ampsandsound Mogwai Single-Ended Amplifier

Hey guys, I'm a long time lurker and this is probably my only review of any audio gear, while i'm new here, but i have been in this hobby for 15 years now.

Preferences :

I like a warmer than neutral sound with a small kick in the bass, a believable sound-stage, fast transients and I have a very low tolerance for peaky treble. As much as I love detailed sound from my gear, I value musicality, tone and timbre even more.
Preferred Genre of music is - Old school rock ( think dire-straits, AC/DC and Pink floyd) & Jazz

Gears used in this testing :

Roon - Pi2AES - YGGY A1 - Jensen Isomax transformer for Bal to SE conversion - Mogwai SE running KT88 tubes - Focal Utopia/ HD650 / Yamaha HP2 ( modded ) / ZMF Atrium / ZMF Auteur/ Hifiman Edition XS/ Hifiman HE-6 / Hifiman Susvara

Build :
i ' d like to start by saying that i'm not the first owner of this amp and i got it used from a friend back home and i don't think he is the first owner either. So this device has been around the block for a few years and I have been using this for the last year. It is still in great shape, barely any wear and tear. The volume pot is of very high quality and I have had no issues with it being noisy or any tracking issue.

I have legitimately used this amp everyday and have plugged headphones in and out countless times - again the headphone outs are rock solid. I have never had the luxury of owning speakers so the speaker posts to the back were never used.

Right from the wooden chassis to the metal top plate and the transformers have held up very well despite the amps age.

There are also two inputs one that is coupled with a transformer and one that isn't . the inputs can be selected with a switch to the back.. all the impressions are with the transformer coupled input

There are two HP outs as well one 32 ohm tap ( used for this review) and a 300 ohm tap that i use with ZMFs alone

I have the Rev 1. And it has two hp out and a speaker out to the back which can be used as a 8ohm hp out with an adapter. The Rev two comes with 3 hp outs.

So build - built to last the end of days

Support :

Justin Webber from Ampsandsound is an absolute sweetheart. Always ready to help with any queries and tech support. No, I did not know Justin before I got the amp, I started talking to him after and he has always been kind and polite. So in this day and age where even reputed brands find ways to not honor warranty , Justin provides lifetime warranty for his products. So anyone looking to buy these can do so with the utmost confidence that shud the crap hit the fan, he isn't gonna leave u holding the bag.


Sound :

I hesitate to talk about the sound of an AMP in isolation because it's about as useful as tits on a turtle. Synergy is everything. The yggy A1 is a fairly clinical dac that does pretty much everything well but sometimes can get a little bit too intense and “soul-less”. The Mogwai SE, though not the last word in ultimate resolution, has all the soul in the world.

It can be described as a rather full sounding amp with a nice kick in the bass and a fair bit of warmth with specific tubes like the EL34 ( mullards & Telefunkens) and kt88 . The 6l6gc tubes that Justin likes are a little more neutral .

This whole thing started as a quest to build a chain around the utopia & HD650 . The other amps i tried along the way include

Otomon 45 SET amplifier
KOTL - It's a diy OTL amp based on PMillet designs
EC ZDS
Lyrita audio 2A3 SET amplifier
Auris Nirvana
Auris Headonia
EC x DROP ZDT Jr
BHC crack ( Speedball)
A variety of chinese SS & tube amps

They are all fine amps but they all missed the mark by a fair bit. Though neither of my headphones in question are exactly hard to drive, they are quite amp picky.

This chain I linked in the beginning of this wall of text is the best I have heard for these two particular headphones. With the hd 650 there was perfect control in the bass ( mine are modded and sound close to the JAR 650 , IMO) , a lush and thick mid range with no treble weirdness. The sound stage went from a typical 3 blob to moderately spacious ( come on it's still a HD650, the mogwai ain't gonna change that) . The timbre was just perfect.

There was a lot of engagement and musicality that made it frankly difficult to care about all the little things in audio and life in general. The dynamics were off the charts and since i chose to go with the tube rectifier instead of a SS plug the mogwai was just OK when it came to speed

With the utopia it was just an aural orgasm, Bass was punchy, textured with amazing extension and a sense of speed that is eerily close to ESTAT levels. The bass wasn't muddy and it didn't bleed into mids.

The mids of the utopia are as close to perfection as I have ever heard in the hobby, it's liquid and transparent without being too forward like the HD650. The Fabled BE timbre of the utopia was just not present in the upper mids and treble on this chain, and i fully attribute this to the mogwai cos none of the other amps i tried/owned managed to do this. No biggie i know, but as mentioned earlier tone and timbre matter more to me than absolute resolution and ultimate detail.

