Quote Originally Posted by Wakefield Turntables View Post
Part II - Loading

The M44-7 according to Shure likes to see 400-500 pf loading. I'm now glad I'm not using the SME 3009 as I've heard that several people have tried to measure the capacitance of the old tonearm cable with varying readings, sometimes differing markedly from one channel to the other other. I'm glad to say that my cables are a known entity and that the loading capacitance in each channel is pretty much perfectly matched. I have been trying to work out some figures with respects to what my M44-7 is currently "seeing". Here goes :-

Cartridge to Phonostage

Natural capcitance loading of Croft MM stage 100pf
Cartridge tags & cartridge leads 10pf
Connector from tonearm to intrinstic tonearm wiring 10pf
Internal tonearm wiring 15pf (SME source)
Tonearm connector accepting intrinsic wiring 10pf
Tonearm connector 5-pin plug 10pf
Tonearm cable 60pf (Yannis Tome source)
Tonearm cable to RCA 10pf

TOTAL 225pf

So, I'm missing around 225pf loading. This means i'm not getting the best from the M44-7, so it's looking like the EAR 834P may be a better option for optimal cartridge loading. At least I can make the EAR make the M44-7 see the 450pf. Hmmm anothor conundrum to ponder.

I've spent a little more time on setting the cartridge up tonight using Dr. Feickharts protractor, cartridge tracking force and antiskate are both sitting at 3g, things appear a lot clearer. The deck is still not perfectly level in all planes but I'm not that far away, the bubble in the spirit level doesn't quite sit perfectly central but it's not so far away, I'm hearing great things. I also need to address the speed accuracy of the 401 as it does not have a speed controller like the Garrard 301 that I own and I'm not prepared to mess around rewire everything for this experiment, I'll dig out the timing laser and alter the speed control that way. Usually we can be accurate within +/- 0.01 RPM. Both cartridges stylii are new the M44-7 has a Tonar stylii to the same specs as the original https://www.turntabletrainingwax.com/tonar-n44-7-stylus mine cost £19 delivered, I'm sure you can get cheaper if you shop around. I must confess to not knowing where I purchased the M55E replacement but I do know it's new and zero hours usage. Currently the M44-7 has around 6 hours usage. I'm trying to get 3 hours a day.

Things I could do to further improve this Experiment
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1. Vertical tracking height for cartridge has not been properly set yet.
2. Could use Townshend Isolation platform for further improvement of airbourne vibration and such like.
3. Tonearm needs a very very small amount of tweaking.
4. Feed the phonostages with a cleaner power supply. Could this produce a bias in that the 401 has a clean supply and the phonostages don't?

Factor Affecting the Absolute Performance of the Shure Carts
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1. The M55E appears to be a marginally better match for the SME V-12.
2. The Croft phonostage (if loading capacitance is set at 100pf) lessens the chances of accurately matching old Shure Carts.
3. I'm compromising the absolute speed accuracy of the 401, I could use a Roadrunner/Eagle PSU combo to match speed to 0.001 RPM rather than
0.01 RPM accuracy.


Steps Taken to Maximise Performance
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1. Using Baerweld tracking, setup with respected Dr. Fieckhart protractor
2. Using a true Reference tonearm which matches both the M44-7 and M55E very well.
3. Turntable perfectly level in all planes.
4. Tried to make sure that the 401 is running with a clean power supply, supplied with a PS Audio P10
5. Motor decoupled from 401 less vibration getting into cartridge
6. Tried to improve the trackability of the Carts by making sure the vinyl is as flat as possible and then using heavy record clamp and peripheral
platter ring on vinyl.
7. Both cartridge stylii are new and I have allowed a 30 hours break-in period for any cantilever stiffness.
8. Accurately known and matched loading capacitance for left and right channel cartridge channels.
9. 401 platter damped with a Tenuto platter mat.

I think that's enough for tonight. Maybe some pictures tomorrow.

Stay tuned...
This could be why I don't get the best out go my M55E with my Croft phono stage?