HQS power amplifiers





Driving the loudspeakers... Caring for the music...

The JMF Audio HQS power amplifiers have been acclaimed for their high output power combined with a faithful, natural rendering of music. Since 1988, the most influential audio professionals, such as American studio designer Tom Hidley, and world-class studios (Nashville, New-York, London, Capri, Tokyo, Paris...) have trusted the HQS power amplifiers to monitor the quality of the recordings and productions, with great pleasure of listening. 

While it first met with success in the studios, the JMF Audio technology was humbly aimed at celebrating music, for all music lovers.

Jean-Marie Fusilier designed and built the HQS power amplifiers without the preconceptions, the marketing considerations, the deadlines or budgets that generally limit commercial designs. Being an expert engineer in high-frequency, infra-red and power electronics, Jean-Marie Fusilier approached audio differently, by passion, with pragmatism, and developed innovative solutions. These set the fundamentals of the make JMF Audio, established in 1985. 

The JMF Audio founder desired a lively yet controlled rendering for all types of musics... Even with high sensitivity loudspeakers, this meant significant driving force, precision and very low noise floor. The tube technology which he used to cherish was therefore left aside. Regarding the solid state technology, it was common belief that only a pair of matched output transistors could lead to musicality, which was still only suitable for intimistic listening.

Jean-Marie Fusilier took up the challenge to design a high output power amplifier offering a superb musicality. 

The philosophy behind the JMF Audio HQS power amplifiers can be summarized as follows: 

> A huge reserve of energy for instant delivery at the output on fortissimo. Achieved with the proprietary RPS concept involving bespoke toroidal transformers and bespoke high performance capacitors.

> High voltage electronics for superior headroom and higher efficiency. A linear amplification by design, a short signal path starting with a precision trimmed balanced input stage. These are key features of the LDA driver board, the center piece.  

> High current output capability for best possible control, allowing the amplification structure not to rely on compensations such as feedback loops, yet featuring a high damping factor by nature. The base of the proprietary MTP concept. 


A philosophy as set in the beginning and still followed today, sometimes with the exact same components...

Complementing the major aspects, the details are of significant importance regarding the musical result: 

Since their introduction, the JMF Audio HQS power amplifiers have taken advantage of the long researches of their designer on the sound neutrality of passive components, semiconductors and materials as well as on the amplification structure allowing fast response, stability and linearity at every stage. The JMF Audio HQS power amplifiers utilize selected and uncommon components for audio applications: high frequency precision transistors, matched differential pairs, bespoke passive components, selected and noble materials... 

Due to the requirements for specific components from the aeronautic, aerospace and fast-train industries located in France, some companies have specialized in providing custom parts. Thanks to our initial activities in high-frequency electronics, as told in the History of the brand, we have collaborated for over 30 years with such specialists, which allowed JMF Audio to obtain the bespoke components and parts, especially passive, that best suited our criteria, for serving music. 

HQS 9001 mono amplifier (one channel)

The JMF Audio HQS power amplifiers are able to deliver formidable currents, with serenity. Large signals never happen to mask small signals. Possibly unique...  

We have pointed out that the reaction of the loudspeakers (the counter electromotive force) was a commonly underestimated phenomenon. The loudspeakers have to be under control. In living rooms, at moderate listening levels, the JMF Audio HQS power amplifiers allow an ample rendering of music, in an absolute comfort.    


JMF Audio defines dynamics as linearity down to the lowest levels, especially when the message is complex. This is another aspect that we consider very important. Linearity allows the reproduction of the least details, the subtle ambiances and the wide and coherent natural sound stage as caught at the recording. A challenge... 

And especially desirable when enjoying music at moderate levels. The notes last longer with JMF Audio power amplifiers.

The HQS3200-UPM, the mono power amplifiers that propelled JMF Audio in the world class recording studios in 1988, were renowned for being extremely natural sounding, revealing the details yet being able to deliver huge currents, providing a lot of headroom. The JMF Audio’s HQS power amplifiers were awarded in Japan as the best audio amplification technology, in every category. Consequently, JMF Audio never felt necessary to present an amplifier to a contest in the following 30 years.     


