"AMBER" - New HeadAmp from Alexey Nikitin (ex CREEK  Audio)

Photo and review's fragments were taken  from the http://www4.head-fi.org forum

 FIRST IMPRESSIONS

EXTERNAL BUILD

First impressions of the ANT amp registered  a big fat zero. It's a standard Hammond case, the likes of which I've been  drilling and ruining for a couple of years now. Admittedly it was the prototype  that I was viewing, but slightly crooked RCA sockets, standard low cost  instrument-type volume knob and just a total lack of any effort on the visual  front did not bode well. The power brick is: well, you get one. It's like  anything supplied with anything DC-powered that you buy. It is not a fancy PSU.  It is world voltage however, so it'll work anywhere. Alex assures me that it  tests better than most of this ilk.

The picture you're  seeing is of the production PCB. All in all, it looks several hundred dollars  cheaper than the US-based competition: I won't bore you with the parts in use  (take a look at the pictures for that), but it's well below the standards at  first glance than what's in use by the other amps, commercial or DIY at this  price level. Where's the Blue Velvet / Noble? Where are the Black Gates? The  cost of the opamps is not an issue so where's that gone? If we're assuming Alex  isn't overpricing the amp, it tells you that a lot of the cost is in the labour  that went into making each amp, as well as a serious investment in honing this  design that has to be recouped. As for the parts picks, Alex says that he tested  a wide range of bits and he put the best that he could find for the target price  into the amp. He also stressed the amount of toil involved in matching the  transistors and opened up the prototype amp for me when we first met. From what  he was aiming at in terms of the parts populating the board, although I  appreciated his stress on the intricacies of construction, I had to admit it  looked like a CMOY-level project. I was not hugely impressed.

BUILD QUALITY

The internal build in general reflects the  indifferent externals. It is acceptably executed in order for the amp to do it's  job and tidy, but lacks finesse and attention to detail. The build quality does  not approach Ray Samuels layout and detailing, and nor does it approach  JMTAudio's superior standard of "DIY soldering". There is room for improvement  in all of these aspects.

TECHNICAL DESCRIPTION

So, unimpressive parts and looks  aside, what exactly have we got here as far as the layout of the ANT amp is  concerned? Some technical talk later and my hopes are up as some impressive  specs were issuing forth from Alex. The ANT is not an 'opamp' based amplifier.  Simply put, as far as the layout goes if you think about it like a solid-state  tube amp, you're not far wrong. The thing that he puts particular emphasis on is  the extremely low distortion of the amp.

• Completely FET-based, discrete components only, very precisely hand-matched  transistors
• Class A, Single-ended, Zero-Feedback
• One capacitor in the signal path (at the output)
• 15v 250ma power requirement
• Less than 5 ohms output impedance, no output resistors, 10K input  impedance
• Panasonic FC caps
• S/N ratio of >96db, THD <0.3% mostly second order, 3rd order <0.03%  (ref: 0.5V output into 100 ohm load)
• Frequency Response - 5hz ~ 50khz into 30 ohms

Interesting, and the numbers are good. But the proof is in the listening, so I  fired it up

SONIC PERFORMANCE

RESOLUTION

Within a day of listening, I'd kind of got past  the looks of the amp. Within two weeks, I'd totally got past it. Of note is a  concentration upon detail, and I had to conclude by the end of evaluation that  although it's not the best I've heard, this ranks as one of the most  effortlessly detailed performances I've had out of the HD650. Pedantic levels of  'detail etching' are avoided, and instead the amp maximises the ability of  phones to resolve in an unobstrusive way. Not much else to say to pad out this  section: The ANT is certainly not holding the Sennheiser back. If anything, the  HD650 is holding back the ANT.

