Hey people,
some days ago I built two chipamps with TDA7293 chips (laser engraved, measure pin5, 10 & 11 against backplate all 3,xx MOhm, they seem authentic). I used dual-pcbs made by JLCPCB, but put just one chip on. Parts are nothing special, just what I had lying around. Input caps are 4.7µF WIMA MKS and the other one has 2x 1.5µF epoxy-coated recycling ware 😉. Just for curiosity I measured the DC-offset. Therefor I shortened the input, no speaker, Multimeter "Kaiweets KM601" at 3 digits right of the comma, and put +/-27V DC in it. It measured 0,000 for both amps. Am I making a mistake, or is there really no, for me, measurable offset?
best regards
Jochen
some days ago I built two chipamps with TDA7293 chips (laser engraved, measure pin5, 10 & 11 against backplate all 3,xx MOhm, they seem authentic). I used dual-pcbs made by JLCPCB, but put just one chip on. Parts are nothing special, just what I had lying around. Input caps are 4.7µF WIMA MKS and the other one has 2x 1.5µF epoxy-coated recycling ware 😉. Just for curiosity I measured the DC-offset. Therefor I shortened the input, no speaker, Multimeter "Kaiweets KM601" at 3 digits right of the comma, and put +/-27V DC in it. It measured 0,000 for both amps. Am I making a mistake, or is there really no, for me, measurable offset?
best regards
Jochen
Shortened via 4.7uf cap or directly using a piece of wire? Even datasheet has (Min -10mv, Max 10mv) offset figure.
Shortened via a internally shortwired RCA-Plug. They play music, everything seems fine. I was about to measure a pair of "LM1875" chipamps. If they got 0.000V, too, the mistake is on my side. I'll tell you soon.