Present models bring the listener yet closer to the artists with precision, beauty of timbres, nuances and respect of ambiances... The last revision F introduced for the 30th anniversary of the recognition in Swiss studios are, in our opinion, a summit. 

LDA 3rd generation super linear high-voltage powered driver board. PGP pure gold. (one channel)

The LDA mono driver board, the center piece and jewel inside the power amplifier, is in charge of voltage amplification of the delicate incoming line signal by a factor of over 30dB. Since 1985, the driver stage has featured the innovative and still unrivaled hand calibrated precision input stage, enabling 100dB of common mode rejection of interferences carried by the input cables, this means more than 30 times better than found in professional balanced circuitry. This parameter having been enhanced by integrating psychoacoustic criteria starting from 2012. 

Un-balanced incoming signals automatically take advantage of the symmetrical amplifications structure. The proprietary DC coupling allows a direct signal path (cutoff below 3Hz with offset error detection). These features have been common to all designs and have taken advantage of improvements with time, on technical and sound quality aspects.

A total of 6 adjustment points require manual calibration after a 100 hour burn-in period on each driver board.

The LDA mono driver board features metal case ulta low noise discrete components (military grade), bespoke capacitors on the power supplies (made in France), temperature compensated current biasing. Every components and connectors on the audio path have been selected for their reliability and on listening for their natural sound characteristics. 

The JMF Audio proprietary PGP pure gold finish of the multi layer printed circuit board is incompatible with the automated processes. The hundreds of components populating both sides of the board are hand mounted and soldered one by one by our specialized technicians with JMF Audio's bespoke solder, using a magnifying glass. A work of art that recalls jewels manufacturing.

HQS 9001 MTP super linear high-current output stages. PGP pure gold. (one channel)

The proprietary MTP type output stage, in charge of the signal amplification in current, employs multiple selected transistors (42 per channel on the HQS 9001) which have their own biasing (hybrid, class A on small signals since 2009), thermal compensation, fail-safe circuit. The biasing being independently calibrated to match the transistors and associated driver board's characteristics. 

Thanks to the naturally stable design of the power amplifiers, the output stages provide a pure direct path, without the added inductive component that is normally mandatary in solid state designs. 

The JMF Audio elements are entirely hand crafted in our workshops and pass severe tests. Since revision D, every power amplifier has even been verified by listening in our studios after an operational period of over 100 hours, so as to ensure its future owner will receive the best.

Key features:

- RPS ultra stable power supplies. Specifically made to measure capacitors and toroidal transformers.
- LDA ultra linear and direct amplification structure (featuring PGP gold).
- DCS servo, direct coupling, no capacitor link on the amplification path.
- DPO direct output design: naturally stable amplification design requiring no output inductance. 
- MTP output stage: multiple transistors, individually controlled, 330A capability for HQS9001.

- TRB temperature regulated circuits (with quick thermal stabilization starting from revision C)
- PGP specific gold plated analog audio boards (LDA amplification an MTP output stage).

- SCD sealed case design (no dust can enter), passive cooling (option silent heatsink cooling fan)

- Ultra low noise floor (and cross talk on stereo version).

- LSS made to measure dia. 6mm output terminals (120A rated!) with specific PGP gold
- Automatic detection and protection against input offset, too high frequency, high temperature, overload.
- Vu meter for input signal magnitude monitoring (switchable starting from revision F).
- Hand wired, soldered and mounted. Drastic control and selection of all components.

- All models feature the same voltage gain, which definitely facilitates multi amplifiers setups (active setups).

- All power amplifiers are upgradable to the last revision (starting from revision B, new chassis). 


