Fidelity Research FR-64x

@invictus005 

You remind me a soft of the dudes Nelson Pass is talking about, here is a quote: 

So here we are in the New Millennium, and thanks to Tom Holman and THX we’ve got lots of gain in our electronics. More gain than some of us need or want. At least 10 db more.

Think of it this way: If you are running your volume control down around 9 o’clock, you are actually throwing away signal level so that a subsequent gain stage can make it back up.

Routinely DIYers opt to make themselves a “passive preamp” - just an input selector and a volume control.

What could be better? Hardly any noise or distortion added by these simple passive parts. No feedback, no worrying about what type of capacitors – just musical perfection.

And yet there are guys out there who don’t care for the result. “It sucks the life out of the music”, is a commonly heard refrain (really - I’m being serious here!). Maybe they are reacting psychologically to the need to turn the volume control up compared to an active preamp.

I suppose if I had to floor the accelerator to drive 55 mph, maybe I’d think the life was being sucked out of my driving. Then again, maybe I like 55. Nice and safe, good gas mileage…

Is impedance matching an issue? Passive volume controls do have to make a trade-off between input impedance and output impedance. If the input impedance is high, making the input to the volume control easy for the source to drive, then the output impedance is also high, possibly creating difficulty with the input impedance of the power amplifier. And vice versa: If your amplifier prefers low source impedance, then your signal source might have to look at low impedance in the volume control.... 

Because you have a different P2S mount distance. Try this: forgeret about the Sony protrcator and mount the PUA 7 at 235mm from the spindle and your  Feickert protractor will works with any alignment you want.

R.

@chakster Nelson doesn't sell passive preamps nor makes them. He only sells active preamps. B1 buffer was meant for DIY amateurs.

People who actually design circuits laugh at passive preamps. If this is something you want to use, go ahead. But you are seriously ruining any resemblance of good sound. And I honestly cannot take your opinion seriously on anything else. 

Since I run tubes, and will have a Koetsu mounted on my FR64S, I guess it will be a miracle if I can discern any music at all from the DISTORTIONS! I'm ready for the challenge!

@lewm : As I said to you in my post ( one of my latests to chakster. ) you have nothing special on what you bougth not even that " unique unidin ".

This I pasted from other forum:

""" 

in 1938 by LÖFGREN and his solutions through his calculations/equations where the object was and is to calculate the overhang and offset angle in any tonearm/cartridge combination. These are the main outputs in those equations that between other things gives both null points in any kind of alignment choosed and distortion levels.

The input variables need it to make the calculations are:

1- most outer groove record distance 2- most inner groove record distance and 3- tonearm effective length.

Does not exist null points for Löfgren B ( example. ) as a one and only solution: NO.

Null points depends directly not the kind of alignment but which outer/inner most groove distances we choosed as inputs in the equations/calculations. If we change these inputs null points will change it does not matters which kind of alignment we are using.

For years those two inputs were specified by the IEC and latter exist other standard DIN and exist JIS too ( any one of us can have our self standard too. ).
The IEC values are: 146.05/60.325 mm where the DIN: 146.3/57.5 mm

Through the calculations we achieve too the distortion levels that depends on where " are " the calculated null points. The calculations tell us the distortion levels in between the null points and outer both null points.

Overall the UNIDIN is higher in distortion level than Löfgren B in MF. example/picture.

Now, UNIDIN is it something special?: NO.

As I said everyone can have its " own solution " changing the inputs. If we use DIN against IEC standard the overall distortion level will be higher as is the uni-din.

So Löfgren or Baerwald has not an exclusive null points it only depends on the input choosed in the calculations ( there are several calculators over the net. ).

If we change the most inner groove distance input using IEC, this is that instead of 60.325 mm we take as input 54 mm then we have those null points in the picture as uni-din....""

and you are correct when posted: "  I could do my own geometry, "  and you can do it in less than 5 minutes ! ! !

R.