Elekit TU-8150, 6V6 Pentode Triode

Click pic to enlarge. Cover off the TU-8150 for convenience. Input 1 in front is used. Note the Op Amp has been removed from its socket (to the front of the lower/right channel 6V6). Note also the red jumper to the back of the same tube is set to Pentode Mode. The 12AX7 is not on fire - there is a decorating diode underneath.

Review: Elekit TU-8150 (DX), Part II

See Part I for Basic Info. Part III  (Smaller Loudspeaker Matching) and Part IV (Input 2 mod) have also been published.

In this article, I tested the Pentode and Triode Modes, and assessed the effects of the Op Amp as well as the difference between Inputs 1 and 2. All using 6V6 and System II (Shindo Monbrisson preamp; for details see Part I). You will notice that I played exclusively LP's for these sessions, so any lack of power should have been instantly evident. High Impedance Earphones, Tweaks and Potential Mods are addressed.

Listening

• Pentode Mode vs Ultralinear Mode In later vintage and modern tube amps, the pentodes are frequently run in Ultralinear Mode (all Mullard 5-20 and Williamson's types are). The reasons are complex and I am not equipped to go into it, but if you google "Pentode vs Ultralinear" you will find a huge amount of basic info as well as discussion out there, some heated. Suffice to say there is a pentode mode revival of sort and there is no consensus on which mode sounds better. While Elekit recommends Ultralinear (same power output as pentode; 2.9 WPC), my experience tells me it is worthwhile to experiment. In the pic above, right behind the output tube is the screen grid resistor, which is connected on the tracks to the one side of the red jumper. As for the other side, the line straight ahead is Ultralinear Mode, tied to the Center Tap; a little outward is the Triode Mode, tied to the plate and one end of the output transformer (hence tying the screen and the plate); and a little inward is the Pentode Mode, tied to the other (B+) end of the output transformer. Pentode Mode Operation Personally I found the Pentode Mode to be more natural sounding. This I think is due to what I perceive as better dynamics (both micro and macro). The effect is subtle but audible. Zubin Mehta's justly famous Mahler Symphony No. 2 (London LP) was rendered in all its splendor - there was enough power for the big moments, yet what captivated even more was the delivery of the VPO in the softer music, the sweetness and heartbreak and transcendence.

• Triode Mode This reduces the output from 2.9 to 1.6 WPC, but with most material I really did not notice the drop in power, even if the preamp volume knob has to be churned up a little more. I did a lot of listening in this mode, which to me seems to add a little more refinement to the sound. The popular EMI compilation of Nat King Cole's Greatest Love Songs (EMI/Capitol UK) can sometimes be a little sharp (I suspect the mastering is digital) but here it was just perfect. More, I just bought a few cosmetically seriously challenged jazz LPs recently, and listening was so good that I finished the crop in just one evening. The many instruments in Oliver Nelson's Fantabulous (Argo) all had ravishing timber, and the swing was well neigh irresistible. Coleman Hawkins was no Brazilian jazz champion but his playing on Desafinado (Impulse) was as usual golden toned and comfortable. Some people could not stand Hank Jones' Happenings (Impulse) because he was using a Baldwin electronic "harpsichord" but I enjoyed its being so different and the Elekit made the best out of the quaintness. Even in mono, Jimmy Smith was king of his instrument. I just dug his interplay with Kenny Burrell, his often partner, on Organ Grinder Swing (Verve). Gene Ammons' The Twister (Prestige) had a starry cast but the mono sound was not quite as good as the others. Nonetheless, all thoroughly enjoyable, as was Mancini's fantastically recorded Peter Gunn (RCA), though I'd not call it jazz. All in all, a magnificent session. Of course, with really large scale music, like the aforementioned Mahler, the Triode Mode inevitably chokes the music a little when compared with Pentode Mode. One should also note that to many the more robust sound of the Pentode is worth more than the more refined sound of Triode.

• Op Amp The Elekit TU-8150 is no doubt primarily geared towards the desktop and earphone crowd, and hence has an unusual arrangement in preamplification. The manual says: "This model contains a preamplifier stage configured with an OPamp to resolve the problem of low gain when connected to a portable audio player..." Gain vs Volume At first I didn't notice much difference, but after a lot of careful listening I did realize that it was best to relatively maximize the preamp gain and minimize the amp's main volume, thus bringing about more refinement and expand the soundstage. To experienced audiophiles, manipulation of the volume and gain (like old ARC gear) can be beneficial. This also means the stock Op Amp has a (very mild) deleterious effect on the sound. Bypass As I don't plan to use phones or portable devices and use a real preamp with gain, I naturally looked for ways to bypass this stage. Looking at the schematic, this Op Amp Preamp stage is before the main volume pot (50K), utilizing power from the 12AX7's heater supply. This gain stage could be bypassed simply by removing the Op Amp. By doing so, the sound improved a notch, a little airier and smoother. It is not going back in my system though I may yet try the OPA2227 that I have.

• Input 1vs Input 2 Input 1 is the frontal 3.5mm mini-jack, and Input 2 is the rear RCA input. The Elekit spec sheet curiously stipulates Input 1 as "Priority". They may be referring to the fact that as soon as a mini-jack is inserted into Input 1, Input 2 is disengaged. In the schematic, one notes that Input 2 is routed through a 10k resistor (R101 and R201) into Input 1. This is probably to equalize the levels of the 2 inputs. Using Input 1 Using an RCA to min-ijack adaptor I re-routed the signal from my preamp to Input 1. Without going through the 10K resistor, the sound definitely had a little more gain, and improved in clarity and presence, all this despite the use of adaptor. Prokofiev's Piano Concertos (Ashkenazy/Previn/LSO, London LP) sounded wonderful - the piano sparkling, the woodwinds characterful and the low brass growling!

