Massdrop Cavalli Tube Hybrid Amp

Pics or it didn't happen (I am sorry for my now-lapsed obsession with vaporwave-themed unicorn barf strips):

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Possibly to my benefit I'm too brain dead nowadays to type very much up or string more than a few vacuous thoughts together so maybe these impressions will be blessedly brief. (EDIT after posting: LOL NO)

@Bill-P was amazingly generous and (carefully) tossed this amp in my general direction for cost of trans-pacific shipping. This is in all respects a bargain. Comments will be entirely preoccupied with the amplifier as the integrated SDAC didn't play very well with my computer for whatever reason, regardless of whether I happened to be running Windows 11 or Linux Mint.

Quick aside: if video game support were significantly better on Linux I wouldn't bother dual booting Win11 and Linux Mint. It just feels a lot cleaner and more refreshing, making the choice of name for the distro an apt one.

Another aside: sorry for the 30-odd edits, keep finding grammatical knots to disentangle.​

DISCLAIMER:
I've had the opportunity to listen to quite a few nice affordable amps over the years but in order to cover my ass in that I'll avoid speaking out of my ass, I'll primarily be making direct comparisons to the Magni 3+ while making more offhanded remarks about how the MCTH stacks up to stuff I've had the pleasure of having on-hand for extended periods of time. The Modi 3+ is also the only DAC I have on hand other than the Fulla 2 which is on indefinite loan to family so it's fully possible that a lot of the nitpicks will be attributable to that instead.

Transducers: Klipsch Heritage HP-3 (bit less bassy than stock with added venting cut into pads); Sennheiser HD600 (not quite stock); Etymotic ER2XR (very accessibly-priced but horrific aftermarket cable that makes them sound leaner and brighter than stock-- disgusting! Ugh! BLERCH!)
Other amps: Schiit Magni 3+
DAC(s?): Schiit Modi 3+
Tubes: only stock Electro-Harmonix 6922 used.

Solely from a tonality standpoint I feel the Magni 3+ is more of a straight shooter in that it's better inclined to reveal shortcomings in transducer voicing than many other amps I've tried; the HP-3's elevated treble is more bothersome on the Magni than it is on the MCTH while the treble on the MCTH is in turn a bit more fatiguing than on the ZDT Jr. and sounds comparably fatiguing to the Liquid Carbon v1 with the Klipsch, albeit in a slightly different way. Besides being warmer than the Magni 3+ with less in the way of ultimate sub-bass or upper-treble extension, the MCTH has a notable, but not particularly painful to me, mid-treble tizz using the stock 6922s that makes critical listening at higher levels that much more fatiguing, e.g. in Michael Jackson's Thriller album or, amusingly, the track below (which I unironically adore):



Don't even get me started on the Goo Goo Dolls's Iris or P, B, & J's Young Folks. Those tracks need something effectively dead in the upper octaves to be tolerable, and I'm not even exaggerating by all that much. Still those are tracks that were nearly unlistenable on most amps I've owned so that's not in any way a strike against the amp.

While extension on either extreme of the frequency range falls short (see: the brain-rattling bass on Noon from Alva Noto and Sakamoto Ryuichi's Vrioon or the hi-hats in the Drum Test Track off Chesky's Headphone Demonstration Disc; the Magni doesn't sound as if it rolls off quite so quickly), the MCTH manages to delineate very busy passages very well as in Radiohead's Pulk/Pull Revolving Doors or the teeth-clenching climax of Weird Fishes/Arpeggi. It manages to keep from homogenising into walls of sound as the Lake People G109A might tend to without coming off as "dry" and overly stately, excessively careful, as the Magni 3+ might-- there's more a sense of liveliness and groove to the MCTH. While the Cavalli does seem somewhat lacking in upper mid aggression on some tracks that rely on that grit to sound right (e.g. Metallica's Welcome Home (Sanitarium)), in this instance that's as much the fault of the Klipsch headphones as the upstream; it sounds perfectly usable on both the ER2XR and the HD600. The Klipsch essentially has just enough upper-mid crunch when paired with the Magni for these kinds of tracks with not a sliver of a decibel more to spare, so the MCTH is perhaps just a bit too polite by comparison.

ADD: blind spot in my listening routines, there's a bit of a glare to female vocals e.g. Dave's True Story's Lilly 110-140 that's grating at higher volumes. Curious how it's distinct from distorted guitar crunch, but the HD600 can be a bit too much with this upstream.

