simply has isolated inputs, which would be the case if the amplifier is isolated otherwise. In the case of many home AV setups, though, the PCB's ground is tied to the video and audio grounds, which can cause problems there.
Frequence response : 85 Hz - 20 KHz
Sensibility : 84 dB/1W/1m (2,83V@1KHz)
Impédance : 4 ohms
Recomanded power rate : from 5 to 15 watts RMS
Filter cut frequency : 3,5 KHz - 12 dB/octave
About loop isolator: I'd need a shema, to build it myself.
Update:
My Hi-Low worked fine with other games until now. I just discovered that my 500ohm main vol. pot can't be turned to maximum since it cut the sound (there is a squizzing noise and the sound disappear). I tryed two or three times consecutively and the sound shutted down definitively and no way to make it work again. There was a ''pop'' on the speakers and finish.
Maybe there was a shortcut somewhere, but my amp and my speakers are still working well since I tested a CPS2 board after that. So, maybe my Hi-Low blowed up. I just hope that's not my games cardchips...
> is it a risk to blow the soundchip of my games pcb by doing any kind of tests?
Btw, in the past, when I was using only a mono speaker (before to buy all that stereo stuff), the main vol. pot worked great also at maximum. Maybe the 500ohm main pot does have too much value to support both amp. and Hi-Low...
Maybe are they using a converter like Capcom or Sega?