• 1 + 1 > 2 Assessed on its own, each maneuver produced only a small improvement. But, interestingly, the overall improvement proved to be beyond the sum of the increments. Now, the music was comfortably expansive and luxurious, but rhythmically sophisticated when called for.

• Potential Mods It is because of the excellence of the amp that I think mods are valuable for users like me: 1) The long signal signal path of the RCA Input 2 is certainly not ideal, but looking at the schematic one can disable R101 and R201 and solder a jumper wire between the RCA terminals and TP (Test Point) 3 and TP4, thus bypassing the Op Amp stage altogether; 2) Even if the Op Amp is removed, because of the associated circuit the signal still passes through 2 more resistors before reaching the 50K main volume pot - the 4.7K resistors (R102 and R202) before pins 6 and 2 of the Op Amp and the 22K resistors (R103 and R203) connecting pins 6 and 7 and pins 2 and 1 before the 50K main volume pot. That is 26.7K (22K + 4.7K) of resistance that can be bypassed if TP3/4 are used. If one uses the RCA Input 2, even with the Op Amp removed, there is a total of 36.7K of resistance before the 50K volume pot, making a total resistance of 86.7K if the main volume is maxed out. One notes that in SET amps the line level signal usually directly goes to the main volume pot, and 100K is the more popular value. One can use jumpers and eliminate those 4 resistors (R102/R202 and R103/R203). One can also try a 100K volume pot. While I would think the fewer resistors in the signal path, the better the sound, I am not about yet to do the (simple) surgery - the sound is entrancing enough, so let it wait, but I am pretty sure I'd carry these out one day (maybe Part IV?).

• High Impedance Headphone The Headphone Outputs are taken from the output transformers, so naturally they are of excellent quality. My 600 ohm Beyerdynamic DT-880 performed even better than my lower impedance AKG 701 (see Part I). Prokofiev's Piano Concertos sound almost as enjoyable as through the horns. Note though the volume had to be cranked up, so head-banging rock fans need not apply, but then this is not their kind of headphone amp. For those who value all-roundedness and tonal splendor, this is as good as I have heard. Although my Schiit Vali 2 and Magni are connected to a different source (an old Proton CDP), I do think/extrapolate that the Elekit surpasses them. From recollection, the performance does not suffer in comparison with my Manley 300B (transformer coupled) and Nagra PL-P Preamps. Mind you, I am listening to LPs!

Highly gratifying!

Perhaps that is enough for now, so further testing, including with different loudspeakers, will have to be treated in the next episode.

AkitikA GT-102 Power Amplifier, Audiomaster LS3/5A, Linn Kan, LM3886

Review: AkitikA GT-102 Power Amplifier, Part I
LS3/5A vs Linn Kan

A Tale of Two Amps It's funny how things are. After building and enjoying the Elekit TU-8152, somehow I was on a roll, and summoned enough resolve and energy to build the solid state AkitikA kit, which has been languishing on my "workbench" for several months.

Kudos First of all, Kudos to Stereophile, where I first read about AkitikA. Even though I don't have that much time on my hands, I am a sucker at heart for affordable kits (think: my cheaptubeaudio roots). Midway through Herb Reichert's Review, I have already decided to buy it. I hope Stereophile some day will get to review Elekit!

Second, Kudos to AkitikA, for offering such a good sounding product at such a low cost. Even more admirable is the fact that they did not raise the price even after the rave review, a rare thing in my experience (unlike Bob's Devices, for example). It has to be said too, that it makes some successful tube kit providers (like Bottlehead and Transcendent, to cite only two) seem overcharging (imho these probably got too successful for their own good, and I know their products; they are definitely too expensive when compared to, say, Elekit).

AkitikA The Official Website is excellent, organized to a T and instantly confidence inspiring. Founder Dan Joffe is a bona fide electronic designer as well as amateur musician (hence I believe his ears), who started it to update Dynaco products. Its niche was, and is, the restoration of solid state Dynaco equipment. The Updatemydynaco pages are fascinating. In fact, the amplifier modules are very similar to those in the GT-102. They almost make me want to get some of the ss Dynaco's on the cheap and do some restoration! It also seems Joffe is a respected figure in some DIY forums.

AkitikA GT-102 This is a stereo power amplifier, with a very successful predecessor, the GT-101. The Stereophile review and the official website are excellent and thorough, so I need to provide only brief comments, only those of interest to me.

• LM3886 Op Amp What really got me interested is that it uses the LM3886 Op Amp, the same Op Amp used in the iconic 47 Labs Gaincard amplifier, which I still own and love, and which has spawned countless Gainclone amps (I completely agree with Reichert's succinct comment on this, which is that most of the clones, including successful commercial ones imho, just don't have that je ne sais quoi quality of the original). In passing, I should mention that I have not formally "reviewed" the 47 Labs Gaincard (4706), but I have commented on it often (should you have the time, use this link and this link for the bits and pieces I wrote; pardon the disorganization).

