Learning from the past must be a lost pursuit in some kind of inherent human retardation. Consider all the wars we’ve fought, several times over. All our current money problems? It’s all happened before. Now consider that when our audiophile friends in Japan started dusting off old Western Electric gear (and Klangfilm, RCA, Altec, Leak, etc), they heard things that were lost in modern equipment.
Of course it’s all been talked about: about single drivers, horns, SEDHT, transformer coupling and how their Renaissance delivered a different version of the truth from what state-of-the-art high-end designs were delivering. Lagging behind the speakers, amps, preamps, tubes, and topologies were phono stages. Most companies that are building single-ended triode amps packed with iron are still using one of the standard designs: feedback type, passive type, or split feedback and passive. These designs used various arrangements of capacitors and resistors, usually sandwiched between two triodes. Lurking out there in the mist was something completely different: the LCR filter. I’m not capable of delivering a dissertation on how the LCR stage does what it does. However, it boils down to this: the signal goes through one very special choke, fewer resistors and almost no capacitors. In my opinion, the result makes lame ducks of the traditional CR type circuits. If I understand correctly, an LCR network is/was used to accomplish the RIAA curve on many records; put another way, the RIAA preemphasis, during record mastering, used an LCR network. Yet again, iron has proven mightier than the condenser, which was the original order of things. So why did CR circuits come to rule the RIAA roost (also NAB, NARTB, IEC, etc.)? Because it’s cheap and easy to use. The kind of choke needed for the LCR network is expensive.
LCR designs have made their way around the internet for some years, with a small cadre of DIYers advocating their superiority. But as a friend put it, they’re expensive if you don’t like the result. Those high quality chokes don’t come cheap and are only offered by a handful of winders. You might be out a couple hundred dollars for some caps and resistors, which can be reused on a different project, on some rearranging of the traditional CR network. You might be out a couple thousand dollars depending on which version of the LCR circuit you chose. So, a few guys are preaching the good word, but very few were accepting the invitation. Fortunately for those of us who don’t want to build an entire phono stage from scratch, which would be most of us, these designs are starting to appear in real products that you plug and play.
A True Believer?
I first heard the Allnic H-3000, Allnic’s top phono stage, at this year’s T.H.E. Show, at Tom Vu’s KT Audio Imports room with GamuT amps and speakers, and a Musical Life front-end. About a month later I heard it at Albert Porter’s place, where he was auditioning a new phono stage every few weeks. My first impressions at T.H.E. Show were positive, but I was stunned by what I heard at Albert’s. T.H.E. Show can be a confusing experience with unknown room acoustics and systems with all new equipment. Hearing multiple phono stages in an otherwise unchanging system made it easy to hear how good the Allnic was. Anyway, after listening to the Allnic H-3000 and considering its virtues, a tune came to mind: “Savoy Truffle” by George Harrison. A snippet:
