Q&A about the hum problem
Q: I got a loud hum with this T7 phono
preamp.
A: For the hum noise, in the beginning, we
have to clarified that all phono preamps have a certain of background noise. It
won't be loud, while a little loud is just normal. Turntable is a kind of
analog players and cannot be compared with digital players in this respect.
Besides, there are many factors which may lead to bad noise. To find the right
reason, you need to do some tests and here are some instructions.
Reason A: T7 isn't connected to ground
well.
This is the most common and unnoticed
reason. Please test it following the steps as below.
While the device is playing music, picking
up the GND copper part of T7 with your fingers. If the background noise is much
lower, then T7 isn’t connected to the ground. For this issue, we prepared a 3m
wire in the package for you to solve it by yourself. Just use it to connect the
GND with any large mental item in your home like windows or mental tables.
Reason B: T7 doesn’t match with your
amplifier well.
There is a possibility that T7 may not
match with some digital amplifiers well, which may lead to very loud noise.,(we’ve
test it with few T and D Class digital amplifier. And found that. The T Class
amplifier is best. Very quite back noise.. But. The D Class amplifier with loud
noise. )
That’s why we recommend using professional
pure HiFi amplifiers like AV amplifier or vacuum tube amplifiers (it will be
better if the amplifier isn’t equipped with Bluetooth).
Reason C: The RCA wire has a poor quality.
A good RCA wire
will be equipped with an anti-jamming magnetic ring, which can effectively
reduce various interference.
Q&A about the sound distortion problem:
Reason A: your turntable output signal
isn’t PHONO. Maybe is LINE OUT. Please check the turntable output JACK. if
there is a PHONO/LINE OUT switch. Please set it in “PHONO’ mode.
Reason B: T7’s RIAA function part broken.
Please contact us to get replacement main board. (or if you’re DIYer. You also
can repalcement it. It’s 80% the OP chip burn. (the IC mode is: 2068, you can
repalce it to 5532 or similar chip.