• Design and Spec's As a tube man, I am certainly lost. You can get all the info you need from the links. The AkitikA website has the downloadable massive manual, which goes into great details on the design for all to see. It is useful to know, unlike the ultra-minimalist Gaincard, it has a lot of power regulation and protection, and power-on relays. I note from the website that not a few users use them with difficult panel and ESL loudspeakers without problem, despite Stereophile's measurements which show the amp working best into higher impedances, which AkitikA agrees with. Official data shows it to be 50 wpc into 8 ohms, almost doubling into 4 ohms, but Stereophile's data is contradictory.

• Component Quality From the pic, you can see that they are of very good quality.

• Price $314 for the kit ($488 for assembled) + $26 shipping. For the complexity on offer, I am impressed. This man is not only a designer, he must be a good businessman who can deliver the goods at this price. On the other hand, perhaps he is not a good businessman as one wonders how can he make a profit. More, there is a 30 day money back guarantee, which I doubt anyone will use.

Building the Kit I did it in several sessions. I did not keep time, but I think it was more than eight hours, part of it due to some mistakes that I made.

• Instructions The manual is massive and, except for a few places, very clear. I do think even a novice will be able to do it. Personally, I like the Japanese manual style (very detailed diagrams and few words) even better, but then this solid state amp has a lot more parts than most tube kits, so I understand.

• The Printed Circuit Boards They are of good quality, but on the small side. Checking all the parts and stuffing the boards took quite a bit of time. No SET amp, this!

• Soldering I must emphasize that one must follow the instructions and use a small solder tip. In many places, traces are tightly spaced and there may only be room barely larger than the solder tip to solder on. I'd surmise some novices will find this a little challenging.

• Wiring Being a Tube Kit Builder actually hampered me a little here. Ground This amp uses a Star Ground that is not so common with tube stuff and that actually demands more wiring. It took getting used to that the ground wire of the speaker post is much shorter than the hot wire. Harness One has to build a harness with different wires and lugs, a little tricky, but all was well explained. But I made a mistake here (see below). Here for connection to the loudspeaker post I substituted my trusted Belden 9497 for the stock cable. Signal Cable This is where I made my biggest mistakes. I followed the instruction on Page 27 that tells you how to dress the cable but did not refer to the full instructions on Page 51. Big mistake. Here I substituted the Gotham GAC-2, which I had used successfully for my PAS 3 project, for the stock one. On the amplifier module, after soldering the +/hot wire to IN, the instruction on Page 27 is to solder the drain wire to IN GND, which I did with the bulkier shield of the GAC-2. Then I wondered why there is no mention of the -/ground wire (which I thought should go into the extra and vacant IN GND). Later, when the RCA Connector Ground Lugs were installed, there was no mention of the drain wire/shield. Non-plused, I went over everything and still scratched my head. Finally I read the instructions on Page 51. On my! Basically it tells you to remove the -/ground wire from the stock shielded cable, and use the shield/drain wire as -/ground! This is most unusual, and I have never encountered this before. I was not about to undo the harnesses, so I soldered the GAC-2 shield onto the RCA Connector Ground Lug, which already had the -/ground wire attached. For the amp module end, I unsoldered the GAC-2 drain/shield, cut it, and soldered on the -/ground. This is as I would make an interconnect, shield attached where signal starts and not attached where signal ends. I am not sure what changes this makes to the sound. I wonder why AkitikA prefers to use the drain as -/ground wire - I'd guess the sound of coaxial wire is preferred. In that case, for me Gotham DGS-1, a coaxial cable, would work even better. I'd suggest adding a line on Pg 27 on the special nature of the cable. Lesson: follow every instruction!

• Operation Mine worked flawlessly from the word go. The relays kick in after a few seconds and one is ready to go. Smooth. And, it is dead quiet.

Listening

• In System III I To test out the amp with as little outside influence as possible, I first employed my System III's front end, comprising the Sparkler S303 CDP and Schiit Saga used as passive preamp. Not to mince words, I was impressed right from the start. Warm Up does not seem to be necessary. Sound is very good from the start.

• Linn Kan I grabbed these for my first session, as they were easiest to get to. These are first generation (I) and employ the same KEF woofers as the fabled LS3/5A. They were placed way in-room, on my Sonus faber stands (kinda near-field listening). The Linn Kan usually prefers close to wall placement as its treble is sharper and bass leaner (than the LS3/5A), and in this position it can sound lean even with tube amps (like my Elekit TU-8300 300B amp). Not the case here. With the AkitikA, the bass is rich, yet tactile, making this the best sound I have had from the Kan I. The Saga is very transparent, and can sound sharp, yet here the combination work superbly well together. The sound is detailed, with notable rhythmic elan. Vocals, male or female, were perfectly rendered, as exemplified by the vitality on offer in Hugh Masekela's Hope (CD, Triloka, OOP); and by the subtle and sinuous delivery of Rokia Traore in Bowmboi (CD, Nonesuch/tama, also OOP).

• Audiomaster LS3/5A (15 ohm) Delighted, I was thus motivated to retrieve my LS3/5A. From the Stereophile review, I knew it'd work a treat and it sure did. The sound was even better than the Linn Kan. Being a fuller sound benefitted the vocals of Traore and Masekela even more. Here I'd say Herb Reichert's findings are right on the money (even if the Falcon LS3/5A he uses are likely sharper sounding than my vintage pair). The sound is so good that I am sure you could do worse by using an inferior tube amp. The AkitikA is warm and inviting, yet its fast transient speed actually complements the LS3/5A, which is usually a little slow sounding with tube amps.

