After reviewing the Merrill Audio Veritas monobloc power amplifiers in January 2015 Stuart Smith auditioned the American company’s $4800 Thor amps. 

I’ve had the Thor amps now for around the six month mark and they’ve been doing a great job in the main system having become our reference and so I thought it about time that I finally got around to writing a few words about them for you.THOR2S

Regular readers will remember I reviewed the Merrill Audio Veritas amps back in January of 2015 commenting “Hard to fault in my opinion but I just don’t give perfect tens. Had I the means to buy the review amps I certainly would.” Sadly my financial situation didn’t allow me to make the purchase and so, after speaking with Merrill and him assuring me that the Thors, despite their much more achievable pricepoint offered up a good percentage of what the Veritas would…he also mentioned that many people have found distinguishing the two very difficult. Let’s scotch this one from the off…the Thors are not ultimately as good as the Veritas, but they’re not far off and they cost a lot less, with the Veritas costing $12 000 and the Thors costing $4 800 for a pair.

The Thors use Hypex Ncore tech in the UcD Modules and the cases are, like the Veritas, milled from a solid billet of aircraft grade aluminium. Commercially they are available in a high gloss black finish (mine are a unique pair in opalescent white) and they are pretty dinky affairs measuring just 23cm x 23cm and stand just 9cm high including their Stillpoints. Along the front in pretty subtle lettering is milled THOR and round the back you have the Furutech IEC mains input, a Cardas XLR input that is Silver with Rhodium plate and the absolutely brilliant (in my opinion) Cardas patented speaker binding post that are Rhodium over Copper… I said it in the review of the Veristas, but I reckon these are without a doubt the best way of connecting spade connecters to your amp!  Underneath each amp you have the muting button which glows red when on and looks pretty cool reflecting off the marble slabs I have the amps standing on. A note here is that you must not play about with connections etc even when the amps are muted and you must ensure they are disconnected from the mains!THOR3S

Power output is rated at 200 Watts into 8 Ohms and 400 into 4 but they can be double-height bridged for 700 Watts into 4 Ohms.


These are Class D amps and I know from experience and reading the various Facebook groups that this technology does not find favour with everyone. However, put down your prejudices and realise that Class D has come a long way in recent years and is not what you may assume it to be. Class D amps have a reputation of being bass light and favouring the midband, but that’s just not the case with these specific amplifiers. I’ve used them with a wide range of loudspeakers (Triangle, hORNS Mummy, Audio Physic Avanti 3 and the Avantgarde Duo XDs) and I’ve never found them lacking in the bass at all… I’ll expand on this in a bit.

I’m not going to babble on about a whole load of specific tunes I’ve listened to with the Thors in place as I’ve listened to just about every genre you could imagine (sadly no Mongolian throat singing but I’m working on that) with them over the months and they seem to perform equally well with everything.THOR6S

Like the Veritas amps what you do immediately notice is an absolutely silent background, particularly when using a passive pre (I used the Bespoke Audio and Music First Baby Reference passives). This was an interesting observation on my part because I thought I needed to have my Coffman Labs valve pre in front of the Thors to stop them sounding cold and sterile…this is clearly not the case. What you do get is a beautiful clarity of sound that is just sparklingly clear throughout the frequency range. The Thors don’t have that certain indefinable quality that the Veritas had but the flavour (or lack of it) is the same and partnered with the passive pre amplifiers I mentioned these are “high-fidelity” in the strictest sense of the word, neither adding nor taking away much at all. Let’s wheel out the hifi reviewer clichés shall we… “an open window to the recording”, “veils lifted”, “see through to the source transparency”… you get the picture I think. This clarity of sound allows you to get the most out of your chosen music and brings you closer to the original recording than I’ve experienced with more conventional amplifiers. It also allows you to change components up stream and be immediately aware of the different seasoning these changes bring to the cocktail.

You’ll be well aware that we like to play pretty loud and you can crank the Thors up to pretty realistic levels with the right speakers, but you don’t get the impression that the flavour of their presentation changes at all…there’s just more volume and that same clarity right to the point where you know you need to turn it down or the neighbours are going to be hammering on the door.THOR7S

The Thors are also fast amps in the sense that they will play quiet to loud bits in your music without missing a beat and the bass is also fast and taut… I like taut bass and anything that doesn’t deliver in this department gets the cold shoulder immediately from me. Deep Purples ‘Smoke On The Water’ was a real treat when the bass guitar comes in, as was our other bass test track from Hardfloor. Drums have slam, hats are crisp and the spatial bits within the mix are all there in front of you. Soundstage and imaging is predominantly a factor of your loudspeaker choice in my honest opinion, but with the Thors in place there is the feeling that imaging is tack sharp and accurate…this is another must for me!

