Norma HS-IPA 1 is a modular (but in this case, fully loaded) integrated amplifier from Italy that includes a DAC, phono-stage, and headphone amplifier. The unit costs £3650 as tested and here Janine Elliot takes it for a whirl.

A front shot of the norma modular amp

To be sent a parcel from Cremona, Italy, really got my heart pounding. Coming from the bedrock of stringed violin marvels from Stradivari, Guarneri and Amati, plus the composer Monteverdi, this should hopefully be a very musical amplifier. Indeed, Enrico Rossi, CEO, chief engineer and designer aims to conjoin technical skills with musical sensitivity in the same way as those great instruments were made. Manufacturing two ranges of HiFi(REVO and HS) the HS series includes the integrated amplifier, HS-IPA1, and a separate DAC, the HS-DA1. The HS-IPA 1 is a modular amplifier allowing plug-in DAC, phono stage, and Class-A headphone amplifier, should you wish to use these facilities. Up for review here is the fully loaded HS IPA1 coming in at £3650, which is highly reasonable for a complete Class-AB package. Enrico Rossi started it all in 1987 with his first amplifier the NS 123. In 1991 Norma was bought by Opal Electronics, a company that designs and builds electronic measuring instruments, and Enrico began a long research and development program to produce his first set of products to be released in 1997. The REVO IPA-140 amplifier has received great coverage since its release and the HS-IPA 1 continues many of these designs, not least being able to add a DAC and using MOS-FETs. The HS-IPA 1 is half the price in its most basic form but is no less an amp.

CONSTRUCTION

This is a half-width unit available in silver or can be purchased in anodised black for a further £79. The unit continues Norma’s philosophy of minimalist design, though this is deceptive; there are actually 10 buttons on the front panel; six hidden within the blue Perspex LED display panel, the first being the standby switch (the main on/off button is at the rear, something I never like!). There is also no wiring, rather there are direct connections to the various levels of printed circuit boards using metal rods. The whole circuitry is based on the shortest signal path. The unit is modular, allowing you to choose the “extras” you want, though they cannot be retrofitted by yourself. Fully laden the back is full of good quality gold plated socketry, though no balanced connections as in the IPA 140. The unit up for review had the addition of the DAC, phono-stage and headphone amp making it exceptionally good value. The basic amp comes in at a very reasonable £2595, so adding these three additions for a further 1.5k all built into a single unit is excellent in terms of both value and space-saving. The amplifier is a Class AB MOSFET design (3 per channel, as against a total of 12 MOSFETs in the IPA-140) offering 75W into 8Ω (150W 4Ω) and delivering 24A continuous current meaning that it is capable of peaks of 100V providing ample headroom. The power supply section is derived directly from the REVO IPA 140 employing 10 special filter capacitors with the custom-designed 300W toroidal transformer on its side at the front behind the blue display panel, with three secondary windings, one for each section of the amplifier. That display is large making it ideal for me sitting 6 feet away from the unit without my glasses. The choice of MOSFET accounts for the unit’s warmth and analogue sound, something I particularly like in this review. The unit comes with 4 RCA analogue inputs, the second is the phono input (if installed) and the fourth RCA input can work as a line output for subwoofer or part of a multi-speaker AV setup. The phono-stage works for both MM and MC, with dipswitches to allow you to alter set up for your own particular cartridge, though the otherwise excellent instruction manual does not indicate how to alter the dipswitches.  The Class-A headphone amplifier can be adjusted between 16Ω, 32-60Ω, and 200-600Ω with the use of jumpers, this time well explained in the A4 size manual. With no jumpers connected the unit is connected directly to the loudspeaker’s power output, if your headphones need to be connected across such a high load (I remember my aged PWB electrostatic headphones that took all the power from the loudspeaker terminals!). This headphone amp should work with most, even inefficient planars. All’s good except that the ¼” headphone socket has to be at the rear of the unit which will take a bit of searching to plug in. Luckily, once connected you don’t need to remove the plug in order to get the speakers working again; simply press the HEAD button on the front panel (the instruction manual doesn’t make that clear, so I worked that one out) to cycle between the two replay systems. Luckily most decent headphones have long leads. For digital replay, the dedicated PCB provides a choice of 2 Toslink, 2 S/PDif, and a USB input. The Burr Brown DSD1794 chip allows FLACs up to 24bit/192kHz and DSD64 though the latter is DoP (DSD over PCM).

