Rockola 1484 cartridge

geschrieben von - posted by Cquadphil 
Rockola 1484 cartridge
21.09.22 11:15
Hi I'm fixing a Rockola 1484 jukebox. It basically works pretty well, some lights need fixed and a few switches cleaned but overall it's in good condition.

The main problem is low volume and poor sound quality. I think this is because of a damaged cartridge. I have attached a photo of the cartridge with the stylus removed. To me it looks damaged and not properly connected. This might explain why the amplifier will only play in mono mode.

Is there a replacement cartridge that I can get, I can't find the original cartridge part number in the service manual.



Re: Rockola 1484 cartridge
21.09.22 14:40
Hello Philip,
a stereo cartridge has 4 Pins, sometimes marked with L+, L-, R+, R-. If you have a cable with 2 wires and shield to the amp, the shield is connected to L- and R-, red is usually R+, green or white is L+.
In your tonearm, I can see 2 resistors that should be connected in series to R+ and L+. The resistors have been added for cartridges that produce high output levels, however they also kill high frequencies because of the RC input network used in the RO1484 amplifier (PEC) Try to remove the resistors and see what you get.
In my 1484, I am using the Pfanstiehl P132. [] Note the improved bracket that Stamann is now shipping with the system.
I am quite happy with the sound of the P132 after some tuning:
1)Instead of removing the two series resistors in the tonearm which is sometimes recommended, I am using 2x 470k with 330pF capacitor in paralell. This improves bass and high frequency response and reduces the signal levels to better fit the operating point of the amplifiers AVC. Here is a picture how it is connected. []
2) In the original wiring the two cabinet speakers are connected in paralell and the amplifier is switched to Monoraul when used wothout external speakers. I connected the speakers to the left and right stereo terminals and switched the amplifier to Stereo. This gives "some" stereo effect although the speakers are very close to each other. It also results in more bass because in Monoraul position the bass is cut intentionally in this amplifier design.
Rgds Jürgen
Re: Rockola 1484 cartridge
21.09.22 18:02
Hi Jürgen, thanks for the quick response and such a comprehensive answer. I will order and install the recommended cartridge. I have also read the posts on adding the RC matching network, you have done a lot of good work in the area. I will also try to install the RC network. I will need to source the surface mount components and improve my soldering skills.
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