• In System II Further encouraged, I connected it to my System II front end, comprising Sony XA-5400ES SACD/CDP, Technics SP-1200 Mk II/Shelter 201, Thorens TD-125/SME3009i/Denon DL-304, Aurorasound Vida phonoamp and Shindo Monbrisson preamp. The sound gained from System III, richer and with an even wider and deeper soundstage. With a tube preamp, vocals are naturally even better. Shirley Horn's priceless You won't forget me (CD, Verve) was so utterly compelling that I just had to listen from start to finish (which never occurred before). Not only were the fine modulations of Horn's voice as well rendered as I have ever heard, the piano (herself) and the solos of the guests (a starry cast, including Miles) had startling definition and realism, as did the ambience and audience noise (little). On Richard Galliano's Bach album (CD, DG), I too could not help just sampling, and had to listen to the entire Violin Concerto. For either album, I was not at all sure I'd exchange the amp for even the best tube amps.

Comments

• Sonic Assessments Overall, there is little question that the AkitikA is an overachieving amp. The most gratifying thing is, no matter what I played, I was gripped and could not stop listening. I am likely to keep it and the LS3/5A for a quick listening system, such is the synergy between them. The LS3/5A works well with UK classics integrated amps like the Naim Nait, but here it is taken to a wholly new level. Rhythm and Pace The AkitikA even trumps the UK amps in PRaT that the flat-earthers so covet. Solid State? Although the AkititkA is just a little warm sounding but, lest you misunderstood from the listening notes above, it is not tube-like. Although vocals and instrumental timbers are alluring, the treble, though not lean, is not quite as harmonically fleshed out as a tube amp. Tube die-hards may demure, but the AkitikA compensates by its enticing performance in other areas. My Mods Here I must say that my substitution of the signal cable and the loudspeaker cable must have an effect on the sound. For people who don't know, the Belden 9497 cable is a very even performer that I have written a lot on; it almost never sounds bad with any loudspeaker, that I am confident about. The Gotham GAC-2 is a very reasonably priced but superior shielded two-conductor cable, which I used for my PAS 3 project (you can read about its effect here). Both cables are likely more transparent than stock offerings. Note that while I'd say the AkitikA is a little warm sounding, I'd not use the word "dark" at all, and my mods may have contributed a little in this area. YMMV. Gainclone? This is not your ordinary "Gainclone", as it is certainly a much more complicated amp. Does it bear any resemblance to the 47 Labs Gaincard? I don't have the latter with me but I know its sound pretty well. I'd say: 1) with both one just keeps on listening to the music; 2) both have rhythmic finesse, but I think the AkitikA is even more accomplished; 3) the 47 Labs Gaincard is a little warmer; 4) obviously, the AkitikA is more powerful.

• More Coming This is Part I because I intend to further explore this amp with my other loudspeakers, in particular the electrostatic Martin Logan Source. I also may break my own rules and try it out with my 104 db horns (think a Jimmi Hendrix track), which has been the exclusive provenance of my tube amps! I may also take it to my friends and see their reaction. Lots of thoughts, too little time, but this is a fun amp for sure.

• LS3/5A vs Linn Kan Both are superb loudspeakers. The LS 3/5A is a little more emotive and more suitable for in-room placement. Here is what I wrote before about the Linn Kan I vs LS3/5A.

You can rest assured there is more to come.

Elekit TU-8150 6V6 6AQ5

Click pics to enlarge. Right, atop my Wavac MD-811.

Review: Elekit TU-8150(DX), Part I

Update: Part II (Triode vs Pentode; Input 1 vs 2) and Part III (Small Loudspeaker Matching) and Part IV (Input 2 mod) have been published.

Being a long time Elekit fan, I own many of their products and have written a lot about their more recent offerings in my Blog. Should you be interested, here are some links:

Overview: Elekit, Part I
Elekit TU-8500 Full-Function Preamp
This article contains a 6V6 Overview

Imagine my delight when I learned about the new TU-8150. Beside 300B, my TU-8300 can run all sorts of common pentode/tetrode/beam tubes but that does not interest me. IMHO, none of those tubes (including NOS) run as triode can hold a candle to 300B (even current production). So, why does the TU-8150 interest me? Because it can use one of my absolute favorite tubes, the even more lower-powered 6V6, which neither the TU-8300 nor the TU-8200 can. If you run through my blog, lately I have been using vintage 6V6 push-pull amps, and I have been clamoring for a 6V6 SE amp, which I have heard to good effect before (here).

I immediately rang up and ordered one from Viktor of vkmusic, and I got the amp in 2 days. If you are in North America, buy from him, a die-hard supporter of Elekit who has contributed much to the company, who also offers reliable technical support.

This Flyer summarizes the Features of this amp:

DX version  Note that vkmusic supplies the kit as "DX" version, with the following upgraded parts: 1) Amtrans AMRT carbon resistor set; 2) 2 x Amtrans AMCO 0.1 for the Coupling Capacitors. And this is the version I built.

Building the Kit Like all Elekit's, building the kit was not difficult. The manual is beautifully illustrated and logical. Note: 1) the only difficulty I had was soldering the thick metal tabs that anchor the frames of the output transformers. My 40W solder, even temperature-controlled, was just not powerful enough, and it took me several attempts; 2) be careful with soldering the loudspeaker binding post - I had it upside down and had to redo it; 3) vkmusic's upgraded Amtrans resistors are longer than the stock resistors; Victor advises kind of an S-bend to shorten the distance between the legs so as they can be stuffed onto the board, but I found that too elaborate, and just bending the lead right where it exits the body does the job for almost all of them. I had it finished in a couple of days over the Lunar New Year.

