alpha2delta, PS1 phono stage
A HiFi WigWam review by Richard Bowles
“Vinyl is the real deal. I’ve always felt like, until you buy the vinyl record, you don’t really own the album.” Jack White, The White Stripes
Although vinyl is apparently enjoying something of a renaissance among the younger generation, many enthusiasts have never been tempted away from it. I doubt I am the only person with a system primarily geared towards vinyl reproduction, so any developments and new entries into the marketplace are bound to come up on my radar sooner or later. Hence, after some anticipation, the latest arrival for review here is alpha2delta audio’s PS1 phono stage, produced and designed by Jessica Kinchin-Harris, who will be known to many forum members.
The unit(s) arrived, carefully and well (double) packaged. The PS1 is a two-box design, with a separate power supply and a pair of umbilical cables. These are relatively short, so the units need to be stacked, or positioned side by side. The former may give concern about interference pickup, but the instructions state this is not a problem, and in use here, the noise floor proved commendably low.
Setting up was very straightforward. There are concise and detailed instructions, and very welcome front panel controls for loading, with six positions to set resistive loading for moving coil cartridges, and six to set capacitance for moving magnet designs. A third rotary control allows switching between MM and MC, and both inputs can be used, allowing for two turntables or arms (though only one MM and one MC). On the rear, there are small switches for two alternative gain settings (for moving coil) and a ‘balanced’ switch. The unit is single-ended output/input, and the balanced setting allows the circuit to ‘float’ respective to ground to eliminate ground-loop hum.
To get the ‘elephant in the room’ out of the way early, the aesthetics are to my eyes a bit disappointing. The front and rear panels of the demo unit(s) are a plastic compound (and the rear ones flex disconcertingly), the graphics look a little clumsy with a somewhat odd font, and the control knobs have a ‘cheap’ feel to them, with excessive play. There are also rather bright, blue LEDs for power and cartridge selection. That’s the bad news. The good news is that production models are available with panels in acrylic, wood or metal, and with options for control knobs and for printed or etched writings. All customer units are (hand) built to order.
Circuit designThe power supply is solid-state rectified and, judging by the shape and weight, has a substantial toroidal transformer. The HT supplies are separate per channel, and use no electrolytic capacitors. The ‘business’ end is all valve, dual mono and serious attention has been paid to the layout and design, as well as to the choice of valves. There are no electrolytic capacitors in the signal path, and the circuit uses zero feedback and passive RIAA equalisation. High-quality components feature, and internal signal wiring is in silver. The cartridge loading options can be customised during build, and Lundahl transformers are used for moving coil step-up. The loading switch also has an ‘open’ setting, to allow an external step-up to be used. Overall, the circuit is a mix of traditional and novel, is very low noise and has highly accurate RIAA equalisation.
ListeningI am not going to do the conventional, and describe how the unit performs with individual LPs. This is a review of a phono stage rather than of different records, and musical tastes differ anyway. I will nevertheless say that over its time in my system, the PS1 had to cope with everything from the Mobile Fidelity ‘one-step ultradisc’ pressing of Simon and Garfunkel Bridge over Troubled Water, to some incredibly poorly recorded 1970’s bootleg albums; and from the Sex Pistols to Shostakovich. It also had to handle my incredibly low output and fussy Audio Technica ANV50, as well as an AT95EN and an Ortofon 2M Black. None of which seemed to trouble it in any way at all. I have always believed that a system should be able to play pretty much anything and make it sound as good as the recording permits, and this is certainly true of the PS1. While it was in residence, I also had the chance to compare it directly with a few alternatives, and it fared extremely well, including against competition from a notably higher price bracket. Right from the start, the PS1 showed a substantial width and depth of the soundstage, together with a very realistic presentation of instruments and vocals, being vivid, dynamic and ‘fast’. It gives a big sound, but without seeming in any way false or overblown. Bass is tight, well defined and precise, treble has a delightful sparkle and mids are smooth and clear. This is no deliberately engineered ‘pipe and slippers’ valve presentation. Far from it. There are rich layers and textures, and instruments are located superbly. Percussion is notably good, with both highs and lows having palpable speed and ‘drive’, and brass and woodwind instruments have an excellent ‘edge’ to them. The best phrase I can come up with is ‘vivid realism’. There were some real highlights during listening, and more than a few ‘wow’ moments, even with familiar recordings. Sonically, the PS1 is a perfect example of how, when correctly designed, valve equipment can do so much, so well, without any downsides.
The tech stuff
- Gain: 41.7db, 59.7db, and 65.7db @1kHz (customisable options)
- RIAA frequency response: 0db to -0.4db, 20Hz - 20KHz
- No rumble filter: -3db is at 3.5Hz
- Noise: <-120db
- Channel separation: >120db
- THD @ 1Kz: < 0.05%
- Main unit: 80mm (h) x 230mm (d) x 230mm (w)
RRPStarting from £3000, depending on specification and upgrades
A2D phono stages start from under £800
ConclusionsI am reasonably familiar with a number of phono stages, including some very high-end ones. Some have a deliberate ‘valve’ or ‘solid state’ sound, with the former being overly lush and smooth and the latter overly harsh and ‘edgy’. The PS1 treads a delicate path sonically, offering all the benefits of valves and none of the downsides. It offers a usefully wide range of adjustments. It makes a well-recorded instrument sound real, it portrays human voices extremely well, yet it can manage speed and dynamics. If it’s on a recording, you get it. The downsides are purely in the slightly ‘low-rent’ look and feel of the unit, though customer units with metal panels ought to mostly address this. There is some serious competition at the price point, but if you value your music listening, the PS1 definitely needs to be on your audition list.
- Very flexible range of loading settings
- Customisable to individual requirements
- Ability to run two turntables/arms
- Dynamic, detailed but not overly harsh or bright
- Big soundstage width and depth
- Physical appearance and feel
- A lot of competition at the price
Last edited by a moderator: