Decware Zen Taboo MKIV

This is an incredibly useful visualization. Even for people who generally understand these things, as they say, a picture is worth....

 

yes. Link here. Thanks for checking it out!

 

I have heard this amp at several Seattle Can Meets. Connected to OG Yggdrasil with rubidium disciplined LiveClock to Dante Rednet D16 AES output. Sound quality from this specific system always appealed to me. If I hadn't gone the path of EC Studio B, Decware Taboo mk IV would have been my alternate choice.

 

The Decware X ZMF OTL was a highlight of CanJam Chicago, so I was very excited to hear the Taboo. It’s an interesting, flavorful amp, yet I had some trouble finding its sweet spot. I wish I had some other Audezes here to test with. It’s absolutely beautiful in person.

Lucid mode is like nothing I’ve heard before. It’s not just crossfeed. Very cool, hard to describe with words, and I would love to understand what’s being done to change the sound like this.



Focal Utopia: The revealing chameleon

• Slightly blurry
• Euphonic
• Smokey
• Can hear a slight hum during quiet passages
• Taboo is less refined than Feliks Euforia

Hifiman HE1000se: By far the best match

• Vibrant
• Cohesive
• Musical
• Detailed

Audeze LCD5 & ZMF Auteur: It’s fine

• Pleasant though not exciting

Abyss AB1266 Phi TC & Hifiman Susvara: Too demanding

• Require full volume on high gain
• Lean but not terrible
• Loses steam in the bass

 

Thank you so much for the opportunity to hear this loaner. While I was limited in how much time I got to spend with it, I did put it head to head against my DNA Starlett (stock tubes), both fed from the Holo Audio May DAC. Used SE output to the Starlett, and XLR output to the Decware. Tested with the copper mass modded HD 600. Not an ideal pairing for the taboo, but what I like to listen to, and I don't have any planars currently.

Before I dive into my findings, I just want to say, this amp is really my perfect hi-fi aesthetic, and the build quality was superb. Having this in my house and physically interacting with it was just such a joy.

I had not actually gotten to listen to my system in a couple of weeks when I sat down to test the decware. My first impression was that it was really going to give the Starlett a run for its money. It did a lot of things I really liked, vocals were really euphoric, bass was very fat/rounded/full but still relatively accurate sounding, and had good separation that really let details hang in space. Overall it was just an amp that felt like a warm cozy blanket with everything you threw out at it.

Then I switched to the Starlett, and it really was better in just about every way. It had significantly better clarity and everything just sounded more refined but still really inviting and non-fatiguing. It was hard to ignore with the Decware that it felt like there was just a bit too much grit to everything and certain stuff could come across a bit brash and harsh. For better or worse, what it does on top of that is this odd injection of euphoria/atmosphere sort of thing. Like putting vocalist in a smokey lounge room vibe. I first suspected something was up on the track "Maneater" by Hall & Oates. I looked at my notes, and I wrote "This track has a lot more atmosphere than I remember". Sure enough, when I swung back to it on the Starlett it was a lot more true to the recording.

Not trying to say the Decware is bad though, but it is certainly a flavor/mood sort of amp. What it did was helpful with some stuff. For example, I really liked the track "King James" by Anderson .Paak more on the Decware. While the Starlett sounded more accurate and more realistic, the Decware really injected some life into the track. Drums and bass on it were just, superb. Full, slam, feel it in your chair stuff. It also highlighted another strength of the Decware where it slightly edges out the Starlett, and that was separation/layering. It really does a great just of creating a wrap-around effect and then letting details really hang in space and layer nicely.

It seems the Decware really excels when you lean into its strengths. You want a guitar solo to just rip and not shy away from being a bit gritty, bass that is so full you can feel it, details that hang in space, and to put your vocalist on a single spotlight hazy lounge stage? Then this is the one for you. A track that really exemplified this was the stunning recording "Sister" by Angel Olsen, something I have listened to probably one hundred times. I found myself utterly captivated listening from the Decware. When the bass line kicks in, you feel it in your soul, and you can see it on the stage in front of you. Then her angelic voice just comes in, her and the mic isolated just oozing hazy atmosphere. When the heavily distorted guitar comes in you can't help but grin, and then the guitar solo just absolutely rips from the heavens, giving it to you full force, absolutely visceral.

