A fent említett erősítő nem szólal meg, a relé meghúzz, és a -40V kint van a kimeneten. Egyik végfok tranyó sem zárlatos, de a komplementer párok nem egymás mellett vannak, ezt szeretném meg tudni hogy a Q11-Q18-ig melyik helyen milyen tranyó van.
Sziasztok!
Csereérett lett a lemezjátszómban a tű, szerintetek mi a különbség ezek közt?
http://www.ebay.com/itm/Needle-Turntable-Kenwood-N-67-N67-Sansui-SN-P212-/261045663066
és
http://www.ebay.com/itm/KENWOOD-SANYO-MARANTZ-SANSUI-TURNTABLE-NEEDLE-STYLUS-819-D7-/270408521961
Hello,
Last week I picked up a nice Kenwood KA-3500 40watt intergrated amplifier in pretty good shape.
Upon using it a bit more, I noticed a bit of distortion at high volume, more so in the left channel. I checked the DC offset at the speaker terminals, and the L channel said 100 mV, while the R was 25 mV. I understand this isn't so good for the L channel at least, but unfortunately this amp doesn't have any DC offset adjustments. Am I right in saying that to fix this I'd have to replace the output transistors?
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On a related issue, in the service manual I found the section on BIAS adjustment, and I read online how it can affect the DC offset. So I hooked up my voltmeter to the test points, and I got 4 mV on the L, and 8 mV on the R. In the manual it says should be 40 mV.....(!). Is there something wrong here? I tried carefully adjusting them, but they only go to 30mV with the pots fully on, this doesn't seem right to me.
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I compromised at 20 mV BIAS for both channels, and now the DC offset is 50 mV for L, and 5 mV for R, which is better, less than half what they were. I'm wondering, will I damage anything doing this, should I put them back to where they were?
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The service manual is on site here.
Let me know if you want me to upload an english copy of the Owner's Manual, it has a better schematic in it all on one page, easier to read.
I've also included some pictures. They're not my actual unit, but mine is exactly the same, but less dusty.
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Thanks for reading this. Many thanks in advance, and have a peaceful Palm Sunday! :taps2:
Bellarmine
Üdv! Sajnos már bontottan kaptam az erősítőt és szükségem lenne a tranzisztorok pontos típusára és pozíciójára Q1-Q18-ig. Minden megoldás érdekel. A kenwood_kr-910_sch_[ET] erősítőhöz van rajzom,de nem teljesen egyezik és elakadtam. Ha valaki tudna segíteni azt nagyon megköszönném.