Beydas Douk T8 Pro GE 5670 WE 274B 350B 80

Click pics to enlarge. R, WE 350B.

Letter from Shenzhen (24-4): Listening Notes

Douk T8 Pro, Part II (Transient Speed)

ETA Preamp, Part IV (Contact Woes, Failed Pot Replaced, GE 5670)

BRZ 6L6 SE Amp, Part IV (WE350B, Defective Volume Pot, Failed 6N2 Adaptor)

BRZ FU-50 Amp, Part III (with 80 Rectifier)

Douk T8 Pro Equalizing Preamp, Part I, Part III (on XLR use)

Eastern Transmission Audio (ETA) 6N3 SRPP Preamp (Parts I-III)

BRZ 6L6 SE Amp (Parts I-III)

BRZ FU-50 Amp (Parts I-II)

Lately, though still based in SZ (hint: not for long), I have had the opportunity to conduct some listening sessions in HK, much of it reported in recent articles. I had been busy writing those up as well as with private matters, so it's now time to update you on what I've been up to around here in SZ. It's basically tinkering with what I have here, AND with some tube rolling. Not just any tube, but some old stock Western Electric tubes brought over from HK; with WE, it's always a transformative experience! But I shall start with humbler stuff.

Loudspeakers: Beydas 15 ohm and 11 ohm "LS3/5A"

Previously, I detailed my Struggle with Beydas 11 ohm after I returned form NYC in September 2023. Some time later, I substituted the 15 ohm version and also initially had a rough time adapting to it (chronicled here). After a while, I again "tamed" it to my satisfaction. Then, sadistic me reverted back to the 11 ohm and again had to struggle to get the best sound. But, through all these, I gained some insights:

• Whether for initial run-in or after long disuse, (re-)running them in is a must.

• 15 ohm This version is really quite lean in the bass but easier to manage in a way. The lack of bass heft (at least 10db less than the 11 ohm) ensures good transient response and clarity in the midband and ease of partnering. When properly matched, sound is very lucid but the lightness in the bass shall not suit all, though I find its bass pitch and definition highly satisfactory.

• 11 ohm This version is much more bassy, but at the cost of some loss of definition in the lower midrange and bass. Therefore, more care has to be taken with partnering equipment. Overly rich-sounding gear or "tubey" stuff may not do so well, resulting in a sound that is rolled off in the treble and smeared lower down (reader Collins has complained of this, but I don't know his associated equipment). Transistor or T- and D- amps likely do better. What one needs is better speed and definition in the amplification. E.g. my Douk T8 Pro Preamp suits it more than my others because of its superior transient speed (see below). The Beydas 11 ohm also respond well to my leaner sounding BRZ FU50 (when used with a suitable rectifier). When optimized, sound is perhaps a little closer to the real LS3/5As than the "15 ohm".

2 Preamps: Douk T8 Pro and ETA 6N3 SRPP For this period, I've been mainly using these 2 preamps.

• Douk T8 Pro This Preamp has continuously surprised me by its versatility. Mind you, this is the only Preamp in my active use arsenal here that is not pure tube, being a tube buffered op-amp design. But why not? The very expensive MBL 6010 (which is garbage imho) is just an opamp preamp that sells for the price of a car! But to compare the Douk with MBL is to tarnish the Douk, which has much more flexibility and sheer life to it! Transient Speed As mentioned before, its prowess here saves the day in many a situation. It serves the 11 ohm Beydas (which can be darkish) well. With tube gear, sometimes things gets slowed down and, when overly so, is not desirable. A faster transient preamp can make the difference. That said, faster transients can exact a cost. Things can get breathless, which is NOT the case here, thank God. Perhaps sometimes one wishes for a trifle more lingering, a little more harmonics, but one adapts. Suffice to say, it proves very useful here in SZ. XLR Use Finally, one day I brought it over to HK (with stock small wall wart). I connected it (with Gotham GAC-3 XLR cables) between the XLR output of my Marantz 94 Limited DAC and an early iteration of Bryston 4B amp, driving the B&W Matrix 801 Mk II. Sound was very good. At low volume, I swear it was even more detailed than many of my hifi preamps, the hybrid ARC SP-11 included. But, ultimately, at higher levels, it did not prove to be better at matching with the Bryston than my RCA output only tube preamps, be them MFA Magus or even Counterpoint SA3000. So, not a success yet. Capacitor Mods There being so many, I have to contact Douk on which ones are the most important. But this is in the agenda.

