28 November, 2023

BRZ A20B 6N2-6Π3C SE Amp vs 6L6GC 5881 EL34 12AX7

Click pics to enlarge. Top, on the amp, Mullard box-plate 12AX7 (on adaptor) and Tung-Sol 5881. Front, from L to R, Valve Art Chinese EL34, East German RFT EL34, Mullard xf1 large brown base EL34, Executone 6L6GC, 6SN7 adaptor.
Review: BRZ A20B 6N2-6Π3C SE Amp, Part II, Tube Rolling
Letter from Shenzhen (23-14): Digging through my Hong Kong Tube Stash

Overview: 6N2/6N1 Tube Rolling Guide, Part I
Part I gives details of the amp and slight modification.
Part III is quite substantial and a must, as it covers Tube Rolling of 6S_7 types, Capacitor Mods and Preamp Matching!

Note that basically Part II and III combined gives a detailed Overview of 6N2/6N1 Tube Rolling!

Left, adaptor for 12AX7 https://m.tb.cn/h.5kfN5Fb

Tube Rolling As the closest equivalent to the 6N2 is a 6AX7, which nobody has, one would want adaptors that would allow use of the much more ubiquitous 12AX7. They differ only in how the heaters are wired (the 12AX7 heaters can be wired either 12V or 6V). and the adaptor's small circuit board takes care of the conversion. One can then also roll in the extended lower gain 12A_7 family for different effect. Without need for adaptor one can also roll in pin compatible but similarly lower gain 6CG7 (like a larger 6V U7). One can also roll in 6SN7/L7 (like an even larger 6V U7+) with yet another adaptor. These 2 tubes, especially the latter, draw more current but the amp should be OK with them.

Right, adaptor for 6SN7 https://m.tb.cn/h.5PQ8s5u

Tube Adaptors for 6N2 The ingenuous adaptors have a small round circuit board at the bottom, where the pins are soldered to the underside and the socket clips on top. The small circuit board takes care of the conversion, basically rearrangement of pins. For some, for a premium, there are deluxe versions with a metal surround. My cheap versions are just wrapped in heat-shrink. One should be gentle when handling these. As the top socket is soldered onto the bottom circuit board, one should grab the top portion when when inserting tubes, and grab the bottom portion when inserting onto the amp. This is to prevent stress on the solder joints.

Please note that I'm not one of those 3-noters (one who A/Bs tubes and proclaims the gospel after very short clips - many of these people in HK; yes, I have seen some ass turn the amp off and on after 3 notes of 蔡琴). If a tube is not downright bad, I listen to quite a few albums before even considering switching. Short A/Bs are the quickest way to proclaim one knows something when one doesn't.

ROUND 1:6CG7/6DJ8/12AU7/12BH7
First, I just happened to have some of these old stock tubes around (for testing of the Douk T08 Pro as substitute for 6N1). These are all pin compatible but all of them are lower in gain than 6N2.


The first tube I tried were the 6CG7s. Immediately noticeable was that the gain was lower than the 6N2 (Beijing). I had to crank up the preamp (6J4/6P3P) quite a bit to achieve the same volume (finally, a use for these high-gain preamps!). The GE has that lightly veiled quality one so often finds with that brand. The Japanese Selectron was superior, combining nicely the crispness of the 6N2 with some 6CG7 warmth. Very good (if you have the gain in front)! Then I rolled in the 6DJ8 (Amperex Holland). Same low gain. I heard the typical cleanly sorted sound of the 6DJ8. Good but a little too light and I preferred the Japanese 6CG7. Then the adaptors arrived. I did not have an X7 on hand and so used the 12AU7 (Australian Radiotron). Gain was about the same as 6CG7 and the sound was very nice, just a little lighter. In time, I may test this out further. Then I tried the higher gain 12BH7 but did not like the thickish sound (often the case when used as U7)

