It was working fine yesterday, and now nothing.
I am sorry, but I am a total noob when it comes to resistance check. Break it down in easy to follow steps
Yes I thought that too, but when I set up in stereo left channel plays fine
Just right not working
Hi ryan391,
You need to make sure the fault is not a shorted Black speaker socket or shorted input (RCA socket) before moving on. Either will stop the ACA working. The fact it was working hopefully means something has moved since then.
With the Rear switch in the central position:-
Put your meter on resistance (range 2kΩ) and put one probe into the Red speaker socket and the the other probe into the Black speaker socket, You should read between 500Ω and 1000Ω (1KΩ). If you read zero ohms there is a short on the black socket. Usually the metal post of the socket is touching the chassis as the washers are not installed correctly.
Now set the resistance range to 200kΩ and put one probe on the outer gold ring of the RCA socket and the other probe on the central RCA connector, where the red wires are soldered to. You should measure about 50kΩ. If it is zero then there is a short. Usually a blob of solder or strand of wire.
Let us know how these measure so we can fix or eliminate them.
You need to make sure the fault is not a shorted Black speaker socket or shorted input (RCA socket) before moving on. Either will stop the ACA working. The fact it was working hopefully means something has moved since then.
With the Rear switch in the central position:-
Put your meter on resistance (range 2kΩ) and put one probe into the Red speaker socket and the the other probe into the Black speaker socket, You should read between 500Ω and 1000Ω (1KΩ). If you read zero ohms there is a short on the black socket. Usually the metal post of the socket is touching the chassis as the washers are not installed correctly.
Now set the resistance range to 200kΩ and put one probe on the outer gold ring of the RCA socket and the other probe on the central RCA connector, where the red wires are soldered to. You should measure about 50kΩ. If it is zero then there is a short. Usually a blob of solder or strand of wire.
Let us know how these measure so we can fix or eliminate them.
Yes, I have swapped left and right. works fine in stereo left, but nothing right.
If switch is up and connect left black and right red, works too. bias on the boards are stable and equal too.
Also tried a balanced input cable. in Center stereo mode switch up works as mono, switch up, does not
If switch is up and connect left black and right red, works too. bias on the boards are stable and equal too.
Also tried a balanced input cable. in Center stereo mode switch up works as mono, switch up, does not
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I completely rebuilt the amp that was faulty. I have two working ACA's. Now the newest possible problem maybe nothing. But one is louder than the other. I have them all biased at 12.3. I am using my pre amp to center the stage. Before anyone asks. I have swapped every conceivable thing. I even swapped the pre amp just to make sure. Any ideas?
so in an ideal situation R11, R12 and R10 would be perfectly matched on all channels and both amps? Otherwise, nothing is wrong just not matched?
They would have to be miles out before you noticed any problems but it can happen if you fitted say a 100k instead of a 10k or a 3.9k instead of a 39k You would notice that for sure.
Small differences such as tolerances (even if you used 10% or even 20% tolerance resistors) would not not be immediately obvious such is our perception of volume and loudness.
Small differences such as tolerances (even if you used 10% or even 20% tolerance resistors) would not not be immediately obvious such is our perception of volume and loudness.
I took apart the newer, quieter amp. I pulled R11, R12, and R10 out checked and reinstalled. No change.
I think maybe one is just a little more powerful than the other? could this be?
They sound great, although I have to adjust balance to the left by 5 clicks to have. better center stage.
I think maybe one is just a little more powerful than the other? could this be?
They sound great, although I have to adjust balance to the left by 5 clicks to have. better center stage.