In the above pic, note that the 6V6 socket modules are idling. Also note that the board uses pins which one inserts into the main board. The unit shows the 6AQ5 board installed. It is actually below the top board, which is just for anchoring and leveling with the taller 6V6 socket. Look carefully and you will see 3 levels where the sockets are.

Listening (6AQ5)

• Tubes I did a lot of initial listening using the 6AQ5, which is a smaller tube with similar electrical characteristics to the larger 6V6. The stock pair are very late production GE 6005's (note different vendors have different tube options). For the 12AX7 I used an old D-getter RCA grey-plate in lieu of the stock JJ.

• Jumper It was set to Elekit-recommended Ultralinear. The jumper's plastic handle felt loose but I was assured by VK that it is OK, as the same jumper has been used a lot in other models without any problem.

• Op Amp  Op amp was the stock NJM4580D.

• Power Socket Note that the Power Socket is the Figure-8 type (C7/8) which some may frown upon. I used the stock power cord.

• Sound with System II As used, the system comprised the Sony XA-5400ES SACD/CD player, Technics SP-1200 Mk II/Hana EL Cartridge (report to come on the Hana), Aurorasound Vida Phonoamp, Shindo Monbrisson Preamp and YL 4-way horns (104 db). The amp wasted no time in making an impression. My attention was seized by the very good Rhythm and Pace. At first there was a little grain in the treble, which quickly decreased with time, but it should be noted at least half an hour of warm-up is required for it to sound its best. Sound with the 6AQ5 is generally very full bodied and rich, perhaps just a little homogenous - after all, the new tubes and transformers especially needed to be run in (longer than caps and parts in my experience). But given the good transient performance, all was engaging. Dynamically it did a very respectable job. To cite two examples: the audiophile favorite, stimela (track 12) from Hugh Masekela's album Hope, while not as explosive as it could be (this is after all 2.9 WPC), sounded lively, involved and full of microdynamic detail; and Yannck Nezet-Sequin's Bruckner 5th (ATMA, not particularly well recorded) sounded organic and big, as it should, much better than it had previously through earphones. By this time, I was enjoying it hugely.

• As Headphone Amp At this point, I took time to construct my AkitikA amp kit (report to follow). I moved the TU-8150 to the living room, behind my workbench, and fed it with my Linn Karik CDP. Through the AKG-701 earphone sound was luxurious and detailed. Nielsen's three (somewhat quirky) instrumental concertos sounded better than I have ever heard them in the readings by NYPO/Alan Gilbert (Dacapo). The sound was so good I actually played this CD multiple times through the kit-building period. It should be noted: 1) the loudspeaker outputs automatically disengage themselves when a headphone plug is inserted. But I think as a precaution, to make sure there is loading when the amplifier is on but headphone not plugged in, loudspeakers should always be connected; 2) Using the TU-8150 as integrated headphone amp, the volume and dynamics were respectable and sound is excellent.

• Back to System II After I finished building the AkitikA, which took several days, I re-installed it in my System II. Sound was surely a little better than before and I thought it was close to being run-in. I played the wonderful Rokia Traore's Bowmboi. While it was very good, I knew her voice was a little too smoky and that there is more delicacy and sinuous delivery to be had.

• On to System III Desiring a slightly crisper delivery, I switched to System III, comprising Sparkler S-303 CDP and Schiit Saga as Preamp directly into the Elekit. Surely, Traore's voice was how it should be. Similarly, Masekela's men also had more rhythmic snap. This was in part due to the snappier delivery of the Sparkler, and in part due to the non-euphonizing nature of the Schiit, which did an excellent job driving a long interconnect. However, on some material, a bit of shrillness creeped in when played loud. In the end, I still prefer a tube preamp. By now, I knew that I had wrung most of the performance out of the amp, so it was time to move on.

 Listening (6V6)

• Switching to 6V6 It was pretty easy. Only 4 screws needed to be removed to take off the upper chassis. Then I replaced the 6AQ5 boards and its top boards with the 6V6 boards (now only two tiers). I plugged in the pair of 6V6 I had been using in my Grommes LJ5, Sylvania smoked glass VT-107A's.

• Sound with System II Everything else being equal, the 6V6 immediately sounded cleaner and clearer, as if a thin veil had been lifted. Now, Masekela's men and Traore sounded like in System III above, yet when the music got loud there was no roughness. From this point on, I concentrated on music only and here are a few that I really enjoyed. The first was Alberta Hunter's Amtrak Blues (CD, CBS). This lady is truly legendary and her life is an incredible story (wiki entry, make sure you read it). I actually got to hear her live and at the time bought her later The Glory of Alberta Hunter on LP. Her full voice on this CD is a delight and the session men were also very well recorded. And then there is Miles in Tokyo (CD, CBS/Sony), not the best recorded of the many Miles albums, but I positively dig the player of saxophonist Sam Rivers, who only appeared with Miles in those few days but was generally credited for pushing the sound of the Miles Davis Quintet forward. And two LP's were particularly outstanding. Boulez' Varese LP (Columbia) had delectable rhythmic swing and brilliant playing, a marvel from start to finish. Zubin Mehta's Bruckner Te Deum (London) had me dashing to turn down the volume, as the masterpiece opened with a choral fortissimo on an organ pedal. Yes, the amp clipped as I had the volume too high, but I was able to finish the piece at a slightly lower, but still very satisfyingly full level.