As I go to HK now perhaps once a week to run errands, a few days ago I took the opportunity to return to my old house and dig through my stash of tubes. I didn't spend that much time on it, and quickly fished out a few 12AX7s, 6L6GC  and EL34 types for testing. I didn't include KT66/7581/7027 types due to concern about resistor ratings. They are unusually small (see pic in Part I) and there was a TB buyer comment that said the amp broke down because he used the wrong tubes (he didn't specify but I'd guess it's a power tube) and he had a pic of KT66 on the amp! Not exactly confidence inspiring! And forget about KT88! And, since the amp runs Ultralinear, I'd forego my favored 6L6G/GA too. I don't think I have a WE350B in HK (a few in NYC). Note too that the tubes I took are not necessarily my favorite tubes, just what I could find quickly.

12AX7s. From L: Mullard Long Plate; Likely GE with support rod; RCA long black plate; Telefunken smooth plate, and Mullard box plate.

Round 2: 12AX7
The first 12AX7 I put in was the Mullard Long Plate. It had about the same gain as the 6N2. I was shocked by the sound - rich but audibly veiled. No go. I then slotted in the tube second from left in the pic. Its grey ribbed short plates and support rods almost make it look like a GE 5751. Much better sound, clear and sorted. Then it was the turn of the Mullard box plates. Surprise, a very even performance! Just as clean and sorted, but with a little extra body. Good. Next was the RCA, which was a little less clean at the edges, slightly less focused, but imparting a somewhat larger sense of presence. RCA 12A_7 types have never let me down (unlike GE and even Mullard). Finally, the Telefunken smooth plate. Initially I was tickled by the litheness and seemingly enhanced upper harmonics, especially noticeable with strings. After a while, one realized that all came at the cost of lower mid solidity. One more thing, with more dynamic large orchestral music, the Tele is more parched and restricted than the others. These findings are all par for the course, and consistent with my previous understanding of these tubes.

Round 3: 6L6GC/5881/EL34
First was EL34. The Chinese Valve Art's had long ago been used in my (re-issue, VAC made) Marantz 9 to very good effect. The sound was very good, a little cleaner but also a little less emotive, and so commensurate with the Russian 6N3C. The Mullard xf1 large brown base EL34 was quite different. Compared to the Russian and Chinese tubes, there was significantly more microdynamics and a mellifluousness. Unfortunately, it too has a slight veil that I did not quite like. The Double D getters are my favorites but I have yet to find them. Slotting in the German RFT cleared up all the fog but also lost some subtlety - still reasonably good nonetheless. I was surprised when I introduced the Tung-Sol 5881. Previously these have not been favorites (as you can see in my review of Elekit TU-8800; as mentioned in Part I, that article also voiced some of my tube preferences, worth reading of you like to roll tubes). The 5881 is very controlled (too much so sometimes) and cleaner than the usual 6L6 types, but in this amp with just enough sparkle at the top to make it sufficiently lively. Surprisingly listenable. At first,  the 5881 handily trumped the Executone 6L6GC (likely Sylvania) that followed, which sounded just plain. But after Part III was first published a few days ago, I rolled in again the Executone (Sylvania) 6L6GC); holy, it overtook the 5881 in performance! Perhaps my better driver tubes on adaptors help, or perhaps tubes unused for the longest time need a bit of re-running in too. So I'm adding these lines to tell you how tube rolling results may change as things change. It's too bad that I could not try my preferred 6L6G/GA in this amp - they likely may not do well in UL operation. For reasons mentioned above, no higher current types were tested.

