http://www.audiologica.co.uk/audiolab_8000ppa.html 01403 789 226 [email protected] Brand new and sealed Delivery to Norway will be tax-free (just £405 plus delivery to pay, £465 total delivered) The 8000PPA is designed as a reference quality phono stage, for the best possible reproduction of precious vinyl collections. With Moving Magnet, Moving Coil and a special MCx30 stage for very low output moving coil cartridges, the 8000PPA gets the very best from all turntables, from the modest to the truly exotic. Very serious vinyl fans might even have two decks for 45rpm and 33rpm discs - here 8000PPA is a perfect choice with two completely independent inputs. Thanks to 'Straight-Line' Technology and razor-sharp adherence to the RIAA equalisation curve, excellent sound quality is assured. Audiolab 8000PPA Phono preamplifier - review in Gramophone Magazine It is scarcely an appropriate thought, but two meetings with, and several telephone calls from, Philip Swift, Managing Director of Cambridge Systems Technology Limitedâ€â€Audiolab--about new products in recent weeks put me in mind of the famous London bus analogy: we wait expectantly for what seems like an eternity, knowing that something is on the way, and then two arrive at the same time. Audiolab has never rushed a new product on to the market and the wait after first learning of its existence can be considerable indeed. Perhaps the longest incubation period of all was for the 8000T FM tunerâ€â€that took a couple of yearsâ€â€but the wait was worthwhile, for what ensued was an exceptionally fine product in every way (the 8000T was reviewed by GH in June last year). For this issue I have been looking at what must be just about the most carefully thought out phono preamplifier currently available on the domestic hi-fl market and next month Keith Howard will report on the long-awaited 8000CDM CD transport, which partners the already well established and highly regarded 8000DAC digital-toanalogue converter. I have delved into the subject of RIAA phono equalization several times recently, registering the growing number of stand-alone units such as this which are dedicated to the purpose. With so many pre- and integrated amplifiers coming on to the market which make no provision for the conventional LP pickup cartridge, the availability of ancillary 'black boxes' which will perform the necessary gain and equalization is especially welcome. The low level and delicate nature of cartridge output signals means that the initial signal processing needs to be managed with great care if the end result is not to be compromised, so a circuit dedicated to just that one job is really much the best solution; too few complete amplifiers which do cater for the phono cartridge pay anything more than lip service to its well being. The 8000PPA has taken three years to come to fruition and is the first product to use Audiolab's "zq" 'intelligent' amplifier technology. Essentially this is an advanced implementation of the well known DC servo arrangement, whose main purpose is to keep the signal path inviolate by the elimination of potentially degrading coupling capacitors. Except for those which determine the RIAA equalization time constants none are used at all in this circuit, not even in the feedback paths. High impedance ("Z") summing points (differential nodes) combine and process the signal input and the multiple feedback signals so as to produce an output which is free of interaction effects and distortion. The DC servos are under the control of a microprocessor (hence the ,q "â€â€for intelligence quotient) which constantly monitors an array of test points around the circuit and alters the servo time constants dynamically so as to ensure that the final output has no DC bias. Instantaneous muting occurs in the presence of an 'alien' signal (for example the sort of transient produced when a stylus is inadvertently dropped on to a disc) or when a change of input selection or gain settings is made. Perhaps the most ingenious part of this circuit is the dynamic behaviour of these servos. The requirements conflict rather: a very large time constant is required to allow the audio signal through unmodified, yet a very quick response in correcting any DC offset is necessary so that muting need only be brief. With this circuit Audiolab have achieved a low frequency performance which extends down to 100mHz (0- 1 Hz) while the offset detectors combine with the digitally controlled muting system to ensure that large subsonic signals are prevented from reaching the output. This is an essentially 'bomb proof' circuit which will see to it that your loudspeaker drive units are handled with kid gloves regardless of the use and abuse which may occur back at the turntable. Built into the usual (445mm wide) Audiolab cabinet, the 8000PPA has the familiar elegantly simple black anodised aluminium fascia, with its mains power push-switch on the extreme right. The various settings are managed by an array of three small touch buttons. "Input" allows for the connection of two turntable systems and the settings