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Phase inverting problem

Hello,

I have a Conrad Johnson PV-12A pre-amp. It is phase correct for the phono stage, phase inverting for the line stage.

My power amplifier is a conrad johnson MF2100. It is phase correct.

So my first idea was to connect the speakers to the power amplifier the wrong way (black to red, red to black) and then connect the cartridge the wrong way around as well (R: + and - reversed, L: + and - reversed). Then the phase should be correct for everything.

But there lies the problem. When I switch the connections on the cartridge, I get a really loud hum, makes the music barely hearable. Perhaps it has something to do with the fact that R- is connected to the cartridge body, it is some kind of earth? Anyway, switching the connections on the cartridge is not an option. So, what to do?

My only idea so far is, seeing that I only have one line input (cd), is cutting open the RCA cable and switching + and - of the line, and connecting the speakers to the power amp the correct way. So, I'll do just that. But maybe there's a better solution that I'm missing. Any ideas?
swaf
atmasphere's avatar
atmasphere
11,794 posts
 
Also, running the cartridge(Clearaudio Talisman V2 gold)thru MM stage and not the transformers in MC also has sonic merits.Experimenting with loading, so far 100 ohm sounds good, less cartridge ringing.

I guarantee that the load had no effect on ringing! If you look at the inductance of the cartridge, you will see that it is so slight that the load could not possibly affect it at audio frequencies.

The reason it is making a difference has to do with the apparent fact that the Steelhead is sensitive to Radio Frequency Interference (RFI) at the input of the phono. The RFI is generated by the resonance of the inductance of the cartridge, in parallel with the capacitance of the cable- the two form a tuned RF circuit. The energy of the cartridge sets this circuit into resonance- and that is the source of your RFI. By adding the load, you are detuning the RF circuit so it can't resonate.
lacee
811 posts
 
Thanks Ralph for the clarification.
It's great to have the real reasons behind what we are hearing explained.
Noise is something that you never know you have until you do something that lessens it,hence I will be doing more experimentation with loading and capacitance eventhough it's a MC.
What I can say about my experience with loading and the Talisman cartridge was that 100 ohms was a bit rolled off but fuller sounding than running it into Clearaudio suggested 300 ohms, at least with the gear I own.
And that was with low cap Nordost Heimdals from the arm and Heimdals from the phono stage.

And things varied from recording to recording.
I'm not about to tally up what settings sound best for each lp I have, so I've settled for compromises,never the best, but unfortunatly a fact.
luvmuzik66's avatar
luvmuzik66
6 posts
 
What happened to the topic? I also have a CJ PV10A (with no balance control). I did switch polarity on both speakers as per CJ manual. Maybe its just me but i think it sounds ,fuller, open and huge sound stage. Phono sounds the same I think. Have to do more testing since I just got the CJ yesterday. BEL Canto eVo 200.2 amp, VPI hw19 mkII/ jelco 10 inch, grace  f9, Wave Touch Grand Teton SE speakers.
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