Around the back of the amp showing connection options

A number of important operations can be selected or changed from the front panel or via the remote control. That remote control, RC-43, is particularly nice; made from a solid billet of aluminium and with lots of very long but small buttons making it equally suitable as a back scratcher if you didn’t use it for your hi-fi. It is operated by 3 CR2032 watch batteries, rather than the more common AA/AAA cells. Lots of features can be recalled via the remote, such as system changes and features for example selecting ‘Line In 4’ as a Line Out socket and altering brightness of the screen, but being a universal remote some buttons don’t function. The front panel is particularly good; large LEDs with sound level indicated in dBs and showing sample rates for the digital inputs rather than simply having rows of tiny blue LEDs that you have to go right up to the unit to inspect, as in so many DACs. On switch on the LED even counts down the 10 seconds as the amplifier reaches a state of readiness. Cool.  There are also a significant number of fuses on the circuit boards showing some excellent care for design, plus some spares in a jiffy bag stapled to the instruction book, in case any need replacing. That build quality is exemplary.

SOUND QUALITY

I began by listening to the amplifier without its “add-ons” to hear it in its natural state and using the Graham Audio LS5/9s loudspeakers. STS’s 40 Year Anniversary 15ips celebration tape, recorded on RTM LPR35 tape, has a wide variety of music and gave me a good chance to test the quality, an album I have been regularly playing of late. What was very noticeable was the precision and transparency in the performance, with particularly good bass and mid-frequency definition, and no loss at the higher frequencies. The Dutch Swing College Band played a number credited to His Majesty King Bhumibol. The brass and woodwinds were clear and well-spaced out in the sound-stage, with precise and natural percussion. This is a very relaxed and smooth number but no less detailed and responsive. Turning to guitars the Gypsy Kings played a more animated number ‘Gitaria’. The guitars were placed back behind my speakers, contrasting other music I played which had them in front, showing good detail to placement front and back. The room reverb and audience responses were also very natural. Turning to “India with Jazz”, a mix of western and eastern instruments this was highly infectious music; the tabla and sitar contrasting well with the guitar and piano. I particularly noted the precise initial transients from the tabla. This track just wasn’t quite as exciting as I remember it, but no less enjoyable. Next to classical music from George Handel, Chandos Anthem No. 7 played by Solo Deo Gloria, this beautifully performed and sounding very controlled and transparent.

Inside the amp show a well laid-out multilevel construction

Using digital inputs was largely via S/PDif from my DAP and USB from my computer using Foobar2000 and streaming using Qobuz. The Norma allowed me to play up to 192Hz and DSD64 (DoP). Performances from all sources were clear and accurate. Handel organ concertos (24/88.2 Academy of Ancient Music) gave an excellent warmth in the lower frequencies, just lacking some of the excitement that I know the organ could give, though this did improve after the unit was warmed up. This is an excellent performance and recording. Next up was ‘Vivaldi in Venice’ from Chasing the Dragon, a well-used album in my reviews and equally well performed and engineered. The mechanics of the woodwind instruments very apparent showing great detail in retrieval of the music. The performance was forward sounding, highly musical and engrossing, almost valve-like at times. There is a love-hate relationship with MOSFETs over BJT designs, but the former seems to be having a revival these days, not least because they have high input impedance, making them easy to bias. Playing Genesis ‘Selling England by the Pound’ had grandiose detail, particularly in the bass and mid frequencies giving the MOSFETs something to enjoy. Only the cymbals just were not as bright as they could have been. The digital stage of the Norma is, however, very good and adding that to the basic package is a sound investment.