A few other things to be noted with this amp is that it is very powerful and has a bit of a noise floor. With great power comes a slightly gray background. I have never needed to go past the 11 o'clock point on the pot even with the susvara and the HE6 ( 4 screw grill modded) . with the right tubes i think it is nearly 8W per channel.

The background noise goes away when using EL34 and a 6sl7 combo. The KT88 my favorites - do have a little bit of a noise floor

The sheer number of headphones the mogwai is capable of driving to potential is staggering and it makes this my “END GAME” ( god i hate that term ) amp.

There will be more headphones and dacs, but i think ill be sticking with the mogwai SE for a very long time. At Least until I hear something that knocks me head over heels like the mogwai did.

Other positives include the number of tubes that can be rolled and the fact that most of these tubes don't cost an arm and leg, total tube replacement is under a 100$ if you are patient enough to wait for a good deal.

The amp itself is a little expensive but I think its well worth the asking price.

I hope you guys enjoyed my ameteur attempt and verbalizing the virtues of what I consider one of the best amps. If you din't enjoy it, Please don't hold it against the mogwai .


Cheers and happy listenin

I have been a fan of Justin Weber & Ampsandsound from the beginning. I first heard his name on the Klipsch forum, from there we began our association (friendship). I contacted Justin because I was in a position where only Headphones were possible in my living space. After a brief discussion I bought his 2nd SE84 (First Version) it was quite petite in structure but it offered a HUGE sound, Very Musical. I have bought 4 more of Justins amps in the interim All of which were fantastic amps in there own right.

Enter my latest dealing with Justin the MOGWAI this was Justins personal amp as you may imagine it has all the bells and whistles, Like the input CineMag Transformers. 2 Years ago I was finally able to get back to speakers, I had turned my back on headphones. I was concentrating fully on the speaker aspect of audio, I built a respectable system surrounding my DIY open Baffles with which I am very HAPPY. I thought headphones were a thing of the past. Justin offered to sell his personal Mogwai and from all the press I thought why not all his other amps were great and It has speaker taps.

Mogwai offers 3 wpc in either speaker taps or Headphones (no dividing network) it should drive my single drivers with ease. The Mogwai came packed in Justins usual over the top packing fashions took me 20 minutes and a few choice swears to see the actual amp. (I Love that). Of course I tried the amp first with my main speakers and while it performed admirably I knew rather quickly I would keep my Decware SE84c monos in that position. I no longer have good or even decent headphones, what I do have is a pair of highly regarded (Rightfully so) Final Audio E2000 IEM

Mogwai is OVERKILL but what the hell, both are here and no harm can come to either. I have spent several hours now with that combination to my wife's chagrin I am now on the hunt for proper headphones. (that speaks volumes to me alone). I was not prepared for the experience I was about to have with Mogwai. For me music needs to pull out emotion if it cannot I tend to be underwhelmed, I also live for PRAT and realism. I want the performer in my room singing to me & me alone. I want to have involuntary movement, spontaneously get up and do a dance, play my air Drums & Guitar. I absolutely Love it when the little remaining hair on the back of my neck stands up and sends a shiver down my spine.

The Mogwai has done all that but there's more I was actually shocked last night playing Neal Diamond "I am I said" I got very emotional to the point tears actually welled up in my eyes. The song triggered something in me that it failed to do on my speaker setup. Stevie wonders Superstition had me up on my feet acting like a fool to the delight of our boys & my wife. The Mogwai offers as I expected a superb balanced sound extended bass and treble (though never harsh) , and a glorious tube mid range. I never expected to be brought to tears and forced to look at headphones yet again.

For me there are no downsides when it comes to sound using the Mogwai. Thank you so much Justin Mogwai is a grand slam my friend.

Disclaimer: I am very new to this hobby, this is my very first review, and my impressions are to be taken with a grain of salt as I have limited experience with headphones, DACs, and Amplifiers. I am still learning how to accurately describe what I hear and convey it to others accurately. The Gizmo action figure is mine, does not come with the amplifier and was added by me to the pictures. 
 

 
 
 
It was my first Canjam, I planned on taking my time, visiting each booth, and enjoying everything this experience had to offer. Most importantly, however, I was determined to come away with a new amplifier for my beloved Audeze LCD-4s (200 ohm). I went from Audeze to Cavalli, Chord to Questyle, Schiitt to Cayin ... I was left wanting. Finally, I arrived at the Ampsandsound table, the beefy Mogwai stared at me as if to say, "I won't disappoint you". Justin Weber, owner of Ampsandsound, arrived and we exchanged pleasantries. I unpacked my LCD-4s, connected my source material and turned up the volume. Wow. I was at my desired listening volume, but I was compelled to turn it up until the sound became distorted. The volume soon became unbearable, yet the sound was still clear and undistorted. Wow. My search was over, Justin was kind enough to offer a show discount, I called dibs on the Mogwai, we shook hands and I departed for the day, but regularly returned throughout the weekend to have extended listening sessions with my new amp. 
 
 

 
 
The Mogwai is sturdy and built like a tank. The unique design has all the inputs on the top plate, towards the back of the amp, including the power adapter, speaker connections, RCA inputs, and the 1/4" single ended input. Towards the front, the input bulb (6SL7) is flanked on the right and left by the output bulbs (KT 88s). Towards the front left is an volume knob. 
 
The Mogwai replaced my former DAC/AMP combo Burson Conductor Virtuoso 2. My set up for this review: Macbook Pro, Chord Dave, Mogwai, LCD-4, Utopia (borrowed from a friend), Nordost Blue Heaven Power cables, Nordorst Blue Heaven RCA phono interconnects, and Nordost Blue Heaven A/B USB. 
 
The Mogwai's sound is lush and warm, providing a large soundstage and excellent bass extension. The highs are rolled off a bit, eliminating some of the harsh peaks some headphones possess. For this review, I used both the Utopia and LCD-4 through the Chord Dave's built in amplifier, and then through Mogwai (Chord Dave in DAC Mode).
 
 

 
 
 
The Chord Dave drives the Utopias well, and provides a large soundstage, excellent instrument placement, and detail. However, driven directly from the Chord Dave's amp, the Utopia is too bright for my taste, and the fatigue makes longer listening sessions difficult. I winced as Adele hit her high notes in "All I Ask" and as the crowd applauded at the end of Diana Krall's "A Case of You". Metallica's "Enter Sandman" was only enjoyable only at lower volumes. Powered by the warm Mogwai, however, those harsh highs were wonderfully masked. The bass had more authority and extension. The soundstage was widened. With those harsh highs neutralized, and the volume turned up, the music was not only heard, but felt. I could hear Diana Krall's lips separate and inhale before her intoxicating voice filled my ears. The drums in the beginning of Disturbed's "Down with the Sickness" were heard and felt like never before. A friend who heard the combination of the Utopia paired with the Mogwai and reported in our discord channel that he just had his "Mind Blown".
 

 
 
The LCD-4s powered through the Chord Dave's amplifier left a lot to be desired. It lacked the power to effectively drive the LCD-4 to its potential. All the magic of the Chord Dave was on display, albeit at a distance, as I was unable to turn up the volume of the amplifier to an enjoyable level before it began to distort. It's as if you are on a phone call in a noisy area, and you cover your other ear in an attempt to concentrate on the voice of the person you are talking to. Through the Mogwai, the magical bass of the LCD-4 was heard and felt with authority.  Instrument placement and separation was wonderfully accurate, and the soundstage was again widened. The drums and cymbals in "Enter Sandman" were authoritative and I could almost feel the power of the swing as the drummer struck his instrument. With the Mogwai, the LCD-4 could be listened to crystal clearly at higher volumes, making it feel as if Adele and Diana Krall were not only singing to me, but for me. Eric Clapton's "Layla" had me at the table just off the stage, each instrument wonderfully separated from the other and perfectly placed. The Mogwai enhanced the already beastly bass of the LCD-4 and brought to life the excellent detail retrieval of the Chord Dave's DAC. 
 
Overall, I would describe the sound of the Mogwai as warm, detailed, and laid back. It is not fast and dynamic. When I listen through the Mogwai, I feel the music, the emotion, the excitement and I can do so for extended listening sessions without harshness or fatiguing. It pairs wonderfully with bright headphones and enhances all the best features of warm or darker headphones. It has an excellent midrange, putting the vocals up front and in your face. The sound stage is large and instruments are well separated and accurately placed. The bass is tight, palpable, and not overly extended. Other impressions I have read make a point to say the Mogwai responds well to tube rolling, although I myself have done very little tube rolling, so I am unable to offer suggestions and pairings. 
 
Justin from Ampsandsound was awesome throughout the whole process, from demoing to shipping the Mogwai. After it arrived he was always available to answer my questions and was eager to hear my impressions. I have one minor gripe with the Mogwai, and that is the headphone input is in the back, making it tedious to connect and disconnect if it sits inside a cabinet or inside shelving. I relayed that to Justin and he said he is looking into rectifying that with future models. 
 
The Mogwai is made in the USA and retails for $1850. The following specs were taken from the Ampsandsound.com website. 
 