Real instruments sounded real across the board and electronic music had the requisite pace and rhythm with the Thors plumbed into the rig. As I’m writing this I get the impression that the words I’m using suggest a cold and sanitary sound, but that’s not the case I don’t think. A double bass sounds warm and fat (as does synthesised bass) but then hats are steely and razor-sharp…what I’m saying, perhaps badly, is that the Thors add little to nothing to the tonality of an instrument allowing it to be what it is and given the silent backdrop the Thors afford you get to hear all the attack and decay of an instrument. THOR4S

These would be great tools in a studio environment I reckon, but they also do their job in the home setting. They are that “open window” and as such crap recordings will sound crap, as will poor electronics before the amps. Let’s be honest here and say that high fidelity (in the truest sense) is not always the end goal for audio enthusiasts and most like to add a bit of flavour to their set up (some prefer a warmer more relaxed sound, whilst others may favour a faster more steely approach) and with the Thors in place (along with a suitable pre) you can tune to your tastes with the DAC or other source components…and of course your loudspeakers.


The Merrill Thor amps look great, offer a clean and pure sound and cost less than half the price of the Veritas amps and as such I reckon they offer pretty decent value for money. For a reviewer they are a great tool as they just don’t seem to add a great deal of character to the sound and so they are great for assessing other equipment. However, they are also eminently listenable in the home set up and I can honestly say that I’ve never listened to more music than I have with the Thors. They are an easy and yet accurate listen, with enough power to satisfy all but the most power hungry of speakers. Comparing them to the Veritas they don’t seem to have quite the same dynamic quality I enjoyed so much, but they’re really not far off not all.

Here’s the thing… if you want to add colour to your set up at the amplifier link of the chain then you need to look elsewhere, if you want to have an amp that does little but amplify then you need to audition these. I have a lot of amps come and go and I like to hear what they bring to the table in terms of their character, but having the Thors in place just feels like I’ve slotted back in that tool that neither adds nor takes away very much and as such I heartily recommend them.

After writing this review I’ve just read through the review of the Veritas and the two are very similar indeed!


Build: 9

Value: 9

Overall: 8.95

Price as reviewed $4800 

Pros :

Transparent and revealing

Fast and taut

Relatively good value

Cons :

Transparent and revealing

Not quite as dynamic as the Veritas

Stuart Smith

Designer’s Notes

The Thor Monoblocks were conceptualized to provide a lower priced entry to the VERITAS Monoblocks while retaining as much as possible of the VERITAS Monoblocks. In creating these units, the power and the size were considered independently and coincidently ended up being about half the price and half the power.  When completed the Thors retain between 75% to 80% of the VERITAS Monoblocks characteristics.

The design was to still use Class D and very clean power supplies in which an SMPS power supply was selected.  The original boards are modified and the modifications were decided on by using focus groups that helped with the voicing of the Thor Monoblocks.  The base technology is the UCD from Hypex with 75% of the Ncore technology implemented in this. This is then further modified by Merrill Audio for the final product.

The chambered Chassis is made from Aircraft grade Aluminum. It is CNC’ed out from a solid block of aluminum, then painted with high gloss Black car finish and baked. (The limited edition Pearl White Monoblocks were double baked).  While it is small, the chassis is designed for good airflow to keep the internal operation cool.

As with the VERITAS, the high quality Cardas XLR, Cardas Patented Speaker binding posts and Furutech IEC is used. The Thors also provide for a remote trigger like the VERITAS. There is only 1 Speaker Binding post on the Thors instead of 2 like the VERITAS as the size limited the easy to use layout. Stillpoints Ultra mini risers are also provided and an upgrade to the Symposium Rollerblocks are provided.  Part of the focus group was to test out different power cords to would provide a match to the Thors. Since we could not come up with a cost effective power cord that worked well, a custom power cord was build using Furutechs Silver plated 27 stranded pure copper wire and terminated with Cardas AC plugs. These are only available in US and Schuko. The Cardas plugs were chosen as it complimented the Furutech cable very well in sound.

Internally, silver plated, Teflon sleeved pure copper wire is used throughout from the power supply to the audio signal. All lines are kept as short as possible.  A synergistic fuse is also included to improve the sound. The Fuse is not user accessible as the fuse is the protection of last resort. The synergistic fuse does affect the Sonics hence the extra cost was justified. The Thors have a slew of internal protections.  Should all of them fail, then the fuse will blow. At this point the customer should return the units to see what has failed and have it corrected, which should be an extremely rare occurrence, should it happen.

We were more than please with the final result of the Thor Monoblocks that is being offered at a great price using the economies of scale and design derived from the VERITAS Monoblocks.

Merrill Whettasinghe



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