Well, as it happens I have very recently had the delight of comparing two turntable power supplies on my own deck. I was asked by Les W. at Avondale Audio is I would like to try his reborn TAPS and this I did, comparing it to my Armageddon (note: I do not use an LP12). Whilst both these supplies are transformer coupled units they go about their business in quite different ways.
If I may, I have copied my comments below:
First Impressions
A few weeks ago I was visiting Les at Avondale Audio (as I do from time to time) and he showed me a prototype of a forthcoming turntable power supply; this is to be called the TAPS (Turntable Auxiliary Power Supply). The purpose of this supply is to feed any AC 24 pole turntable motor and is his take on the problems that the Naim Armageddon and Linn Lingo (amongst others) seek to address. Well, after a bit of a chat Les asked me if I would like to borrow it and, if I wanted, post my findings; so I did borrow it and here are those findings.
The TAPS has a number of unique (in my experience) features. It is not a supply that regenerates the waveform in the way that supplies like the Lingo do. The TAPS is more like the Naim Armageddon although the actual application is quite different. I did ask Les if he would outline the circuit for me and this is what he told me:
There are six main stages, and these are:
1/ The mains enters the unit and enters a resistor buffer.
2/ It is then routed through the first transformer that steps the voltage down.
3/ The signal then goes through a resistor, capacitor network for wave shaping.
4/ Then on to a Common Mode Inductor.
5/ Another resistor, capacitor network.
6/ Finally, a transformer raises the voltage back up to 110 volts. However, this final voltage can be adjusted in 2 volt increments to reduce motor vibration and enhance the flywheel effect of the platter.
This final point is a key feature of the TAPS. On the production version you will be able to adjust, via a front mounted dial, the specific voltage fed to the motor. The advantages of this are twofold; not only is motor vibration reduced (and therefore noise likely to be fed back into the system) but the platters rotational mass is now much more clearly defined as the dominant source of rotational energy. The flywheel effect of the platter is able to dominate irregularities in the motor feed (rather like the Nottingham Analogue decks).
As mine was a preproduction version it did not have the adjustable output voltage but was preset at a minimum level just sufficient to maintain platter rotation. It is also worth mentioning that although my deck uses an AC 24 pole motor, like the Linn LP12, it is not a Linn. In day to day use I employ a Naim Armageddon and so the Taps was compared directly to this.
This was a most interesting comparison to make – whilst the supplies were quite different the type of difference was quite unlike those that you find with amplifiers, speakers or pretty much any other component. Because of the low output voltage of the (pre-production) TAPS is was necessary to spin the platter up to speed by hand but once 33.3rpm was achieved I never heard anything to suggest that the speed was anything less than 100% accurate or consistent. This was not an easy comparison to make (even less easy to write) as in many fundamental ways the two supplies were very similar, and yet, they were also quite audibly different.
Let's look at the similarities first. Both supplies had a very similar overall presentation in that the apparent dynamic range was the same and top to bottom extension was also similar; neither supply gave greater bass or treble. Dynamic impact was also very similar and sharp transients (like sudden bass notes or guitar riffs) were equally well conveyed on both; I did wonder if the Armageddon, with its greater torque, would be superior in this regard but that did not seem to be the case. PRaT was of a similarly high standard on both units and bass lines were easy to follow on both (sometimes easier on the TAPS).
Now, let us consider the differences. There were two main differences; firstly, the Armageddon had the curious quality of making the music almost seem louder – not so much in a volume sense (volume levels were carefully maintained throughout the comparisons made), more as if one was sat slightly closer to the musicians. The TAPS, on the other hand, gave a slightly more distant, considered perspective. The second main difference was in terms of stereo portrayal. The TAPS gave an extremely tightly focussed presentation and placement of sounds and instruments across the sound stage was excellent, as was depth. In comparison the Armageddon seemed slightly more 'vivid' but at the same time instrument position was a little more smeared and less tightly focussed. A couple of times, with the TAPS I heard some very subtle movement of voices within the soundstage which just weren't apparent with the Armageddon. Voices in particular sounded more compact on the TAPS than the slightly larger, and closer, quality imparted by the Armageddon; putting aside the manner of presentation, dynamic inflection seemed equally good on both.
In terms of motor noise there doesn't seems to be much in it – perhaps the TAPS does give a quieter background but the difference is small. I should add that I spent a lot of effort to isolate vibration from the motor when I designed my deck and backgrounds are already very quiet indeed; the addition of magnetic lift to the main bearing helped significantly in this regard. LP12 users may well find the difference more pronounced.
There is no doubt, in my mind, that this is a very successful design. It is not a copy (in any way) of any existing product and offers a most welcome addition to the ranks of existing designs. The ability to adjust the output voltage to the motor is particularly interesting (and unique as far as I am aware) and I would certainly like to experiment with this. I will certainly be badgering Les to try a full production model when they become available. Anybody considering a power supply for their AC motor powered turntable should definitely consider the TAPS. I know that Les has yet to finalise the exact presentation of the unit but it is likely to be about the size of a Naim half width case (Armageddon, Nac72, Hi-Cap) and be black with a black anodised, brushed aluminium, front panel. A front mounted dial with LED indicators is planed to adjust, and indicate, the chosen output voltage to the motor. Price has not been finalised but like all Avondale designs I am sure it will be more than competitive.
Records used in the above comparisons:
Antony And The Johnsons 'I Am A Bird Now'
David Bowie 'Hunky Dory'
Dead Can Dance 'Aion'
Dead Can Dance 'Toward The Within'
Laura Marling 'Alas I Cannot Swim'
Lou Reed 'Berlin'
Talk Talk 'The Colour Of Spring'
I did offer Les the chance to read the above before I posted it but he declined as he said he did not wish to influence my findings – can't say fairer than that.