 

The metal cylinders next to the transformer that say decware designed on top. Are those on xlr input optioned amps only?

 

Yep.

 

Many thanks to Decware and RD for making this loaner possible.

I'm reaching a point that I got to once upon a time in car audio - I stopped enjoying music because I was listening to the equipment. Therefore, I spent my time listening to music rather than the amp and my thoughts will reflect that and not be particularly "reviewy".

Qobuz/ALAC -> Audirvana -> Pi2AES -> 1656 modded BF MB -> amp -> headphones

I experienced PSU hum on the amp. It's audible both through headphones and from the chassis (transformer). I keep an Emotiva cmX2 around just in case and after plugging the amp into it, the chassis hum disappeared and the hum heard through headphones got quieter but never completely disappeared. The manual states that should you experience PSU hum, you should change to the lower gain setting. This helped to some degree but not completely. The hum is not heard once music starts playing so it may not be a bother for you.

Dual volume pots; this to me is like stepped pots - some will like them, some won't.

Crossfade/Lucid mode - another preference thing so I won't comment.

Sound: all listening is with the stock tubes provided with the amp and only headphones.

To me this is a mid forward amp. Particularly, I perceive a bump in the upper midbass/lower mids. Unfortunately the two headphones I use the most (HD600 and Diana V2) are generally focused on the mids so the combination with this amp ended up sounding congested and ultimately fatiguing. It's a much better fit with my Focal Elegia although there was still some congestion present. I would use this amp with headphones/speakers that lack a bit in the midbass area and/or need a bit more body with male vocals. I find this amp much better suited to acoustic music rather than the more rambunctious genres like electronic, rap, rock, pop.

Separation lags behind both LAuX and SW51+. Imaging and soundstage are both behind as well. Micro-dynamics are decent, macro-dynamics leave me wanting more (probably due to the rolled off lows and highs). I don't listen to much live acoustic music so I can't competently comment on timbre.

Power-wise, driving planars was not an issue and I think very efficient speakers should be a non-issue as well.

 

Just so I am on the same page. I know the taboo was made with older PF Audeze in mind. Where do they fall in? Are they low-z enough to be grouped with the modern orthos or are they a demographic of their own?

 

Thank you to Decware and SBAF for the opportunity to try out the Zen Taboo Mk IV. Below is my review.

A few caveats: this is the first time I’ve listened to a tube amp outside of meet conditions, so I cannot compare it to any other tube amp. Additionally, I only used it with headphones (Utopia and HD6XX) as my speakers are not efficient enough to try the speaker outs of the Taboo. Finally, I’m in the middle of “finalizing” (ha!) my at-home DAC and transport so used my trusty portable setup (Chord Mojo and AK A120) to feed this amp.

Out of the box, it is an impressive looking unit that suits by aesthetic preferences of dark wood against black. I’ve spied the Decware website many times before but seeing it in person shows, to me, how great it looks in person. The Taboo has three dials and two switches that are unmarked, so I had to download the manual to figure out what each does. In hindsight, the amp looks better without any markings and using the dials and switches become second nature.

After lowering the volume and settings, I warmed the amp up before having a listen. I won’t get into a technical critique on how as I don’t have enough exposure to different setups/sounds. I will say that I enjoyed listening to music and hearing things in songs that I have not noticed before. I think the Lucid Mode had a lot to do with bringing subtle sounds more to the forefront. One of my test tracks, Diana Krall’s “East of the Sun (West of the Moon)” Live in Paris version, has a recording of someone coughing. On this amp, I didn’t have to look hard for this moment. The Lucid Mode and the Bypass Switch was fun to use, and I wish I had more time with the amp to figure out what my preferred sound and settings are.

 

Loaner Impressions

I thoroughly enjoyed my time with the loaner and I am extremely grateful that you guys allowed me to participate. Still, the loaner kind of came at a bad time for me since I had to send my Yggdrasil A2 back to Schiit for repair the same week I had the loaner. The LKS mh-DA004 is a very good DAC but not near the Yggdrasil A2. It is far more aggressive than the Yggdrasil but somehow this doesn’t result in more detail. The LKS is usually reserved for late-night, low volume level speaker sessions.