Present models:                                       (click on photo to access model page)

HQS9001 mono

HQS7001 mono

HQS1050 mono

HQS6002 stereo

* The HQS1050 is based on the same chassis as PRS1.5 preamplifier and DXC2.2-MKII converter


- Sensitivity
- Impedance
- Connection

- Common mode rejection
- Type
- Monitoring

All models have the same voltage gain (which eases multi-amplification)
3 pin XLR - metal housed, gold contacts
100dB CMRR, based on psychoacoustic criteria since 2012

High precision balanced input stage (impedance matched to PRS1.5)
Level metering on bargraph (-15dB to +3dB) (except HQS1050: -3dB, +3dB)
Input offset, overload and high temperature indicated by LEDs

- Output power RMS
HQS9001 600W / 8Ω 1000W / 4Ω 1700W / 2Ω      3000W / 1Ω
HQS7001 380W / 8Ω 700W / 4Ω 1000W / 2Ω
HQS6002 250W / 8Ω 450W / 4Ω 550W / 2Ω      per channel
HQS1050 150W / 8Ω 250W / 4Ω      on 2013 model

- Ouput stage current
- Operation load limit

- Connection


- Monitoring

Noise floor and hum
Audio signal coupling
Protection circuits

Finishes front panel






Power supply





Fan unit (HQS9001)

HQS9001: 330A,  HQS7001: 112A,  HQS6002: 80A/channel

HQS9001: 1Ω (operational)  HQS7001/6002: 1Ω (limited)  HQS1050: 2Ω (limited)
(automatic current limiting on permanent loading) 

JMF Audio dia. 6mm terminals (120A continuous rated) (adapters to 4mm provided)

The HQS1050 additionaly features WBT gold terminals for fork and banana

Full output power and high temperature indicated by LEDs

Better than -125dB (mono) -122dB (stereo) un-weighted 1kHz (meas. dating 2012)
3Hz..100kHz (-3dB) 3Hz..40kHz (0dB)
DC coupled (exclusive DC servo circuitry)
Standby switch on front panel (prior to revision F)
Automatic protection against high frequency large signals
Automatic DC protection below 3Hz
Automatic protection against overheating and input offset
Automatic protection against overload and short circuits

Aluminum machined brushed anodized 

Wood walnut laser engraved

483 W x 550 D* x 183 H* mm (HQS9001-F new massive aluminum chassis)
483 W x 500 D* x 140 H* mm (HQS7001, HQS6002)

*without fan unit and including feet
HQS9001-F: 52kg/pc,  HQS 7001/6002-F: 25kg/pc,  HQS1050-F: 15kg


100V AC, 120V AC, 230V AC (HQS9001, HQS7001, HQS6002 internal selection)

100V AC .. 240V AC (HQS1050 automatic)

The HQS9001 is equipped with mains voltage supervision circuits and would not power up may the actual mains voltage be different from the selection.


Silent, automatic and variable speed fan unit, no air path inside amplifier (no dust).


Celebrating the 30th anniversary of the JMF Audio's power amplification recognition.

Soundville Studios, Lucerne, Switzerland 

> Read the article



Owners' comments:

It is known by conoisseurs that the JMF Audio power amplifiers have seduced music lovers from all areas for over 30 years. Whether these experienced audiophiles and sound engineers used to defend tube designs or whether they used to trust famed brands in solid-state technology, they found in JMF Audio the precision, timbres rightness, amplitude, greatness in the presentation of music.

We are thankful to the enthusiastic JMF Audio instruments-for-the-music owners for their feedbacks, comments and the wish for some of them to get the information published. 

However it has been decided to limit the comments on this page to just a few. Music enthusiasts are invited to discover and experience for themselves. JMF Audio would be pleased to guide and advise a representative.

Please refer to the Contact page and our Policy.


Mr. J-P., France, (HPM500, HQS9001, PRS1.5) 

"My HQS 9001 offer the sweetness of the best tube amplifiers and we can feel a total control of the speakers [...] they reveal an incredibly detailed three dimentional soundstage ; a dynamic contrast I had never suspected..." 


