cable question

renishaw · 07-30-2003, 02:07 PM

This isn't really a production question, but its a studio question so maybe some of you can help me out...

I need to connect a soundcard to an amplifier, then the amp to two monitor speakers (probably gonna be alesis ones or tannoy reveals).

-the soundcard output will be a mini-jack connector

-the amplifier input has two screw terminals marked 'hot' and 'com'.

-the amplifier output has two screw terminals marked '4/8 ohm' (depends on a switch next to it), and 'com'.

-the monitor input will be xlr probably

What i don't know is how you tell which wire goes to the 'hot' and which goes to the 'com' terminal. I assume one is positive and one is negative.
Also, if there's only one pair of connectors for the output, how do i connect two speakers? Do i just screw two +ve wires on one +ve terminal or what?

(e) · 07-31-2003, 05:41 AM

Your amp sounds pretty old...

Sure there isn't a 'video in' on your amp or something like that at the back of it? If you connect your computer to your your amp and then have the speakers also connected to your amp all you should need is a basic lead (forgotten the name but people in a shop would know).

multi-purpose · 07-31-2003, 06:22 AM

I believe you will use the following wiring theory:
From "mini jack" to banana (Soundcard to Amp):

Ring -> cold (channel A on amp)
Sleeve ->com (channel A on amp)
Tip -> hot (channel B on amp)
Sleeve -> com (channel B on amp)

From banana to XLR (male or female) (amp to speakers):
RIGHT SPEAKER:
1 + 3 -> com (channel A on amp)
2 -> cold (channel A on amp)

LEFT SPEAKER:
1 + 3 -> com (channel B on amp)
2 -> hot (channel B on amp)

Sorry for the crudeness of my reply, but it was wrote in a hurry (I am on a break at the mo). The above wiring configuration will set channel "A" on your amp to drive the right speaker and set channel "B" on the amp to drive the left speaker. Have a look at the speakers and check if they have a resistance of 4 or 8 ohm resistance and set the amp accordingly.

N.B. It is ok to have higher resistance speakers on a system than lower resistance ones. NEVER go below the min resistance stated on the amp, in this case 4 ohm's

Hope this has helped, if you want me to draw up some wiring diagrams i will be happy to do so.

P.S. While wiring directly to the amp keep an eye on levels.