SX-780 Quiet on Aux and Tape Monitor Inputs

[audionoob86]

Recently serviced and tech said all inputs functioned.

It works fine on Phono and FM but it’s very quiet when using tape 1 or 2 and AUX.

it does not seem to be driving the speakers properly. Sounds like just the tweeters maybe and the meters barely move).

I’ve tried multiple input cables and sources.

It seems like most people have the opposite problem (quiet FM and aux is fine).

Maybe something happened during transport?

Thanks

 

[kwayde]

Recently serviced and tech said all inputs functioned.

It works fine on Phono and FM but it’s very quiet when using tape 1 or 2 and AUX.

it does not seem to be driving the speakers properly. Sounds like just the tweeters maybe and the meters barely move).

I’ve tried multiple input cables and sources.

It seems like most people have the opposite problem (quiet FM and aux is fine).

Maybe something happened during transport?

Thanks

Try working the tape monitor and function switches back and forth multiple times. Could be a dirty switch. Multiple times.

 

[markthefixer]

YUP...

 

[audionoob86]

I think the input signal volume was just too low. It was my phone via an Echo Input via 3.5mm headphone jack with RCA output. Then tried the phone directly.

The FM was obviously a unique signal. I read the phono input takes a much lower signal volume/input thus sounding louder when using the phone than the aux and tape monitors.

Summary, user error on my part lol. Turned up the phone and all good.

It didn’t seem to have much affect when I was first testing it but I was being cautious cuz the kids were asleep.

 

[mrk229]

You don't want to put any high (line) level signal directly into the phono input for several reasons.

1. It amplifies a very low level signal form the phono cartridge, putting a high level signal into it will at the very least most likely result in tons of distorted audio and at worst damage a component in the phono pre-amp.

2. Records are cut and pressed with a specific EQ (RIAA). The phono pre-amp has an inverse EQ to return the audio back to a flat(ish) frequency response.
Inputting a flat signal from a line level source (assuming it is at an appropriate level) will result in a very bass heavy lack of highs sound.