That said, the Magni pulls notably ahead for resolution of textures and midrange clarity; this manifests in how it's scarily easy to pick up slight changes in vocal intensity and overdrive, lilts and subtle inflections and catches of the voice, significantly moreso to my ear than on the ZDT Jr., Garage1217 Project Sunrise 3.1 (with an LPS), or the Liquid Carbon; this is pretty evident in the like of Regina Spektor's Pavlov's Daughter or Florence and the Machine's Sky Full of Song. Even the low voices on Kate Bush's Get Out of My House are alarmingly clear and intelligible on the little Schiit which genuinely made me question the price of the amp. Vocal presence is to the advantage of the MCTH on the like of Sinatra's In the Wee Small Hours and Only the Lonely; the Chairman gets unseated and pushed from the forefront when listening to the Magni on low gain for whatever reason, though flipping to high gain remedies this to an extent.

Highlight: I had never noticed precisely how wet and phlegmy-sounding that cough ~42 seconds into Pink Floyd's Wish You Were Here was and I love the hell out of that track. This was a properly strange moment for me, giddy at what appeared to be a bad smoking habit manifesting in an ectoplasmic-sonic apparition. Given I'm supposed to pretend that I have good taste in music that's probably more acceptable an example to offer than, say, how the industrial shuffling sound pervasive in Twenty One Pilots's Heathens sounds much grittier and distinct

Full disclosure: I wasn't sure if the above stuff re: vocal nuance on the Magni was just me being out of practise listening critically but when I checked other impressions prior to posting this I saw @Torq mentioned the exact same thing in his review of the amp. I feel compelled to swear that I noticed that without anyone's help, haha.​

The little Schiit is also better at picking out individual voices singing concurrently such as on the Wacken 2013 recording of Nightwish performing Romanticide. It's not that the MCTH is particularly bad or even just average here-- image delineation on the MCTH is about par with the like of the Project Sunrise (likely better— haven't had ears on the Sunrise in an age) and possibly just a whit worse than on the ZDT Jr. The ZDT Jr's imaging capacity however is impinged on somewhat by its warmer voicing, which tends to diffuse presence more; while likewise skewed towards a warmer voicing, the MCTH nonetheless sounds much more balanced by comparison.

Headstage-wise the MCTH isn't nearly as three-dimensional as the ZDT Jr. was in the sense that the headstage is merely good in terms of front-to-back layering by comparison and not "there are presences in the room with me", unless listening to binaural audio in horror games of course in which case it's too good at sonic placement. Paramore's Hard Times exhibits good sense of room with the MCTH as well as surprisingly clean delineation of individual sounds, though it's not a particularly busy track. The Magni seems sparse in terms of front staging by comparison, but the MCTH doesn't pull too far ahead in terms of center stage population despite having relatively less hollow-sounding sonic images. The staging is definitely more compact than the Lake People G109A but honestly the better overall delineation and sense of contiguousness from side to side means that it's a categorical improvement other than in sheer size.

With all three transducers used (all dynamic headphones, sadly) the MCTH managed to present an admirably out-of-head experience with good depth and decent lateralisation. I've never thought the HD600 to be particularly poor in stage size or claustrophobic so much as its staging capability being more heavily reliant on upstream components-- the MCTH offers a compelling argument to that effect with how you can have vocal lushness as well as distinctly-placed instrumentation in the background. The amp doesn't quite manage to bring the climax of the Living Stereo version of Rimsky-Korsakov's Scheherazade to life on the Sennheiser but it does a great job of resolving individual sections, though not instruments.

It does make TSwift's My Tears Ricochet sound oddly disjointed in that there's this odd sense of incomplete admixture between her vocals and the background kerfuffle, and there's a pervasive sense of hollowness to vocals that never quite goes away (note: hollow tonality is different from hollow sonic images, latter is more a function of how elements on the headstage present themselves while the former is entirely voicing), but the amp makes it alarmingly easy to hear into that background kerfuffle. Far be it from any sort of empirical but there's also a real sense of emotional hooking with tracks like Exit Music (for a film), again by Radiohead; something about the amp's pairing with the HD600 here sent chills down my spine and made me cry a bit.

While not necessarily as resolving of detail as the Magni 3+ I do honestly think I prefer the MCTH by a fair margin other than the slight treble tizziness, as distinct from the Magni's being harder sounding (i.e. treble pain is a couple kHz lower). Naturally none of the transducers used are relaxed in the upper registers but some amps e.g. the Liquid Carbon and Project Sunrise, did help ameliorate these to assorted extents.

