concert lead H E L P

[RoReitz]

I am the proud owner of a 74 concert lead (bushel basket specal) some one removed the small transformer that connects to the power amp side? My question is can any one tell me or draw a diagram of whear all 10 of those wires need to go and are transformers all the same concert bass concert lead of the same vintage? I have 2 concert bass amps (both working after a lot of soldering and electronic catalog searching) and the color codes seem to be the same but the connectors are different concert bass has round pins concert lead has flat pins... any help will be appreaceated!!!!

[JoeArthur]

That's interesting.

I'd suggest looking at the schematics available on this site.

[RoReitz]

that is where I started. someone with a lot more skill at reading schematics might be able to do it but I don't think i can??

[rick.heil]

I think if all you've got now is the colors of the wires, your best bet would be to do something like this:

-assign each physical wire a number
-trace each physical wire back to a component or chain of components that's unique
-write down the number of the physical wire on a printout of the schematic
-repeat for all the wires

One of the more veteran users might be able to tell you if the transformer is the same, I don't have experience with the concert series at all.  If it is, would the wires possibly even be the same color?   Might be, might not be, but I wouldn't trust that and blow the transformer by accident.  Maybe if somebody could post any pictures of the guts of their Concert Lead?

[JoeArthur]

that is where I started. someone with a lot more skill at reading schematics might be able to do it but I don't think i can??

Well, it's all there sort of in black and white. 

The connectors may be different, but the pin numbers and the wire colors should match up between the bass and lead. So verify these pin and color combinations with the bass first:

Orange - pin #2
Red - pin #7
Yellow - pin #3
Green - pin #8
White - pin #4
Gray - pin #9
Blue - pin #5
Violet - pin #6

Brown - seems to go directly to the collector of the driver transistor. This would make sense since to go to a transistor on the heat sink, it would be a waste of wire to make it go back to the circuit board.
Black - pin #1 - The bass schematic implies a connector of some sort instead of a pin on the board.

[RoReitz]

First I want to thank you for all you time and effort!! I see orange pin 2 red pin 7  those wires on the transformer are even directly opposite each other on the transformer so hat makes sence and the black wire and brown wire are oposite each other also and longer wires than the rest so that adds up also.....now how do I find the numbering sequence on the board most of the pins are in 2 lines accross the end of the board??

[JoeArthur]

how do I find the numbering sequence on the board most of the pins are in 2 lines accross the end of the board??

Every Concert board I've seen has the pin numbers printed on the circuit board next to the pins.

[RoReitz]

any other suggestions no number on this board ?

[JoeArthur]

any other suggestions no number on this board ?

It's been a while since I had my concert apart and I can't recall how the power amp board is oriented.  And yes, I am also too lazy to tear it apart for you to find out.   

So look at the top of the power amp PCB. On the shorter sides, you'll notice that one side has 11 pins, and the other side has 8 pins. You shouldn't really have to count them - it should be readily apparent.

Once you figure that out, position yourself so that the side of the board with the 11 pins is to your left. Now, just to check that you are positioned correctly, the long edge closest to you should have the least number of pins - the "edge" should only have one pin - about 1/3 of the way to the right side, and there should be 3 pins clustered behind it.

Now focus on the row of pins along the edge of the left side. The pin in the lower (i.e. closest to you) left corner is pin #1. Following the left edge up (i.e. away from you), the pins are numbered sequentially.

So, from that lower corner of the board (pin #1), following the left edge and in a direction away from you, the transformer leads correctly placed should be in this color sequence:

black
orange
yellow
white
blue
violet
red
green
gray

[RoReitz]

I will let you know how it works.............