• ETA 6N3 SRPP Preamp (pic above with 5670 tubes) As mentioned previously (in Part III), the Preamp developed problems in RCA Contact as well as Volume Pot. RCA Terminal Woes I thought I rectified this after re-soldering but it irritatingly still periodically failed (even sometimes as I write) to make contact with my GAC-2 (brought over from HK) which has the "Canare" plugs I bought from Apliu St (and SZ 万商) ages ago (and I never had problems with my gear in HK). These plugs manifestly don't agree with the ETA's RCA terminals, which look of "reasonable quality" outwardly. Some wiggling is usually required to enforce contact. But I'm thinking of changing them out. Incidentally, my cheap Rean plugs don't have this problem. Volume Pot I finally dug out the spare tiny cheap Volume Pot that came with one of the kits. It's 100K instead of the ETA stock 50K. What the hell, I just did the surgery, not too difficult. Voila! The pot functions well (for now) and I could use it at all positions, even with my BRZ 6L6 Amp! GE JAN 5670 Finally, I yielded to temptation and bought a few from Taobao (cheaper than HK or US). These were from '86, last of the Mohican's, but came matched in sections (as JAN tubes are wont to be). Of course, I'd have preferred WE396A /2C51 but those now command very high prices. At first, I was non-plussed by the sound of the GE 5670 - controlled and finely textured but overly reticent. For quite a while, I reverted back to my Douk T8 Pro (with 6CG7) for more oomph factor. BUT, guess what? The 5670 gradually came to life, becoming livelier and more dynamic, and now can serve in most situations, though some may still prefer the more gun-ho nature of the Russian 6N3. This tube takes quite a while to run-in! I have more to say on this tube but it shall be in another article devoted to tubes.

3 Amps: APPLause 300B, BRZ FU-50 and 6L6 SE; WE 274B and 350B For the past months, especially when the weather was cool, I have rotated these amps, especially the hotter 300B (yes, my most powerful one, LOL). BUT, I brought over the a WE274B ('82) and later WE 350B ('79). Boy oh boy, are they game changers! Yes, they are late old-stock productions, but their merits just shine through. I'm confident they are miles ahead of current re-issues.

Now, my system is powered on basically from the moment I wake up to when I go to sleep, minus the 2 hours I go out for lunch and a walk, so we're talking about 10-12 hours a day for most days. While I write and multitask and so on, I would not be in critical listening mode. Most likely, I'd be sampling new releases. All these activities mandate a system that sounds decent enough but do not warrant putting in the very expensive WE tubes, which are reserved for very critical listening! Believe it or not, I had a hard time establishing the hierarchy of my amps. That is, which to choose for "casual" listening, and which to choose for more dedicated sessions?

I love exploring new releases. While some are just superb, more are disappointing, even from artists I follow. Believe it or not, a change of tube sometimes just changes how I perceive the music and make me re-evaluate. No WE can make a deadwood dance, but a shift of perception from merely metronomic to rhythmically more savvy, or from plainness to more harmonically fulfilled, is definitely possible!

• WE 274B Of course, this immediately transformed the sound of my tube-rectified APPLause 300B amp and BRZ FU-50 amp. The sheen, rhythmic subtlety and ease of delivery is immediately evident. Mind you, many audiophiles, including many I know, are arrested in the tonality stage and judge everything by a few vocal recordings (kinda like HiFi News Kessler) and these people often fail to grasp what makes WE great. Problem is, should I run the 274B for >10 hours a day? I cringe...Mind you, many modern tubes tout themselves for guaranteed 3000 hours but, man, this is less than a year for me! I know, WE tubes can last forever, but we still want to use them when everything is optimal, not wasted.

• APPLause 300B Putting aside the 274B, this amp runs well on my Chatham 5R4WGY and Philips JAN 5R4WGB and National Union old 5U4G. The hotter the weather, perhaps the less suitable this amp. It just occurs to me to swap out the Linlai 300B and exchange with my older Russian and Chinese 300B's in HK. Soon. No, I'm not going to bring my WE 300Bs over to SZ, as I'm in Retreat Mode. I tried my Tung Sol 80 (ST engraved) too: it works despite arcing on turn on; and current drops to 130 mA for both channels combined. Fine with me, but the 80 works better below...

