I think my along inputs are messed up but not sure

Put what switch On line in?

dmajor100 wrote:Put what switch On line in?

On the back of the 4000 near the analog ins, the really tiny phono/line in switch.

Really i didnt know there was a switch,ill have to check That.

Doh!

Glad you sorted it out - last thing I wanted to learn about was multiple MPC4000s with failing analogue inputs.

The small switch kicks in the RIAA equalisation curve which boosts bass and cuts highs to compensate for the fact that vinyl records are recorded with prescribed (by the RIAA) amounts of bass cut and treble boost.

It's the only way you can fit enough bass information in those tiny grooves.

I expect it was the bass end that was causing the distortion as you would have been boosting bass that was already at full level.

So is this just for the phono inputs ?

dmajor100 wrote:So is this just for the phono inputs ?

Yeah, that's the way it actually works - the RIAA eq is applied only to the whatever is connected to the RCA phone inputs, and the switch selects which connectors (phono or jacks) will go through to the sampler input.

See page 4 of the User Guide where it says only a turntable should be connected to the phono inputs (and not one with a built in phono stage/preamp).

And I forgot something, not only does the phono input apply the RIAA eq it also boosts the overall level of the phono signal massively, so that is mainly where the distortion comes from when you put normal levels through a phono input.

Problem solved guys thanks for yalls help

Easily missed, you must be glad it wasn't something more sinister involving $$$$$.

The good thing about having the line/phono switch is that you can leave a turntable and the line inputs connected at the same time, and just use the switch to set which one goes through to the sampler input.