I've been thinking of modifing my Sonneteer phono stage.Housed in a full sixe case there is a transformer at one end and the circuitry in the other.
I was thinking of either removing the transformer or the circuitry and putting them in a seperate box.
If say i put the circuitry in a seperate box is plastic best?
Could I build a sheild of copper linked to the ground?Do I ground the cartridge on the power supply box or the circuit with a wire leading to the power supply ground?
As you can see I am a novice at this but it doesnt look too hard , just cut the wires from the transformers make a plug join the wires via the plug to the circuit board and place it in a different box.
But is there more too this and is it worthwile?
I see that most high end phono stages have a seperate box for power supply to keep it far away from the circuits so is this a good route?
Also i often pick up radio broadcasts on the MC input will moving the circuit from the power supply solve this?
Any other suggestions?
I was thinking of either removing the transformer or the circuitry and putting them in a seperate box.
If say i put the circuitry in a seperate box is plastic best?
Could I build a sheild of copper linked to the ground?Do I ground the cartridge on the power supply box or the circuit with a wire leading to the power supply ground?
As you can see I am a novice at this but it doesnt look too hard , just cut the wires from the transformers make a plug join the wires via the plug to the circuit board and place it in a different box.
But is there more too this and is it worthwile?
I see that most high end phono stages have a seperate box for power supply to keep it far away from the circuits so is this a good route?
Also i often pick up radio broadcasts on the MC input will moving the circuit from the power supply solve this?
Any other suggestions?
If you don't have any problems with hum, don't remove the transformer.
AM radio problems: Remove the pickup and shorten the input.
Do you still hear the radio?
No, the pickup and the cable is involved.
Yes, the has problems. The first thing I can think of of is unsufficient decoupling av the power supply voltage, either too little, bad caps or wrong placement. The amp may be shielded more.
You may need a mains filter.
Since you use MC you could app up to 1-10 nF as input load. You could also add inductors but this is the last thing I would do becauce I hade to break signal paths and/or power wires.
Is the amp CE approved?
AM radio problems: Remove the pickup and shorten the input.
Do you still hear the radio?
No, the pickup and the cable is involved.
Yes, the has problems. The first thing I can think of of is unsufficient decoupling av the power supply voltage, either too little, bad caps or wrong placement. The amp may be shielded more.
You may need a mains filter.
Since you use MC you could app up to 1-10 nF as input load. You could also add inductors but this is the last thing I would do becauce I hade to break signal paths and/or power wires.
Is the amp CE approved?
As peranders said, if no hum, keep it that way.
Also check the cables and connectors. Maybe there is a loose ground connection. Try a different cable, with a good shield. Try adding a seperate ground connection between the TT and the preamp. Check the cartridge. Some have a ground connection between one of the 4 pins and the arm. Try gounding or not the cartridge.
As you may guess, endless thing to try.
Also check the cables and connectors. Maybe there is a loose ground connection. Try a different cable, with a good shield. Try adding a seperate ground connection between the TT and the preamp. Check the cartridge. Some have a ground connection between one of the 4 pins and the arm. Try gounding or not the cartridge.
As you may guess, endless thing to try.
Ground
I have a ground connector on my pre amp .When you say try a seperate connector on your pre amp do I connect to both phono amp and pre amp or just pre amp?
I have a ground connector on my pre amp .When you say try a seperate connector on your pre amp do I connect to both phono amp and pre amp or just pre amp?
With preamp I mean the amp where you plug-in the TT, so it would be the riaa stage. I your case the phono amp.
If you have a separate ground connection on it, try connecting a thick (0.75mm^2 or so) from the chassis of your TT to that ground post on the phono amp.
If you have a separate ground connection on it, try connecting a thick (0.75mm^2 or so) from the chassis of your TT to that ground post on the phono amp.
Radio Broadcast Reception
Hi sleepy,
I once modified my Mark Levinson JC1 AC moving coil cartridge preamplifier by installation of a few turns of wire on a ferrite bead and a small silver mica cap to ground after that in the signal iput leads.
The mysterious voices in the background were gone and sound improved too!
Hi sleepy,
I once modified my Mark Levinson JC1 AC moving coil cartridge preamplifier by installation of a few turns of wire on a ferrite bead and a small silver mica cap to ground after that in the signal iput leads.
The mysterious voices in the background were gone and sound improved too!
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