The headshell of the FR-64S tonearm presents its own challenge....

DarkLantern blog - darklanternforowen.wordpress.com

A tight fit, but done

(If you've ever seen an FR MC 201 cartridge, you'll remember how small it is.)

DarkLantern blog - darklanternforowen.wordpress.com

i remember those little blue things

looks tight with the headshell wires.

does the fr201 and koetsu share mounting hole to stylus tip distance ?

I'll bet you are glad it has a removable headshell 

The best thing about this design actually, is the removable cartridge plate in the h'shell, with its one-screw fixing.

The cartridge can be screwed to the plate & wire-connected..
Then the cartridge can slide & rotate inside the headshell with one-screw fixing, nice.

DarkLantern blog - darklanternforowen.wordpress.com

When aligning a cartridge, I always check out the dimensions on John Ellison's Baerwald/Lofgren alignment spreadsheet.

This can save a lot of trial & error time by zeroing straight in on the correct cartridge stylus-to-pivot distance (Effective Length) for the 2 null points.
For every tonearm pivot-to-spindle distance, there is only 1 Effective Length (or Overhang) & Offset Angle, for your chosen (eg Baerwald) alignment. (PS. John calls Baerwald - 'Lofgren A'.)

Usually, you measure the tonearm Pivot-to-Spindle (mounting) distance, then John's spreadsheet will give you the optimum Effective Length to place your cartridge.

In this case, my tonearm Effective Length is fairly fixed by the tight headshell mounting scenario, but I have a wee bit of tolerance in arm-pivot mounting placement.

My measured Eff Length is around 245.5mm. So, optimum Pivot to Spindle distance (from the spreadsheet, as below) should be 228.7mm.

All I need to do now is to set the cartridge Offset Angle (~22.4 deg) at the 2 Null Points.

(This 22.4deg Offset Angle, incidentally, is a little more than the FR-64S's 21.5deg headshell angle - like a lot of tonearm manufacturers, especially in the earlier days, FR adopted their own alignment. In this case, it looks to me that FR optimised this arm's geometry for a slightly smaller inner groove diameter than the 60.3mm that we typically use today.)

DarkLantern blog - darklanternforowen.wordpress.com

Apr 29, 2020 16:39:01 GMT 12 michaelw said:

i remember those little blue things

looks tight with the headshell wires.

does the fr201 and koetsu share mounting hole to stylus tip distance ?

I had a pal who had a MC201.
Yes, small & blue (online pics below).

You can see how short this (ultra) low output MC cartr. was.
Mounting hole-to-stylus distance is shorter than the Koetsu I'd say.
There seems to be no convention for this dimension, I see variations from 7.5mm to ~10mm (Koetsu).
Usefully however, the FR-64S cartridge plate has 2 mounting hole options (~5mm apart)

DarkLantern blog - darklanternforowen.wordpress.com

blue cartridges ... hmmmm...

Finally, FR-64 installed, cartridge aligned, ready to go....

DarkLantern blog - darklanternforowen.wordpress.com

nice !
it sits as far forward as my sme

Yes, the SP-10 really best suits a 12" tonearm.
Or a 10" one at least - the FR-64 is 245mm (9-5/8")

DarkLantern blog - darklanternforowen.wordpress.com

I recently stumbled across this pic of an SP-10MK2 in the Obsidian plinth, with a FR-64 on-board.

Technics' own tonearms for this TT were 250mm (10" approx) Eff Length.

In my case, it is possible to mount the FR-64 a bit further rearward (as in this pic), but I have chosen to install it into the mounting hole made for the Kenwood tonearm (250mm).

DarkLantern blog - darklanternforowen.wordpress.com

BbOwen Y, do you need/want a new Headshell for your FR tonearm?

www.trademe.co.nz/electronics-photography/home-audio/turntables/listing-2658127839.htm?rsqid=78bbbb95178d4b469599d5383daad7c6-002

Thanks sub - I think I may know the seller...?

DarkLantern blog - darklanternforowen.wordpress.com

It's time to put the SP-10 on a dedicated TT support:



This 3-legged steel stand was made by the company the acquired Sound Creations (~10 years ago?).
The stand legs are about 1/3-filled with lead shot, with adjustable spikes under.

