C
Cap217
Active member
I am struggling to find a way to know what colors are for each output impedance. I don’t want to take for granted that old amps are wired properly. Not only that, I have a 72 and a 73 that have the same color wires but one impedance selector has been messed with I think. Id like to learn how to tell and look at all my amps.
This will be for the vintage push selector for impedance. I will eventually get into the switch but not yet.
The amps in discussion will be a 1972 100w super lead that has been modded with by Abrahams with the mod 5. It looks like the selector where it shows the ohms is original but the wires on the selector were soldered at some point. The writing where it shows the ohms also has 1-2-3 where 1 is 4 ohm, 2 is 8 ohm, and 3 is 16. I am assuming that the wires are soldered back at the stock spots. This amp has NFB off the speaker jack.
The next amp is a 1973 100w super lead that seems to be mostly untouched. It is a handwired that had work done by Plexi Palace years ago. There are some cap changes and I was told its because the old mustards didn’t test to the right value. Besides that it seems original. The selector where it shows the ohms has an 8 ohm that looks original but I see a larger 4 and a larger 6 (I assume this is 16). The wiring seems untouched on the back of the switch. Like the 72 I do see a number, but only number 3 that is next to the large 4. This amp has NFB off the black wire.
Why I am questioning this is because looking at the wiring inside the amp, they are identical (minus NFB purple) but the selector switch on the 1973 has obviously been altered. I can just go off the 1972 numbering or I can find a way to be 100% sure what is correct.
Attached is a drawing I did of both. They are both with the chassis upside down so keep that in mind. I am also assuming how the selector with the pins work. Center is common and wherever the other pin is connected, that lines up with a wire color on the inside of the selector.
I am showing amp upside down from the inside, then amp from the back while its upside down and how the wires connect, then how it lines up for each ohm upside down. Hope this makes sense.
What I see is on the 72 it looks like yellow=8, black=4, green=16 and that lines up with most everything I find online.
But on the 73 its different because it looks like someone put old stickers and swapped 4 and 16 ohm. Yellow=8, black=16, green=4.
Is there a way to be positive of what ohm is what? I have read that you can use an ohm meter and the selector on 4 ohm, the lowest reading is the 4 ohm. If on 16 ohm, the lowest reading is on 16 ohm. Im not sure if this is real or not.
I am going to post pics from my phone in the next post.
This will be for the vintage push selector for impedance. I will eventually get into the switch but not yet.
The amps in discussion will be a 1972 100w super lead that has been modded with by Abrahams with the mod 5. It looks like the selector where it shows the ohms is original but the wires on the selector were soldered at some point. The writing where it shows the ohms also has 1-2-3 where 1 is 4 ohm, 2 is 8 ohm, and 3 is 16. I am assuming that the wires are soldered back at the stock spots. This amp has NFB off the speaker jack.
The next amp is a 1973 100w super lead that seems to be mostly untouched. It is a handwired that had work done by Plexi Palace years ago. There are some cap changes and I was told its because the old mustards didn’t test to the right value. Besides that it seems original. The selector where it shows the ohms has an 8 ohm that looks original but I see a larger 4 and a larger 6 (I assume this is 16). The wiring seems untouched on the back of the switch. Like the 72 I do see a number, but only number 3 that is next to the large 4. This amp has NFB off the black wire.
Why I am questioning this is because looking at the wiring inside the amp, they are identical (minus NFB purple) but the selector switch on the 1973 has obviously been altered. I can just go off the 1972 numbering or I can find a way to be 100% sure what is correct.
Attached is a drawing I did of both. They are both with the chassis upside down so keep that in mind. I am also assuming how the selector with the pins work. Center is common and wherever the other pin is connected, that lines up with a wire color on the inside of the selector.
I am showing amp upside down from the inside, then amp from the back while its upside down and how the wires connect, then how it lines up for each ohm upside down. Hope this makes sense.
What I see is on the 72 it looks like yellow=8, black=4, green=16 and that lines up with most everything I find online.
But on the 73 its different because it looks like someone put old stickers and swapped 4 and 16 ohm. Yellow=8, black=16, green=4.
Is there a way to be positive of what ohm is what? I have read that you can use an ohm meter and the selector on 4 ohm, the lowest reading is the 4 ohm. If on 16 ohm, the lowest reading is on 16 ohm. Im not sure if this is real or not.
I am going to post pics from my phone in the next post.