My Current gear:

DAC - L.K.S. mh-DA004

Headphone amp – Audio GD Master 9

Headphones – Senn HD650 Kiss, HD 58X; Audeze LCD2C

Preamp – custom built, 2 chassis
*custom Khozmo ladder volume control and input switch
*Dual Neurochrome Universal Buffers as the output stage
*Dual AMB Sigma 22, AMB Sigma 11 power supplies

Amps – Neurochrome Modulus 186 monoblocks

Speakers – GR Research Super 7

Preliminaries:

As a speaker amp: Lets get this out of the way. The Taboo might work out for you if you have 99db+ sensitivity speakers but somehow I kind of doubt it. My speakers are around 95db. I gave this a shot because any amp I use is only responsible for 200 hz and up, plus the midrange and tweeters are planars (4 Bohlender Graebener Neo 10s and 1 Neo 3 per channel). The result was a very, very, very, very delicate and precious ORFAS-type sound and on top of that, was clearly missing detail. Great with vocals and some acoustic instruments but boring and too light-footed. Decware has way better speaker amps, I’ve heard them.

Dual Volume Controls: I did not find this nearly as annoying as I thought I would and I am kind of neurotic about things like balance. I just eye-balled it and it was all good. The pots were really smooth and well-matched. I really thought I would hate this so I am surprised to find myself here.

The lack of a single ended HP output is a bummer but of course I knew this going in. I have an AKG Q701 that I would have loved to hear with It. I have fond memories of listening to the K-501s from a Woo Audio 6.

Lucid Mode: Too hit or miss for it to be a feature that I would consider when buying this amp. The difference was very subtle on most stuff including 50’s and 60’s jazz where instruments were often heavily localized in either the right or left channel. Sometimes it makes a huge difference – John Coltrane’s sax on “Summertime” moves from strictly the right channel to damn near center position. But Wayne Shorter’s sax on “Deluge” goes nowhere and starts to sound weird the more you increase the “Lucidity”.

Overall Impression/comparison:

Comparisons were made with the LKS feeding both the Decware (balanced) and the Master 9 (RCA).

This is a fantastic amp. It gives up some power in the bass when compared to the Master 9, but opens up the midrange just a tad. I found the top end to also be somewhat relaxed when compared to the Audio GD. The result, for the midrange especially, is that the Decware gives you a row 10-like view of the music while the Master 9 is something like row 6. @purr1n made a diagram in the Yggdrasil LIM thread titled “Perceptual Tonal Signature”. To me, the Decware is akin to the DAC2541 in that chart with less of a bass rolloff. The Master 9 is sort of a Frankenstein’s-monster with a slightly lower level A2’s freq response from 20hz up to 800hz, but then remains flat until rolling off on the top end but to less of an extent than the Decware.

Both amps are within my preference range: detailed, adequate bass, and most importantly – an uncompressed midrange, and a somewhat rolled off, controlled, non-annoying top end. Not to throw shade but, amps like the Jotunheim don’t last long in my house.

My educated guess is that the Decware is generally a far more relaxed amp than what I heard from it. As I mentioned, the LKS is aggressive. I find balanced out from the LKS to the Master 9 to be too rough during longer listening sessions. Even on speakers, I watch the volume. Switching to the Yggdrasil is accopanied with a sense of relief. RCA out to the Master 9 tames this quite a bit. But, I never got a hint of this roughness or aggressiveness with the Decware, it was very smooth.

Generally speaking, my preference was for the Decware with thicker, darker songs or songs with a cramped sounding midrange. My preference was for the Master 9 with well-recorded music, classical, or songs with an even frequency response emphasis.

There has been a couple of mentions on how the Decware handles electric guitars a while back in this thread. I kind of very slightly disagree with the laudatory assessments. I found the Decware to be too tonally light with Derek Trucks acoustic guitar on Susan Tedeschi’s “Lord protect my child”. It lacked grit with most metal and “metal-pop” like Evanescence. It got closer on classic rock like The Who’s “Who are you?” and songs like Lenny Kravitz’s “Low”. Don’t get me wrong, it was very good, but I found the Master 9 to be better here on all three of my headphones.