It was originally used under an AURA TT & later a Trans-Fi Salvation rim-drive TT:




Serendipitously, it happens to be about the right size for the re-plinthed SP-10.

Although fully welded, actually it is not as rigid, torsionally (twisting in the horiz. plane) as I'd like, for a DD TT.

DarkLantern blog - darklanternforowen.wordpress.com

make a matching wood stand ?

That’s a great looking TT.

AMR-iFi R&D

Thanks guys.
Sound is improved noticeably - more defined HF & images, more 'present'.
Seems to dig deeper, more inner detail.
Much stronger ambient decay & 'sustain'.
Clearer & cleaner.... however, my feeling is that this TT can give more, more leading edge 'snap'.

Time to address the SP-10 electronics maybe, the PSU & maybe resin-damp the motor chassis.....

DarkLantern blog - darklanternforowen.wordpress.com

As noted above, the above steel TT stand is not TOTALLY rigid - spiked to the wood floor, it resonates a little rotationally (ie. in the horiz plane), if struck with the fist sideways.
Not a lot, but there is a little more resonance than I'd like, under the PLL-controlled DD TT.

When examined closely, I see that:

- The leg tubes are relatively small diameter (overall proportionally) - 38mm diam.

- the horiz bars (rectangular section tube) are nicely mitred to the round tube, but are not fully welded on 4 sides, at the vertical leg joint. They are welded only on 2 edges (of each of the top bars) & crucially, only on the underside of the bottom bars. These are the edges that will not be readily visible & avoids having to grind smooth after welding. (See below.)...


(Top bars joint. The bott bars are not welded on the inner sides, ie. only one weld at the bottom.)

DarkLantern blog - darklanternforowen.wordpress.com

Compare this with an earlier steel TT stand that I have (made by Sound Creations' Robert McAdam):




This stand has larger 52mm diam. legs & the horiz bars are fully fillet-welded (& ground smooth) on all 4 sides of each horiz bar joint: (As below)




I think I will have to try the SP-10 on this TT stand as well.

DarkLantern blog - darklanternforowen.wordpress.com

Jun 20, 2020 16:26:34 GMT 12 Owen Y said:

It's time to put the SP-10 on a dedicated TT support:



This 3-legged steel stand was made by the company the acquired Sound Creations (~10 years ago?).
The stand legs are about 1/3-filled with lead shot, with adjustable spikes under.

It was originally used under an AURA TT & later a Trans-Fi Salvation rim-drive TT:




Serendipitously, it happens to be about the right size for the re-plinthed SP-10.

Although fully welded, actually it is not as rigid, torsionally (twisting in the horiz. plane) as I'd like, for a DD TT.

You sold the rim drive tt Owen ?

No - I still have the TransFi Salvation TT.
Also the AURA.

The latter needs to go to a good home.

DarkLantern blog - darklanternforowen.wordpress.com

3 of these.... aluminium cones under the TT, produced the best sound yet from this TT.
(Makeshift hardwood shims under the cones, on top of the steel stand.)

Increased clarity - of tone, harmonics, separation, incredible guitar reverb now.
Leading edges not 'sharp' but clear, without edginess.
Importantly, bass is still weighty & resonant.
No downsides as yet.

Fits the hypothesis that rotational stability, is the most important parameter for a PLL servo speed-controlled TT like this.


(Note that I am not supporting directly onto the steel baseplate - tried that earlier & it brought some 'brittleness' into the sound.)

DarkLantern blog - darklanternforowen.wordpress.com

The speed error correction would work with lower flutter given a stable base from which to work.

AMR-iFi R&D

Finally have the SP-10 onto the more rigid steel stand - sharper, cleaner, clearer images & image 'localisation'.

The steel tubes 'chimed' like a bell when tapped mid-tube, so I added lead shot in the bottom portion of ea leg - no need to 'over-damp' by completely filling & C of G is kept nice & low if only partially filled.

DarkLantern blog - darklanternforowen.wordpress.com

Really fantastic to read this through from inception to completion, I always wonder how a project like that works, super informative/educational!