I have an Orion 275R on the bench, it’s the same board layout as the 275G4. I picked up the amp not working... after inspection i found nothing burn or nuked... I put the signal generator to it and can trace the signal through the electronic pot all the way over to the filter section of the crossovers. What is going on over once it gets there is the signal is going to ground. I pulled the LF444CN op amps and injected signal to there outputs and got nothing in the full pass mode. If I put the amp into high pass I can inject signal and it will make it to the amp section. If I put the amp in low pass I can inject signal and it will make it to the amp section. But this is only with the LF444CN dual op amps pulled.
There is 4 8-Pin SIPs that sit by the crossover adjustment pots the number on them is LC82-5100G-S-9919 with the amp in full pass the amp section is connected to pin-8 when filters are on the amp section is connected to Pin-4...
From the way this SIP is wired up I am going to say they are OP-Amps even know the silkscreen on the board has them labeled (R29) (R30) (R24) (R25). I think one of them is bad and putting the signal to ground when in the full range mode. I have not got to pull them and inject a signal to there outputs I will be doing that in a lil bit and will take some pix...
Has any one had this problem or know where to get the SIPs from, I have searched for them and cannot even locate a data sheet on them.
There is 4 8-Pin SIPs that sit by the crossover adjustment pots the number on them is LC82-5100G-S-9919 with the amp in full pass the amp section is connected to pin-8 when filters are on the amp section is connected to Pin-4...
From the way this SIP is wired up I am going to say they are OP-Amps even know the silkscreen on the board has them labeled (R29) (R30) (R24) (R25). I think one of them is bad and putting the signal to ground when in the full range mode. I have not got to pull them and inject a signal to there outputs I will be doing that in a lil bit and will take some pix...
Has any one had this problem or know where to get the SIPs from, I have searched for them and cannot even locate a data sheet on them.
Email me. I have a partial schematic that I drew up. It should be close enough to be helpful.
babin_perry@yahoo.com
babin_perry@yahoo.com
Well i pulled all the quad op amps and put signal to it traced it out and jumped the opamps as i went.. found i was getting signal to the digital pot but not getting any signal out... so i jumpperd the digital pot and traced the signal out to the amp section all looked good.. set the signal to 500mv, clipped the vcc and gnd to the digital pot then powerd her up.. i now have audio out the amp. i am going to put some sockets in tormorrow when i get home from work and test again with the opamps installed.. i orderd some DS1267-100...
THANKS for the drawing perry... helped a lot!
THANKS for the drawing perry... helped a lot!
When you power up the amp, check the signal on the digital input pin of the digital pot. I think it's pin 8. Do you see a stream of pulses when the remote voltage is applied?
If not, confirm that you have the oscillator input on the PIC IC. If not, confirm that you have supply voltage on it.
If not, confirm that you have the oscillator input on the PIC IC. If not, confirm that you have supply voltage on it.
yea i checked the crystal.. i am getting a good 1MHz signal from it through the microchip to the digital pot.. it seams that the digital pot is just grounding the signal for whatever reason..
Sam
Sam
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