Replacing AR3a pots with fixed resistors

[Guest RobertAr3a]

I've just read through the "Restoring the AR3a" document and am very grateful for it being posted. A great source of information. Now to the topic at hand. I like the sound of my AR3a's with the level controls at the "white dot" position. I would like to bypass the pots and substitute fixed non-inductive resistors that will mimic the action of the pots at their "white dot" positions. According to the above document (page 10), the resistance from the "B' terminal to the "1" terminal is 3.25 ohms on the mid pot and 1.75 ohms on the tweeter pot.

First question: since the pots are identical and are at the same position ("white dot"), how can these resistances be different?

Second question: (I'll only ask this for the mid pot since the tweeter pot is conceptually the same): Suppose I open up the mid pot, and remove the wiper, remove the 16 ohm wire wound resistor, and re-assemble. (Easy to do, I have opened it up many times for cleaning). Now the 1, 2 and "B" terminals become simple convenient places to solder wires and resistors to, and the 16 ohm resistor in the pot is out of the circuit.

Now, assuming the resistance measurements cited above are correct, I get a 20 watt, 12.75 ohm non-inductive resistor and solder it from terminal 2 to terminal "B", and a 3.25 ohm non-inductive resistor and solder it from terminal "B' to terminal 1.

Note that the resistance adds up to 16 ohms. Will this mimic the action of the mid pot at the "white dot" position ?

(I understand that the exact resistor values may be not available and that I would have to use the closest match available. PE has some that are very close).

Thanks in advance for your responses.

[onplane]

First question: since the pots are identical and are at the same position ("white dot"), how can these resistances be different?

Robert, pots are identical, but the drivers are differnet. AR recognized that and knew that the tweeters lagged the mids. Thus when the speakers were setup, they positioned the pots slightly differently so that the white dot resulted in the resistances you quoted.

Please remember for many speakers that was 30 years ago. Today many folks believe the tweeter ouput has degraded vs the other drivers. Before you hard wire anything, try the tweeter at max output.

I have completlely removed the tweeter pot in search more output. I do get a little more, but my 3a's still lag my AR TSW's by one ton! It's not even close.

Now, on top of this, Robert, ... our ears have degraded over time and most of us need some additional help in the high end.

Hope this helps ...

Regards,

Jerry