The things my turntable required to get up and running were a new drive belt ($35), new rubber "mushrooms" for isolating the player from…
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First, some encouraging words for the budget-minded hobbyist or the DIY audiophile of any means: The Thorens TD 124 Mk.II that I purchased last year for about $700 (including a TP-14 tonearm that isn't quite usable) required only $120 in parts to achieve mere functionality—all manufactured in Switzerland by Schopper A.G. and sold in the US by Audioarts. And of the improvements I've put in place since that time, the most effective by far was the cheapest.
THE COMMITMENTS: Original Soundtrack
MCA MCAD-10286 (CD only). Paul Bushnell, Kevin Killen, Alan Parker, prods.; Kevin Killen, eng. AAD. TT: 46:54.
MCA MCAD-10286 (CD only). Paul Bushnell, Kevin Killen, Alan Parker, prods.; Kevin Killen, eng. AAD. TT: 46:54.
1991 was the Year Of The Soul: James Brown's epic Star Time! box set, the monumental nine-CD Stax/Volt singles box, Rhino's Didn't I Blow Your Mind This Time? series of super-bad '70s blaxploration, Atlantic's CD reissues of complete Stax/Volt albums, and finally the release of the movie/soundtrack, The Commitments (footnote 1). If you haven't seen the movie yet, SEE IT! It's loud, ballsy, and probably the truest film about the…
When David Hafler sold his Hafler and Acoustat companies to in-car audio manufacturer Rockford-Fosgate a year or so back, things went quiet for a while as the new owners made arrangements to transfer production of both brands to their Arizona facility and took stock of where their new acquisitions stood in the marketplace. Then, at the 1989 CES in Las Vegas, the company made a reasonably sized splash with the first in a new range of Hafler products intended to lift the brand out of the hobbyist-oriented identity it had, perhaps inadvertently, adopted in the last few years.
The Iris…
Following this mechanical switch array, we get to the heart of the Iris, what Hafler has cutely (and somewhat annoyingly) termed the "Cyber-Optic" volume control. One problem with relatively inexpensive preamplifiers is that the lower financial resources available to the designer forces him (or her) to choose an inexpensive, logarithmic-taper, volume-control potentiometer. As well as having a limited lifetime, these often feature variable tracking between the two channels, particularly at low levels, which leads to drastic changes in channel balance dependent on the listening level chosen.…
The Iris's build quality is very good at the price, with metal-film resistors and what appear to be polypropylene capacitors used in critical locations. The main power supply consists of an LM317/337 voltage regulator pair, following two 2200µF reservoir caps, which provides regulated and smoothed ±16V rails, though local decoupling is provided for each channel of the phono and line stage with electrolytics bypassed with plastic-film capacitors. All the integrated circuits used are socketed, for easy replacement, and, with the exception of the Tape, Mono, and EPL switching, the lack of…
Sidebar 1: System
In my own system, it was used with the following source components: the new Philips LHH1000 two-box CD player, its transport section also used to drive the Sony DAS-R1 D/A convertor; a 1975-vintage Revox A77 to play my own and others' 15ips master tapes; and a Linn Sondek/Ekos/Troika setup sitting on a Sound Organisation table to play LPs. Power amplification was provided by a Krell KSA-50 power amplifier, while loudspeakers were either Celestion SL700s or Vandersteen 2Cis, each pair sitting on their dedicated stands and bi-wired first with Monster M1, then with…
Sidebar 2: Measurements
I regard the fundamental measurement for a phono preamplifier as being the flatness of its RIAA de-emphasis. As can be seen from fig.1, the Hafler Iris is excellent in this respect, being within ±0.05dB across most of the frequency band, though a slight (+0.25dB) lift appears in both the low bass and the top audio octave. The latter probably correlates with the small overshoot apparent on a 5mV 1kHz squarewave fed into the phono input via an inverse-RIAA network (fig.2), though it is hard to explain why the sound should be more HF-lifted—ie, "dry" or "whispy"—than…
Sidebar 3: Specifications
Description: Solid-state preamplifier with one phono input (MM/MC switch-selectable), seven line-level inputs, two tape loops, one external processor loop, and IR remote control. Specifications: Frequency response: 20Hz–20kHz ±0.1dB (phono), 20Hz–20kHz ±0.1dB (line). Line-stage bandwidth: 6Hz–150kHz, —dB, into 10k ohms. Input impedance: user-adjustable, 47k ohms in parallel, with user-selectable capacitance, 220pF as supplied (phono MM), user-adjustable, 100 ohms as supplied (phono MC), 20–28k ohms (line). Output impedance: 316 ohms (main), 2150 ohms (tape-out…
Psst! Got a minute? I'd like to bend your ears a bit and tell you about a component that'll lift you from the doldrums of audio angst and transport you to the relaxing calm induced through the enjoyment of music. That's what it's done for me, and I'm so excited about it I can't wait to tell you.
Imagine an amplifier which will fill your room with sound yet doesn't require two people to lift and a pallet to sit on. Imagine an amplifier you don't have to sell something to own.
Imagine an amplifier which will look right at home sitting beside your treasured art objects. Imagine an…
A useful, optional accessory is a Kevlar/carbon fiber base to set the B-50 on. It is manufactured by Sicomin and is shaped the same as the B-50. It comes with three spikes to couple it and the B-50 to the shelf (or whatever) on which it sits. It raises the amp about 1½", leaving that much more room in back for hook-up handiwork.
Turning the unit upside down and removing the bottom plate reveals a neat interior with optimum use of the available space. All input connections are hard-wired directly to a glass-epoxy printed circuit board with the input selection relays located nearby. The…