Comments
  • The Basics and Value of this Amp This is an imperfect, but eminently likeable, amp. Grant you, I bought it for NO good reasons (at least I thought so) - I just wanted to see what I'd get for this ridiculous price, and I was really quite pleased, to say the least! BRZ is a company that builds super-budget products. They are all encompassing, manufacturing everything from DIY boards to chassis and both ss and tube amps. That's why they can undercut everyone. Now, these are built to a ridiculously low point, so expect occasional hiccups and less than ideal parts quality. DIYers can possibly reverse engineer and improve parts quality. Caps are easy but resistors are more problematic. Keep that in mind when you read about my cautions.
  • The Basic Sound The Heart is in the Right Place. That is important. Even with stock Beijing 6N2 and Russian 6N3C the sound was musical and pleasing. That tells me the transformers are OK in quality (at least for now; and their FU-50 amps holds up very well in my system)! In fact, in this setup here in SZ, the sound is arguably even more musical than the far more expensive Elekit TU-8800 in NYC with Klipsch Hersey (if my memory holds).
  • The Driver Tube Technically, the 6N2 is like a 12AX7. Use of just one triode is not the best driver for 6L6 or EL34 (better for EL84). In conversations with Shawn P, he remarked that his much more expensive (but still bargain by American standards) Decware EL84 and EL34 amps also use the 6N2 (although the latter uses 2x), and Decware advises Preamp Gain. This sounds right, but not for those stuck with passive "wire without gain" beliefs! So, it'd be good if you have a preamp with gain. The preamp sure helps, but there is intrinsic limitation on how much half a 6N2 can swing. So, sometimes, adjusting the volume knob on the preamp is a little tricky. Phase? Each channel being driven by a single triode, Should this amp be phase inverting? I don't know and BRZ doesn't give me an answer. I don't have a scope, so I just reversed the loudspeaker cable leads. That seems to focus the sound more in the center, leading me to think this amp is phase inverted.
  • Who is this amp for? It's a good Entry Level amp (and the stock tubes sound quite good), particularly for those starting out on the SE path. Those people can roll tubes a little bit but I'd not go crazy on that, as the cost would be disproportionately high compared to the cost of the amp. While it's surprisingly good (my Beydas 3/5 are not so efficient), it is not for rock fans. It benefits from a Preamp with good gain. With the power tubes, unless proven otherwise, I'd like to err on the safe side. Given the official BRZ recommendation and the looks of the small resistors, I'd say this amp is NOT for the ambitious Power Tube Roller. Don't use power tubes that draw significantly more current than 6L6GC and EL34. I'd NOT use KT66/7581/7027 (and KT88)! Due to the Ultralinear operation, I'd also not use lower rating tubes, like 6L6G/GA. It's a restricted window. This amp is also for those who, like me, have a stash of EL34 and 6L6GC type tubes. With real world loudspeakers, I'd withhold recommendation for those who want to use it as an integrated amp - better results with a preamp with gain.
  • Limitations Beside the practical tube use limitations detailed above, some re-emphasis on the sonic ones. As inferred above, due to limited driving power of the 6N2 (or equivalents), while a modest improvement can be obtained by tube rolling, do not expect night and day differences. While it certainly is not the most powerful amp (I estimate it to have a little less power than 300B), neither does it come across as wimpy or lackluster - the slight softness contributes a certain pleasing euphonic character. I have been listening to it happily ever since it arrived.
Part III will have Tube Rolling with 6SN7/L7, Capacitor Change, Preamp Matching, and more!

All Mullard. xf1 EL34 and box plate 12AX7. Tubes more expensive than amp.

22 November, 2023

Overview SE Pentode Tetrode vs DHT BRZ 6Π3 6H3C 6N3C

Click pics to enlarge.

Review: BRZ A20B 6N2-6Π3C SE Amp, Part I
Letter from Shenzhen (23-13): Back to Normal

Part II detailed Tube Rolling and Summation
Part III is quite substantial and a must, as it covers Tube Rolling of 6S_7 types, Capacitor Mods and Preamp Matching!
Part IV introduces the WE 350B and a new development, Failed Volume Pot!!!!!

Note that basically Parts II and II combined gives an Overview of 6N2/6N1 Tube Rolling!

