Class D for Repatriated Merlin TSM MMI


I recently repatriated a pair of Merlin TWM MMI from Singapore. Calvin Ho of CK Audio made its return home quick and painless.

I have read the forums and understand that most seem to prefer tube amps. I know that is is against convention so far as I've read, but, due to heat, space, my back and weight, I am inquiring  of any successful synergistic  pairing of Class D amps. (Yes, I am trying to avoid 55 pounds of iron)

My sense are these little guys might benefit from lots of power but like everything the proof and synergy is in the pudding.

Thanks for any experience one can share.

 

 

derekw_hawaii

Haven't heard them myself, but I've been told from a very reliable source that the new Atma-Sphere Class D amps sound like their OTL tube amps.  I have 2 pairs of TSM's myself and use AS on one of them.  If in fact their Class D amps do sound like their OTL amps (or even close) you'd be in for a real treat with the Merlins.

I also have MMi with the master RC networks. They sound incredible with my Black Ice Audio F35 integrated amp. I have a Legacy i.v2 Ultra class D amp which has not sounded bad with any speaker I've tried it on. Just haven't had a chance to try it with the Merlins.

Good luck. These are one of the all time great monitors. I have compared and prefer them to the current ATC SCM19 speakers, also very good monitors.

I have a March Audio P502 and it's been doing wonders for my inefficient Vandys and Maggies, with 500 wpc into 4 ohms of brute force power. Tremendous detail, clarity and drive. Many choices for Hypex and Purifi but I prefer March for build quality. They've gone all Purifi though, but that's probably enough power for you. Don't think you can go wrong with a Purifi amp, great value and I appreciate the small form factor and light weight.

soix, Budget would be $5k max, probably in the used market, as there may be more value there.  Clarity (absence of veil) and soundstage, ,but I would like to be emotionally invested in whatever I listening to.Not into analytical listening.

marco1, I've heard of but not that much commentary on Ralphs Class D. I need to check out the sticker those.

vinylvalet. Thanks for the referral. Never heard of these. If you ever get to hook the Merlins up, please drop a comment, pm or publicly.

I am inclined to put much greater weight upon actual listening pairing.

@derekw_hawaii  The Merlins aren’t that tough to drive and Bobby P at Merlin (R.I.P) used to pair them with modestly powered amps all the time. Yes, Atma-Spheres were a natural, but the S30s or a pair of M60s were ample. I believe Ralph’s Class D are $8K and sold out for the moment.

The guy who’s advice would be best is Rich Brkich at Signature Sound in Liverpool, NY. Rich spent more time doing shows with Merlin and probably sold more Merlins than anyone else. He is intimately familiar with every aspect of every model and probably every pairing. He’s a modest, knowledgable guy is always happy to help any Merlin enthusiast get the most for his money. Cheers,

Spencer

Well, I think you should stretch a little and go for the Atmasphere GaN momoblocks or the AGD Tempo di GaN amp as they’re only $400 -$500 over your budget and will very likely give you many years of SOTA sound reproduction. As a backstop and if you can’t stick a crowbar in your wallet and buy one of those amps, an option that’d still give you awesome sound but at a huge discount is a McCormack DNA-125 with full SMcAudio upgrades for $1750 where the upgrades alone probably cost upwards of $2000. This is a near SOTA amp by many accounts, and you can send it to SMcAudio and have them install their Gravity Base Jr. for $400 or full Gravity Base for $900 and up the performance even further and still be WAY below your $5k max.

https://www.usaudiomart.com/details/649847769-smc-modded-mccormack-dna125-power-amp-excellent-condition/

If you can stretch I’d go with one of the GaN amps, but if $$$ is a concern I highly doubt you’d be unhappy with the upgraded DNA-125. Of course another option would be the $3k LSA GaN amp from Underwood Hifi. It never ends, but I’m sure you’ll be thrilled with any of these awesome amps and your excellent speakers. FWIW, and best of luck.

Temple Audio Bantam One 

100w Integrated from the UK. I’ve never listened to it but have listened to other very good sounding Temple digital amps. 
 

http://www.bantamone.com/

+1 Rich Brkich at Signature Sound. Very nice, honest and helpful guy. Certainly the world's best Merlin expert.

Talk to VerdantAudio on this site.  He may have a demo AGD Tempo di Gan that he can send to you to try on your speakers.

