Elekit TU-8150, Almarro M1A, Dayton B652, JBL L20T, Micromega MyDAC

Dayton B652 on top of Almarro M1A. Click to enlarge.

Elekit TU-8150 (DX), Part III
Almarro M1A vs Dayton B652 vs JBL L20T
Review: JBL L20T, Part III
Review: Micromega MyDAC, Part III

*Elekit TU-8150: Part I (Basic Info; 6AQ5 vs 6V6), Part II (Pentode vs Triode; Input 1 vs 2), Part IV (Input 2 mod).

*JBL L20T: Part I (Basic Info), Part II (partnered by SMSL T-Amp, interesting contrast to partnership with Elekit).

*Micromega MyDAC: Part I (Basic Info and Test), Part II (loose ends, including desktop).

I didn't really want to switch out my big horns, but in the name of thoroughness, there was still ground to cover. I tried out other smaller loudspeakers for a glimpse into real-world compatibility, so as readers and potential buyers can judge for themselves.

Horses for Courses In so doing, I discovered that, due to the design, it was more complicated and time consuming than I anticipated and I had to re-think and even partly unlearn what I had found before. However, as a result, I learned more than I thought I would! Now, I am pleased.

Due to the issues involved (differences in gain structure between the 2 inputs, as well as the presence of an Op Amp preamp stage), the Listening Notes are organized a little differently from usual. Readers should cross-reference with Part II for best understanding.

For most of the listening I used my System II front-end: Sony XA5400ES CDP; Thorens TD-125/SME 3019i/Denon DL-304; Aurorasound Vida Phonoamp;  Shindo Monbrisson Full-Function Preamp. Cables are various Gotham for interconnects and Belden 9497 for loudspeakers.

Listening Notes

• The Reality of 2.9/1.6 Watts When it comes to such flea power, I probably have experienced more than most people, including SE fans. My own Sun Audio VT25/10 SET amp (estimated 1.5-2 Watts) worked reasonably well with my Klipsch La Scala. My 45 amp (estimated 2.5 Watts; DIY'ed by a friend) worked superbly well with both my La Scala and even Tannoy Canterbury. I have heard my friend's Sun Audio 6V6 SE amp work with his Altec 605, and another friend's Sun Audio 45 SET amp (same amp as the VT25/10, just slightly differently configured) work well with his Lowther. But certainly all flea powered amps are not all created equal, and the rated output power, like much else measured in hifi, is only an indicator. A 1.5 Watts Western Electric Push-Pull Amp, like the WE 46 (here) sounds a LOT more powerful than a SE(T) amp of equal or higher rating (the same also holds true of even higher powered SET amps - a Wavac or Verdier 300B sounds a whole lot more powerful than, say, a Spark 300B amp). Preamp For low-powered amps, it is usually highly desirable to have a preamp with good gain. You need all the help you can get for that first watt. Forget about "Straight Wire with Gain", or passive preamps (a TVC with gain may be an exception). So for most of the listening here I used my Shindo Preamp, and maxed out the volume of the TU-8150. Of course, the TU-8150 does have a preamp section in the form of an Op Amp, which makes things a little more complicated, as we shall explore. Volume Setting When used with a preamp, keep in mind that in the TU-8150 the volume pot is after the Op Amp, so it can be maximized when used as a power amp.

• Room Size and Effect For such flea-powered amp, I feel compelled to say something about my room, so as to put things in context. Mine is around 300 sq ft, large for small loudspeakers and low powered amp. However, as you can see in the pic, my bookshelves are in-room and near-field (my seat is right behind the Thorens TD-124 turntable), making it easier. Thus, the sound would have less bass than placement closer to the front wall (easier for the rear-ported Almarro and the front-ported JBL than the infinite baffle Dayton), but the room is well energized and the large and open soundstage is good compensation. But if your room is smaller (but not too small; otherwise you might as well go desktop), that helps.

• Loudspeakers Used Some of my smaller loudspeakers, like the LS3/5A's and Sonus faber Electa Amator are not good candidates. I round up the usual suspects. Almarro M1A The Almarro M1A is one of my favorite bookshelves (reviewed here). While I know the 89 db, 6 ohm loudspeaker works well with SET amps, I really wondered about one as low powered as the TU-8150. As we shall see, it was hardly a success. Dayton B652 This $30-35 loudspeaker is a wonder (reviewed here)! Although not for head-banging stuff, it does well with most acoustic music. Like the Almarro M1A, the B652 is also a 6 ohm loudspeaker. Its sensitivity is spec'ed at 87 db, lower than the Almarro, but it seemed to play louder and with more ease than the Almarro. I attribute this to its first-order crossover design, which usually are easy to drive (witness Loth-X, Reference 3A and B&W CM1, to name a few). Not at all a bad job, but... JBL L20T I dragged this pair out last, not expecting that much. It is a wonderful loudspeaker (reviewed here), but from my experience, large and classic JBL's usually prove to be much less SE amp friendly than Tannoy's of equal sensitivity rating, not to mention Altec and Klipsch. But this is the smallest model, which has about the same volume as Almarro, but much larger than the diminutive Dayton. It is rated at 87 db, same as the Dayton. Notably, the impedance rating is higher than both Almarro and Dayton, at 8 ohm. This may be of some import, as we shall see later.

