Pioneer Exclusive P3
Pioneer Exclusive P3a
(1978 > 1981 > 1986)

EMT notwithstanding, the Exclusive P3 was the winner of the large test made by the Stereo Sound staff in 1980 and is, undoubtedly, the most successful high-end & high-priced turntable in Japan !
It seems every other audiophile went for the P3 and later on for its upgraded P3a version. And those who didn't have enough cash for it often went for the smaller PL-70LII...

The P3 featured Pioneer's staple Direct-Drive SHR system (Stable Hanging Rotor) but executed in a far larger mode than on the well-known PL-L1000 or the contemporary PL-L1. A triple insulation (oil-damping + spring + rubber) perfects the already immune to vibration 45kg ensemble, while the real 5mm glass dustcover participates in said 45kg.

If the signal-to-noise ratio of the original P3 amounted to a then-tops 78dB, that of the revised P3a skyrocketed to an unbelievable 95dB ! However, there is a trick here, a magic trick uncovered by Mr X, P3 owner, and his japanese technician :

"If you notice the change in DIN B rumble specs for all top tables in 1980 vs all top tables in 1981-1983, the SP-10Mk2 is something like 78dB, same as the Exclusive P3, and similar to the Yamaha PX-1 and others. In 1981, the P3a and soon afterwards the Technics SP-10Mk3, and the Kenwood L-07D all had specs in the low-mid 90s. Based on the fact that a number of brochures also say that they measured 78dB because they could not actually measure below that, and then suddenly two years later they were leaps and bounds higher, with almost no price change on similar tables (like the P3 to P3a price change), I got suspicious and started asking around. In the end, I asked the guy at the Pioneer service center where all the Exclusive tables are serviced.

When I got a P3 serviced there, I went out of my way to ask about EVERY little thing which was different, either visible or not visible, thought to be audible or not. Over a few phone calls and meetings, I got a long laundry list of extremely minor differences. The two which he thought would make an audible difference were the arm (the P3a arm has what is called a Dynamic Resonance Absorber, which is a small weight loosely attached to the armtube just before the armtube collar (which tends to make the straight arm a bit more flexible in lightweight cart compliance usable range as well as reducing resonance).

The other change was a switch to a lower capacitance phono cord. There were a few small circuit changes, but they are relatively minor. The motor, most of the controller circuit, general controller principles, transformer, power supply, insulators, etc, are all the same.

There was a physical change in the metal base (that you can see as the top photo on the page). It was an exotic mix of metals to create a rigid but non-resonant base. The turntable is not centered on that base which while it does not affect sound, was seen by the engineers as something they 'missed'. On the P3a, they do a better job of centering it by shaving thickness in some places.

So where does the 78dB --> 95dB difference come from? I asked him that too because I was exasperated at not being able to explain it based on changes. His answer, translated and redacted, comes out as the following : "It is 'numbers magic'. Sometime in the very early 80s, the EIAJ (Electronics Industry Association of Japan) changed their DIN B measurement methodology to, according to the marketers, 'better measure what the ear hears'. They changed something to account for the shape of the human ear. Left largely unannounced, they 'flattened' the weighted curve, and added another filter, which had the effect of raising SNRs by 'about 20dB' depending on the piece of equipment being measured."

I asked him whether they measured anything when tables came in to get repaired. He said that in fact they measure all tables according to that newer "DIN B (EIAJ, A-network) standard because that is the machine they have now. When I asked how much better the P3a measures vs the P3, he said, "They come out the same - non-statistically-significant sample difference".
The only difference which comes out in testing is a lower speed drift amount : the P3a has a potential speed drift of half the P3 (though when they service the P3, they tune it to P3a control specs). I then asked whether he had done any of the other mega tables which showed such great specs and he said, "No, but the whole curve shifted upward for everyone - there was no way to avoid it."

Later, he said that the thing to measure to check real rumble differences would be the JIS rumble spec which used continuously from the late 1960s or early 1970s. In that way you could compare like-for-like across time and manufacturers."

95dB was therefore magic indeed ;-)