Sound on rig but not in working cabs!

[jammajup]

Hi guys

 

I have a sound prob here which is driving me insane,why would a game sound work on a test rig but not in cabs?

the board in question is a tiger heli board which works fine on my rig but if i connect it up in two other cabs there is no sound even though there is 12V+ reaching the board in both cases?.

Other game boards and MVS work fine in the cabs as normal and all speakers in the cabs and rig are 8ohm,if the audio amp is not 100% i always expect them to be dead!, is it possible they may become fussy about o/p requirements?

 

Jj

http://www.jammajup.pwp.blueyonder.co.uk

[Cassidy Nolen]

Check how it gets its speaker ground. Sometimes I have seen boards that have a separate ground for audio than the regular ground. Might be picky.

 

 

I have had this happen too, and usually sell the game without sound.. Of course I am not motivated to fix it either

 

 

Cassidy

[jammajup]

Hi

I have heard of this problem with the seperate ground too but i always thought that all grounds were connected somewhere on the circuit

and so have never thought anything of it.

All the grounds are connected on my rig to form one ground line,i could will try to isolate the speaker ground to the psu but do not all grounds connect to the psu anyway?

[Cassidy Nolen]

They all tie back into the PSU, yes. I wonder though if there is something that is wierd about the way the amp works on the pcb. Just a thought. Worth doing some tracing with a voltmeter and seeing.

 

As a side note, I have an old stereo receiver in my classroom that powers two little tweeters mounted in the walls. I blew the left channel years ago, but it works fine to power little speakers. It cant drive a woofer or a midrange, but still enough to power a little speaker. Try swapping your test rig speaker into the cabinet (if you can) and see if it works that way. Then you'll know if its a wiring or a speaker issue for sure.

 

Cassidy

[jammajup]

Hi guys!

Problem with sound solved,during the re-building of my test rig i had reconnected two of the wires to the incorect places!,

SP- on board connector to a Gnd in rig and visa-versa (one of the Gnd on board connector wired to SP- in rig) what was

confusing me was the fact that the sound on some boards were actually working fine this way.

To make things worse a Gnd connection on one of my cabs had become disconnected some boards that worked

on rig did not in this cab,etc just one of those things i guess!

Thanks for the help anyway

Jj