I stopped by RadioShack on the way home and they had an Texas Instruments LM324 in stock so I picked it up, it looks like the same schematic as the BA10324A. I also have a ECG859 which is a quad low-noise JFet-input op-amp and here is it's datasheet:
http://www.datasheetarchive.com/pdf/getfile.php?dir=Scans-002&file=Scans-0044729.pdf&scan=y
I'd prefer to use the ECG859 since I've got an open bag of them from a local tag sale purchase and can return the RS LM324. I still have to test, but if my BA10324A turns out to be bad would either of these parts be suitable replacement?
http://www.datasheetarchive.com/pdf/getfile.php?dir=Scans-002&file=Scans-0044729.pdf&scan=y
I'd prefer to use the ECG859 since I've got an open bag of them from a local tag sale purchase and can return the RS LM324. I still have to test, but if my BA10324A turns out to be bad would either of these parts be suitable replacement?
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I dont believe it. I think this amp is actually FIXED! I put the 16th pin of the 494 back on the pad and now the whole amp is working as it should! Man.... i cant believe I paid for shipping this thing out to California and back...
So ladies and gentlemen;
1. Dont mess with the POS card!
A. Install it with the "Stereo/Brided" lettering faces twards the Gain controls and RCA inputs.
B. Make sure the edge where 95% of the pins are shorted is rising out of the amplifier's PCB and facing twards the Power/Speaker terminals
2. Make sure your RCA shields are not detached from the circuit board.
Perry, Thanks for the grand tour on fixing this beast. I'm going to run some more tests and set the bias pots. I'll run this amp for awhile on the bench to see how she goes. Who knows; maybe this bad boy is destined to replace the PPI PC2150!
Thanks again!
So ladies and gentlemen;
1. Dont mess with the POS card!
A. Install it with the "Stereo/Brided" lettering faces twards the Gain controls and RCA inputs.
B. Make sure the edge where 95% of the pins are shorted is rising out of the amplifier's PCB and facing twards the Power/Speaker terminals
2. Make sure your RCA shields are not detached from the circuit board.
Perry, Thanks for the grand tour on fixing this beast. I'm going to run some more tests and set the bias pots. I'll run this amp for awhile on the bench to see how she goes. Who knows; maybe this bad boy is destined to replace the PPI PC2150!
Thanks again!
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The final problem ended up being a disconnected Rca shield from the PCB.
The confusion with the pos card exacerbated the issue, since I was not getting sound I must have been led off the Rca path and misled by the orientation of the pos card. Wrongly installing this card caused symptoms of major component failure but that was never the case. Installing it wrong must have miswired a bunch of stuff like the 324 and other things. Fortunately nothing fried in this case. The repair cost me nothing but solder and time.
The confusion with the pos card exacerbated the issue, since I was not getting sound I must have been led off the Rca path and misled by the orientation of the pos card. Wrongly installing this card caused symptoms of major component failure but that was never the case. Installing it wrong must have miswired a bunch of stuff like the 324 and other things. Fortunately nothing fried in this case. The repair cost me nothing but solder and time.
this has given me inspiration to get my boltar X fixed, the manual is very vague about how the POS card is to be installed, i mean, which is the front on a gen X amp
This amp has been running pretty awsome in my car for the past 7 months. I had a audiophile ear in my car for about 30 minutes last night who suggested i replace the opamps to help remove some of the high volume low audio sourced hissing apparent throug the sub when the music source is between trcks. Since this amp has no crossover, i think a noisy opamp is starting to reveal itself.
This amp likely has njm2068d opamps. My options for upgrade could be opa627, opa637, or the less expensive National lm4562.
Would any of these work well? I know Zed has a burr brown upgrade for these amps...
This amp likely has njm2068d opamps. My options for upgrade could be opa627, opa637, or the less expensive National lm4562.
Would any of these work well? I know Zed has a burr brown upgrade for these amps...
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