In my last post I related my recent sonic woes. I'm glad to report that, with time, things have become normal again. For no good reason, I happily resorted back to the Beydas LS3/5As. During this time, just because of the crazy low price, I bought something I never thought I'd and have been enjoying it since it arrived. I seize this chance to cover some of my fundamental beliefs.
Overview: SE Pentode (Tetrode) vs DHT I've had quite a bit of experience very early on, long before I started using the name Cheaptubeaudio on Yahoo Group. In fact, my first SE amp was not DHT - it was the Audion Sterling SE EL34. Its very reasonable price (at that time) and performance started me on the road to SE amps. 300B vs SE Pentode/Tetrode Things happened in rapid succession from that point on. I acquired my first SE DHT amp, the original UK Audio Note Kit 1. The 300B immediately overtook the EL34. Sometime later, I got an Audion Silver Night 300B. It was very good and different enough from the ANUK, but what was glaringly obvious was how much better sounding the same company's similarly built 300B is over the EL34. Yes, there are idiots out there who insist EL34 SE rivals or surpasses 300B, well, well...I went on to have numerous 300B amps , only some of which I have written on (AES SE-1Softone/ICL, Advance, Sun Audio, Manley Neo-Classic [switchable PSE/PP], Verdier, Wavac etc, through the APPLause I use in Shenzhen now, and know many others well through friends, like Cary 300Bsei and many DIY ones, even the garbage Sophia.). But I did have one of the best SE Pentode/Tetrode amps - the built-like-a-tank old tube rectified Wai Lee 伟利 Amp (HK), whose trannies were said to be wound from WE material and which could use 2x 6J5 instead of one 6SN7). That was a versatile amp that took in every kind of tube, including esoteric ones, like 12E1. Suffice to say, DHT still reigned supreme. Later on, I never really dabbled much in SE pentode amps but did own one in the form of Elekit 8300 (a 300B amp that can also use pentodes, but again I always went back to 300B). More recently, I reviewed the Elekit 8800 (I urge you to read this article as it gives you my take on the various pentodes and tetrodes). Here, let me just say again that I still retain an interest in SE EL84 (as in my Almarro A205A) and SE 6V6 amps , as I think these tubes inherently sound better than the higher powered pentodes/tetrodes). Also, one can also make a compact and good sounding SE amp out of the triode-pentode 6BM8/ECL82 (I have San Ei and Elekit).
Point: take away the few losers or poorly built ones, In SE mode, DHT amps simply sound better than Pentode/Tetrode. Point: a good modern day 300B amp and good modern 300B tubes will sound superior to a good pentode/tetrode amp with even the most expensive NOS tubes. So, the 300B inherently (even in a modern incarnation) sounds good! But 300B is not the end-all.
And so I went on to explore other DHTs to great satisfaction. 2A3 (Sun Audio, Softone/ICL); 10/VT25 (Sun Audio); VT62 (Japanese San Ei) 45 (DIY and Yamamoto A-08S), 6C33 (Japanese Audio Professor, Almarro A318B), 845 (Unison Research Smart 845), 211 (Kondo Ongaku), FU-50 (BRZ). There are others that I'd try (like 205)!
And then, there is the very odd but miraculous DH (Pentode run as Triode) 2J27 (Nobsound/Douk E6 PREamp). Also, let's not forget that triode odd bird (but indirectly heated) 6SN7 (the amazing LTA MicroZOTL)!!!
SE Pentodes/Tetrodes Triode vs Ultralinear In deference to the low efficiency of most modern loudspeakers, many of the designs opt for the higher powered UL operation. A few allows switching between Triode and UL, and it's a very rare bird that uses pentode (like my Elekit 8150). It's a balance game, but I personally am not a UL fan and don't think it really sounds like Triode. But, given real world conditions, UL can work well and to each his own. 
BRZ 6N2-6Π3C SE Amp Now, given my preferences, the only reason I bought this amp was because it's ridiculously cheap and I have all the upgrade tubes needed! Why not have another toy! But it turned out more than OK.
Design Solid State Rectification. Driver tube is the Chinese 6N2, and power tube is the Russian 6Π3 (=6H3C/6N3C) operated in UL. A rather simple circuit judging by the circuit board. FYI, this tube is a 6L6 type that likely is not even as robust as an old 6L6GC/5881 etc. I used to hate this tube, but here it was surprisingly OK.
Built Not to the level of the BRZ FU-50 amp (link above), but the looks is still crazy good for this price! Chassis is nice. The main circuit is on a smallish board. Immediately noticeable are the very small resistors, and one cannot help but wonder about their ratings (see pics below). The main coupling caps are blue nominal RIFAs, as is typical of this company. Unlike the FU-50 amp, the signal wire is generic Chinese, not even the very cheap (but good) Canare 2B2AT in the FU50 amp.
Bluetooth A Selector toggles between the Line In and BT. Note that the Input RCAs are soldered onto the BT board. So signal goes through both the switch and the tiny BT board before it goes to the volume pot. Sorry to say (see below) I never tested the BT before I did my mod.
First Impressions Right out of the box, the amp sounded quite decent. I was both surprised and pleased. It has a warmth and musicality that benefitted the music, and in some ways the mid and bass were better than the FU-50 (likely greater watts). The Russian 6Π3 sounds better than I remembered.
Stock. Lower right corner is the BT module
MODS As I have no need for BT on the amp, and looking at the signal path, I decided to remove the BT module and upgrade the signal cable with my trusted Canare 2B2AT (this is my go-to mod wire, see here; also see pics below). The stock cable was terminated on both ends with computer plugs. As the stock RCA sockets were soldered onto the BT board, I didn't bother removing them. Instead I installed a pair of my own. The sound improved in clarity.
Caveats There are a few. First, I asked BRZ whether I can roll in higher current tubes, like KT66 and KT88. The answer I got was equivocal, only 6H3C/6N3C or EL34 recommended. So! At your own risk.
Initial Conclusion This is a surprisingly good amp with the stock cheap tubes. I have plenty of old stock 6L6 and EL34 types, which I shall bring back from HK and test out. Also I have bought adaptors for use with the 6N2. The Tube Rolling would be in Part II.
There are 2 thru-holes for the L and R channel signal cables, but the shield is occupied by
the computer type connector, so I soldered the shield to the center pin.
Probably can do without the shield!
After removal of the BT board. The 6V current source are insulated.
The BT module. If you want to keep this module, you can easily solder
your preferred wire to the thru-holes next to the connector. This way
you can retain BT function and still upgrade the wire.
A small red hotspot on the plate of one of the 6H3C tubes. Common. Let's see.

