Juke box amplifier section matching and levels? Installing MP3 player in jukebox

[Pipercub]

A fall project I have is to integrate an MP3 player into a 45RPM juke box. I picked up a $32 walmart DVD player that also plays MP3s so I can burn a DVD wih 4.7Gb of MP3s. The player displays folders and filenames as well as track/artist when playing. I also picked up a 5 inch LCD monitor intended for use in the headrest of a car. My plan is to integrate the display into the record changer area in a corner with a chrome "faceplate" so it blends in and looks like it belongs. The DVD player will be installed internally with the remote sensor hidden on the front pannel so the remote can be used. A simple A/B switch will be used to flip between the DVD and 45RPM audio feeds.

My question is this, what sort of impedance matching and line level adjustment do I need to do so that the line level of the DVD player is right for the amplifier in the jukebox? I would assume that the 45RPM line level is lower than the modern DVD player's so I don't want to overdrive it and end up with distortion.

[D_Zoot]

Pipercub,

2 Issues come to mind to do what you are thinking.  First is impedence and level matching the inputs to the audio amp of the juke.   You didn't mention what is the juke is, that might be a help.   If it's an older juke using a ceramic cartridge then it *should* work as-is.  A ceramic cartidge outputs near standard line level signals.   If it's any form of a magnetic cartridge, then you would have to find a way to reduce the output from the DVD player.  Mag cartridge levels are much lower than line level and the juke's pre-amp will be designed to boost accordingly.

Another issue is going to be sound quality.  Vinyl recordings had a specific EQ curve applied during mastering,  known as the RIAA curve.  The purpose was to get around some limitations of vinyl, mostly in the bass region.   A proper record player pre-amp will apply the inverse of the curve to restore the sound.   If you plug a DVD player, or any non-vinyl source into any pre-amp that was designed for vinyl you will likely find the sound quality less than spectacular.


Soooo...  what's the juke ??   There may be ways of dealing with this if you don't mind a little hacking into the amp    


D

[Pipercub]

The machine is yet to be bought, the auction isn't until Oct. 30th so unfortunatly I have to wait  bit to know the specs for the juke. But the RIAA curve and level type per cartridge is damn good info, thank you for that. I grew up with records and 8 tracks but never payed much attention to the details of the gear. I was looking through the automotive audio offerings on ebay this morning because I recalled seeing line level/EQ/ and impedance matching units and sure enough there are several that will do all these funtions in one and need a low current 12v supply.