Small audio mod?

[+DarkLord]

Okay, I've got a specific need that I'm pretty sure someone around

here has already done at some point in time.

 

I use my Mega ST4 and SC1224 monitor to run my BBS, DarkForce.

 

I'd like to do a small audio mod to bring sound out via a plug (1/8th?)

to a small set of speakers.

 

Reason being, to hear pages from the "Chat" option on the BBS requires

that the monitor be on 24/7. I don't like that,  even if I'm using the screen

saver.

 

With a mod like that, I could leave the monitor off but still hear the bell for

Chat pages.

 

Thanks.

 

[ParanoidLittleMan]

If I get it correct, you want to connect ST audio output to speakers. That will work only if those speakers have amplifier.

Then just need to 'steal' audio from monitor cable, or connector at Atari - audio is pin 1 on 13 pin Atari video connector.  GND is pin 13 (that solo one down) .

[anzac]

Hope this helps 

Edited April 24, 2021 by anzac

[+DarkLord]

Thanks everyone for all the info.

 

The stereo mod is a bit more than I need for this,

so I'll be going with the single RCA jack out.

 

PS Pretty sure that stereo mod was released

commercially as the TweetyBoard...

 

[ParanoidLittleMan]

Mega ST has no stereo audio at all.

[+DarkLord]

Right, the TweetyBoard design gave 3-channels out on standard ST's.

 

Gave great sound, especially music but you had to equip it with a

toggle switch to go back to stock because digitized samples did

not play from it correctly.

 

[tjlazer]

If you got one of those VGA adapter boards you could do just this and turn off the LCD.  You would need a screen than can do 15HKz though like the NEC 1970vx.

[+DarkLord]

4 hours ago, tjlazer said:

If you got one of those VGA adapter boards you could do just this and turn off the LCD.  You would need a screen than can do 15HKz though like the NEC 1970vx.

 

That's another option - thanks!

 

[+DarkLord]

Hmm, had my Mega ST apart yesterday and from what I can see, the black
plastic cover over the video connector would make it extremely hard for
a klutz like me to get to those 2 pins.

Can they be pulled from an easier place on the motherboard?

If not, does anybody sell a ready made ST video cable with audio out?

Thanks all.

[+DarkLord]

Okay, I was told that the minus side of C35 on the Mega ST4's motherboard is audio out.

 

Reading schematics or ID'ing things on printed circuits is not my strong point. Can some

one please point out the minus side of C35 in these pictures? The + side seems pretty

obvious.

 

Thanks.

 

 

 

 

 

[+DarkLord]

Finally, with lots of help, I've got this installed. Even though it's mono,

it's a huge improvement over the monitor speaker. I've got a pair of

cheap Altec-Lansing speakers set up with it and it still sounds soooo

much better.

 

Thanks to everyone who pitched in, appreciated! 

 

 

 

 

 

 

 

 

 

 

 

[walter_J64bit]

That's awesome! When I got my STe and seen the audio out as RCA jacks. I used a RCA to mini jack so I can use my Creative SBS 20's With my STe!

Edited June 20, 2021 by walter_J64bit

[+DarkLord]

My Mega ST4 is jealous though - you've got *stereo*!