DLS Ultimate A4 The Big Four

Fabulously high end looking and feeling product. All the connections and Allen headed bolts are Gold plated and the power and speaker connections are all encapsulated in clear Acrylic housings and are tightened with Allen headed grub screws. There are push-button toggle (in/out) switches to activate crossovers’ functions and multiplier switches. The labels are all neatly marked in a subtle near-colour to the heatsink. The RCAs are very high quality panel mounts and bear covers for keeping dust out until you use them. A large and chunky product, it is about the heaviest in the entire group of eighteen amplifiers tested within the mega-group. The DLS Ultimate A4 has two sets of DC power connections that are in fact fully parallel such that you can affix a power capacitor directly to the amp’s power rails without the extra connection junctions normally created with power blocks etc. The extra terminal between the live and ground on the secondary set serves to act as the positive voltage feed for an optional fan, should you wish to enshroud your amplifier in a custom housing which is likely at this high end level. The manual is more comprehensive electronically than any I have ever seen, even including a components sheet detailing the Burr-Brown and Analog (sic) Devices brand fine tuning integrated chips and bragging about their own DLS Audio Grade and Tantalum fine tuning capacitors. The whole feel and appearance is totally high end and all the small golden switches and potentiometers fit their holes to the millimetre.
– Class AB- 4 x 85w RMS @ 4 Ohms – 4 x 145w RMS @ 2 Ohms
– 4 x 220w RMS @ 1 Ohm – 2 x 250w RMS @ 4 Ohms bridged
– 2 x 400w RMS @ 2 Ohms bridged
– Extruded brushed gunmetal coloured Aluminium heatsink with Aluminium plate end pieces and steel plate base. Power & Protect LEDs
– Dual sets of 4Ga. Gold Plated power terminals with Allen headed grub screw connection, encapsulated in clear Acrylic housings, with second remote terminal used to drive optional fan
– 4Ch RCA input on high grade discrete gold plated panel mounted sockets with prophylactic dust covers until use
– Subsonic filter function possible by setting HP filter to 20Hz
– Front Crossovers: Lowpass 50Hz to 125Hz, Highpass 20Hz to 200Hz or 60Hz to 600Hz by 3x button, all @ 12dB per Octave
– Rear Crossovers: Lowpass 45Hz to 200Hz or 90Hz to 400Hz by 2x button, Highpass 20Hz to 200Hz, all @ 12dB per Octave
– Input sensitivity: 02V to 7.0V
– Stereo & bridged operation
– Frequency response not quoted
– Signal to Noise Ratio >100dB
– Channel separation not quoted
– Fuse Rating 150A x 1 by very close external fuse & holder
no internal fuse fitted
like JL Audio 300/4v2- HxWxD(mm) 73 x 465 x 240mm
– Supplied with Swedish/English detailed whole-range manual and electronics components list
Review by Adam Rayner
To the uninitiated, referring to an amplifier for a car that costs a cool eight hundred smackers, as being ‘Good Value for Money’ (as I am with its nine out of ten VFM rating) might seem bonkers. But consider that for Audison, with their Thesis range, posh can go all the way up to £3,000 for a stereo amplifier and don’t get me started on Krell or Classe in home amplifiers, as the sky’s the limit.
So why can an amplifier cost so ruddy much? Well it’s about the zone where mere electronic design is transcended by artistry. At this level stuff isn’t just designed by a clever fellow and sent into production, this equipment gets listened to by those with known good ears to see if electronic component choices make for the right results. The differences might seem small but if you were played a commodity-type amplifier and then A/B’d to another rig, identical but for a much better amp, you would of course hear the difference. Even if the rigs had been sound pressure level matched, so that louder was not just better.
This product is about ‘Real’ HiFi for cars. It’s for those who want the best sound and know that the logarithm is badly against them. Making something to go boom is one thing but making super quality sonics is a lot more challenging. Diamond Audio’s D7 was £2,500 and the DLS vacuum tube preamplified product, the TA2 is priced at £1,500. So for what this actually is, it represents high end VFM!
I loved its posh construction, right down to the smooth-as-a-piston-in-a-well-lubed-pot manner in which the RCA’s penises penetrated the solid Teflon dielectric RCA panel sockets. They intromitted perfectly.
Like the Tru Technologies Steel 44, this amplifier does feel like it could benefit from a stonkerating high resolution signal from a pukka line driver once up and running on the test rig but it worked well on the signal I was able to muster. Immediately the delicious levels of detail, sweetness and terribly fast resolution of those oh so important high frequency/high rise time sonic components was right in your face. If the Tru Technology Steel 44 played the Morel Supremo 6 speakers well, this amplifier was awesome and made you see why the speakers were £1,400 a set.
The amplifier wasn’t just superbly clean and pleasant, it was also able to go loud as well, with a creditable 125.4dB raised; measured via the SPL side of the AudioControl SA-3055 RTA that we use to check stuff out. Not just made to go loud, it’s about the scale of things, you can hear the size of the sound stage even at sensible or lowish levels as the headroom is just enormous. This headroom also makes for vast dynamism with the sound able to go from clear and pleasantly restful to major emotional impact and goose bumps in a fragment of a second. I found myself just simply enjoying the test disc yet again, when I should have been getting on with fitting the next amplifier to the rig.
The crossovers are comprehensive, clever, wide ranging and intelligently designed. It doesn’t feature a whole load of extra silliness, just the best of what DLS reckon really matters and these work very well and are clearly intended to be used, and not just put there as some punters might complain if they were not present. A completely brilliant single footprint four corner solution for an utterly audiophillic installation and scores so brilliantly in so many directions (including that crucial VFM thing) that is garners only our second ever audio-based State of the Art award.
This product is everything it claims to be and makes me feel good that it even exists.
Sonic excellence on the Hoof!
Overall 9.6
Sound Quality 10
Power Output 10
Features 9
Build Quality 10
Value For Money 9