Low end impact is something that I somehow don't feel entirely satisfied with on either of these amps, and that's probably just another aspect where the Modi 3+ simply fails to deliver besides an amorphous headstage based on others' impressions of the unit. While the MCTH has more gratifying slam and head-rumble (Jamiroquai, Love Foolosophy; Timecop1983, On the Run) it doesn't feel like it's making the headphones really lean into their punches. The Magni isn't as much to my preference here as the MCTH is, though it's a matter of tradeoffs here I suppose-- the Magni 3+ sounds more focused in its slam, albeit with less mass; conversely the MCTH is BIG sounding despite the slam not being honed to nearly as fine a point. Pick your poison.


Asinine, asonic considerations:

I'm not the biggest fan of how the amp looks, and it takes a lot of lateral desk space relative to other amps I've had on hand that are either more vertically oriented or simply take up less desk surface area. The front vent holes make it seem like this was meant to accommodate a three-tube design when there's just the one, and the tube that is there is recessed into the chassis. While this does help cat-proof the amp to an extent, I think it provokes silly jokes.

yes I have an infantile sense of humour.

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On the topic of asinine and infantile jokes, I genuinely love the knob on this thing. It turns very smoothly and there's a sense of weight and inertia that feels properly class to operate. The channel balance is excellent on this specific unit as far as I can hear and I can get non-earbleed levels on the Klipsch HP-3 without needing to implement digital attenuation on (nearly) all tracks despite it having greater advertised gain (18dB) than the Magni 3+ set to high (15dB). Unlike the MCTH, I definitely need to cut a few dB off the top when using high gain on the Magni with the HP-3.

The tube I'm currently using may be nearing EoL for all I know but there's distinct hiss when using the Klipsch HP-3 in quiet settings, though for whatever inexplicable reason none is really audible with either the HD600 (which is to be expected) or the ER2XR (what the—?). Regardless I'm not bothered overmuch by hiss so long as it doesn't overwhelm music, and I'm really picking nits when it comes to that hiss.

Would have loved a more pronounced chamfer on the knob and perhaps selectable gain, but honestly that's nitpicking. Front panel buttons have a satisfying level of resistance and sense of tactile and audible feedback when fully depressed, very crisp. The unit is solid and feels like it could survive a fair bit of rough travel, tube chub aside.

 

I just took in a well used MCTH & I'm wondering if the stock tube may be due for retirement.

My impressions so far are of a grainy lowres amp with few of the positive traits I'm reading in others' impressions. I'm also getting L channel noise on all but my least efficient headphone.

Does this sound like the symptoms of a dying tube or did I just expect too much from a now ~$100 hybrid?

 

The resolution is a limitation of the amp but, from my limited experience, I'd say it's perfectly in keeping with an amp in its price range - these things, I suppose, are a function of perspective. For amps under $300, I'd not consider the MCTH to fare poorly according to these criteria. I also hear some graininess in the treble.

I'm not sure these issues are signs of a dying tube but the left-channel noise might be - I should defer to others with more experience, though.

 

It does sound like a bad tube by the way you describe. New tubes are cheap and not bad to have a backup anyway.

A stock MTCH is ver clean and clear amd should not be super gainy at all.

 

Thanks. As it is it's far behind my THX One & what I remember from the Lyr 2. Good to know that's not normal behavior.

What affordable tubes would maximize clarity? I don't want to throw anything warm-tilted in as I'm matching it with a pair of slow headphones. Digging through old 6922 tube rolling threads I wasn't seeing much matching that description under $50.

 

Purchase the OEM tube that came with it. It’s a fairly neutral tube and it’s cheap (Electro Harmonix). If you want to spend money you can always find a Siemens 6922 but at that point the tube will run you about $100 minimum.

 

Is there any opamp in the MCTH? Or is it transistor-only (+tube)?

 

Google is your friend (search for: Massdrop CTH discrete)

https://drop.com/buy/massdrop-x-alex-cavalli-cth-tube-hybrid-amp/talk/1781082

 

I think we are the only ones that call it the “MTCH.” Most of the time on other sites I see it as “CTH Drop” or just “CTH” or some other variation.

Early on Marv asked for this to be called MTCH to differentiate from the older DIY CTH. He found it a different amp. Here it is from the first post in this thread.

I still love the microdynamics and microdetail of this amp. And amazing how much a good power supply improved it. Not a slammy authoritative amp, but still wide and deep. And on the used market, a super value amp.