Comments Let me cut to the chase: this little amp is now my favorite Elekit amp!

• Operation Ultra steady. I have it on all day and it barely gets warm.

• Sonics It is always hard to describe the sonics of something. For this amp, I would choose Fluent. Many tube amps are easy listening, sometimes referred to as "liquid", but that is not at all the equivalence of fluency, which mandates a good sense of rhythm and superior transparency. Nothing about the TU-8150 grates on you, and everything contributes to keep your interest. Playing disc after disc attests to the superb musicality of this little amplifier with a big heart, neigh, soul!

• As Amplifier As with most flea powered amps, particularly if you play vinyl, personally I'd use this with a Preamp to maximize the gain and delivery of the first watt. However, it will sound pretty good as an integrated amp (my System III's Schiit is essentially passive volume). Volume Knob Setting when used as Amp The TU-8150 employs an IC in its preamp section, so it is not just a passive volume knob on an amp. That said, I found not much degradation when the volume knob is maxed out - no overloading or undue hardness. Dialing back may bring a tad more refinement, but the optimal setting is likely dependent on the rest of the system. I have it anywhere between 12:30 and 3:00 Power My YL horns are 104 db, so I have no problems, even with big pieces, as you can read above. I'd think it will work well with loudspeakers over 90 db in sensitivity. Just for the hell of it, I did briefly hooked it up to the LS3/5A, but even with volume knob of both amp and preamp maxed out, there was only moderate volume; however, even then the music sounded nice and lively, not seriously compromised nor muffled, which to me means loudspeaker matching will not be too difficult in general.

• As Headphone Amp I think this shall make a very nice headphone amp. But make sure the loudspeakers are connected if you even want to pull out the headphones.

• Hybrid? The presence of an op amp in the preamp stage will turn off some tube purists. But I ask myself, do I actually heard sand? Honestly I cannot say I do. The sound is rich and creamy when it is supposedly to. I have heard many all-tube amps that sound a lot more transistory (like German Octave, not to my taste). Elekit has had a long history of using IC/op amp in their products and the designer's skill is apparent.

• 6AQ5 vs 6V6 In my listening, the 6V6 is unquestionably better. I am staying with 6V6 just because I have a large stash. Although electrically similar, the bigger envelope of the 6V6 likely confers an advantage (just as 6SN7 has it over 6CG7). However, I am equally sure the performance of the 6AQ5 can be much enhanced by rolling in older and better tubes. The suppled GE's are coded 82-52, which is from the very end of 1982, just before tube productions ceased altogether. Older 6AQ5's are plentiful and cheap and one can have fun rolling tubes.

• Power Cord The supplied C7 doesn't look very promising. The best way to upgrade would be to buy a C7/IEC adaptor and use your regular cables.

Coming Next I named this article Part I because there are more things that I'd like to test on and that will take time:

• Pentode and Triode Operation These should be very interesting to try out. Triode lowers the output from 2.9 wpc to 1.6 wpc. I think it will work for me but for most others it will be academic.

• Op Amp don't have anything other than the OPA2227 Victor sent me for the TU-8500. Victor told me it is OK to use here too, so I may try it.

• Tubes I may tube roll a bit, particularly the 12AX7. I won't go crazy about it, but I may get a few nice used 6AQ5 to try out.

• Loudspeakers I'd like to try out others, particularly my Almarro M1A, for compatibility, so readers with less efficient loudspeakers can get a better idea on what to expect.

• Power Cord Not my usual area of interest, but in this case I shall seek some improvement using either adaptor or DIY power cord (the C7 female connector is not easy to get).

• Headphones I'd like to try my high impedance (600 ohm) Beyerdynamic.

As I finish writing, I also just finished listening to Strauss' Alpine Symphony, one of my favorites. Great stuff! This is not the best version in performance or sonics, but it was awesome enough!

Note: Part II has been published.

Happy New Year of the Pig

I love Google for taking the care to celebrate everyone's festival and holiday. This year it is the Pig's turn, and you can see the other 11 animals waiting in the wings.

The left pic shows Piggie, friend of Gerald the elephant, in the highly popular children books of Mo Willems that say more about friendship than adult authors. My favorite pig!

Happy Year of the Pig

In the US, it is Chinese New Year's Eve, but in Asia, it is already New Year's Day, and folks had already finished their big family meal.

I wish to say Happy New Year to all my friends in Hong Kong - I miss you fellows greatly. In many ways, HK has shaped my audiophile journey more than the US. Especially in the 90's, exposure to gears, be it modern or vintage, was unrivaled - priceless education.

Pigging Out

It is going to be a quiet evening for us here, but yesterday our unruly crowd made another Long Island trip (roll down page for last trip) and pigged out, not once but TWICE. That was like pre-celebration of New Year for us.

First we visited R. Simon and Andy worked hard to fix his Walker pump, while I continue my "job" of picking fault with the main system. The paella seafood lunch, with risotto and garnished with sweet peppers, was absolutely marvelous.

VAS Stephen brought over the Linn LP 12 he hot-rodded for R. The Akito arm was re-wired with VPI tonearm wire. His ruby stylus Denon "DL-103" was also installed. Together with VAS step-up transformer, the combo seemed to be making good music but I was too deeply in conversation at the dining table to listen critically, only sauntering in and out of the horn room.