Turning to the phono-stage was where the real fun began. Using my Pre Audio turntable and AT33sa cartridge I set the load impedance to 100Ω which gave the cartridge extra top-end and a clarity I love. There are three moving coil settings on the phono-stage; 100, 510, and 1,000 ohms plus 47 kohm for MM cartridges. There are also seven gain settings with a spare position for customization from the manufacturer, all operated from 4 microswitches. Art Blakey and the Jazz Messengers ‘Moanin’ was first on the platter. Reminds me of evenings I spent cycling over to a gentleman’s house playing jazz records and cassette tapes when I was a child. He was mad on jazz and got me my first interests in it, though probably the process of visiting a single man as a child wouldn’t be kosha in today’s suspicious climate. The title track has a repeating 4-chord ostinato over which the trumpet (Lee Morgan) performs his melodies and Art Blakey, on drums, plays a similarly simple motif. The Norma relished the music and the phono stage was just right, and better than I would expect for a plugin. With the name ‘Norma’ I either had to wear a pair of jeans or play some Elton John. I decided on the latter but rather than “Candle in the Wind” I decided on my favourite album ‘Here and There’ recorded in London and New York. “Funeral for a Friend” is a particularly ethereal track and excellently performed on the Norma with its tight bass end and musical mid-band. The performance was fluid with a clear piano central and drums spanning the complete soundstage. “Take me to the Pilot” was powerfully portrayed with a good transient speed. Turning to blues/rock and John Mayall’s ‘A Special Life’ this didn’t have as much life until I turned the wick up; the amplifier does work better at higher level. Listening took me back to my own background of playing gigs in pubs and clubs as part of a band. In this album, Rick plays keys, harmonica, guitar organ and vocals. Clever guy. Rock worked well, giving a full-bodied engaging sound. Changing discs to Eagles excellently engineered  ‘Long Road out of Eden’ the vocal harmonies and guitars were very open and spacious showing the extremes that Enrico has gone to make this amplifier as musical and pleasant to listen to over long listening sessions. This was like good old-fashioned audio as it should sound in the 21^st century, if you hear what I mean. The bass was controlled and the cymbals pin-sharp and timing spot on.

For the classical listening I turned to Tippet’s four symphonies (London Symphony Orchestra, Sir Colin Davis). The first symphony is the easiest to digest though has enough brutal force to challenge any MOSFET. It might not be the most tonal music but there are some engaging musical lines between string and brass. Most importantly there was no fatigue listening to these, the amplifier being controlled, engaging and most importantly – musical. The HS-IPA 1 was excellent with all types of music I played. Similarly, the headphone amplifier was accurate and engaging, with enough in reserve for my inefficient 300Ω Sennheiser HD650 cans.

CONCLUSION

For a complete package of amplifier, DAC, adjustable MM/MC phono-stage, and class A headphone amp this is both an excellent value and excellent achieving package from a relatively unknown marque that should warrant some serious listening to in today’s highly over-stocked market. £3650 is particularly good value. Just wish you didn’t have to pay extra for one in black.

AT A GLANCE

Build Quality: Excellent construction, particularly inside.

Sound Quality: full-bodied tight bass, good speed and transparency.

Value for Money: £3650 for the silver “package” including DAC/phono-stage and headphone amp is excellent value.

Pros:

Excellent phono-stage

Excellent bass and mid frequencies

Transparency

Cons:

Some may find sound a little too restrained.

Price: £3650

Janine Elliot

Review Equipment:

Pre-Audio/ AT AT33sa (turntable), Ferrograph Logic 7 (reel to reel), Azur PC/Fiio DAP/Qobuz (digital sources) Graham Audio LS5/9 plus Townshend Super Tweeter (speakers); Sennheiser HD 650 and Audio Technica ATH-W1000 (headphones) Tellurium Q, Ecosse (cables), Townshend Seismic stand.

SPECIFICATIONS

· User-configurable output connections (subwoofer, tape, etc.)
· Extreme low noise, high resolution and high speed.
· Wide band ( >1 MHz ) schematic topology.
· 2 x 24 A continuous output current (100 A peak per channel)
· 2 x 75 W RMS / 8 Ohm – 150 W RMS / 4 Ohm
· High filtering capacity with numerous low impedance capacitors.
· Regulated power supply for both Gain and Driver stages.
· Toroidal transformer specially designed for audio applications.
· Multi-function display.
· Remote control of all functions.
· Dimensions (HxWxD): 118x214x370 mm, weight: 12 Kg.

  HEADPHONE OUTPUT (OPTIONAL) :
· 6,3 mm Jack connection.
· User-selectable output sensitivity.
· High-current, high-voltage output.
· Drives dynamic and orthodynamic headphones (16-600 Ohm)​

  DIGITAL INPUT BOARD (OPTIONAL) :
· 5 digital inputs, USB, 2 x SPDIF RCA, 2 x SPDIF OPTICAL.
· USB input and SPDIF full bandwidth, up to 24 Bit / 192 KHz.
· High Resolution Digital-to-Analog converter, DSD-compatible.

  PHONO INPUT STAGE (OPTIONAL) :
· High quality, low noise phono section.
· Compatible with MM/MC cartridges.
· User-selectable Gain and Input Impedance values