14 November, 2023

Updates on My Systems TDA-1305 DAC SMPS

Click pics to enlarge. Top, Sansui F55 flanked by Beydas. On Center Shelf of Rack is the FU-50 amp. Lower rack the APPLause 300B amp. On top of rack a pair of 新时 597 Resonators.

Letter from Shenzhen (23-12): Updates on My Systems
Current Trajectory: Sonic Sleuthing - Struggles, Trials and Errors

Most readers of this blog arrive via a Google Search. Of these, a number have become regular readers, and they of course are of most interest to me, like family, They identify with our approach and values. Not only that, a sub-fraction believe the devil is in the details (indeed) and sometimes, like family, scrutinize every word (I can tell from some of the comments) or even pic. Sometimes I cover my journey in great detail, which I know is of no use to most people, but I think interesting to these readers who like to mine the fine lines. So, it's time to inform you of some of the changes here in my system. In the most important ways, configuration and most gear have stayed more or less the same as in my Mid-Trajectory article (if you look at the pic of system then, it's not so different from now, top pic)

Sonic Woes
Before I left on my trip to NYC (and UK) in mid-June, as is my wont, I made sure I turned off everything in my system(s) in Shenzhen. When I came back in early September, the system sounded foggy and sluggish. I was quite surprised but thought it was just wake-up woes.

It was not that simple. After some time it started to really bother me. Now, in NYC, on much more expensive and better gear, I exclusively listened to real albums, on CDs and LPs. Hence, some friends teased that I'd not be able to go back to streaming! But I knew my systems well, and was sure that was not the cause.

