JMF HQS 7001 monoblock power amplifier Associated Equipment

Sidebar 2: Associated Equipment

Digital sources: dCS Vivaldi Apex DAC, Vivaldi Upsampler Plus, Vivaldi Master Clock, and Rossini Transport; EMM Labs DV2 Integrated DAC, Meitner MA3 Integrated DAC; Innuos Statement Next-Gen Music Server; Small Green Computer Sonore Deluxe opticalModule; Uptone Audio EtherRegen with SOtM sCLK-OCX10 Master Clock and sPS-500 power supply; Nordost QNet switch and QSource linear power supplies (2); HDPlex 300 linear power supply; Synology 5-bay 1019+ NAS with Ferrum Hypsos linear/switching hybrid power supply; Linksys MR9000 mesh router and Arris modem; Apple 2023 iPad Pro and 2017 MacBook Pro laptop with 2.8GHz Intel i7, SSD, 16GB RAM.
Preamplifier: Dan D'Agostino Momentum HD.
Power amplifiers: Dan D'Agostino Momentum M400 MxV monoblocks.
Loudspeakers: Wilson Audio Specialties Alexia V with LōKē subwoofers.
Cables: Digital: Nordost Odin 1, Odin 2, and Valhalla 2 (USB and Ethernet), Frey 2 (USB adapter); AudioQuest WEL Signature; Wireworld Platinum Starlight Cat8 (Ethernet), OM1 62.5/125 multimode duplex (fiberoptic). Interconnect (XLR): Nordost Odin 2 and Blue Heaven subwoofer, AudioQuest Dragon, Canare (subwoofers). Speaker: Nordost Odin 2, AudioQuest Dragon. AC: Nordost Odin 2, Valhalla 2, Valhalla 1; AudioQuest Dragon and Firebird. Umbilical cords: Ghent Audio Canare on HDPlex 300 LPS and NAS; QSource Premium DC cables with Lemo terminations for QSources; SOtM sPS-500 umbilical cable for SOtM Master clock.
Accessories: Grand Prix Monza 8-shelf double rack and amp stands, 1.5" Formula platform; Symposium Ultra Platform; Nordost 20A QB8 Mark III, 15A QB9 Mark II, QKore 1 and 6; Titanium and Bronze Sort Kones, Sort Lifts; Stromtank S 2500 Quantum MK II power generator; AudioQuest Niagara 7000 and Niagara 5000 power conditioners, NRG Edison outlets, JitterBugs; Environmental Potentials EP2050EE surge protector/filter; Wilson Audio Pedestals; A/V RoomService Polyflex Diffusers; Resolution Acoustics room treatment; Stillpoints Clouds (8); HRS DPX-14545 Damping Plates; Marigo Aida CD mat.
Dedicated listening room: 20' L × 16' W × 9'4" H.—Jason Victor Serinus

JMF Audio
228 Voie des Chartons
88650 Anould
(310) 975-7099

georgehifi's picture

Nice to see a linear amp review back on deck.

JMF specifies 300W-8ohms, 500W-4 ohms, 850W-2 ohms (this says to me bi-polar)

JA measurements: 310W-8ohm, 515W-4ohm, 760W-2 ohms (this suggest mosfet taking an almost 100w dive into 2ohms, regardless of just 3vac line drop)

Cheers George

a.wayne's picture

Looks like Bi Polar not enuff class A bias for MOSFETS ..!


a.wayne's picture

When was this changed from 33% of rated output to a 1/8 ..?

John Atkinson's picture
a.wayne wrote:
When was this changed from 33% of rated output to a 1/8?

The 1/3 power pre-conditioning had always been unpopular with manufacturers as it required large heatsinks, so in 2000 the FTC revised the pre-conditioning requirement to cope with the advent of multi-channel class-AB amplifiers - see my report on the FTC's "Amplifier Rule" at

I continued using the 1/3 power pre-conditioning for many years, but fairly recently adopted the revised FTC test. I now only apply the 1/3 power test when an amplifier remains cool with the 1/8 power testing.

John Atkinson
Technical Editor, Stereophile

Ortofan's picture

... a pair of power amps in order to attain a state of "bliss" when listening to music reproduced by Harbeth 40.3 XD speakers?
Harbeth's US distributor (as well as a retailer) might well want you to believe so.

However, you might want to know which amp Harbeth's owner/designer Alan Shaw uses at UK hi-fi shows to best demonstrate his company's products.
He has bought and uses Hegel H360/H390 integrated amps. The H390 presently sells for a mere $6,600.

Further note that Mr. Shaw has indicated that a peak power output of about 150W (@ 6 ohms) is likely to be sufficient for most home listeners using his speakers. A Hegel H190 is capable of about 225W continuous and about 320W peak (@ 6 ohms), and is now available for only $2,800.

If JVS observed that the -12dB indicator illuminated only briefly, and the -9dB LED never lit, then he was using, at most, about one-tenth of the maximum output power of which the JMF amps were capable - so, well under 100W. While the H190 would meet that requirement, it would struggle with the 1 ohm EPDR of the Alexia V speakers; however, the H390 would handle it with relative ease.

funambulistic's picture

I was expecting your cost analysis the first day this review dropped. Now do the Luxman!

Ortofan's picture

... that Luxman integrated amp was recommended to Alan Shaw, he deemed it to be too expensive, so instead he bought the cheaper Hegel units.
(Plus, he was under the incorrect impression that Hegel products were made in Scandinavia.)