Headphone Specific:

KISS modded HD650 – The Master 9 has an unfair advantage here as my HD650 is kiss modded-voiced to somewhat match the Master 9’s bass output. I kept sticking material on until I got the bass I wanted. That said, the Decware managed to win more than its share of rounds. Lorde’s “Green Light” is sonically dark but has some sibilance. The Decware tamed the sibilance somewhat without altering the tone of the song and was the clear winner. On most stuff, the HD650 just sounded fuller, more powerful, and more refined from the Master 9. But again, this would be an equal battle if I removed some of the material from my HD650 as the my main complaint was the lighter bass I was hearing from the Decware, especially considering what I heard from the HD58X with the Decware.

HD58X – I’m not fully endorsing purchasing a $2500 ~ $3000 amp to drive a pair of $150 headphones, but maybe you should think about it. The slight sense of greater space in the midrange does wonders. The only knock here is that the looser and less detailed bass of the 58X paired with the Decware’s slight bass roll-off will rear its head sometimes and might bother you if you focus on it. The Master 9 bested the Decware on songs where thicker, looser bass and mid-bass roam free like on Lizz Wright’s “Leave me standing alone”. The Master 9 tightens things up here. But, thinner sounding early 90’s pop and R&B sound phenomenal for the most part. Think early Mariah Carey and Janet Jackson’s Rhythm Nation. Most genres sounded good to exceptional with this combo

LCD2C – The Decware is the overall better match for the LCD2C. The Master 9 really emphasizes the things I like least about this headphone. The depressed midrange and the fact that the bass runs away from the rest of the range on everything but decently recorded pop, R&B, and Rap. But man the Yggdrasil A2+ Master 9+ LCD2C is an absolute beast with most pop music. The Decware somehow smoothes out the frequency response, and brings the midrange up by opening things up. Depending on what you are listening to, this can result in a boring sound but overall the Taboo IV+LCD2C combo could be my daily driver and not just for pop.

Conclusion:

Whether or not I preferred one amp over the other was dependent upon what song I was listening to nearly 90% of the time. I am pissed that I don’t get to hear the Taboo with the Yggdrasil A2. The Master 9 is better from the Yggdrasil and I suspect the Decware would exhibit even more midrange voodoo with the Yggdrasil in the chain. Its definitely still on my shortlist for a tube amp with the Woo Audio 22 among others.

 

That's not surprising, considering the Taboo MKIII was, iirc, basically designed for the original, pre-Fazor LCD2...Steve had redesigned it to be the best planar amp he could, and the LCD2 was the planar to beat at the time. It makes a lot of sense the MKIV would still have great synergy with the LCD2C.

 

Decware Taboo IV Loaner Review

Spoiler: Playlist

Anner Bylsma Prélude to Bach’s Suite for solo cello No. 1 in G major
The 5 Browns Malagueña from Andalucia Suite
Pamela Frank/Zurich Tonhalle Orchestra Mozart’s Serenade No. 7 for orchestra in D major
John Williams/John Etheridge Extra Time for 2 Guitars
Duplessy & The Violins of the World Kung Fu
Tool Chocolate Chip Trip
Kaki King Ingots
The Beatles Norwegian Wood
Eagles Hotel California (from Hell Freezes Over)
Carl Anderson Heaven on their Minds
James Brown It’s a New Day, Pts. 1-2
Earth Wind & Fire Shining Star
Los Lonely Boys I Don’t Wanna Lose Your Love (Live at Blue Cat Blues)
Led Zeppelin Moby Dick (from How the West was Won)
Daft Punk Giorgio by Moroder
Cream Badge
Ben Harper & The Blind Boys of Alabama Take My Hand
Horace Silver Quintet Finger Poppin’
Maynard Ferguson Birdland
Phil Woods Rain Dance (Live from the Showboat)
Bill Evans Trio Detour Ahead [Take 2]
Ray Charles/Count Basie Orchestra Oh, What a Beautiful Morning
Macy Gray Redemption Song
Joni Mitchell California

Work has been killing me lately and I didn’t get to spend as much time with this amp as I would have liked. My primary comparison was against a AmpsandSound Mogwai SE (not SEv2). Both are similar SET amps that can drive efficient speakers and headphones. I’ve had the Mogwai for years now and know it pretty well… (it started life as an OG Mogwai, that Justin upgraded to an SE while adding the Jupiter caps from the Bigger Ben).

