Double Bass How to Wire 1/4" Mono Phone Plug

[borgward]

Which part of a phone plug is common? I usually don't mess with plug ends, I just buy the best cords I can get for longevity. I am testing a Heathkit Model A7 mono tube HiFi tube amp. A whopping 6 watts! There are four connections on the back, common, 4 ohm, 8 ohm, and 16 ohm. I have lamp cord that I will attach the mono plug to one end. Which part of the plug is common?

I will plug it into one of my cabs for testing. There are pages on the web where people have converted The A7 to be guitar amps.

 

[Francois Blais]

The signal is the tip, everything else is the common.

 

[DoubleMIDI]

I guess these are the speaker outputs.
If this is true, common means a (common) ground for all types of output impedances and 4, 8 and 16 Ohms are alternative signal outputs for the speaker, depending on the speaker input impedances.

 

[megafiddle]

Which part of a phone plug is common? I usually don't mess with plug ends, I just buy the best cords I can get for longevity. I am testing a Heathkit Model A7 mono tube HiFi tube amp. A whopping 6 watts! There are four connections on the back, common, 4 ohm, 8 ohm, and 16 ohm. I have lamp cord that I will attach the mono plug to one end. Which part of the plug is common?

I will plug it into one of my cabs for testing. There are pages on the web where people have converted The A7 to be guitar amps.

If you are referring to the terminals in the phone plug, the longer terminal with the strain relief tabs on the end is the common. The shorter terminal is the signal.

-

 

[Vince Waldon]

We may not be understanding your question correctly, since there really isn't a "common" on a two-wire connection like a mono plug, but in case what you mean is "ground" or "shield" the wiring looks like this:

 

[Don Kasper]

I have lamp cord that I will attach the mono plug to one end.

I believe the OP is describing "Speaker" cable, not "Signal" cable. In this case it only needs to be consistent in terms of "+/-" on each connector (each connector should be soldered the same regarding the "+/-" Halves.) There is usually a marking of some sort on lampcord (on the exterior insulation) to keep track of each HALF.
BTW - IANAE (I Am Not An Electrician!)
Thanks.

 

[Killed_by_Death]

All you need to do is make sure the same wire goes to the tip on both ends.
If there's no marking on the jacket of the lamp cord, you can check for continuity with an Ohm meter.

 

[farace]

One side of a lamp cord's insulation should be smooth, the other side should have ridges, to keep track of polarity. Every cord I've seen has been this way. (But of course I haven't seen them all.)

 

[borgward]

To sum it up, I am using lamp cord. Could have used speaker wire. Not using shielded cable. The plug goes on one end only. The other end is stripped to bare wire and connected the screw connections on the audio amplifier. That's how it was done back in the dark ages. - (common) connects to the longer terminal on the plug, and + goes to the short terminal that goes to the tip. I used ohm meter to make sure common on the plug connected to common on the HiFi audio amplifier. Thanks for the heads up on the smooth and textured leads of the lamp cord.