Me again! Need to bypass the above from Akai sw155 speakers. I've tried to clean the pots with electrical cleaner (deoxit) but still nothing! Let me rewind, Akai sw155 4way speakers just popped up and naw I got them. At the rear of the speakers we have controls for high and mid. Plugged them in and it was all wrong, scratching pots as I turned them. Decided to clean the pots but no. One speaker is intermittent, other has no high frequency (tweeter/super tweeter)
Adjustments can be made at amplifier so I'd rather bypass.
Sorry unable to take detailed pictures but will try my best.
Adjustments can be made at amplifier so I'd rather bypass.
Sorry unable to take detailed pictures but will try my best.
Hi Bazza!
Referring to the photograph showing the two crossovers side by side, here's how to bypass the level controls:
Move the yellow wire from the central terminal of its pot to the bottom terminal.
Move the blue wire from the central terminal of its pot to the bottom terminal.
Let me know the result.
Referring to the photograph showing the two crossovers side by side, here's how to bypass the level controls:
Move the yellow wire from the central terminal of its pot to the bottom terminal.
Move the blue wire from the central terminal of its pot to the bottom terminal.
Let me know the result.
Fine Bazza. I would measure the DC resistances of the non-sounding tweeter and super tweeter to check whether or not each is open circuit.
If they are not open circuit, the next move would be to investigate the condition of the 28 uF capacitor that is in series with the T/ST combination.
If they are not open circuit, the next move would be to investigate the condition of the 28 uF capacitor that is in series with the T/ST combination.
The T/ST control is at the right of your above image. According to the schematic, the value of the capacitor connected to its left hand terminal is 28 uF.
A simple approach is to test that capacitor by substitution. Either swap the 28 uF capacitor in the working speaker with the one in the non-working one, or substitute a suitable capacitor from your spares box (the value is not critical right now as we're only trouble-shooting).
If the problem follows the capacitor then you know that it is open circuit.
In this age of speaker, it would be a kindness to replace all those ageing bipolar electrolytic capacitors.
For 28 uF use a 27 uF bipolar electrolytic
For 16 uF use 15 uF bipolar electrolytic
For 0.47 uF use 2 x 1.0 uF bipolar capacitors connected in series (end to end).
The 27 uf and 15 uF values are available here: https://willys-hifi.com/collections...lectrolytic-capacitors?variant=36271157346463
The 1.0 uF value is obtainable here: https://willys-hifi.com/collections...cap-ac-1uf-70v-bipolar-electrolytic-capacitor
Note that I suggest you stick to electrolytic rather than film type capacitors as some might suggest. This is in order to help retain the vintage sound balance.
A simple approach is to test that capacitor by substitution. Either swap the 28 uF capacitor in the working speaker with the one in the non-working one, or substitute a suitable capacitor from your spares box (the value is not critical right now as we're only trouble-shooting).
If the problem follows the capacitor then you know that it is open circuit.
In this age of speaker, it would be a kindness to replace all those ageing bipolar electrolytic capacitors.
For 28 uF use a 27 uF bipolar electrolytic
For 16 uF use 15 uF bipolar electrolytic
For 0.47 uF use 2 x 1.0 uF bipolar capacitors connected in series (end to end).
The 27 uf and 15 uF values are available here: https://willys-hifi.com/collections...lectrolytic-capacitors?variant=36271157346463
The 1.0 uF value is obtainable here: https://willys-hifi.com/collections...cap-ac-1uf-70v-bipolar-electrolytic-capacitor
Note that I suggest you stick to electrolytic rather than film type capacitors as some might suggest. This is in order to help retain the vintage sound balance.
HURRAY! We have a full sound. Thanks to everyone..
I've pushed in some wool in that I had removed from the transmission line up to the bottom of the port. The sound is very loose regarding the bass, needs to be tighter much tighter, try them on stands maybe? The mids up to super tweeter is good, the stereo sounds are very pronounced, "I like it"!
I will take pictures.
In the end it was a loose connection !
I've pushed in some wool in that I had removed from the transmission line up to the bottom of the port. The sound is very loose regarding the bass, needs to be tighter much tighter, try them on stands maybe? The mids up to super tweeter is good, the stereo sounds are very pronounced, "I like it"!
I will take pictures.
In the end it was a loose connection !
Well Bazza, loose connections would be the first thing any self-respecting loudspeaker restorer would look for.
But you don't have a
multimeter to test for continuity, have you!
I beg you to go and buy one asap and make things easier for all of us in future. 😍
P.S. Don't omit to replace those ageing electrolytic capacitors, when I won't feel that my input has been entirely wasted.
But you don't have a
multimeter to test for continuity, have you!I beg you to go and buy one asap and make things easier for all of us in future. 😍
P.S. Don't omit to replace those ageing electrolytic capacitors, when I won't feel that my input has been entirely wasted.