Hello everyone
My father likes collecting vinyl records and we have an old turntable the we like listening to sometimes.
We used to have a good preamp for it, but it stopped working properly so my father ordered
this preamp .
We plugged it in and listened to some records and the music just didn't sound good. The treble was very low and that created a feeling of a muffled sound.
So I checked the frequency response with my PicoScope 2205A (would recommend) USB oscilloscope and wave generator and the result is as follows:
Input (5mV sine) | Output(Avarage RMS)
20Hz----------------441mV
100Hz---------------730mV
200Hz---------------735mV
500Hz---------------683mV
1kHz----------------565mV
2kHz----------------385mV
5kHz----------------190mV
10kHz--------------115mV
20kHz--------------72mV
The eBay page claims "Frequency response: 20Hz-20KHz", but according to my measurements at 20Khz the voltage is amplified 10 times less than the maximum at around 200Hz, and the -3db point seems to be at around 2.2kHz.
My questions are:
-Is there any way to "fix" such bad preamp by replacing low quality or wrong value components?
-Do you think it is possible to get a refund? (i.e. do you have experience with returning similar items to sellers on ebay?)
Thanks in advance!