killed needle or something else?

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Hey, I inadvertantly put +&-12V on the input to my record player when hooking up my newly reassembled and upgraded VSPS, (better decoupling mostly so I can run opa2228 without it going into random oscillation - sounds so much better)... All I get is a loud buzz now, and I don't mean the nice kind. I tested the vsps with mp3 player afterwards, its working fine...

I assume the stylus or cartridge is dead... how do I proceed?
 
Killed needle...

Hi Nordic

This is the RSPPC*

*) Royal Society for the Preservation of Phono Cartridges

What type of cart is the problem? MM or MC?

Like ZenMod said - use a multimeter. Set it to continuity and check between the channel pins (White and blue and red and green). If you have continuity, check next between the channels. If you have continuity now, there is a problem. Last check, set to Ohm and repeat the first check, where you should be able to measure resistance.😀

I add that it is unlikely that you would have fried the cart as I've done this without harm to a mc cart.

bulgin:smash:
 
Hmmmmmmmm Bulgin, you appear to be right... It measures fine according to your method.

Dang, either way!!!!!!

Think I made a booboo layouing out or populating that pcb, as it is playing very faintly on one channel and hums on the other with the new cartridge. Swapped the cables... signal fine on both channels, except I'm still useless at aligning cratridges etc...

Ai tog.

Now to tempt fate I'm laying out the Graham Maynard vinyl amp from 1975.

http://www.zen22142.zen.co.uk/Circuits/Audio/vinyl.htm

At least in trying to find stuff on google, I found a fix for the unstable speed... simply clean the controler pcb.
 
cartridge coil continuity check - danger!

Be careful about putting a ohmeter across a cartridge coil...I once fried a perfectly fine cartridge this way. All meters send a small current across the load under measurement, and measure the voltage drop. Resistance is then calculated from ohm's law.

Even through this current is small, it can damage (permanently) the coils!
 
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