PA Amp connected to Computer?

frankie11 · 05-17-2005, 01:38 PM

i have the RadioShack MPA-46 PA Amplifier (35WATT) with output ports of COM, 4 Ohms( can't find how to put the sign thing in), 8 ohms, 16 ohms, and 70V....its works when i connect it to a speaker with the normal speaker cables...but i want to put it into my computer's Sound Card input port so i can record with my recording apps. but the things is that i can't get the adapter i made work..can anyone tell me how to make on that will work, where to get an adapter that i can use. Or an adapter on how to change the speaker wire cables to the Red/White audio plugs?.....i don't want to have no use for this little amp, so all help would be appreciated.

Thanks in advance.
Frankie

**Fox** · 05-17-2005, 06:56 PM

I'd be very very careful with this. You don't want to take an 35 watt output and plug it into the input of your sound card. Chances are your sound card and computer won't like it very much and you could possibly zap the card, the motherboard, or both.

What you're looking for is a line out, something that's meant to go from that amp to a recording device or a larger amp.

If you have the capability, some pictures would help a lot as I couldn't find any on the net.

Volt-Schwibe · 05-17-2005, 11:59 PM

radio shack sells a low level line tap, and what it does is take a 500mw sample from the speaker wires of a system.

so, what you do is basically set the whole amp and mic up as normal, and then somewhere along the speaker wire, hack into it, and install the line tap. then you would connect the line tap's low level outputs into the pc's sound card input.

this will work lovely, but would be a small investment.

i can try to explain how to make one, but i can't promise i will find a good schematic.

Volt-Schwibe · 05-18-2005, 02:32 AM

Ok, here we go.

this is a diagram i drew, and the info to use it, i got the required info from an instruction book of mine.

this is basically the same one that radio shack sells, but, the info i have included makes this unit cover a wider range of uses.

Quote:

For 1-50 watts, 10:1 Reduction:

R1= 10k Ohm
R2= 1k Ohm

For 50-300 watts, 33:1 Reduction:

R1= 33k Ohm
R2= 1k Ohm

For Variable Drive, Replace R2 with 1k Ohm Rheostat.

For a signal Filter, to reduce hum, use 10 Ohm Resistor in R3 location.

the line out - and + would be connected to the RCA jacks (red & white plugs) in some fashion.

**Fox** · 05-18-2005, 12:29 PM

I find it scary that I can understand that. You rock, walt.

Volt-Schwibe · 05-18-2005, 01:16 PM

heh, i tried to simplify the wording i used.

in the book, it takes about 500 more words to explain this circut.

but, we aren't trying to learn the entire physics of circuts like this, we just want to know how to make one that works, and the other 460 words weren't needed.

:)

05-17-2005, 01:38 PM	#1 (permalink)
frankie11 Registered User Join Date: May 2005 Posts: 1 OS: Win XP Pro SP2	PA Amp connected to Computer? i have the RadioShack MPA-46 PA Amplifier (35WATT) with output ports of COM, 4 Ohms( can't find how to put the sign thing in), 8 ohms, 16 ohms, and 70V....its works when i connect it to a speaker with the normal speaker cables...but i want to put it into my computer's Sound Card input port so i can record with my recording apps. but the things is that i can't get the adapter i made work..can anyone tell me how to make on that will work, where to get an adapter that i can use. Or an adapter on how to change the speaker wire cables to the Red/White audio plugs?.....i don't want to have no use for this little amp, so all help would be appreciated. Thanks in advance. Frankie

05-17-2005, 11:59 PM	#3 (permalink)
Volt-Schwibe Asst. Manager, Automotive Forums; HJT Trainee Join Date: Jan 2003 Location: Behind you, watching you as you type. Posts: 7,323 OS: Click "My System" to view details My System	radio shack sells a low level line tap, and what it does is take a 500mw sample from the speaker wires of a system. so, what you do is basically set the whole amp and mic up as normal, and then somewhere along the speaker wire, hack into it, and install the line tap. then you would connect the line tap's low level outputs into the pc's sound card input. this will work lovely, but would be a small investment. i can try to explain how to make one, but i can't promise i will find a good schematic. __________________ <signature> TSF is funded by our Admin's pocket, care to help? Power Tip: Subscribe to your thread (Thread Tools) to receive an instant email notification when you get a reply. New Members: Creating a single new thread in the correct section is the best way to assure your thread will receive a reply. </signature> Last edited by Volt-Schwibe; 05-18-2005 at 12:02 AM.

05-18-2005, 01:16 PM	#6 (permalink)
Volt-Schwibe Asst. Manager, Automotive Forums; HJT Trainee Join Date: Jan 2003 Location: Behind you, watching you as you type. Posts: 7,323 OS: Click "My System" to view details My System	heh, i tried to simplify the wording i used. in the book, it takes about 500 more words to explain this circut. but, we aren't trying to learn the entire physics of circuts like this, we just want to know how to make one that works, and the other 460 words weren't needed. :) __________________ <signature> TSF is funded by our Admin's pocket, care to help? Power Tip: Subscribe to your thread (Thread Tools) to receive an instant email notification when you get a reply. New Members: Creating a single new thread in the correct section is the best way to assure your thread will receive a reply. </signature>

05-17-2005, 06:56 PM	#2 (permalink)
Fox TSF Enthusiast Join Date: Sep 2002 Location: NJ Posts: 7,752 OS: XP Pro, CentOS My System	I'd be very very careful with this. You don't want to take an 35 watt output and plug it into the input of your sound card. Chances are your sound card and computer won't like it very much and you could possibly zap the card, the motherboard, or both. What you're looking for is a line out, something that's meant to go from that amp to a recording device or a larger amp. If you have the capability, some pictures would help a lot as I couldn't find any on the net.

05-18-2005, 12:29 PM	#5 (permalink)
Fox TSF Enthusiast Join Date: Sep 2002 Location: NJ Posts: 7,752 OS: XP Pro, CentOS My System	I find it scary that I can understand that. You rock, walt.