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

Showing 1 response by whart

Lacee- I'm not able to answer your technical question about whether the
number of stages causes some sort of phase inversion, but I can tell you,
based on my experience running a Steelhead for a number of years that:
1. It sounds better if power is always on to the power supply and you are
simply switching off the active circuits using the standby switch on the main
unit;
2. I preferred the sound of the unit through a separate active line stage,
rather than running it with its own buffered volume control. Whether that's
directly comparable to what you are doing by running the Steelhead fixed
outputs into a passive line stage, I dunno, but I offer it for what it's worth.
The unit sounded very 'clear' but a bit threadbare running it on its own
(without the addition of the separate line stage, which added more meat to
the bones-
call it 'warmth,' 'richness' or 'euphonic coloration,' it had a less 'forced' more
relaxed sound). At the time i was running a Lamm L2 which may have been
very complementary to the Steelhead, b/c the Lamm had a very lucid, if
somewhat 'dark' sound and rolled off a bit at the frequency extremes.
3. Using Lyra Titan i and later Airtight PC1, I preferred the sound through
the MM inputs run at 47k. The MC inputs sounded uneven across the
spectrum. I did fiddle with the loading and other settings, but that's where I
came out.
4. I think the gain setting on the unit was at 55.
5. I found that tube rolling made a pretty significant difference- my
preference being the NOS Tele equivalents and running other NOS for the
7044 slots. On that note, it may be worth changing out the tubes to see
what difference it makes.
I did a fair amount of fooling around with the unit when I owned it- and I
think that summarizes where I came out.