then chosen for each-cartridge type and gain plus optional LF filterâ€â€are retained by the microprocessor. "Gain" cycles to and fro through three settings: moving-magnet (MM) with a gain of 38dB and moving-coil (MC) with gains of 10 (58dB) or 30 (68dB). The optional IEC highpass 6dB/ octave filter centred on 20Hz (7950RS) can be selected by the third button, labelled LF. The settings are confirmed by spot LEDs: yellow for the input, red for gain and green for LF. A seventh, red, diode lights to show the temporary mute condition. The rear panel has six pairs of gold-plated phono sockets, a pair each for the two inputs and two pairs, connected in parallel, for the outputs. Normally just one pair of these would be used; the second is provided mainly for convenience (for example to make absolutely no-compromise recordings by avoiding the preamplifer). Adjacent to each input is a second pair labelled Load, enabling the ready inclusion of additional resistive and/or capacitive elements for cartridges which need to 'see' a non-standard load. Two chassis terminals are provided for the pickup arm earth leads. Internally, almost the entire circuit is built on a single motherboard which occupies virtually the whole floor area, save for a cut-out at the rear given over to the screened toroidal mains transformer. A small sub-board is situated behind the fascia to carry the controls and LEDs. This is as neat and disciplined a layout as you will ever see, with the components clearly and logically laid out. The microprocessor circuit is shielded by a metal cover to contain any byproduct radiation from its 4MHz 'clock'. No less than nine IC voltage regulators are employed, one set at 5V for the logic circuits and four each per channel for the audio devices. I have not met such elaborate regulation before. A single •pair of high quality LM3I7/337 devices forming a common supply for both channels would satisfy most designers but here a further pair is used per channel (regulating the regulated supply, as it were) to provide what must be near-perfect ±15V rails. All signal routing is handled by encapsulated relays under control of the microprocessor. Movingmagnet signals are sent directly to the RIAA gain/EQ stage but for MC an additional amplifier is interposed to boost the incoming signal by a further 20 or 30dB as required. Both stages employ constant-current fed JFET differential configurations at the inputs of low-noise NE5534 bi-polar operational amplifiers, with the DC set Specification vos formed from BIFET TL072 and TL05I/2 devices. Great care has clearly been taken in the layout of the beautifully made double-sided glass-fibre pcb, with sensitive signal tracks shielded by extensive ground 'lands'. For a unit which performs what is basically a very simple job there is a great deal involved here, yet the complexity is almost entirely due to the electronics 'housekeeping'; the signal path itself is in essence very simple. Performance Measurements of such basic parameters as frequency response, noise and distortion served only to confirm the specification and, in some respects, challenge the test equipmentâ€â€this is the closest adherence to the RIAA curve that I have seen and the HF response tracks the curve to the 315kHz limit of my test gear. As noted above, the IEC-recommended 20Hz pole is included as an option and is perfectly implemented. A few moments with one of my all-time favourite LPsâ€â€the 1979 Philips recording of Debussy's Nocturnes and Jeux with Haitink and the Concertgebouw (® 9500 674, 11180) was enough to convince me of the 8000PPA's pedigree, the hushed environment of "Nuages" conveyed with a tangible presence within the enveloping acoustic, front-to-back perspectives beautifully graded and, yes, a Firm impression even of height. So completely was I drawn into Debussy's world that I forgot I was listening to LP until a surface blemish momentarily intruded towards the end. Yet even this passed without the level of distraction one routinely expected in the old days, and from which CD, when it came, was such a blessed relief. We have noted before that inputs with a fast rise-time register but do not dwell on such glitches. I spent several evenings rediscovering LPs with the 8000PPA and was never once led to doubt the quality of sound I was hearing. Combined with a first-rate cartridge, pickup arm and turntable (for the most part I used a Dynavector XX-1 high output moving-coil in an SME Series IV on a Roksan Xerxes) the unit will present you with everything contained in those precious record grooves and do so without in any way imposing a 'personality' of its own. In that respect it is the very embodiment of the perfect, anonymous, black box
Are you selling the original Audiolab phonostage as hinted by the reference to P-Swift in the review or the current IAG audiolab version that uses different, cheaper and lower spec parts?
Audiolab 8000PPA Just checked the source of the review and it dated 1994! So yes the review is on the older unit whereas the actual units fopr sale are obviously new. Apologies for the error