Then we re-visited Mark. The Accuphase amp had surely improved the bass but it seemed the treble became coarser. No matter, the real purpose was to eat hot pot, to mop up the leftover from last time.

In all, it augured well for the year of the Pig. The same to you all.

Infinity IRS Beta MFA Luminescence ARC Reference Two Reference 600 Goldmund Studio Madrigal Carnegie

On center rack, under the Thorens TD-125 turntable (fitted with a Rabco arm) is the MFA Luminescence preamp; beneath is the Infinity Electronic Crossover; Audio Research Reference 2 seen on bottom shelf of rack to the left; Goldmund Studio Turntable on rack to the right.

I am truly delighted to publish this article on a second pair of Infinity IRS Beta in our circle. The first pair of course is Andy's (first reported here). Ever since he heard them, our friend Mark has clamored for a pair. After many years he is finally able to fulfill his dream. Congratulations!

HiFi Basics VIII: Home Visits, Peer Influence, Mentors and an Open Mind

Peer Influence Perhaps second to the unfortunate hyperboles regularly dished out by audio magazines (particularly TAS), one of the main reasons why audiophiles are so addicted to the hobby is actually peer influence. The more connections (including internet peers) one makes, the more things one discovers and potentially covets. This is the arguably beneficial aspect of having peer groups and peer support. Unfortunately, there are negative aspects too. The Peril of Like Minds One would think like minds would foster growth, but my experience tells me this is not so with audio. Small Circles of like-minded audiophiles usually have nothing much to offer in terms of good sound. Just three very common examples: 1) DIY'ers and modifiers put too much emphasis on material factors and sneer on commercial gear but their creations are often highly unmusical; 2) the majority of Tube Rollers and Vintage Aficionados are too into historical values to pay sufficient attention to performance factors; In HK, the "LS3/5A is the best loudspeaker ever" crowd mostly know nothing about high fidelity, indeed little about music reproduction. The smaller your world, the less the sound of your system is going to improve. Mentors are important in all fields of human endeavor, and audio is no exception. Problem is, no two individuals are alike, and social norms get in the way. The rare truly enlightened mentor works with the preferences and idiosyncrasies of his protege, to encompass them in a solution, but the average mentor often gets in the way, and forces his solution down the throat of his charge. The important thing is, the protege must grow up and there is always a "let go" moment. Unfortunately, in the Confucian East, where respect for the so-called sifu is taken to ridiculous extremes, we are all often left with a bunch of copy-cats. Astonishingly, "#me-too" is proving far too common in our age, even in audio.

Home Visits The audiophile experience knows no bounds. No audiophile, no matter how much time or money he has, can be said to have experienced everything great (our friend icefox in HK comes close though). Thus it is important to seize the opportunities for home visits in order to broaden one's horizon. But there is a catch from my viewpoint. Current vs Old Gears Unduly influenced by the magazines, many audiophiles believe in progress and foreswear anything but recent gear. This is a BIG mistake, as my experience tells me the best systems all have one thing in common - they have at least quite a bit of older or vintage equipment in them. Put it another way, I have heard many ultra modern systems, including much of the most expensive loudspeakers and electronics covered by TAS (like Jonathan Valin's stuff), but while at best they can sound reasonably good, mostly they don't make it to the best (this Blog has a Year in Review feature, where I list the best sound I have heard that year; browse should you like). Mind you, by no means is vintage anything better - far from it, most adherents don't do so well. But, and this is a big but, the discerning ear is capable of turning good vintage into gold. Stores and Shows For myriad reasons, Stores and Shows usually don't put forward the best sound, but they are important for audiophiles starting out or without peer support, especially in the US, where many are not even within driving distance of a dealer. In a place like HK, audiophiles are much luckier  - there are many stores and many specialize in second hand stuff, including vintage stuff. HK is also so small that many audiophiles get to do a lot of home visits.

Progress? There really has not been progress in audio. Detractors will point to the digital revolution (for it is that) but for us old-timers analog is still vastly better. The modern denizen of the world prides (positive) attitude and individuality, but ironically that is precisely what modern audio lacks, and this lack is unacceptable in audio, a venture into the senses. Beware! Reviewers always say something "tugs at the heart string", but if it is something modern or recent, take it with a coarse grain of salt.

Open Mind Hence, it is important to keep an open mind. While I am a big proponent of good vintage gears, efficient horns and low powered amplification, I am not adverse to other approaches. I still own ESL (the overachieving Martin Logan Source), panel (Magnepan 1.7), dynamic classics (LS 3/5A, Sonus faber Electa Amator II), which I enjoy from time to time. And I am certainly fond of BIG Line Source loudspeakers like the Infinity IRS Beta, as executed by my friends (this article tells you why), even if I personally would not take this approach. There are too many dogmatic audiophiles, all claiming there is only one way to heaven, but none of them are right.

Experiment, fail, stand up again, own, disown - there is no expressway. No amount of internet discussion and queries can substitute for hands on experience. Last, I'd like to say, for every successful system, there are dozens of failures. It is easier to identify problems than to appreciate virtues. Only the trained ear can do that. Aside from appreciation of real music (as opposed to audiophile stuff), getting to experience first hand the various approaches to audio reproduction helps one grow. Persist!