USBridge Sig -> USB -> Walnut v3 -> SE -> Mogwai/Taboo IV -> ZMF Eikon/Audeze LCD-X/HD600

• ZMF Eikon (32 ohm tap on Mogwai): The Eikon pairs extremely well with both amps. The Taboo IV comes across as a little brighter with slightly rolled bass... the Mogwai has a little more heft to the bass/mids. The Mogwai hits a little harder and may be a little deeper – both have similar staging (mogwai a little deeper) and similar levels of detail. My personal preference is the Mogwai, but I could see others go for the Taboo.

• Audeze LCD-X (8 ohm tap on Mogwai): Decware product page quote “we re-designed the Taboo from the ground up as a planar headphone amplifier that could still be used to drive speakers (instead of a speaker amplifier that could still be used to drive headphones)”. So... I was expecting a lot out of this pairing… I was disappointed.

To my ears, the LCD-X sounded flat, mid-forward and was quickly fatiguing on the Taboo. I would get 2-3 songs in and have to switch to something else. The Mogwai does a fine job with the LCD-x… almost to the PBJ level of the LAUx and LCD-x.​

• HD600 (32 ohm tap on Mogwai): The HD600 paired well with both amps… more different flavors. The Mogwai balanced out the HD600 highs and added some bass presence while the Taboo accentuated the highs. I think the Taboo would be a better match with a 650.

Tubes

The Mogwai is extremely tube flexible – lots of options and you can easily change the personality of the amp. I run some unobtanium 6889 driver tubes, a 5671 5691input tube and the same 5U4 rectifier as the Taboo. I can put in EL34’s and get something thin/weaksauce, RCA 6L6 GC’s and get something a little more mid-focused (but still great bass), or KT88’s, or 6550’s (great tube), etc. IOW, the tube rabbit hole is very deep and very dangerous on the Mogwai… my box of tubes is quite large.

I stuck with the stock Taboo tubes… I assume improvements could be had with different tubes, but the limited options sure simplifies things and makes it easier for those looking for their first SET amp.​

Random Thoughts

• I’ll get this out of the way – I hate the dual volume controls.
• Lucid Mode – interesting. When I used it, I tended to settle on about 10:00 on the dial. But I had it off as much as I had it on.
• Having both XLR and SE inputs is certainly convenient. But individually toggling Input A and Input B for both channels seems a little over the top.
• I heard very little difference between high and low gain.
• Power hum was very noticeable with both the Eikon/LCD-x, but was slightly subdued with the HD600. The hum resulted in a “greyground” during quiet passages that I just couldn’t move beyond. For me, this was a showstopper. But if your music is bangin’, then you won’t really notice.

Conclusion
While the taboo didn’t live up to its planar billing (for me), I do think it is an outstanding amp. Given the price, it is a great option for those wanting a SET but don’t want to spend EC/A&S/Smurf money… it’s very reasonably priced.

Thank you SBAF for putting this on tour… I’ve long wondered about Decware and I’m glad to have finally heard one. Now a smurf amp is the last thing on my list. The loaner program it truly a wonderful thing!

------edit-----
HD600 has Custom Cans Copper Mass Damping kit with bored foam, along with ZMF perforated suede pads

-----edit-----
typo

 

I am glad this is said. On higher Z cans (Atrium, Lcd-2.2pf) the difference was very little. On the lcd-24 it was much bigger and more in line with what you would expect from a gain switch.

 

First off, thanks to everyone who has put this together. It's not often a piece of equipment of this caliber is loaned out so it was fun to take part of it.
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Streamer: Lumin U1 Mini with LPS upgrade
DAC: Mojo V2XA
RCA: BJC LC-1
Headphones: ZMF Atrium, LCD-24, LCD-2.2pf
Tubes: Chatham Potato Masher Recti, Amperex Bugle Boy 6DJ8, all others stock

Impressions are from both my unit (2017 SE full out beeswax caps upgrade) and the SBAF loaner (2021 BAL Miflex caps, those caps being an option that replaced beeswax as the top option). In general the loaner bal unit needed a little less volume, was a little clearer, and had a tiny bit more sparkle. It also felt like it's iron weighed a bit more.
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So the Decware Taboo Mk.IV:

If i had to do a one phrase summary I would say this amp is a "dense brick of powerful mids."

