[dkd7]

I have had this cart for about 6 months on my 1200 Mk5 and have recently acquired a Phonomena II. Granted there are many more settings than I have used before, I'm curious as to how to find the correct loading.

I understand it's based on your own preference and that the highs are more affected by higher loadings, but at what point are the settings either hindering or allowing too much stylus movement?

301 Mk2 specs:

Output: 0.4mV
Output impedance: 33ohms
Compliance: 13x 10-6cm/dyne



Phonomena II loadings are as follows:

30, 40, 50, 59, 80, 100, 121, 150, 243, 280, 380, 475, 660, 1k, 2k, 50k, 100k Ohms

Gain: 40, 44, 46, 48, 50, 51.5, 52.7, 53.7, 56, 57.5, 58.4, 59.4, 60dB

Currently I'm running it at 58.4dB and 1K Ohms but would like some more insight on how the loadings affect this particular cart.

 

[dlaloum]

I posted this earlier today on another forum... it seemed relevant:

what you are creating with the combination of inductance resistance and capacitance is basically an equalisation circuit... - a low pass filter.

Altering the parameters shifts the rolloff frequency, as well as the slope of the rolloff after that point, and also whether you generate a resonance at the rolloff frequency (which manifests as an amplitude boost at that frequency, and frequencies around 1 octave up and down from the rolloff frequency).

This is most audible with MM/MI (high inductance) cartridges where the rolloff point is in almost all cases well within the audible range, and therefore the loading can be used almost like a treble control...

With MC's it gets more complicated.

The electrical resonance at the rolloff point is located well outside the audible zone up in the ultrasonic range.

But in some cases the resonance generated can be a boost of well over 20db - in cases like that simple background noise can end up being boosted to the point where it starts chewing up the available phono stage bandwidth.
In the worst case it may clip - in which case all sorts of nasty distortions get generated - including down within the audible frequency range.

In other cases the frequencies in the UHF range can (depending on the design of the particular phono stage) and frequently do generate intermodulation distortion within the audible range.

So what is heard is not in fact the resonance itself, but the indirect result of the resonance in terms of distortion.

Adjusting the loading can lower the resonance or eliminate it, and by eliminating or reducing it you also eliminate or reduce any associated IMD (Inter Modulation Distortion)... and of course reduce the likelihood of clipping and clipping artifacts.

Regardless of the myths floating around - the alterations of electrical parameters have no impact on the mechanicals of the cartridge as the magnitude of the forces involved is many orders of magnitude smaller than the forces involved in the stylus/vinyl interface.

So yes back EMF exists in a theoretical sense, but is irrelevant to vinyl....

The real issue is that MC loading is very unpredictable, as the response of differing phono stage designs is different! - a circuit prone to IMD from HF peaks will respond positively to loading changes.
Another which has ample headroom, and a circuit which is very wideband and not prone to IMD might not respond to loading in any audible way!

And unless you have access to appropriate lab equipment, you have no way of knowing which category yours falls into - hence it becomes a black art!

Without detailed measurements it is hard to know, but when people change the loading and hear a difference with an MC, the chances are very very high that the difference is due to the presence or absence of an audible distortion - this distortion product is then perceived as brightness or dullness etc...

Actual frequency response measurements show that changing the loading has not impact on the frequency response when measued by frequency spot tones. It does have an impact with pink noise, but a pink noise measurement includes the distortion as part of the measurement, which is why it better reflects the perceived frequency response as opposed to the "true" F/R.


With regards to calculating the "ideal" load - there is a good calculator here:

http://www.hagtech.com/loading.html

But to calculate the loading, you need to know the cartridges inductance... which is not readily available for many cartridges!


Hope this helps and does not confuse things too much!

bye for now

David

[neobop]

In a more practical vein, there are audible consequences of MC loading.  If in fact, you have ultrasonic ringing and overload due to HF resonance or cart self inductance/resistance, then IMD would be obvious.  Seeing that you've already found a setting at 1K that seems good, I assume HF overload isn't a problem.  If this assumption is wrong, please correct. Does it sound harmonically distorted (bright)?

Unlike a HO cart, with MCs HF performance isn't affected as much.  A higher setting usually gives a more wide open stage at the expense of focus and detail.  Load it down, and the contrary is true (usually).  Advise is often to load as high as possible w/o losing detail.  With cart resistance of 33 ohms and recommended loading > 100, there's nothing unusual here.  If you liked the 30 or 40 ohm setting, I'd guess that HF overload is why.


 

[TheChairGuy]

What sounds good IS good.

Keep playing with settings until one strikes you as the right balance, overall.  Many of us on the Vinyl Circle can wax lyrical about loading, but it ultimately comes down to your preference, regardless.

The Denon's are uncommonly good value cartridges in today's market. Set it the way that's best to you and enjoy the heck out of it 

[tomytoons]

The Phonomena is a nice phono just because of all the settings. I had a Nova.
I agree listen to it, but I bet it is around the 1K -2K settings.
Enjoy!

[dkd7]

dlaloum, that is a nice write-up, does make a little more sense now.  I did leave one thing out and that's the factor of 10 or 15 that is mentioned when multiplying the cart resistance....not sure how the multiples are derived.

Seeing that you've already found a setting at 1K that seems good, I assume HF overload isn't a problem.  If this assumption is wrong, please correct. Does it sound harmonically distorted (bright)?

I don't know for sure if HF overload is a problem, I want to say that it's a tad bright, but I was adjusting the VTF down from 1.6 to 1.4, then tried 1.3 and I believe at around 1.3 the highs were distorting slightly. The S's were more pronounced when using Synchronicity as a test LP. There seems to be a more pronounced soundstage at 1.4-1.5g. Some have had good luck at 1.2-1.3 so I thought I would give it a try.

This is with the loading at 1K, I haven't tried anything over 1K yet.

With cart resistance of 33 ohms and recommended loading > 100, there's nothing unusual here.  If you liked the 30 or 40 ohm setting, I'd guess that HF overload is why.

I haven't tried anything under 100, the manual states to load it above 100 so I'm only assuming that 30 or 40 would be taking a step backwards but it's worth a try. Seems most owners of this cart state it needs at least 300 ohms so is this where the multiplier of 10 comes into play?

This is making alot more sense now for sure. I do have the Hi Fi News test LP so this will aid my research. Unfortunately it came warped so I'm awaiting a replacement.

The Phonomena is a nice phono just because of all the settings. I had a Nova.
I agree listen to it, but I bet it is around the 1K -2K settings.
Enjoy!

 I was thinking 1K was at the upper limit but I will give it a try.

I know it may sound like I'm asking for everyone to tell me what sounds best to me but just trying to understand how all the settings impact the music and in what ways. I appreciate all the input.