Mr. M. I., Asia

"In my opinion, my friend owned the best sounding amps on earth: the HQS3200. Now that I received the HQS 7001, I can say that it is even better: more detailed, more precision, more punch. Along with the PRS1.5, CM4 and SR8, the sound result is very very very high definition... we were schocked"  (via e-mail)


Mr. A. M., Luxembourg.

"My HQS9001 provide a more lively music. There is a feeling of comfort... Notes last noticeably longer, there is always something to hear..."


Mr. B. F., USA, (HQS 6002)

"The sound is imperial, calm. Beyond sound quality, the facts that the case is sealed and that passing to 230VAC is easy (for when I'll be back in Europe), give me the feeling that I purchased an apparatus for a lifetime, without any doubt regarding my choice."


Mr. M.C. (HQS7001 later HQS9001, PRS1.5, DXC2.2-MKII)

"Indeed the HQS7001 have been in service for two months on my Revel Salon 2. [...] To my great surprise, even at high level, I have never seen the least led [vu-meter] light up..." [...] "I listen for hours!" [...]   (via e-mail)

Having moved to the HQS9001 a few years later: "the most spectacular is the low frequencies that go down to the basement with a natural, a precision and an articulation unknown to date. The overall listening is clear with a depth and a volume that make forget about the speakers." (via e-mail)


Mr. R.Y. (HQS6002, PRS1.5, SR8, CM4), Singapore 

"I’ve been using a Japanese [tube amplifiers] and cables were [from Denmark] or [from Netherlands]. The most notable difference was the liveliness of the music, the soundstage and details. Your amplifier is also quieter." via email (2011)


Mr. Mic A., world class studio owner and sound engineer in New York City, USA 

"After my visit at Masterfonics in Nashville, when my own recording studio was built, I took time to run a comparison again and realized that your amplifiers sounded more natural and accurate, especially in the bass, with a greater sound stage rendering. I have used your amplifiers since and have placed the preamplifier in front, linked with your extraordinary modulation cables. [...]" (phone conversation, 2007) 


Mr. Carlo Talamona, world class studio owner in Italy

"I have owned my (JMF Audio) power amps since the early 90's and I believe they are still on top..." (phone conversation, 2007)


Mr. Alain Amouyal, classical music composer, world class studio owner, France. Silcord Productions USA.

"Frames for a Fairy Tale", performed by the London Symphony Orchestra, recorded at Abbey Road, London, post-production and masters controlled with JMF Audio power amplifiers. (1999)


Mr. N. Stawski, recording/mixing engineer, co-producer, Paris (HQS9001, PC3, SR8) 2014:

"I first auditionned and compared your amplifiers in the recording studio I used to work in. When the time was right to create my own studio, there was no question about the choice of power amplifiers. We understood each other. The sound is so precise and soft, easy. With your monitoring, I hear the space around the musicians, the low is ultra detailed, this is great for mixing control. [...]"


Revisions history:

 F Major upgrade, 2018. Inheritance from the revision D of the PRS1.5 preamplifier. 

> Read the first impressions in New York studios


Third generation LDA signal amplification circuit board. Latest PC3 power cord. 

New machined aluminum chassis available for HQS9001.

 D / PC3

Added PC3 power cord and internal mains filter (no applicable to HQS1050)

New XL heatsinks for HQS7001 and HQS6002 (no fan unit)

 D Improved LDA amplification circuits, MTP output stage and RPS power supply
 C Improved LDA amplification circuits, MTP output stage and RPS power supply

First models with new chassis, LDA, MTP and RPS. Prototypes, upgrade recommanded

The HQS7001 is added to the product line


Initial reference studio monitoring amplifiers (new series, following HQS3200 and HQS2400)

JMF Audio products are designed to be references and to last. The base of these instruments is safe and modular. Upgrades are proposed for clients to take advantage of the results of our continuous research and development efforts, without the need for product change. It means "details", but details make the differences and can lead to the exceptional. The device revision (B, C, D...) is indicated by a silver badge located on the rear panel and is linked to the product serial number in JMF Audio's tracking files. 

> More information about our upgrade policy.



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