What the taboo really brings to the table is a thick dense plate of midrange. Electric guitars in hard rock ensembles hit you with a force. Thick, meat-on-the-bone, and rich throughout. If you love mids, especially rock guitar mids, this is it. The texture is there, timbre is on the "heavier" side, and the footprint is felt.

The overall sound is very round at the ends. Bass isnt elevated, but it is felt. It is more subbass rumble than mid bass kick, but neither is standout or substandard. Just not noteworthy.

Treble seems to be the same. Rounded but neither a highlight nor detractor. There is still sparkle and a little bit of top end sizzle but if feels like there is a cap there holding it back. Like putting a tight lid of saran wrap on top of your prized casserole, the treble is trying to push out and bend the wrap, but it never escapes. This does tend to kill any air that is trying to be expressed and once again keeps it all pressed back in towards the mids. Sometimes it felt there was an eq slider on the treble that was turned down.

Stage and presentation is pretty flat. I wouldnt call it holographic as the depth just isnt there and it is more like a photography. It is also a little more grey than black background which promotes that dense brick characteristic. Dynamics are also good but shortened by that grey background on the quiet side of the dynamic range.

Detail was good, micro detail being the best ive heard so far. I will say this is the highest tier amp ive trued to date, but i was hearing things i just could not on other amps.

Lucid mode was neat but headphone and track dependant. If it was on, i would not go above 1/3 on the dial. It thickened things up and added presence to background details, but could make things sound fuzzy. Switching lucid off, cleaned it up but it was noticably thinner. I wonder, and imagine, this would be a trip when used with speakers.
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The Atrium worked very well with the Taboo and loved the lucid mode. It kept that big, powerful, and lively feel. Once again guitars felt like you were standing in front of a full amp stack.

The LCD-2.2pf had all of its trademark characteristics fully blown up rather than balanced out. The Taboo was said to be made for this headphone and you can tell why. It gives a lush and velvety signature which was something i had not head before. Laidback without losing energy, syrupy without being molasses. It really is like suede on your ears.

The LCD-24... Hmmmm this was my least favorite. Wasnt bad, wasnt great, i felt it was a little too "grainy" overall. Like an over sharpened photograph, it was a little much.
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Tube rolling had some effect but i felt less changed than rolling in say my BHC. I did not roll the output tubes as although i purchased some sweet Amperex el84s, the glass chipped around one of the pins and i think vacuum was lost on it. The chatham rectifier did keep things tighter than the stock, and the bugle boy 6dj8 added some more sweetness.
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All in all i think most amps have a flavor, the Taboo seems very heavily flavored for it's marvelous mids. And more than other amps i think you need to be ready for that.

 

Decware Zen Taboo Mk IV Loaner Impressions

I’d like to thank @ChaChaRealSmooth and @rhythmdevils for lining up and organizing this loaner tour and Decware for so generously allowing us to check out their amp. I thoroughly enjoyed listening to it.

I’m afraid I don’t have much experience with tube amps at this price point. I followed the common advice here on SBAF to stick with high-performance bargain amps like the ZDT Jr. and the SW51+ until going all-in with a high-end amp, which I did earlier this year when a generous Friend put his Stratus up for sale. On a performance spectrum from the ZDT Jr to the Stratus, the Zen Taboo Mk IV is much closer to the Stratus than the ZDT Jr even though it’s priced half-way between them. The tl;dr is that if you’re looking for a tube amp for orthos, the Zen Taboo Mk IV is excellent, and it offers a high degree of performance for the price (with the caveat again being that I have only the Stratus as a point of reference).