The Mighty Infinity IRS Beta, another pair!

On Sunday, Andy, Kevin, James, VAS Stephen, his lovely wife Jenny and I descended upon Mark's Long Island home to listen to his newly acquired Infinity IRS Beta.

Background This Stereophile Review by J Gordon Holt et al is truly excellent (no one writes like that anymore). Each side has 4 x 12" woofers - making it the equivalent of a 24" woofer. Given enough power, the system certainly can deliver real world dynamics. While touted, as Holt describes, the IRS Beta is certainly not without flaws. The Beta was supposed to be the flagship, but its success spawned the even bigger IRS V, which was regarded by some, including Harry Pearson of TAS, as better and the best (here). Unfortunately, the V's monstrous size and weight (the floor has to support 1,500 lbs), not to mention price, precludes its use for most people. Regardless, the IRS Beta is truly a legend.

Rather than dialing them in himself, Mark basically emulated the settings of Andy, which deviate significantly from the settings Arnie Nudell recommends. Infinity advises to have the bass cross over at 110 Hz, and the three knobs behind the panel to be close to center, which is not how Andy hears it (note too that JG Holt literally did it differently from Nudell; see link above). This is legitimate - after all the knobs have to be used to accommodate the room. It should be said too that the dimensions of mark's basement are quite close to Andy's (by eye).

The system we heard on that day comprised the following:

CD Transport: MBL 1521
DAC: MSB Link (Nelson) with Powerbase
Turntable: Goldmund Studio/Goldmund T3F arm/Madrigal Carnegie Cartridge
SUT: Ortofon T20
Full Function Preamp: MFA Luminescence
"Buffer Preamp: Audio Research Reference Two
Panel Amps: Audio Research Reference 600
Bass Column Amp: MBL

I have recently been evaluating RCA Living Stereo LP's and CD's (article to come), so I immediately played the SACD (CD layer) of Munch's famous recording of Saint Saens' Organ Symphony, one of my all-time favorites. Just a few bars were more than enough to convince me that this system is going to be Best Sound of the Year in my Year in Review, and it is just January! So, I can totally understand the beatific smile on Mark's face. No, one does not come across this kind of sound often, and I reckon most audiophiles have never heard sound like this. You could pick out and "touch" any instrument in the mix, so clear was the soundstage. Most impressive for me were the clarity of the celli and the breathlessly chirping woodwinds, which most systems would struggle with.

This is not to say the system is perfect but the virtues far outweigh the deficiencies. While there was no grating in the treble, there was a certain "whiteness" to the sound. While this is to be expected from ribbons, I did think it should be warmed up further. With vinyl playback, I was surprised by how close the sound was to digital.

MFA Luminescence I had thought the MFA Luminescence (used for phono amplification and fed into the "Bypass" of the Audio Research) would contribute more warmth - the unit of my HK friend jules sounded warmer from memory; but then this model had gone through many iterations and a lot depends on tube rolling too. We played a Carpenters CD, and the voice of Karen Carpenter was definitely too lean. James started to tinker with the crossover frequency, opining that 134 Hz sounded better, but Andy and I would not agree; to me that muddled the sound. What really made the difference was Andy's highly effective move to switch the loudspeaker cables, which fleshed out the sound and restored normalcy to Karen Carpenter's voice.

Goldmund Studio/T3F arm and Madrigal Carnegie Cartridge These are exotic but coveted items.  Andy has the Goldmund Studio turntable but I have not heard it. It is an unusual beast, a direct-drive on a suspended chassis!!! Andy says it has a very special ambience (Roy Gregory of HiFi+ seems to be impressed too in his survey of new direct-drives). Andy told me the one Mark has is a later version with a better JVC motor than the original's Pabst, and the T3F arm is also better than the T5 arm. As for the Madrigal (Mark Levinson) Carnegie Cartridge, it too has a solid reputation. Judging from remarks made in this vinylengine thread, Benz was the OEM and its sound is highly neutral and resolved (various people compared it to the Ortofon MC3000, Ortofon Rohmann and AT OC-9), which jells largely with my own impression. Mark uses it with the Ortofon T20, which is itself on the neutral side. No wonder I found the sound to be quite similar to the MSB digital (I have to say MSB is not a personal favorite either). Next time I visit I shall bring a few SUT's that I think will change the sound.

In all, a fuller mid bass would be beneficial (for all ribbons indeed) and Andy suggested moving the bass columns more into the corners. This was not carried out as the loudspeaker cables were not long enough. As we left it, the bass contour could use some shaping. I thought the MBL (I don't like their electronics, especially in the bass - they all lack a tactile feel) was likely not the best candidate for the job. As this article went to press, I just learned that Mark had recently changed to an Accuphase amp, which reportedly did a much better job.

Rome was not built in one day, and neither would a great Infinity System be. Andy took a long time to arrive at his current settings and Mark had benefitted greatly from his experience. I am sure further improvements can be wrought with time, but it is already mightily impressive.

It was a great day. Icing on the cake was the joyful time we spent eating Chinese Hot Pot, one plain, the other fiery hot. There were fish balls aplenty, two kinds of beef, squid, large prawns, conch, bamboo shoots and other vegetables, all washed down with all kinds of alcoholic beverages. What was particularly gratifying was the long time spent at the table debating various issues.

Here, big thanks to Mark's wife and father-in-law, who had to skip church service to prepare all the food. There was so much leftover that we are already scheming for a return visit to mop them up.