• Op Amp In Parts I and II, with my 104 db horns, I preferred to bypass the Op Amp (removing it). And so I started this way. But with these smaller loudspeakers, even using the louder Input 1 the preamp volume had to be cranked all the way up. Even then the sound was not too dynamic. Obviously, for more inefficient loudspeakers, the Op Amp is necessary.

• Input I vs Input 2 I started with the less loud Input 2 (RCA). Both the Almarro M1A and Dayton B652 played pretty well, but it was clear the Dayton was louder and more lively. On orchestral music, the M1A's texture seemed a little thick in comparison, which I took to be an indication of not enough power. I then switched to Input 1 (with 3.5mm to RCA adaptor) and surely the sound immediately perked up, especially for the M1A. However, as the Op Amp is in use now, the preamp volume knob had to be carefully controlled as otherwise overloading can be heard (in the case of M1A). Even with no overloading, it was clear that, compared to Input 2, though more incisive, the sound lacked body (lean midbass and bass). What I am not sure about is if this is just a question of loading, or if the (low) quality of the 3.5mm adaptor has something to do with it. I thought to DIY an adaptor but that would have to wait.

• Ultralinear Previously, in Part II, using my horns, I preferred Pentode Mode to Ultralinear, and so with these smaller loudspeakers I started with Pentode. But the more I listened, even with careful attention to overloading, I found the distortion to be bothersome at high level. At first I thought that was due to clipping or overload. Remembering that Ultralinear reduces distortion, I switched back to Ultralinear and was amazed at the much cleaner sound.

• JBL L20T After I thoroughly tested the Almarro M1A and Dayton B652, I was a bit frustrated to be honest, particularly by the M1A. And so I hauled out the heavy vintage JBL pair with a heavy heart, so to speak. As soon as the music started I almost jumped out of my seat. GREAT stuff and a dream match that only happens once in a while! Everything became more three dimensional, more vital, and that tone! A revelation, Amen. Even using Input 2 the sound now had dynamics and scale that sounded like much larger loudspeakers. I had been listening repeatedly to Bernstein's exemplary late DG recordings of Copland's Appalachian Spring (LAPO) and Brahms 4th (VPO). All the loveliness and lyricism of the scores were brought out like nothing before, yet the proceedings felt tight and inexorable, which these scores also need. The volume was cranked pretty high up, but even with the Op Amp in place there was no undue "sandy" texture - mass strings had body and sheen. Only when the volume got really loud did a little bit of steeliness creep in, but that is expected as the distortion rises, and even pure tube amps would do the same. When I start discussing the music, you can tell I am beginning to really enjoy the music rather than just dutifully digging out facts for this article. Some albums I just had to play more than once. Kulanjan, the great collaboration between Taj Mahal and Toumani Diabate (Hannibal/Rykodisc) was simply stunning. The contrasting timbers of the guitar and the African Kora and the modulations of the 2 male and 1 female voices were effortlessly, and mellifluous. I know this album well, but as rendered by this humble pairing of Elekit and JBL, it is the best I have ever heard it. Rhythmically it has more swing than even on my horns! And in Kancheli's Lament, every whisper of the violin (really low in volume) as well as volcanic orchestral outbursts were highly atmospheric. This combination gets to the meaning of all kinds of music! Phono Playback So far with the small loudspeakers I have tested only with CD. The extra gain required for Phono proved taxing for the M1A and even the B652. But it is a different story for the L20T. Through the Aurorasound Vida the sound was irreproachable, lively and detailed. On Neumann's Leipzig Gewandhaus Ma Vlast (a late 60's East German recording, first issued in the US on London LP, so many later reincarnations, including CD, were mostly of German origin), the tonal splendor of the Leipzigers and the majesty of the reading were utterly compelling. A great but little known recording, extremely well recorded to boot (as is usual for East German era stuff). Similarly, Haitink's first Mahler 9th (Philips) displayed a cavernous soundstage in which the famously warm Concertgebouw woodwinds played echt characterfully, and the burnished brass tone! And William Tell, in that greatest of all Rossini Overture recordings, Piero Gamba/LSO (my LP is a cheap latter-day Holland London pressing), had an adrenaline-infused and BIG sounding Alpine storm (which much predates Strauss' essay, and I heard a chirping woodwind figure that likely was quoted by Strauss). Wow!

