I was fortunate enough to get an Advance Acoustic x-i90 because it has a fault.
The amplifier works if I connect the audio source to AMP IN.
But if I try the other inputs, I get no sound output.
All the functions on the front panel seem to work as normal.
https://www.easylounge.com/amplificateur-hifi/advance-acoustic-x-i90-noir-52374
Hard to search for errors without the schematic (have sent an e-mail to Advane Acoustic, but no response yet)
HCF4052BE is used for input select - seems to work fine
There is an JRC4558D op amp where I do not find any signal, so this may be the reason? Have placed an order for a new one to test
Any one else with this problem? Or any one have the schematics to share?
The amplifier works if I connect the audio source to AMP IN.
But if I try the other inputs, I get no sound output.
All the functions on the front panel seem to work as normal.
https://www.easylounge.com/amplificateur-hifi/advance-acoustic-x-i90-noir-52374
Hard to search for errors without the schematic (have sent an e-mail to Advane Acoustic, but no response yet)
HCF4052BE is used for input select - seems to work fine
There is an JRC4558D op amp where I do not find any signal, so this may be the reason? Have placed an order for a new one to test
Any one else with this problem? Or any one have the schematics to share?
Hi. Only one simple essential question - photo shows a external jumpers from pre-out to amp-in , are they present when you tested all other inputs?
Exactly..... as ximikas points out.
You need to link the left and right "pre-out" to "amp-in" to connect the pre section to the amp section. You probably didn´t get the "links",
when you got the amp.
Lucky you, if you got it cheap, since there´s no obvious fault other than "the missing links" 👍 😎
You need to link the left and right "pre-out" to "amp-in" to connect the pre section to the amp section. You probably didn´t get the "links",
when you got the amp.
Lucky you, if you got it cheap, since there´s no obvious fault other than "the missing links" 👍 😎
Ok, so the links are installed, but you have no sound. Some possibilities are faulty input selector ic ,one of, control wrong, maybe mute, or bad opamp in signal path. If you have unit already opened, get a dmm , put it in voltage mode, and measure supply voltages at all 4558. As it's dual supply voltage opamp, you should get kinda -12...-15v ant pin 4, +12...15v at pin 8 , in respect to ground, you can use speaker out gnd or one of RCA's ground for measurement. Also on all other 4558 pins you should have close to zero voltage, up to 0,1 volts should be ok. If you get voltage like +10v at output, probably that opamp is faulty. If all opamps are good, the you may check voltages on 4051 or whatever ics input selectors. They probably would be used with midpoint, and you should have 0v at pin7 and +5v on pin14. Or it may be not 5, but same 12v at pin 14, then all other pins, except control pins, should be middle potential of supply voltage. Signal in and out from ic will be through capacitors. If you find high voltage, close to supply voltage, on signal pins, maybe internal diode inside ic shorted. Refer to datasheet. Diodes can get fault of input overload, when connecting grounded source and having amplifer ungrounded, this potential may reach 110v on 220v mains and input resistors may not limit current enough for diodes to survive. So some tests will help to get more info. Post results what you get by measurements.
Thank you!
I`ll do some more measurements later - I have a multimeter/scope - not a pro setup, but I think it`s ok for this.
There are only two op amps. One is close to the phono input, so I assume that one is for the phono signal.
The other one is near the amp in/out. I believe the selected signal from the two input multiplexers goes to this op amp and then to 'Amp out.' I have tested all inputs (except phono), including optical and coaxial, but there is no sound from any of them. Therefore, I suspect the fault is common to all and located in the final stage of the preamp section
I`ll do some more measurements later - I have a multimeter/scope - not a pro setup, but I think it`s ok for this.
There are only two op amps. One is close to the phono input, so I assume that one is for the phono signal.
The other one is near the amp in/out. I believe the selected signal from the two input multiplexers goes to this op amp and then to 'Amp out.' I have tested all inputs (except phono), including optical and coaxial, but there is no sound from any of them. Therefore, I suspect the fault is common to all and located in the final stage of the preamp section
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