DYNAMICS

Very good: in fact, excellent.  The ANT addresses practically all dynamic requirements that's made of a quality  amp in a convincing manner. Given large changes in overall volume in a short  space of time (sudden orchestral build-ups are a good example), the circuitry  seems to have enough reserve grunt to deliver whatever is required. When urgency  and ultra-snappy transients are required, the ANT rises to the challenge. On  spinning more metal and electronica elements of my listening, the ANT grabbed  the HD650 by the neck and headbutted it to wake it up. The bass drops had the  initial focus and transition nearing electrostatics but the decay and bloom of  dynamics, voice transients were extremely focused without a loss of realism, and  the cymbals came across as, well, cymbals: an overall satisfying experience  musically and from a technical audiophile point of view. Yet while listening to  delicately woven solo piano for example, the amp never stepped out of line by  becoming 'stodgy' or 'stompy', conveying the performance with appropriate  lightness of touch. Once again, it's a notable performance from the  ANT

TONALITY

The sound can be described as 'pure' but it's not what  many would call 'neutral'. There's a certain amount of low-end bloom (without  flab) which reinforces the capabilities of somewhat pop-tuned all-rounders such  as the HD650 and delivers a firmly planted bass without resorting to gimmicks.  Treble and midrange tonality resembles well-balanced amps such as the standard  Ray Samuels XP-7, in that no particular elements of midrange or treble dominate.

IMAGING/STAGING

It's surprising how much imaging and staging can  actually vary with amps. The ANT presented one of the wider examples of staging  I've heard, and enabled the layers of music to be clearly discerned as a whole,  as well as easily being able to focus on individual instruments. No problems  here.

OTHER CHARACTERISTICS
TUBEROLLING, OPAMP-ROLLING AND:

Transistor-rolling? Yes, it's remotely possible although it's not going to  be a straightforward case of whacking in a few transistors, due to the very  careful matching required. I listened briefly to two versions of the amp on  which Alex assured me that only the transistors and the component group around  it had been changed, and it did indeed sound subtly different. 'Voicing' the amp  therefore is a distinct possibility. However, I'd be the first to say that this  method of rolling lacks the romance of swapping tubes around, and it being  somewhat technical in nature kind of kills the essentially non-technical fun of  'rolling'. Maybe Alex can do something about that.

 HEATED CAPS

An  interesting side-fact: The capacitors in this amp noticeably heat up. According  to Alex, this is intentional and the specification of the amp remains more  constant in use, as well as improving the sonics compared to when used 'cold'.

NOMINAL PORTABILITY

The amp is small enough to be transportable, but  as is, it is AC power dependent. Alex notes that the battery board of the PPA  project is compatible when set to deliver 12V, but with the current demands of  the amp the battery life will probably be quite low.

HEADPHONE  COMPATIBILITY

When used with lower impedance phones and a 'high-powered'  source the volume must be adjusted during the initial few millimetres of  movement. The pot used in the prototype had some problems maintaining channel  balance at these levels. An alternative that Alex gave me to try did exhibit  much better control of the channel balance on the initial throw, but exhibited  some sonic deficiencies. This might need more work.

COLLECTED OPINIONS

Emphasising its comparatively simple layout, Alex Nikitin's ANT amp is  definitely one of the better exponents of 'crap in, crap out' precision delivery  that I've heard. I use words like 'smooth' sometimes to be polite to amps which  don't resolve. In this case, no such euphemisms are required and yet the ANT  does indeed sound 'smooth'... a nicely tempered tone which doesn't unnecessarily  accentuate areas of the midrange or the highs. If you own a capable high  impedance headphone such as the HD650, the ANT presents one of the (if not the)  most compelling options for amplification at this price. The source-to-ear  purity level of the ANT is not something that you need to dwell on; it is more  or less right in front of you straight after plugging in and does not wait  around to be discovered: all the more so the better your headphones are. HD650,  DT880, CD3K, RS-1 and ATH-W2002 owners will have good experiences with this amp.  For the reasons stated previously I think Alex will have to make a considerable  effort to improve the currently extremely basic product presentation of the amp.  This is likely to raise the price of the amp though, so it is ultimately a  matter of how much you, that is the potential buyer of the amp, needs that  aspect addressed. What about upgrades? Even the other 'colours', that is  different grades of the amp are unlikely to sell for a fortune... and there will  be a lower-priced entry-level model, presumably at the uber-PIMETA pricing  level. I think that in terms of the design philosophy and in the intention to  paint as clear a sonic picture as possible, the first ANT amp is a success. In  many ways the ANT is a stereotypical 'old-school' homegrown British product,  albeit this time with a Russian flavour. It's low-rent, seemingly low-tech  nature hides a notable level of performance which seems impossible from first  impressions. If you can get past the looks and the build, the ANT 'Amber' is  priced below what it's performance would generally dictate in terms of sonic  performance, even when compared to the better amps I've used. Definitely worth a  try.