• Direct In I wanted to see how the preamp fared without a preamp. I used System III's Theta Data Transport and connected it to my Micromega MyDac with a Belden 1694A, fed it into Input 2 and adjusted the volume using the TU-8150's volume knob. Wow! I must say I was wooed yet once again by the Micromega! The fantastic rhythmic expression was evident with Kulanjan. One day I'd like to match it up with my Sparkler (which I have brought with me to NYC). The sound was really lovely, and when I switched back to the Shindo it was evident the texture was thickened by tube. Some may prefer the greater incisiveness of Direct In, but when running multiple sources (phono) and playing large orchestral works the addition of a preamp adds needed weight and punch, considerable advantages for classical listeners like me. 

Comments

• Elekit TU-8150 in General Though all designed to a price point, all current Elekit products have a reasonably muscular sound and driving power. However, the TU-8150, being the lowest in power, does require the potential user to have a clear goal in mind. 6V6 The cheap and ubiquitous, yet legendary 6V6 tube again reveals its glory. What a sound! There is not much point to run it as a triode (halving its already meager power), since it sounds so good in Pentode (with horns) and Ultralinear (with smaller loudspeakers). Warm Up With the Op Amp in situ, around half an hour of warm up is needed for it to sound its best.

• Elekit TU-8150 for Desktop/Headphone Although I don't have a desktop at the moment, I have quite a bit of experience, and actually think this amp is well nigh perfect for desktop/headphone, and I am sure it was designed with such users in mind. Although low in power, Its superbly detailed and rhythmically sophisticated sound, allied to excellent headphone output, is ideal for the task. Dayton B652 The Dayton illustrates this. It may not be able to energize a room like the much larger JBL L20T can, but it never puts a foot wrong. If I were to build a serious desktop, I'd add a subwoofer (there are good choices even around $100) to flesh up the sound.

• Elekit TU-8150 for In-Room Small Loudspeakers As my experience shows, it may take some time and patience to come up with a suitable partner. Given the very close sensitivity figures of the 3 loudspeakers in question, I can only surmise that the success of the L20T is partly due to its more tube-friendly (higher) impedance (and in the link to my previous article on L20T provided above we know for sure its impedance curve is utterly benign). Based on my experience I'd say it is better in general to have loudspeakers over 90 db's in sensitivity. News Incidentally, recently both Stereophile and TAS recommended in their April issues an affordable high-sensitivity loudspeaker that those interested may want to look into (since you are reading this article, you are probably one). The former reviewed the $549, 96 db, nominal 8 ohm Klipsch RP-600M (not online yet, but read the review in sister website cnet); the latter the $900, 91 db (but 6 ohm) Tower JBL Stage A190 (here). Being a fan of both Klipsch and JBL, I'd love to hear them (unlikely). By my estimate, the Klipsch will surely work a treat (due to its super-efficiency and higher rated impedance), whereas the JBL will likely too. The good thing is, the TU-8150 is so small and light that you can take it to audition loudspeakers!

• JBL L20T This is a gem that surprises by its performance with 2.9 watts. It confounds me because my 5 db more sensitive, but much larger JBL 4312 (12" woofer) does not work that well with 300B (~8 watts). But, good news to me! I am not sure what I like most: the effortlessness, the sweet and articulate midrange, the warm mid-bass/bass, the intimation of a larger scale than the physical size would indicate. All of it! A thought on matching: in the L20T Part II (link above) what I wrote of my impression of L20T vs Almarro M1A when driven by T-Amp was not at all similar to this round. So, you have been warned that synergy is involved and extrapolation, like much reasoning and measurement in hifi, may not always hold court.

• Micromega MyDAC I have never previously heard my Micromega in my US systems. Suffice to say, this brief outing really tickled me! I prefer its sound to the flagship Sony SACD player - more rhythmic engagement and flow. As a matter of fact, just before this is written I briefly moved it to System II and did a direct comparison and my impression remains the same. Perhaps I shall write an article on this and Sparkler in the future. A killer budget DAC, no, a killer DAC, period.

Postscript: This article is long in the making. I am glad I was more than repaid for my efforts. The next installment may take a while. I have to get back my Elekit TU-8500 preamp, match it with the Elekit  for a listen and then roll its OPA2227 into the TU-8150. Salut!