I've done a little research, I don't think I've found anyone that has actually tried it.
What would happen if I combined the commons of a phone cartridge b4 the preamp?
On my tonearm project, I'm thinking of a way to make the arm easily removable. I could add a 4-pin DIN. I think 4 and 5-pin DIN connectors are fairly common in this application.
But I have several small phono plugs and jacks, and I'm wondering whether I couldn't just combine the commons on the cartridge?
Posts I've read where someone else has asked this question have typically been met with responses along the line of channel separation, but just guesses and no real-world experience.
I suppose I could simply short the grounds on my RCA cable going into my current preamp and see if I can hear a difference, but that hardly seems scientific.
What would happen if I combined the commons of a phone cartridge b4 the preamp?
On my tonearm project, I'm thinking of a way to make the arm easily removable. I could add a 4-pin DIN. I think 4 and 5-pin DIN connectors are fairly common in this application.
But I have several small phono plugs and jacks, and I'm wondering whether I couldn't just combine the commons on the cartridge?
Posts I've read where someone else has asked this question have typically been met with responses along the line of channel separation, but just guesses and no real-world experience.
I suppose I could simply short the grounds on my RCA cable going into my current preamp and see if I can hear a difference, but that hardly seems scientific.
Your cartridge is a differential signal generator, combining the negative wires, they are not grounds, makes each channels output only the difference between the positive voltage and the average of the negatives. Itd be the same difference as moving from independent rear suspension to a solid back axle. It really is a crap idea, youd be throwing away a huge chunk of your channel separation and killing the stereo image.
I don't know where you got those ideas, because you are incorrect, its misinformation, sorry.
Having a "common ground" in a stereo system doesn't effect seperation at all.
In fact - 3 wire cartridges have been around since stereo was born.
And no, it cannot be compared to a car's suspension.
Also, preamps, amps, and receivers have been around for decades with a "common ground" system.
Each channel introduces its own signal-to ground independantly.
The decca has always been 3 connections since the beginning and I am sure they are not the only ones. Most preamps join the grounds at the RCA input anyway. I'm odd in that I like balanced connections.
I had the idea on my way to a morning appointment that I should just check for continuity between the commons on my phone preamp, and sure enough, BEEP.
So yeah I'll be using the three pin, because I'm not a purist and I can use parts on-hand.
If the cartridge is a low impedance MC type, there will be common mode current on the ground wire, since the resistance of the ground wire is not negligible. This will cause crosstalk due to voltage drop on the ground wire.
Good to know.
If that ever becomes something I want to try, I could give 1/8" TRRS connectors a try. That isn't what I have on-hand, though.
Indeed, the average MC cartridge is on the order of less than a millivolt, I doubt that "current" would be an issue with tonearm wiring.
After all, we're not running a space heater through #36 gauge wiring.
The generator in an MM or MC cartridge normally 'floats' i.e. it has no connections other than the pairs of output terminals. This means that it can be connected using quasi-balanced wiring -a shielded twisted pair from the cartridge to the phono preamp input. At this point the two signal return wires are usually connected together. Making the join earlier may increase hum and interference, because you no longer have two separate twisted pairs.
I do have some concerns about creating a grounding issue by combining those earlier. Worst case scenario I guess I can switch to TRRS. But then my ability to use a TRS to RCA cable won't be quite as elegant, as I don't have any TRRS to RCA adapter cables and I doubt very much any are made.
> To the left phono ground, or the right.
Or both?
What's the difference? They are normally very close together and bonded through chassis or short jumper.
I think it is sweet that most hi-fi stereo pickups are wired "2-coil floating" so we do not HAVE to share wires between channels. However in ordinary hi-fi I can't think of a compelling reason not to share a common. Do what works for you.
Or both?
What's the difference? They are normally very close together and bonded through chassis or short jumper.
I think it is sweet that most hi-fi stereo pickups are wired "2-coil floating" so we do not HAVE to share wires between channels. However in ordinary hi-fi I can't think of a compelling reason not to share a common. Do what works for you.
Ground loops would only be an issue if the grounds were bonded together at both ends.
Normally, at the cartridge end they are seperate, and it's best to keep them seperate up to the preamp inputs.
No. Not in the usual sense. Draw it out.
Yes, if you take LG around the living room and run RG around the bathroom, anything inside that loop (PCs, LED lamps) would induct into the loop. I assume they run tight together.
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