I have had a conundrum over the last few months. I reviewed the Nord Class D Hypex amp and found it a very good performer, especially at the price. I therefore needed to partner it with an equally good sounding preamplifier at the right price. That was the problem.
I reasoned the only way to achieve an equally good sound quality, at a good price, was to use a passive controller. Passives give excellent sound quality as they normally consist of only a few passive components and they normally do not cost a lot.
I reviewed the Khozmo passive controller and it worked a treat and was about £300 to boot. However, the fly in the ointment was it did not match the Nord well. It could not match the dynamics of the active preamplifiers I tried and the bass was a little soft. Not bad for the money but not quite there.
I then reviewed the Townshend Allegri. This used autoformers. It did not quite gel with the Nord but was a real surprise with the Naim power amps. Where to from here?
I talked to my electronics whizz and he pointed a finger at the Nord using balanced inputs and my controllers using phono outputs. I had tried using a phono/XLR cable, various adaptors and that did not solve the problem. I still needed a passive controller but with a balanced output. Oh, and as I listen slightly off centre a balance control would be good. Oh, and a remote would be great. Unfortunately, passive controllers tend to be sparse on the facility’s front.
However, I already had most of the answer. The guy responsible for the Khozmo passive also makes an upmarket version with super-duper resistors, balanced inputs and outputs, a balance control, a nice remote and a buffer circuit. A what…… Well one of the issues with this type of passive is it uses resistors to attenuate the signal. This may not give an ideal match with the source and the power amplifier and is one of the reasons that people use transformer based passives. A way around this is to use a very simple buffer circuit. This helps to match the source and amplifier to the preamplifier and allows the use of long cables. This preamplifier, the Hattor, also comes in a snazzier case and looks less like a well-built but cost-matched passive and more like a fully-fledged preamplifier. And the price is rather nice as well. $1600 or about £1270.
So after a few exchanges of e-mail, a newly developed Hattor passive preamplifier was dispatched to chez George.
And what a treat it looks. It is a half-sized case with a width of 280mm, height 90mm and a depth of 280mm. It has a digital display that shows the input and the left and right volume levels. There are three push buttons on the front that switch input, power and dual mono. There are two knobs that control input and volume and in dual mono mode they control the left and right volumes separately making it a balance control. Once set both volume controls can be increased/decreased together. The preamplifier is powered by a separate low noise power supply in a nice metal box. The preamplifier has a faux carbon fibre front and is available in other colours. Overall, although a little blingy, it is well made and looks like serious equipment. And it comes in a flight case.
The remote is blingy and made of shiny stainless steel. It has controls for overall volume, separate left and right volume, source and mute. It can also control the brightness of the display. It will show fingerprints but is a solid piece of kit unlike the £5 plastic remotes normally supplied with equipment that look like they come from the spare parts box.
The preamplifier I received had three phono and two true balanced inputs with two phono and two balanced outs. You can order other variants and Arek will supply them. The preamp is fully balanced from input to output, having 4 volume controls with 2 for each channel. Any RCA can be made balanced and the reverse. The volume adjustments are fine with 64 1db steps. Mine came with the Takman Rey resistors. Other flavours are available.
There is an additional board that works as the buffer circuit with +6dB gain, so long interconnects can be used. The preamp can be supplied without the board (or the board removed and shorting links added). This board has 2 opamps that can be replaced with others such as the Burson or Sparkos variant.
So much for the description what did it sound like?
Well I have taken to using a set programme of music to ‘test’ components. My first was my own creation to which I have added that used by the engineers at Cambridge Audio. This list is on their web page. And this programme does really test all the main hifi areas such as bass, mid-range, vocals, dynamics, power, soundstage etc. But it feels less like listening to music and more like a chore. So having done the test programme I went into my ‘latest music mode’. This gave me a better appreciation of this preamplifier.
It worked as you would expect and was really easy to slot into three different pre/power amplifier combinations. The remote works as it should with no clicks, plops or other issues. Not always the case with passives.