Hearing the name Merlin makes my heart smile.  A blast from the past for sure.  Bobby P. would be so pleased to know that his speakers are still being enjoyed, and that people have such high regard.  Good luck with your TSMs.  😎

I believe Ralph’s Class D are $8K and sold out for the moment.

The guy who’s advice would be best is Rich Brkich at Signature Sound in Liverpool, NY.

@sbank @derekw_hawaii Our class D amp is about 5400/pair right now.

FWIW Rich just picked up a set. I’ll be interested to see what he thinks.

Rich - please tell us what you think.  The heat from my AS OTL's during the summer at my beach house can be a little too much sometimes.  I may be picking up the AS Class D's myself very soon 😎

Class D, really? I suppose in the modern unsustainable consumer disposable society they may be relevant and sound ok. The question I pose is, will they be durable and serviceable in 20+ years or just another contribution to electronic waste ? I say this listening to a 30 + year old jfet cascode afe and mosfet ops Hafler 9500. This amp was restored to perfection by myself with all the best components (Audio Note, Mundorf, Dale , Exicon, Cardas, Sparko Labs front end power supply, etc..). Still believe super fast switching will never beat no switching. And tend to believe too much switching is detrimental to ones health. it could possibly be why analog audio is so meditative for me.... Ok thanks for reading my rant about class D. To be honest l, just don't understand class D schematics and topology. I do understand that most here are not builders, but please to those who are not, consider that your choice will limit the supply of anything worth keeping out of the landfill in the future..

Still believe super fast switching will never beat no switching...To be honest l, just don't understand class D schematics and topology.

@pwayland Might be time for you to go listen to some of the better GaN amps from the likes of AGD, Atma-Sphere, etc. rather than hanging your hat on beliefs or needing to understand schematics.  I imagine there were similar sentiments when solid state amps made the scene, but here we are.  

Class D, really? I suppose in the modern unsustainable consumer disposable society they may be relevant and sound ok. The question I pose is, will they be durable and serviceable in 20+ years or just another contribution to electronic waste ? I say this listening to a 30 + year old jfet cascode afe and mosfet ops Hafler 9500. This amp was restored to perfection by myself with all the best components (Audio Note, Mundorf, Dale , Exicon, Cardas, Sparko Labs front end power supply, etc..). Still believe super fast switching will never beat no switching. And tend to believe too much switching is detrimental to ones health. it could possibly be why analog audio is so meditative for me.... Ok thanks for reading my rant about class D. To be honest l, just don’t understand class D schematics and topology. I do understand that most here are not builders, but please to those who are not, consider that your choice will limit the supply of anything worth keeping out of the landfill in the future..

@pwayland If care isn’t taken, all sorts of things wind up in the waste stream. 35 years ago I pulled a set of vacuum-tube Western Electric microphone preamps out of a dumpster. We still use them (refurbished) in our recording studio. So I share that concern! It is for that concern that we have offered warranty reactivation on any of our older products should it be updated or renovated.

The semiconductor industry seems as if it prefers to make switching devices rather than linear devices. So the likelihood is good that in 30 years an older class D amp could be refurbished and put back on the road. Other than the class D module all class D amps have a power supply and chassis like a conventional amplifier. So at worst you would be replacing the module.

Class D as a class of operation proposed in the 1950s when tubes were King. You could make a vacuum tube class D amp if you wanted. The first home units were made in the 1960s and more were made in the 1970s and 80s, some by Sony and Yamaha (many of which are still running, so you have your answer since they are already over 30 years old...)

FWIW there is no health risk whatsoever from a class D module that meets European Directives for radiation. No-one in their right mind would sell a module that didn’t!! IOW they don’t radiate RF energy or the like that could be construed in any way to be a health hazard.

Class D is as durable as any other amplifier tech. I’ve been using a Crown class D amp in my keyboard rig in my band for over ten years. It gets quite a bit of abuse and keeps working fine. IMO/IME a conventional solid state AB amp is at greater risk due to oscillation concerns with certain loads, heat issues and the like. So, like a conventional AB amplifier, as long as the circuit has some protections in place it will be pretty goof-proof.

Its the distortion spectra and how much distortion that determines how the amp will sound. The class of operation does not. It is this very reason why class D can sound as good as the best class A or tube (possibly also class A) amplifiers, since with those amps the ’sonic signature’ is in fact the ’distortion signature’. Whether a designer of an amp understands this fact is a very different topic!

