AMI R80 Volume issue

[ventrue]

Hi all, I own an AMI R80 and it has two issues that I need some help with:

-The pickup only produces a very low signal. I replaced the needle, checked the leads between cartridge and amp. All seem to be fine.
When I plug the pickup in a phono preamp of another device, I have the same result.
The AMP of the jukebox works fine, because if I plug another device in it, the jukebox sounds loud and clear.

-The AMP is an R-4359A which normally doesn't same to belong in this type. But as stated above, it seems to work fine and sounds great.
But it's always at max volume. I can't seem to turn down the volume. The potentiometer works and when I trace it to the amp, the change in resistance when turning the pot reaches the amp.
But turning the pot, doesn't change anything.

I don't know if both problems are on their own, or maybe related.

Any help in troubleshooting would be highly appreciated.

thanks a lot !

[jukenorman]

The R-4359A is older than what would have been fitted to an R80. Probably you need to refer to how it is hooked up in a T1-2 to determine what is wrong with the volume.

I think that the channels of your phono cartridge should be wired out of phase so if they are connected in phase, you will get little output. Again the manual should provide the answer to how it should be connected. Alternatively (reading your post again) maybe they are connected out of phase where they should be in phase? I doubt that your issues are related in any way.

Norman.

[ventrue]

Thanks for your reply.
I tested al kind of connections (in/out phase) but result remains the same.
Could the cartridge be defective ?

[jukenorman]

Yes, of course it's possible the cartridge could be defective - have you tried checkeing the resistance of both cartridge channel with a multimeter to see if they're open circuit?

Norman.

[ventrue]

Hi Norman, thanks for the reply. I checked the shure site and I did measurements accordingly. All seems to check out, but still it doesn't seem to work.
I also connected the cartridge outputs directly to the amp and tried different phase, but all the same result.

[jukenorman]

If you can absolutely rule out any potential problems with cabling, then it's beginning to look like a cartridge issue. Although if you are reading credible resistances from the pickup coils....? Do you have another cartridge you could try even if only as a temporary hook up?

Norman.

[ventrue]

Hello Norman,

Could it be that there is a magnetic element in the pickup while it should be a ceramic ?

thanks

[jukenorman]

No, the R80 and the older jukebox (typically T1-2) that would originally have been fitted with the R-4359A amp would both have used the Shure M44 magnetic cartridge.

Norman.

[Ron Rich]

Hi Guy's.
Could be the needle is "bad" ! Are you using a geu-u-whine Shure ?? I am not 100 % sure, but in MOST mag. carts. the cart itself does NO "work". All the work is done inside the replaceable, needle holder. Ron Rich

[ventrue]

Hi Ron,

Thanks a lot for your reply. The needle is indeed a real Shure.

[Ron Rich]

OK--if good, that eliminates that, and I would venture to say the cartridge itself, too ? Ron Rich