TAD Labs M2500 Stereo Power Amp Review

TAD Labs M2500 Stereo Power Amp Review

Equipment Review 25 – TAD M2500 MK2 Stereo Power Amplifier

Introduction  Technical Audio Devices (TAD) was originally set up by Pioneer in Japan in 1975 as an upmarket specialist brand to develop hi-end speaker systems.  The company was later spun off from Pioneer in 2007 becoming Technical Audio Devices Laboratories Inc (TADL) and expanded its portfolio to include high-end amplifiers, CD players and DACs.  They still hand assemble all their speaker systems on a dedicated line set up in Tohoku Pioneer Corporation, located in Tendo, Yamagata Prefecture, and TADL electronic components are assembled in Kawagoe Plant of Pioneer Corporation, located in Kawagoe, Saitama Prefecture. 

Their current range of electronics includes 2 preamps, 3 power amps, 2 SACD/CD players and a DAC. TADL provide audiophile grade equipment to both the professional and domestic markets but it’s the latter that is of interest here.  Should you be interested I also reviewed the TAD D1000 DAC in review No 11 over Christmas 2020. 

Technology – The TAD M2500MK2 at £22,500 is a stereo power amplifier and despite its size and extreme weight it runs with Class D output stages.  It’s a twin mono bridged transformer-less design built into a single stereo case with totally separate left and right channels. Where it differs from other Class D amplifiers is the inclusion of an analogue input stage consisting of two impressively large mains input high-capacity toroidal transformers and capacitors which add considerably to the weight of the unit.  It provides 250w of power into an 8ohm load and double that into 4ohms.  Class D amps have matured at a great pace and today’s offerings can deliver truly high-end audio quality.  They are also very efficient and the M2500 only consumes 250w of power from the mains supply.  To put this into context we have a pair of large 200w pure Class A monoblocs in the store and when running full steam ahead they will each draw 3kw from the mains supply making even large rooms heat up after a few hours use and the electricity meter to spin for all its worth.  My own Class A/B Michi M8 monoblocs draw 1200w each from the mains when under load so the Class D TAD amps, along with all other Class D amps are not only environmentally friendly but they are much less costly to run. 

The M2500 casework is formed from a single 95kg billet of aluminium to avoid unsightly joins and to provide a stable and vibration free environment for the electronics it houses.  It comes in all black or silver and black and measures 440mm wide x 170mm high x 467mm deep and weighs 43Kg, a two man lift for safety.  On the back panel are a pair of XLR and RCA inputs and the mains input.  The front panel contains just the on/off switch and a small LED which is amber when powered up and red in standby. Class D amps don’t generally get hot in use and the M2500 is no exception keeping cool to the touch even after many hours continuous use. 

The matching Preamp for the M2500 would probably be the TAD C2000 which also includes a DAC for the retail price of £24,500 but at the time of this review we didn’t have one available for me to try.  The next preamp up the range of just two models is the C600 which is a two-box unit at £34,000 but this preamp is a better match to their M700S stereo power amp or their M600 Monoblocs. I’d love to listen to the M600’s at home but at 90kg each there is no way I can get them in and out of the car. 

System Components – The TAD M2500 MK2 stereo power amp replaced my Michi M8 monoblocs for the duration of the review. The Michi P5 served as preamp and was fed from the hard drive of my Innuos Statement streamer/server and streaming via Tidal/Qobuz into the Matrix Audio X-Sabre Pro (MQA) DAC.  All connections were with balanced XLR’s.  Speakers were my usual Marten Mingus Quintet with cables mostly from Jorma Design.  CDs were also used during the review with my Sony CD Player acting as a transport connected to the Matrix Audio DAC via QED Glass Optical cable. 