Now, ever since the Beydas "Stirling" LS3/5a's (here and here) arrived in mid 2022 I had been listening to them. In my reviews I used them as a reference, even if they were not the last words in anything. In real life, if a certain acceptable level of fidelity and musicality is achieved, lazy I would be the last one to tinker with the system. And so it had gone on for almost a year. Although I rotated the 15 and 11 ohms, I listened more to the latter.

Why the deterioration now? I had NO clue! I swapped preamps, changed rectifiers etc - still no clue. Finally I swapped out the bi-wire Belden "1609", which I know to be on the soft side. I tried out the several pairs of freebies that came with the loudspeakers. The "Audioquest CinemaQuest" (as believable as "Stirling" or "Belden") improved things a little but, still, I could not get back my previous sound.

Sansui F55 Redux
Finally, unable to stand it, I swapped out the Beydas/"Stirling" and went back to my Shenzhen longtime workhorse Sansui F55 (See Top pic; Basic Info from a long time ago here). Cables still the "Belden 1609". Wow, the difference was not subtle at all. I got back all the air, treble sparkle, and had a much better bottom end. Agile and lithe, the sound was wonderfully familiar. I know actually very well the difference between the Sansui and the Beydas. Although I have always preferred the greater bandwidth and power of the Sansui, I stuck with the LS3/5As for a long time as a review tool. They are good enough to tell me the difference between gear and were voiced more similar to something most readers are familiar with. I also know the Sansui's are much easier to drive. Previously my Aosibao 6P1 PP amp (now with a problem in 1 channel) drove the F55s much better than the LS35s. And this is also true now for my BRZ FU-50 Amp too. Whereas with the 35, it'd struggle during loud passages, with the Sansui it shows no strain whatsoever. Here, I'd like to clarify that although I use the FU-50 amp as a workhorse I actually prefer the more powerful APPLause 300B. The latter used to have socket problem (pops) that irked me so I did not rely on it. But recently after reworking the sockets and tubes (just by inserting and pulling the tubes repeatedly), the problem went away. But I had already been accustomed to the highly reliable FU-50. It's a bit like the Sansui vs LS3/5a, and shows you, again, that for me, as long as it's within acceptable range, for listening to music I can easily adjust. The system now is so good that I actually rolled in the 80 Rectifier in the FU-50 amp. The 80 is more yin than yang, but a subtlety champ, and the sunlit Sansui can now afford it. Marvelous!

Although the system put the smile back on my face, or cleaned up my ears, that was not the end of the story! No.

UMI on top of the TDA-1305 DAC.

Enter the UMI and Second Try for Beydas Very recently, I got a 2nd gen unit of UMI 1:1 Transformer to review (Our writer ELO waxed lyrics about an earlier version very recently here). I placed it between the DAC and Preamp, and plan to write about it in a dedicated article. For now, let's just say it brought even more air into the already well ventilated Sansui system, which I happily wallowed in. With all that happening, I thought, why not give the Beydas another chance? Well, yes, I swapped back the Beydas. And? Well, slight improvement but still no go. Still lacked energy. No go.

Freak Event: The Power Supply Musical Chair
The 2nd gen UMI has an unusual feature, a 5V DC power is required to operate the XLR connection relay switch. RCA can do without, but I was advised that even then plugging an LPS 5V improves the sound nonetheless. So, I scrambled for testing this. My 1-bit TDA1305 DAC has for the longest time been powered by the BRZ (伟良) 5V LPS. Here are my various Power Supplies. As you can read from the link, I had from the start some reservations about the BRZ LPS. Even then, I connected the BRZ 5V LPS to the UMI and instead powered the DAC by my unused Wanptek SMPS. Guess what? I was SHOCKED that the sound improved markedly. NOT through the UMI being powered (the effect is subtle, as evidenced by removing the BRZ 5V). BUT the DAC as powered by the SMPS became a MUCH better beast! In fact, it exceeded all my expectations! In fact, later I tried the DAC's generic stock SMPS, a tiny thing, and it was still significantly better than the BRZ. Convinced that the DAC is now in full glory, I tried yet again to get my old sound back!

