Parasound JCA100 Tribute monoblock energy amplifier

In December 2023, I took the practice from New York to Los Angeles to attend the Los Angeles & Orange County Audiophile Society’s thirtieth annual Gala. I took the journey as a result of it’s each stimulating and satisfying to spend a day within the firm of greater than 200 audiophiles and music lovers; I additionally needed to see John Curl offered with the Society’s fourth Innovation Award, by George and Carolyn Counnas of Zesto. John was given the award "for his groundbreaking contributions to the sector of solid-state audio amplifiers, circuit innovation, mastering recorders and rather more."

I first met John greater than 40 years in the past, at a Consumer Electronics Show in Chicago, the place I used to be blown away by John’s intuitive and progressive method to circuit design. As J. Gordon Holt wrote in his 1988 overview of John’s Vendetta phono preamplifier, "In the pursuit of audio perfection, Curl little comprehends the that means of ‘compromise.’ His designs are typically really no-holds-barred, utilizing one of the best parts cash should purchase to supply one of the best sound and highest reliability the state-of-the-art permits."

Along with Nelson Pass, Keith Johnson, Dan D’Agostino, and Bob Cordell, all of whom are nonetheless with us, and Charley Hansen, Bascom King, and James Bongiorno, who’ve handed on, John is up there within the pantheon of American designers of strong state amplification merchandise.

After engaged on video recorder design at Ampex, John Curl designed and constructed the sound programs for The Grateful Dead’s highway reveals, then designed the legendary Mark Levinson JC-2 preamplifier and the electronics for David Wilson’s UltraMaster tape recorder. John Curl met Parasound founder Richard Schram in 1989, and since then Curl has designed all the Bay Area firm’s high-power amplifiers in addition to consulting on the design of the low-level circuits of most of the firm’s different parts (footnote 1). I loved a beer with John within the Buena Park Hilton’s bar after the Gala. I additionally chatted with Parasound’s new proprietor, David Sheriff, who had acquired the corporate in December 2022 following Richard Schram’s retirement.

The first new product from Parasound beneath Sheriff’s possession is the topic of this overview, the JCA100 Tribute monoblock energy amplifier, which is priced at $30,000/pair. The JC within the amplifier’s identify stands for John Curl; A100 refers to the truth that the output stage is biased into class-A as much as the utmost energy of 100W into 8 ohms. "Tribute" is certainly supposed as a tribute to John Curl’s lifetime of feat.

Only 100 pairs of JCA100 Tributes shall be made, every set hand-assembled to order within the United States, Sheriff advised me, with a lead time of 46 weeks from the location of the order. Notably, a good portion of the proceeds goes to Curl. "We are utilizing this as an avenue to ‘give again’ financially to John in a significant approach," Sheriff wrote in a follow-up e-mail, including that Parasound "may also be utilizing substantial parts for scholarship seedings for future restore techs (a dying breed proper now, however nonetheless a lot wanted)."

The JCA100 Tribute
When I unpacked the amplifiers, I used to be considerably stunned that, aside from the "97L" and "97R" serial numbers on their entrance panels (footnote 2), they did not look any totally different from the Parasound Halo JC 1+ monoblock that I reviewed in Stereophile‘s June 2020 difficulty. (A full description of the JC 1+’s design, parts, and development could be present in that overview.) The JCA100 has an an identical chassis with substantial heatsinks on the perimeters, the identical controls and connections; it even has a "JC 1+" legend on the rear panel. I requested Sheriff if the brand new amplifier was primarily based on the older amplifier.

"Correct," he responded. "We deliberately needed individuals to grasp that this can be a limited-run, modified JC1+ tribute version. Quite a little bit of engineering and testing. We will not offer conversions/upgrades from JC 1+ to JCA100 or JCA100 specs."

I requested if I’d be right in writing that to fabricate a JCA100, Parasound takes a JC 1+ from its US stock, modifies it, and replaces the entrance panel with the brand new one which has the limited-edition serial quantity.

"Two JC 1s get modified into the matching set, blueprinted for efficiency, faceplate/ears/ft swapped." Sheriff stated that there shall be different tribute merchandise over the subsequent couple of yearsa preamp and a phono preampwhich could be equipped to match. "The PRE and PHONO will solely be obtainable with the serial quantity to the purchaser with the identical serial on the JCA100s," he wrote.

The new amplifier’s specs point out that the output stage’s bias present has been elevated in order that the amplifier runs in class- A as much as the desired energy of 100W into 8 ohms. This energy is far decrease than the JC 1+’s most of 450W into that load. I requested what design choice underlay this discount in most energy? Were there different modifications and modifications to the circuit?

Darren Myers, Parasound’s new Vice President of Research and Development, defined that "the aim of this design was to create an amplifier able to 100W of class-A operation into 8 ohms. To accomplish this, the voltage rails on the output stage have been lowered, lowering the utmost voltage swing into 8 ohms in comparison with a inventory JC 1+. This permits for a manageable quantity of energy dissipation on the output stage whereas having sufficient quiescent present to attain the 100W class-An influence specification.

"To optimize this class-A operation, there are a number of inner modifications utilized to the circuit, together with transformer and part worth modifications. John Curl labored straight with the Parasound design workforce for over a yr to design and optimize the modification course of. John and the whole workforce at Parasound are so pleased with what we have give you. The consequence is actually one thing very particular."

Footnote 1: An interview with John Curl could be downloaded from parasound.com/pdfs/JCinterview.pdf.

Footnote 2: Sheriff selected the overview samples’ serial numbers to mirror the truth that Stereophile‘s web site first noticed the sunshine of day in 1997.

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May 23, 2024 at 04:27PM