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Question about QSXM2, regarding our email conversation

Started by goldkenn, February 18, 2010, 09:09:46 PM

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Let me copy only the subject not yet solve, all those in block is answer from P-A in email;

2) When I first time test the board, I tried to changing R1/E1 (56K)  as loading impedance and left R3 blank, omit J1/J3, direct changing  the loading resistor by a dip 8 way switch (8 resistors on dip, from  10R to 47K), then I don't need to switch MM/MC by J1/J3 but only  switch the dip to match the loading impedance, however the QSXM2  sounds like overloaded with highly distortion sound, I have no idea  where goes wrong, any suggestion?

2  Did you change the gain also? J2

2) No matter how to set J2, the sound also distorted, and very funny is when I switch off the power, without lift up the tonearm, the sound become normal at the very last 1 or 2 second, while the filter caps on JSR04 almost run out of electricity.

2 The same in both channels?

Yes, both channels.


Can your chosen opamps handle +- 18V?

How high is your output level?

You could check the currents through the stages.

Which transistors have you used, pinning?
/Per-Anders Sjöström, owner of this forum

Homepage with my DIY hifi stuff


I use MAX420 and OP07 as refer to the files.

I have not check the output level.

Will check the currents within days.

I built 2 boards, one use all BC550C/560C, another all SMD type, both have the same problem, this is why I have no idea where goes wrong.


Can you rule out the cartridge itself?

Is the sound distorted regardless of sound level?

I think it's a good idea to check all critical cuurents through each stage. Maybe you have taken the wrong value somewhere?
/Per-Anders Sjöström, owner of this forum

Homepage with my DIY hifi stuff