till
Head-Fier
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- Feb 17, 2004
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I just built a CHA47, just a basic circuit with crossfeed, no volume control yet. Power is supplied by one 9 V battery, the rails are split by a TLE2426 and a BUF634. The power supply splits the voltage quite evenly, like -4.13 V vs. 4.17 V.
There is no sound on one channel and without a source I get a DC offset of about 650 mV, in contrast to 30 mV on the channel that is working. I know that this is a bit too much, too (probably caused by the slightly inequal power rails). Well, I just measured again with OPA2132s instead of OPA2604s, and I get 3 mV on the good channel and a whopping 3300 mV on the other!
I checked all resistors with a meter, heated all solder joints and checked all connections... no luck finding the mistake so far. Ideas, anyone? What can cause this large offset?
There is no sound on one channel and without a source I get a DC offset of about 650 mV, in contrast to 30 mV on the channel that is working. I know that this is a bit too much, too (probably caused by the slightly inequal power rails). Well, I just measured again with OPA2132s instead of OPA2604s, and I get 3 mV on the good channel and a whopping 3300 mV on the other!
I checked all resistors with a meter, heated all solder joints and checked all connections... no luck finding the mistake so far. Ideas, anyone? What can cause this large offset?