• BRZ FU-50 This amp I use the most, because it's performs well enough (less power than 300B) and does not heat up the room so much that it can be used in the summer. My Tung Sol 80 (ST) works very well in this amp (with adaptor). No arcing and it complements the slightly leaner sonority of the amp with its richness and, yes, soul. The 80 is a very fine tube, being descendent of the venerable WE 274A. It's a little darker, slower in transient and almost as subtle as the WE 274B; through its DNA has inherited a bit of the old-world magic, that is soul. The ST 80 is still an affordable tube, significantly cheaper than Globe ones, and you should try it! So! The FU-50 amp with the 80 rectifier is my main amp.

• BRZ 6L6 SE Amp Well, SS rectified, so the WE 274B and 80 are out of the equation. In previous installments, I detailed the tube rolling (some with adaptors) I had done for the 6N2 and had mostly used it with my 6SN7/L7. WE 350B Then, about 2 weeks ago, I brought back from HK a pair of the WE 350Bs. Initially, replacing the Executone (Sylvania) 6L6GCs, I was shocked by how lackluster the sound was. I let them run for quite a while and still the sound lacked dynamics. Now, as the 350B is not quite a 6L6 type, I thought it likely needs more drive, which the 6SN7/L7 were not providing (less gain than the stock 6N2) . This is not just a matter of gain (which the preamp can make up), it's the swing required to drive the tube. Adaptor Woes So I sought to drive the 350Bs with my 12AX7 with the adaptor. NO Sound! After some tube swapping, it was clear that the adaptor now works only with 6V filament tubes (like 6CG7), and not with 12V filament tubes. For sure, a solder joint inside has gone bad. Desperate, I put back the stock 6N2 (Beijing). Voila! Sound was much improved! In fact, I was floored by how good the sound was! Yes, even with the lowly Chinese 6N2, surely not the best driver tube, the WE 350B showcased its famous qualities. Like the WE 274B and 300B, it lacks nothing: Rhythmic sophistication, tonal opulence, clarity, wide bandwidth and the most natural of dynamics. Simply put, I heard the famous WE sound, and this in an amp that costs less than 1/20th of the pair of tubes! This also attests to the reasonable quality of the output transformers, no mean feat in such a cheap amp. There are things to watch out for though. The 350B, here run in Ultralinear, surely draws more current than 6L6GC or EL34, though probably less than KT66, which I don't advise in this amp. The Power Transformer is a little hotter than usual, but not excessively so. So let's see how it fares in the long run. vs BRZ FU-50 and APPLause 300B Now, with the WE 350B on board, this little amp has become my Special Reference Amp here in SZ, its sound quality surpassing the BRZ FU-50 and APPLause 300B without WE 274B. Even with the 274B, the FU-50 and APPLause cannot completely overtake the 350B amp. This is an amazing development, which I had not foreseen. Now, you must read me carefully and I stress, this result can only be achieved with old-stock WE 350B, nothing else. Volume Pot Defect Well, small hiccups happen often with these cheap machines, no? Here again, it's the volume pot (remember my ETA Preamp, APPLause Amp), which I basically don't use actively, because I max it out and use a Preamp in front. However, when I change preamps, I turn the volume to zero. During one such swap, I heard crackling noise in the middle of the range, and it was repeatable - sure enough, the volume pot has turned bad. It doesn't affect how I use it, but the problem has to be rectified at some point. So, if you use it as an integrated, this may ruin it for you.

To sum up with some wine analogies: 1) without old-stock WE, a modern day amp can only be a good Pinot Grigio, whereas with WE it can turn into a real French Chablis (Americans beware, the word Chablis is too well known but too little understood stateside); 2) If you fail to properly utilize real WE (many people unfortunately) or perceive the real virtues of WE, then you probably prefer Australian wine to French wine, or prefer Temperanillo to Medoc.

To sum up with just one music analogy: Shostakovich Symphony No. 8 is almost mainstream repertoire now. While most performances are decent (sorry, a good Pinot Grigio), few really go to the heart of the piece. Compare your versions with the Russian National under Paavo Berglund (Pentatone) and within a few bars of the opening you shall (hopefully) know the difference (sorry again, between Pinot Grigio and Chablis, or between Temperanillo and Medoc). LOL!