Michell Orbe SE and VC power supply

Posted: November 24, 2010 in Turntables

By Andrew Harrison, Hi-Fi News, March 2003

Changing a winning formula can be a risky business; the ‘if it ain’t broke don’t fix it’ maxim applies all too well to audio kit. But sometimes, change becomes necessary as much by circumstances as any desire to improve and refine a product. And so it was with Michell Engineering’s range of turntables, which have had the motor type replaced across the range. My experience with turntable motors and their power supplies has shown that seemingly trivial changes in this area can make conspicuous differences in the whole sound. But I wasn’t prepared for the major sonic refit that the change from an AC motor to a DC version would have on the Michell Orbe SE (and VC power supply). Like most belt-driven turntables over the years, Michell always used an AC synchronous motor to drive the platter. This can be an easy, cost-effective solution requiring no more than a couple of passive components to run directly from the mains AC supply, with a fair degree of inherent speed stability as motor spindle speed is locked from the 50Hz (or 60Hz) AC frequency.

Later models were offered a quartz-locked QC power unit which increased performance by lowering motor frame vibration and stabilising any frequency fluctuations by creating a more stable and purer two-phase sinusoidal feed. In effect, Michell’s QC (comparable to the Linn Lingo for the LP12) is capable of substantially improving the final sound available from its AC motorpowered turntables; but a change of design was necessitated by the recent unavailability of the specified Papst drive motor. This Swiss-made unit was one of the best AC motors for the job, and so Michell, along with its electronics partner Trichord Research, developed a replacement DC motor which fits into the same weighty 3kg motor block.

The DC motor option for belt-drive turntables has been exploited in the past by manufacturers such as Pink Triangle and Origin Live, and it has advantages – and disadvantages. In its favour, a DC motor typically has lower vibration, especially compared to the ubiquitous Philips/Airpax motors, and low enough to even allow the motor to be hard-mounted to the same plinth that supports the platter. The principal problems with DC motors are, first, speed drift caused by changes in the DC supply voltage and, second, acoustic noise from the brushes within.

Motor noise wasn’t a problem with the Orbe SE VC. From the outset, the new motor block was as deathly silent as it should be, with no ‘whispering’ acoustic noise to intrude on listening. Speed accuracy was checked with a quartz-controlled LED strobe, and found to be set precisely to 331/3rpm. This is more remarkable considering the subjective replay quality of the SE VC model, – in direct comparison with an AC motor unit on the same deck, the DC Orbe gave music a slower feel.

The impression was of a more sedate, timely rendition, giving more time to take in, for example, a piano concerto in all its layered intricacies, where the AC Orbe would be racing toward the end in comparison.

Timing, the sense that musicians are playing rhythmically and in time with each other, was as excellent as before, but overall pace was slowed subjectively. Coupled with this was a lower noise floor, allowing, for example, the slow decay of a held piano chord to be heard for longer, and very quiet background sounds such as the squeaks of instruments and seating were now apparent.

Stereo stability was also first-class, perhaps better than the older version, letting images lock into space convincing. But the biggest change after ‘speed difference’ was the tonal character, which has changed quite markedly. Treble hash, manifest as a low-level glossy sheen added to female vocals and cymbals, for instance, was never a big problem for the Miche[l Orbe, and so I was surprised when this was removed altogether. Instead I sensed a darker, more ‘analogue’ mood, particularly in the upper presence region. A Clearaudio Victory m-c cartridge mounted on a Rega RB300 Incognito arm was now giving a performance closer to the sublime and far costlier Transfiguration Temper V [HFN Dec ’02].

In conclusion, the latest Michell Orbe introduces real improvement in most areas, but beware of a change in character which might require a little system tweaking, especially if you’re upgrading from the previous version and are wedded to its tonal balance. The difference might not warrant too much concern, and I believe that the positive benefits of the upgraded motor are just too good to miss.

http://www.michell-engineering.co.uk/reviews/rev_hfn_orbese.html

Advertisements

Leave a Reply

Please log in using one of these methods to post your comment:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Google+ photo

You are commenting using your Google+ account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

w

Connecting to %s