Gear
I compared the Zen Taboo Mk IV with my Stratus using the latest Mac Mini using Roon (Qobuz/FLAC files) via USB to my Gungnir A2 multibit, and then with the ZMF Vérité, Audeze LCD-2 Classic, HifiMan HE1k v2, and the Rosson RAD-0, which I had the pleasure of hearing on a long-term personal loaner from a friend. I used the balanced outs of the Gungnir directly into the Zen Taboo Mk IV (and via a Jensen PO-2XR XLR -> SE converter into the Stratus).


General Impressions
The Zen Taboo Mk IV has many of the stereotypical, wonderful magical qualities of tube amps: there’s a good amount of warmth, richness, and lushness, and the amp has a slightly wet sound to it, not unlike the Stratus. The Zen Taboo sounds spacious and much more holographic than solid state amps. It offers excellent separation and layering, and imaging is likewise excellent. While it has a generally warm sound - or what some would call an inner warmth - it does place an emphasis on the higher frequencies (I’m not sure, exactly, it could be in the lower treble). This emphasis makes for an interesting combination of some pleasant warmth from the lower frequencies through the mids and then an emphasized treble, with an overall tuning that comes across as neutral/bright.


Headphone Pairings
This brighter treble applies across the board with the headphones I used. The Vérité became unbearably and unpleasantly bright and fatiguing - to the point where I had to take the headphones off my head before getting half-way through a track.

The HE1k v2 didn’t benefit from the extra treble emphasis: I find these headphones need warmer or, at the very least, more neutral amps than the Zen Taboo, and the Stratus’s warmth makes the HE1k v2 much more pleasant. Put another way, the Zen Taboo did little to nothing to improve the HE1k v2 over a solid state amp.

The LCD-2 Classic was transformed from a dark headphone into one that was almost unrecognizably neutral. This wasn’t to my taste, exactly - I have the LCD-C precisely because of its lovely darker sound - but these headphones nevertheless did sound very good. I got an immediate sense that the LCD-2C were scaling much higher than with my usual, preferred amp for them, the Mjolnir 1, albeit with a radically different sound. This meant that there were improvements to resolution, imaging, separation and layering, and staging. The Zen Taboo was a step back from the forwardness, as well as the slam and macrodynamic strength of the Mjolnir 1. The bass is still slightly floppy, with neither amp fixing this characteristic of the LCD-2C. With the Zen Taboo, the LCD-2 Classic became much better suited to a wide range of musical genres and styles (I usually use them for alternative/indie rock and electronic music).

The Rosson Audio RAD-0 sounded outstanding from the Zen Taboo Mk IV, so the rest of these impressions will focus on this pairing.


Rosson Audio RAD-0
I’ll type up some impressions of the RAD-0 to post in its own, dedicated thread. But the long and the short of it is that the RAD-0 is reminiscent of the old, warmer/darker Audeze house sound, but without such a significant upper-mid/lower treble dip. It’s much more even and balanced than the LCD-4 (which I own but which, with poor timing, I had lent to a friend while I had the Zen Taboo Mk IV). In other words, the RAD-0 has a lovely rich, thick, warm sound, one that’s really very engaging and immersive, much like the LCD-4, but without as much of the LCD-4’s darkness, bass depth or strength, or the LCD-4’s uneven FR, especially its wonkiness/incoherence as it transitions from the mids up into the treble. The RAD-0, put another way, are some of the most pleasantly-tuned, mildly warm headphones I’ve heard. Were it not for two things, they’d be ideal headphones for me: they suffer slightly from a lack of top-end air, and their staging could be more open, airy, and spacious. The Zen Taboo goes a long way to rectifying or offsetting these issues; while there’s still not much top-end air, the staging does become more spacious and open, and besides being a bit more expansive, there is an appreciable improvement when it comes to the space between and around instruments. In other words, the RAD-0 sounds less closed in with the Zen Taboo.

With the Zen Taboo, the RAD-0 has a lovely weighty and rich sound, one that’s almost thick, thanks to the amp’s slight wetness. The tonality of the headphones sounds correct, a bit warm, but not overly so, nor too bright or dark, and nicely balanced and even and coherent. The mids are lovely. Pianos sound very good - not quite up there with Utopia or the SR1a, but not all that far behind them (and the other two are the best headphones I’ve heard for pianos). Stringed instruments sound convincingly real and are nicely reverberant and textured, although I’ve heard better from other amp and headphone pairings. Brass instruments have good blare and crackle, not they’re as bright as they can be. This was readily apparent with trumpets. They’re not piercing. But they were still a bit fatiguing and could come across as slightly squeaky at times. The same could be said for woodwind; the alto sax didn’t have enough bite and was again slightly and weirdly squeaky. Electric guitars sound very good, with decent - but not the best - bite.

