Fidelity Research FR-64x

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.

@invictus005

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.

Are you talking about Nelson Pass new stuff?
You should know that he makes 100 units of whatever model and then it’s out of production. Each model is different all the time. All his stuff available for DIY community, he provides all info for DIYers. So ALL his amps can be made by DIYers including B1 or any super expensive models of power amps etc, but i have the originals made by Nelson Pass.

Remember Pass Labs ALEPH L ?
Two different versions were made, first one was 100% passive, second version was a combination of passive + active circuit. The active has been used ONLY when you need it, so the last Aleph L became active depends on the position of the volume control knob.

It seems like you don’t understand that there is no universal solution, everything depends on our systems. You, like Raul, pretends on absolute opinion, that’s very bad!

@rauliruegas 

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.  

That's was my point from the start to tell you that SONY PUA-7 geometry is unique, the pivot to spindle distance is about 221mm and special template provided with the arm to set it up like that. It's was off from well know 3 alignment methods and we're talking about big difference. 

You see 221mm and 235mm is not the same, it's a bid difference. 

What makes SONY corporation develope their own protractor if they could stick to the old Baerwald? 

@chakster When it comes to passive preamps, there is an absolute, they’re laughably bad! Think it through, it’s a simple Ohm’s law. You want low source output impedance (<200R) and high amp input impedance (>10K). So what happens when you put a 10K, 50K, 100K pot in between? Hint, 10K pot will wreak less havoc than 100K pot. And unless the 10K pot is completely open, it will create progressively a bigger impedance mismatch as it’s turned down. It’s a nightmare scenario.

On top of that, even minor capacitance in the pF region in cables, parasitic, etc. will significantly attenuate high frequencies.

And further, the pot will dominate the sound/noise quality. Wiper pots are very noisy.

And your current induced noise will go up drastically. Using this between a phono preamp and amp is beyond dumb.

With a passive preamp, you’re taking a high quality source component and a high quality amp and turning them both to complete garbage.

Universal solution is a competent active preamplifier.