 

HI
I bought a piece of equipment with this problem at a very good price and thanks to you I was able to repair it.
IT WAS THE 10 UF CAPACITOR
thank you so much

 

Anyone ever get around to recapping the WIMA decoupling caps? I got my hands on a used unit for just €50 - lucky me! - and am thinking of rolling to Miflex KPCU-02 caps.

Also there's a slight crackling developing in the left channel. Volume of the crackling is constant, though a bit less with the volume knob halfway, and masked at normal listening volumes. Not the analog qualities that I was looking for ;-) Maybe a scratchy pot to replace.

 

The crackling might be due to a tube going bad.

 

It could also be corrosion on the pins or in the socket.

Try removing and re-seating the tube. If it's light corrosion, the friction from re-seating may be enough to sort it out.
If the pins are particularly funky they can be cleaned with de-oxidizer or fine grained sand paper.
I have this problem occasionally with one of my other amps. So I always check first before declaring a tube dead.

 

Thanks, tried rolling tubes with some NOS E88CCs with pins as clean as a baby’s butt… didn’t help. More so, they increased the noise while they are absolute noise-free in my Eufonika amp.

My MCTH is powered from a Chinese LPS but it’s the same for both this LPS and the wall wart. At which point I started looking at the pot….

 

If the scratchiness rears its ugly head whenever you mess around with the pot, then blame the pot. I had this issue with the pot of my CTH after the first six months. Removing the CTH chassis to work some deoxit into the shaft of the pot did the trick, and the pot has been fine for the past two years.

 

Will try that before swapping then. And also order a new one, so I have it on standby when I’m working to roll caps anyway.

The WIMAs are 0.1uF right?

 

Well couldn't resist and sprayed contact cleaner between the potmeter and the front plate from the inside. (How on earth do you get that volume knob removed from the shaft?) Worked like a charm, thanks!

Meanwhile have ordered a pair of Miflex KPCU-02s to replace the WIMAs with. Can confirm that they are 0.1uF indeed. Will report back once I've fitted the new caps of course.

 

Surgery complete: replaced the stock WIMA interstage capacitors with Miflex KPCU-02's. I chose them because I like them in my Eufonika tube amps, they are attractively priced, and last but not least: they fit.



The KPCU's have twisted leads that are too thick to go through the holes on the PCB, even when you untwist them and take a single strand. So I sacrificed two resistors from the parts bin and clipped off their leads:



Fastened with self-adhesive cable tie mounts, it fits to a tee:



Listening to it now for less than an hour. Off the bat, they sound a little more forward. Highs stand out more. While not the sibilance kind of high, likely more fatiguing still with crystal clear cymbals, hihats and such. Soundstage seems narrower. Not what I know from my Eufonika amps, so definitely think they require break-in.

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I got distracted before I finished posting this. Soundstage is expanding already. Interestingly voices are getting more center stage attention now. These capacitors are definitely undergoing transformation only hours in. You'll have to give them and me more time before posting further impressions.

 

50+ hours in: bragging rights. That’s where my MCTH with Miflex caps now is.

As I wrote above, replacing the stock WIMA with KPCU capacitors was not exactly a “wow” experience. But break-in seems to be the real deal here. 50 hours in, soundstage is opening up nicely and music seems to be flowing more organically. Treble is tamed and there’s a nice oomph in the lower registers.

At this point, while impossible to ABX and surely subject to brain memory, I’d rate sound quality to be roughly equal or slightly better then the WIMAs. So, bragging rights, because at least mine has got big fat caps.

I do believe that these Miflexes are getting better every night, so outlook is positive. And just to offset the brain burn-in somewhat, this amp is not the only one I’m listening to.

 

At the risk certainty of making this uncontrolled test even less controlled, I made these special XLR-to-RCA cables to invert phase. From my balanced DAC, it wires XLR pin 3 (negative) to RCA signal:



Cable is Canare L-4E6S star quad with some Chinese connectors and sleeving. XLR pin 1 (audio ground) to RCA ground, cable shield wire to XLR shell (RCA end unconnected) for better EMI protection. RCA pin in the picture is a bit off-center, which I later corrected.

So did it "fix" anything? Don't know... hard to say... yea/nah... I cannot reliably pass that online ABX test with and certainly not without listening very minutely. Continuing to listen through the evening, the soundstage does grow on me and become more involving. But brain burn-in almost always does that to me. So who knows.

Think I'm about done making this an endgame MCTH now... edit: could still replace the volume pot but don’t know how to get the knob off!