Wait! There's more! A condensed version: I took the UMI and my BRZ LPS to my JBL friend and tested them there (he uses XLR, mandating use of the 5V DC). As I expected, the UMI did a spectacular job all around. BUT, the revelation was that at his place the BRZ 5V LPS underperformed the generic cellphone charger my friend has. You figure! The BRZ dulled and blunted the sound.

Beydas Redux
Thus equipped, convinced by the newfound energy of my DAC, I once again switched back to the Beydas. Well, well! While I'm not sure I got all my old sound back, I'm sure finally I got much of it back. The sound was still perhaps a bit dark, but not unnaturally so. I then did further adjustments, reverting to using the crisper 5R4 rectifiers for the FU-50 amp, and removing the grills of the Beydas, and the sound improved a little more. All with the same "Belden 1609".  I also switched back to the APPLause 300B and the sound gained much power and solidity, as expected. I was very pleased, and the experimentalist in me pushed on (even if I know the Sansui is ultimately even better for these flea-powered amps). As I write I'm still listening on the Beydas.

新时 597 Finally, I experimented with positioning of these incredible voodoo devices, on which I have not written much. Supposedly they work best upon a vibrating platform, like on a loudspeaker. I positioned them atop the Beydas and it was very good. Then I tried putting them on top of my equipment rack (as in top photo) and it was even better! Much more solid center imaging and energy. The way to play with this thing is endless!

One thing I suspect, but cannot confirm now yet, is that I brought back to NYC 4 pairs, and for 2 months here in Shenzhen prior to my departure I had 5 pairs running in my room. I suspect they energized the room so much that I was spoiled. For my money, using them in the center, away from loudspeaker surfaces, is just as effective, surprisingly! I suspect, for this unique device, the more the merrier. My NYC friends Andy and Kevin all have only praise for this thing! There's an article to come at some time...

Comments Finally, after quite a struggle, my Beydas LS3/5As have become quite listenable again (though perhaps still not quite back to their old days in my aural memory). I'm still not at all sure of all the reasons why! Read the above and draw your own conclusions. Here are my observations and what I think:
  • All LS3/5a's, real or replicas, are not that efficient. With higher power (say, a PP amp, or a classic UK integrated) one can get more control and open up the sound. But people like me also like to run them with low powered SET amps, in which case you would have to do a lot of adjustments to get good results - setup skills are required. My Sansui is easier for my amps, especially the FU-50 (over-spec'ed; I estimate around 5 watts whereas the 300B amp sounds like 8 watts).
  • LPS vs SMPS "Traditional" wisdoms are for the birds. Time and again for me, SMPS outperforms LPS. SMPS is more agile, lithe and alert, whereas LPS tends to be heavy and solid, but to each his own. Keep in mind, many of the world's most high-end brands, like many Swiss brands (as in my Nagra PL-P, also Soulution etc), embrace SMPS. Populist ones, like Schiit, does too! In my case, the BRZ LPS really does not measure up to my mass market (and cheap) SMPSs. One possible explanation for my woes is that the BRZ LPS has somehow deteriorated over time and gotten worse (caps? but it hasn't been that long...).
  • TDA-1305 DAC (https://m.tb.cn/h.5QVYLVp) Although I mentioned this DAC a couple of times before I never really wrote about it. Aside from the Meridian Explorer I used before it, I don't have another one. It has served me very very well for almost 3 years! The Meridian is a little more rhythmic, but this thing is better in almost all other aspects. The thing is around 200 RMB (under 30 USD) and doesn't even have a brand name (the TB link shows the maker)! The USB Input is Default and here's a significant quirk: as long as the USB is connected at the source (my laptop), the SPDI/F (Coaxial and Optical) Inputs will NOT play. To play SPDI/F you will have to unplug the USB cable. There is a small switch on the back that selects between Coaxial and Optical. As seen in the pic below, it uses 2x TDA-1305. Output level seems quite normal to me - not high, not low.. (I'd say around 2V). This is a sweet sounding DAC, just as I'd expect from this chip (as in my Micromega Stage 2). With the Wanptek SMPS, it actually is quite resolved while retaining its sweet quality. Before I forget, I did briefly tested its headphone output with my Grado SR-80e and it was good (of course you can only control the volume from the player). Very good job and one of my best purchases! See, I have bought several preamps and amps but getting another DAC rarely crossed my mind!
And, so! that's what's been happening. Keep checking once in a while, there are more articles to come...