Specs:
Input impedance is 10K ohm with alps pot, .5v for full power.
Input Sensativity 800mV peek for full power out.
32ohm power: 1.8watts RMS @ 1khz, 7.6VRMS
Frequency bandwidth 20hz -1db to 20khz -3db @ 500mw output
Frequency bandwidth 20hz -1db to 14khz -3db full power
Noise on 32ohm tapp @ 580uV
8ohm power: 3watts RMS @ 1khz, 4.7VRMS
Frequency bandwidth 20hzhz -3db to 17khz -3db @ 2watts
Noise on 32ohm tapp @ 340uV

Ampsandsound are an amplifier and loudspeaker builder out of Southern California. I discovered Justin Weber and team through Head-Fi, when reports of their Kenzie headphone amps appeared. Since then, I've kept an eye out, and even considered their 2 channel amps for my system. The Bigger Ben was interesting, for sure...until I caught word of the Mogwai.
 

The Mogwai (US$1850) is a single-ended class A tube amp, that employs 2 (one per channel) EL34, 6L6GC tube, or one the many variants available (KT66, KT77, 6CA7, KT88, 6550). The input is handled by a single 6SL7. This point had me jazzed - I've plenty of these power tubes around from previous amps, and was actually daydreaming about how great it'd be to have an affordable low watt, single-ended amp I could work with. After a couple calls and some deliberation I committed. I was able to grab it when they were offering the show discount.
 

 
 
Justin Weber was quick to respond to all inquiries, and happy to discuss his products. In addition, he delivered the amp before his original target date. The excellent service is much appreciated and deserves mention.
 
Note: Justin does recommend that you do not run both speaker wire and headphones simultaneously. This is due to the fact that there is no voltage divider network, and both outputs are wired directly to the transformer. You will get the best performance this way. I assume for most, this isn't an issue as the Mogwai will play the role of headphone amp most of the time.
 
The speaker binding posts, headphone jack are high quality - everything you might touch feels solidly built. With the Audioquest Nighthawks, there is no noise apparent when the volume is set at my usual level (roughly 9 o'clock), and no music is playing. The Mogwai runs quiet. Of course, as I turn the dial up toward 12 o'clock the noise becomes apparent - sensitive 'phones.
 
Listening:
For all listening, I used a Sylvania 6SL7 V-229 on input duty. My source is the Clearaudio Concept MM 'table and the phono pre is the Parks Audio Budgie.
 

 
 
I had three sets of power tubes I wanted to try out. With the KT66 installed, the sound was spacious. I heard a larger stage with remarkable depth and layering. Overall, a I heard a balanced sound across the spectrum, though they are lacking in bass weight and presence. I've read these Gold Lion tubes take hundreds of hours to settle in - maybe the low end will improve over time. Definitely less mid-forward compared to the 6CA7-Z, but they projected a holographic stage. Paired with the Audioquest Nighthawks, the sound was dynamic and addicting. The Mogwai, Gold Lion KT66 and Nighthawks make good company.
 
Next, I tried my Gold Lion KT77s. These are great tubes, and sounded fantastic in this setup.
 
Currently, my favorite tube in this setup is the PSVane 6CA7-Z treasure tube. It delivers luxurious mid-range, extension on both ends of the spectrum, and all the nuance I want. It's a very engaging and commanding sound. A ton of drive and grunt - even though I was optimistic, I wasn't expecting such killer performance.
 
Ok, so some detail around the Mogwai's performance driving my Tekton Lore (98db) floorstanders:
On Allison Miller's latest release with her band, Boom Tic Boom, I'm hearing more of the room even with the luscious mid-range. Kirk Knuffke's cornet has plenty of both breath and body. The kick drum moves air like you'd expect and the upright bass has a ton of woody tone and blossom in the lower reaches.
 
As for electronic music:
The second track on James Blake's record, Overgrown, has some deep reaching synth bass notes. The Mogwai with the 6CA7-Z delivered on this track with great extension, though limited power and grip. Of course, you're not gonna get full control over those drivers with this amp, but it delivers very satisfying bass. It is tuneful and with plenty of texture - that's also the 6CA7-Z's. The quality of bass in the more common bass guitar range - both acoustic and electric - is excellent. I've been told some prefer KT88 tubes for their linearity and exemplary low end performance. While, I don't have any on hand, I'll eventually give it a go.
 
Overall, the Mogwai's circuit is transparent - all tube swaps were easily apparent - and, this is certainly one of it's strengths. It's also responsive to tube upgrades. You can roll (affordably!) to your heart's content. This was key for me. I'm currently limited to the Nighthawks for testing headphone performance. In this area, the Mogwai delivered quiet performance, musical and commanding sound, and with tons of headroom. I hope to have another pair of headphones to try out soon.
 

 
This is a heck of a lot of amp for the money.
If you want a stout, quiet tube headphone amp, and dig rolling, then the Mogwai is a great choice.