 

I listen to both Class A and D, Tube and SS, enjoy them all for their different nuances and sound characteristics. 

I personally enjoy some of these newer technologies, yes some are a fad but I think Class Amplifiers have turned the proverbial corner.

 

@atmasphere , Thanks for your post, you make some excellent points! I do understand that the different harmonics of distortion are what gives amps their sound etc and I'm sure these modern machine built products sound fantastic. For me, it is about sustainability and being able to fix my own gear. I suppose you could be correct about future serviceability. It seems in the realm of possibility that a machine similar to the ones that build the smd boards, could troubleshoot and rework them. For now it seems mostly that only the factory will service smd boards and after warranty expires well...  For myself, my hands are too big and my eyesight is not good enough to want to go near one of those boards... as I suspect are many techs, so sure just replace the module, but what happens to the old module? I replaced a hypex PS module once and the boys from the Netherlands didn't care to take the core. I do admit that I'm a bit of a retro grouch though. Peace

NAD M33, now a bit under $5k, does everything including easily powering my 4 ohm Monitor Audios.  Has a class D Purifi type amp with nearly zero (inaudible) distortion, plus Dirac Live room correction.  I love mine!

It seems in the realm of possibility that a machine similar to the ones that build the smd boards, could troubleshoot and rework them. For now it seems mostly that only the factory will service smd boards and after warranty expires well...  For myself, my hands are too big and my eyesight is not good enough to want to go near one of those boards...

@pwayland I don't think anyone has eyesight good enough to work on surface mount boards like that without magnifying glasses. But if you have those its a different matter. Its all about the tools you have and like cars or bicycles, the tools change with the times. FWIW we build our modules by hand. If the components were any smaller that likely wouldn't be the case.

WRT the old module, that's not unlike what you run into with bad filter caps and other parts in older stuff. Last year I repaired a set of Adcom amps that had caps that had leaked and thus destroyed the driver boards in the amps. You can't clean them up- the material of the board was damaged in this particular model. The only solution is to replace the boards which is what I did. Not cheap and not particularly easy, plus you wind up with a waste board that is about 3x larger than the typical class D module. So while I understand your concern, the simple fact is this is nothing different with class D in any way whatsoever!

I’ve had Merlins, both floor standers and the TSM MMM Black Magic editions. They respond nicely to higher power delivery though Bobby P ran them a lot with ARS-Sonum tube amps.

I’d be careful with class D amps as anything on the lean side or bright on the top end will sound particularly bad with these revealing speakers. If you can find a used H2O S250 Signature, then you’d be in for a real treat. The H2O is a fantastic amp, detailed yet full-bodied. I haven’t heard Ralph’s amps but they’re on my bucket list.

 

@sbank @derekw_hawaii  @marco1 

Sorry folks, I do not check these forums often so I am often late to comment....

If packaging tracking holds correct, a pair of the Atma-Sphere Class D amps will be here tomorrow (9/10). I will have them for several days before I need to send them off to their buyer, so I will get a chance to hear what they do on Merlin's.

In regards to TSM's . . .

Merlin TSMs between their sealed box alignment and crossover design, are a pretty stable easy load (min impedance is in the low 6 ohm range) and moderately efficient (87dB). So, many tube amps play really well with them. Many TSM users have Ars Sonum Filarmonia amps driving their TSMs (about 30W/ch) [I'll put in a plug here for the current generation of the Ars Sonum Filarmonia integrated amp, and its brother the Armonia power amplifier, which have a number of significant improvements over the earlier versions that Bobby P sold back in the aughts and early teens].

Of course good (smooth, clear - not overly damped) solid state works great on them too. For example, there are a number of Power Modules Belles Aria integrated amps being used on Merlin TSMs. Later version/production TSMs IMO can also really show off what even better solid sate amps can do.

I am very much looking forward to trying Ralph's new amps on the speakers. :-)

Cheers

Rich

@signaturesound  Thanks Rich. It will really interesting the hear how the AS Class D compares to and pairs with the TSMs. Probably the first and only class D pairing observations to date. Please especially comment as to the clarity and soundstage aspects vs the other amps that you have experienced. Happy evaluating over the weekend.