The bass is very good: strong but not overdone; it’s tight enough but with some slight, pleasant bloom - but it’s not bloomy in and of itself. The double bass has a nice sense of being a cavernous, hollow-bodied instrument. Electric basses sound wonderful. The sub-bass is decent but not outstanding, although you get some pretty good rumble.

The treble is lovely and smooth and has decent but not great extension - there’s a bit of roll off (I can’t say how much because my ears don’t work above 14 kHz). Still, you can hear flutes and triangles in orchestral pieces clearly, and they sound right. There’s some sparkle with acoustic guitars, but it could be better. The brightness offered by the Zen Taboo, then, doesn’t transform the RAD-0 into the Utopia.

The staging is very good, as I mentioned previously, although it could do with a bit more depth. Macrodynamics are satisfyingly strong; there’s plenty of percussive impact, but bass slam isn’t the strongest. Resolution’s very good, too, but not at the level of the Stratus. Overall, there’s a lovely sweetness to the sound to this combination, one that’s also very smooth. I think the sweetness comes more from the amp; the smoothness is also a quality of the RAD-0.


Zen Taboo vs. Stratus using the 3 ohm SE out with the RAD-0 (tubes are the Psvane 2A3, LinLai 5U4G, and Voshkod 6N1-P).

What they have in common: a sweetness to the tone; some warmth and richness; a slightly wet, rounded sound but with fairly snappy transients.

The Stratus offers

• a larger stage, one that’s more holographic
• a bigger, more enveloping and bolder sound
  • one that’s richer, more dramatic and exciting
  • and that has more macrodynamic strength
• a more robust sound; piano strikes are more authoritative
• much better imaging, layering, and separation
• greater bass emphasis, and a bass presentation that’s tighter
  • also a bit more sub-bass rumble and extension
• better clarity
• truer timbre - this is a significant difference
• more resolving, better detail
• more sparkle
• better, longer decay
• also more of a delicate sound, one that’s somehow sweeter and with better micro-detail

The Zen Taboo Mk IV offers

• a brighter, slightly more fatiguing sound, one that’s not as smooth and has more etch to the sound - a bit more jaggedness and roughness in the treble
• not as big-sounding, not as spacious or expansive
  • less a sense of being enveloped with sound
• not as rich or sonorous or euphonic
• male vocals are more forward, nicely so
• not the effortless ease of the Stratus

Conclusion
The comparison with the Stratus is clearly unfair, given that it costs almost twice as much, but it’s the only close point of comparison I had for impressions. I should emphasize, then, that the Zen Taboo Mk IV fares poorly only in comparison. On its own, it’s a wonderful amp. I’d be interested in comparing it with something like the Starlett, although I understand that this other DNA amp is less well suited to planars. (With that said, the RAD-0 is not hard to drive). And as I mentioned at the outset, the Zen Taboo Mk IV is much closer to the Stratus, in terms of overall performance, than the ZDT Jr even though it’s priced midway between them.

The comparison with the Stratus is instructive in some ways, though: both amps share a common sweetness to their sound; they’re both slightly warm and beautifully rich, with a slightly wet, rounded sound but pretty snappy transients. The Zen Taboo Mk IV certainly isn’t a more affordable equivalent to the Stratus: its treble emphasis, and some roughness to the treble, means that some care and caution should be applied headphone pairings.

In the end, the Zen Taboo Mk IV pairs nicely with the RAD-0 and, together, they offer a good, tactile sound, one that’s a bit warm, with decent transient attack and a smooth, well balanced sound, with very good technicalities. The pairing could make for a great system.

 

may make sense to merge the 2 impression threads for this amp. The loaner reviews are going in both places...

here's the other thread... https://www.superbestaudiofriends.org/index.php?threads/decware-zen-taboo-mkiv.4854/