So straight into it with the Nord. I connected the preamp to my Esoteric P03/D03 with balanced and later single ended cables from Gamut and Nordost. The preamp was connected to the power amp in balanced mode with Transparent Audio Super and Nordost Frey cables. The power amp was used with my Audionote speakers.
And what a sound.
This preamp really drove the power amp and there was no loss of dynamics or a soft bass. The soundstage was big, big and 3D when it was on the original recording. The overall sound was very neutral in a positive way. This was not neutral and boring as a lot of preamps can be but neutral and dynamic. It captures the excitement in music without over emphasising the treble or bass. No smiley face frequency response here. Much as you would expect with a passive that did not mess about with the sound.
So when playing the well recorded 24/96 Dawn Langstroth album from Linn, the overall sound quality was very good with the voice very clear, the bass natural and the overall sound 3D. When she sings ‘You Don’t Want me’ there is real emotion in her voice. And yes, you can hear this was recorded with Auto-tune. Misa Criolla was recorded in a large church/cathedral where the dying away echo of the choir was easily heard. Dystopian Overture by Dream Theater in 24/96 was a full blown dramatic prog rock track with special effects everywhere.
On the Cambridge Audio tracks, Little Sadie was incredibly lifelike and very intimate. The banjo was very realistic. The Dido and Aeneas Act 3 was achingly beautiful and made me somewhat emotional. The inevitable Tin Pan Alley sparkled and was lifelike with real dynamics. The bass on the Flight of the Cosmic Hippo was big and powerful but you could still hear the tone of the bass with the banjo from Bella Flack being natural and clear.
Great what about going off-piste….. Well I tried some Acoustic from Simple Minds, Applewood Road, Mystery Jets, Eilen Jewel, Emiliana Torrini and Aaron Neville. The music was natural, detailed and where necessary very powerful and dynamic. The preamplifier made it easy to get involved with the music; it made me sad, happy and want to dance…when that is what the music was intended to do.
Products do not exist in a vacuum so how does this preamp compare to others and how did it work with other power amps?
I connected the preamplifier to my Audionote Conquest Silver Signatures and it worked really well. It was far better than the Khozmo passive preamplifier. It was more dynamic and had a more informative bass. It was less stark than the Townsend Allegri and had better music flow and sounded smoother and more, dare I say it, organic. It was not as intense as the M6 but it got the closest I have heard of any other preamplifier. There was real emotion in the music, which the Allegri was less good at. But it could not match the M6. For a £1,270 preamplifier that is great news compared to the far more expensive M6 preamplifier. So if you want a good preamplifier for Audionote triodes, with some semblance of features, then this must be on a list of must hear items.
I then wanted to try it out on the Naim 300. However, with tales of doom and gloom on trying such a combination I sent an e-mail to the guys at Naim. They quickly responded and said go ahead as the newer Naim amps are less sensitive to using passives. So how did it work? Not so well to be honest. The music sounded detailed, clear but had a much smaller soundstage and whilst the dynamics were good the music did not expand as much as it did with the Allegri. In fact, the Allegri/Naim 300 pairing just sparkled far more than the Hattor and Naim 300. The music had far more air, dynamics and snap with very tight rhythms. Not a great success but Naim gear tends to be somewhat singular in what it works with. I accept that Naim is much more universal now but not with this type of passive.
So where are we in summary? Well the Hattor is a great success with the Nord. I understand why a lot of people use this combination. It is a great success and not that expensive overall for a great sounding 400w/channel combination. If you have a valve power amp, then this is also a must hear. It worked really well with my SETs and provided a cleaner sound than some valve preamplifiers and with real emotion. OK the M6 is a better bet but it is a lot more expensive. For Naim power amps, I can’t recommend this pairing especially with the more expensive Allegri around.
So my hunt for a matching preamplifier is now over and as you may have I guessed I bought the blighter. I am listening to it now and boy is it good. Well done Arek.
HiFiWigwam would like to take this opportunity to thank George47 for this exclusive review. Our aim is to become the only trusted source of information regarding HiFi equipment in the industry. We have a new content team made up of professional journalists and long time experienced and respected Wammers who are impartial and give real appraisals, which is worth its weight in gold to any professional supplier or manufacturer.