Performance – Class D amps didn’t get off to a great start with the audio community when they first appeared some years ago, often sounding bright and brittle at the top end and soft in the bass, a mile away from the rich analogue sounds that reviewers and consumers were used to hearing from Valve and Solid-State Class A and A/B amps.  But wow have they now come of age.  The Primare i35 is a fantastic integrated amp and streamer at just £4k fully loaded whilst the Mola Mola Kula Integrated at £10k is fabulous right across the frequency band especially when partnered with the matching Tambaqui DAC.  The TAD M2500 builds on what those amplifiers can do and is the first Class D amp I have used that has analogue mains input transformers.  It is fast, dynamic, and captivating and capable of vast dynamic swings whilst at the same time providing the detail and finesse all audiophiles are searching for. It can ensure your speakers drive units start and stop on a sixpence when required and can deliver the full emotional impact that separates the merely good from the very good, losing nothing to Class AB and only a little to the more analogue sounding pure Class A solid state amps.  Valve amps in my limited experience tend to struggle to provide this level of grip. 

I found it could deliver deep bass without any sign of distress, but it has the almost unique ability to hold and sustain those deep and mid-range notes for as long as they are being delivered by the source and that more than anything makes this amp stand out from the crowd.  Just listen to something with piano to hear this effect but for the full dynamic punch that your speakers didn’t know existed go to ‘Confession’ by Alesso or the opening few seconds of ‘Blue Monday’ by New Order.  Continuing with dynamic tracks for a while I listened to ‘Work Work’ by Clipping, not really my taste in music but it does test a system and the M2500 didn’t disappoint delivering dynamic and punchy bass, who needs a subwoofer? 

It can deliver dynamic slam all day long holding an endless beat and rhythm without breaking into a sweat and without getting hot in the process, but it can do subtle and emotional as well.  Turning to something a little more relaxing such as ‘Can’t Breathe’ by Martyn Joseph and this close miked track that is often reproduced by lesser amps with too much sibilance but the M2500 handled this well, reducing sibilance to something much less brittle making it a much more enjoyable and easier listen.  

Tubular Bells’ by Mike Oldfield is an old favourite and the point where he introduces Grand Piano was delivered way beyond the left-hand speaker and the Bells when they came in were much more convincing than most amps can deliver.  They sparked, reverberated, and chimed with a deeper intensity than I’m used to hearing.  Anything with female vocals came across with feeling and emotion roller-coaster and two tracks highlighted this, ‘Leavin’’ by Shelby Lynne and ‘Poison Words’ by Mary Black both of which the M2500 delivered as good as any Class A/B amp. 

‘Morning Has Broken’ by Cat Stevens is a great track to explore the openness of a system and when powered by the M2500, with or without eyes closed, Cat’s vocals and the backing piano were powerful, expressive, and almost in the room making the speakers disappear with the wide and open soundstage delivered by the TAD amp. 

Late in 1971 Led Zeppelin IV had just released and I was at a party in Walthamstow, or was it Chingford?  Anyway, I took it upon myself to change the record the host was playing and selected Stairway to Heaven (only vinyl in those days), and that was how I met my first serious long-term girlfriend.  1971 remains probably my favourite year for music but it also had other charms and replaying Stairway again via the TAD M2500 took me right back 50 years to that special moment albeit with much more finesse to the listening experience and less distraction.  Audio equipment today can deliver quality we didn’t even dream about in those days, but it’s the memory of past musical treasures that stays with all of us whether from 5 or 50 years ago and the TAD was able to recreate that for me in the most enjoyable way.  

Conclusion – The fact that the M2500 is Class D might put some off or lead them to just dismiss it out of hand before even listening to it, but they will be missing out big time.  It can’t be described as a creamy listen and couldn’t be mistaken for a valve amp but those customers who are totally into valve (tube) amps probably wouldn’t take that leap of faith to even listen to a Class D design.  But this Class D power amp from Japan can match anything from the audiophile elite based in Europe or the USA at the price and may surprise you with how good it can make you feel about your music collection and about life in general.  Give it a try, preferably with a TAD Preamp and you won’t be disappointed.  It can do loud but never without control, it can also provide all its sonic charms at more normal listening levels, even those late-night sessions that require more moderation with the volume control.  If you are looking to drop 20 big ones on a power amp, then this should be on your shortlist. 

Bob at Team Nintronics – May 2021

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