work in progress.
Last edited:
PIONEER SX-440 Output Transistor Replacement?
- Thread starter JB8
- Start date
Hello,
I am French and I use a translator. I'm sorry if my English is not precise.
I dug up this post.
I have the exact same problem with my LX-440. I replaced all the chemical capacitors, as well as the oxidized TO92 which were noisy.
No problem with headphones, however, with the speakers, there is saturation.
I measured the current on each channel, and I found 5/8ma for the 2 channels instead of 35ma. The variable resistors to adjust the current are inoperative.
do you solve this problem on SX-440 ? LX-440 is the same. Thanks
I am French and I use a translator. I'm sorry if my English is not precise.
I dug up this post.
I have the exact same problem with my LX-440. I replaced all the chemical capacitors, as well as the oxidized TO92 which were noisy.
No problem with headphones, however, with the speakers, there is saturation.
I measured the current on each channel, and I found 5/8ma for the 2 channels instead of 35ma. The variable resistors to adjust the current are inoperative.
do you solve this problem on SX-440 ? LX-440 is the same. Thanks
@lebibi - Welcome aboard.
The LX-440 is different from the SX-440. Both units employed the same power supply (W16-021) but that is the only circuit board part shared between the two types. The units are very similar, but when working on the LX-440 be certain to use diagrams for the AWK-008 amplifier, since there are differences between that and the SX-440 employing the W15-073.
The LX-440 is different from the SX-440. Both units employed the same power supply (W16-021) but that is the only circuit board part shared between the two types. The units are very similar, but when working on the LX-440 be certain to use diagrams for the AWK-008 amplifier, since there are differences between that and the SX-440 employing the W15-073.
Since the LX-440 is different, it may be best to begin a new thread regarding your specific unit. If idle current (bias) adjustment is not possible, it would be important to check the external components for those circuits, shown in the altered diagram below.