05 November, 2023

HAVE Shenzhen Audio Show DYLPaudio 老彭 Stirling LS3/6

Click pics to enlarge. 
Letter from Shenzhen (23-11): HAVE 2023 Audio Show

So much has actually happened in 2023 that my mind got kinda jumbled up! Think about this: at the beginning of the year, China/SZ dropped Coronavirus Testing and began to "lie flat", then we had all the Chinese Audio Shows open up (I attended the SZ and GZ), then I spent the entire summer in the UK and US. It's a paradox that, at my age, the more happens, the less time flies.

And so when I received news on Wechat about a SZ Audio Show, I mistakenly thought it was the same one I attended a while ago. Has it been a year? Last one was organized by SIAV and I enjoyed it greatly. No info on the SIAV site. I felt strange, but I went nonetheless, on its first day, Friday, and I was stunned by the lack of attendance. I soon found out it was a different organizer. This one is named Shenzhen International High-End Audio Visual Expo (HAVE). Apparently, its 5th.

It seems HAVE emphatically got beat by the SIAV Show, which took place in late February, and on which I reported. This show was attended by only a handful of exhibitors who had appeared then, and occupied only 1 hotel floor and a few large rooms. There were NOT many interesting discoveries. See the list to the left.

So this report is a mostly a NON-report. I shall skip more detailed descriptions of exhibitors that had appeared in SIAV earlier this year and refer you to my earlier SIAV report. For even more info, you may want to consult my Guangzhou Show Report  (Tag: Show report - Guangzhou 2023)

Among the SIAV attendees that showed up were the great 薄小强, the excellent BT Showfeel, the reliable Tecsun, LALS, Mymei etc. If interested, please refer to my previous reports. Some others are in the pics below, not necessarily by merit.

But, as in real life, sometimes in Slim Pickings there emerge some "Finds". Life rewards the studious, at least I hope so! 

The most surprising is 东莞市黑胶音响技术有限公司 DYLPAUDIO TECHNICS CO.,LTD. Please peruse the website. This company does a huge amount of production and apparently is a BIG OEM manufacturer. MM cartridge that looks luxurious can be had for 10 bucks and ultra high end MCs for a couple of thousands maybe. Many of the cartridges displayed are eerily familiar looking. Some look like Audio Technica and some Ortofon 2M. The boss Mr Peng, 老彭, is a well-known figure, and someone has told me about him previously! I talked to him briefly and he was a nice guy! Apparently, many overseas people rely on him! This is a BIG find. If I can, I shall try to visit him! According to them, they don't attend shows often, so I count myself lucky.

My other surprise came from the Amp maker GoalBon 高班 room. The sound was decent, but I was struck by how nice the LS3/5As looked and sounded. It turned out they were the real UK Stirling, not Chinese replica. The EL34 amp was not cheap at >20K RMB, named LS35 and said to be designed to drive the LS35a, and unusually has an 11 ohm output. That was not what intrigued me. They had a pair of Stirling LS3/6 there! The SZ company is reachable by subway, so you can be sure I shall in due time pay them a visit to listen to the LS3/6!  

Different, but...
More from DYLPaudio. Cartridges from $10!
Stirling LS3/5A and LS3/6!
Unusual bass driver (also below), but I heard distortion
Mullard is now a speaker brand?
Large room, said French loudspeakers and unknown electronics said to be from HK.
Not shown an FU50 amp said to deliver 13 watts. I said to the guy, NO FXXKing way!
Of the HK dealers, only Roksan showed up. No one there.
Big Room with Chinese Mega loudspeakers and electronics. Sound OK.