Anyone use SHUGUANG tubes?

[Leo_Gnardo]

Undertaking a spectrum analysis may be beyond the resource, capabilities and competence of many interested parties, myself included

Yeah they're all identical so why bother. The best thing ever was FETron, which Mesa/Boogie installed as a first stage "virtual tube" in their amps, late 70's. No microphonics, every one sounds identical, requires no filament current therefore no filament-induced hum or buzz, ain't that the cat's meow. Why FETron hasn't completely taken over the preamp tube business, I can't figure. Transistors are uniform and never fail - they ARE the future, who needs tubes anyway. They've been obsolete for 55 years already. It's good to know I've been spinning my wheels the last 35 years or so since FETrons were on the market. Anybody know if they're still made/sold? I could save myself and customers a LOT of time and grief in what little future I have left.

[gui_tarzan]

Tell them to do what you and I and most of the rest here did - buy a damned tube tester if they want to know that badly.

[J M Fahey]

I respect both your and Juan's input as you both have a great deal more experience/education than I. But I honestly hear differences by changing a single tube, in the same amp, using the same location. EG: V1

Thanks for your confidence
Yet I also explained why different tubes in the same amp "sound different": different transconductance means different gain (leaving everything the same, what happens if you just replace them in the same socket) which either means sound will be louder or weaker ... and non linear ear will hear different, or you set volume to a notch or two, up or down, to match level and the omnipresent bright cap or the next stage Miller capacitance do change frequency response, for real.
Bright cap will make sound brighter at reduced volumes; Miller capacitance will make sound duller when pot set to about half track resistance because that´s where its internal resistance is higher, as seen from the next tube.
The point is that the amps themselves are not linear.
I resist yo apply labels to brands, because that is not a guarantee of consistency.
FWIW I remember a Russian datasheet stating after an asterisk, small print footnote, that "characteristics could have a spread of up to 3:1" No kidding.
At least they were honest about it.
If and when I find it, I´ll post it here.
Enzo refers to something similar:

One part of double blind amplifier/speaker/whatever tests the hifi nuts hate, and important part of that is matching the levels of the amps to less than a decibel difference, THEN listen for qualitative differences.

It is one thing to say a JJ OUGHT to sound like a SOvtek, but you plug the two in alternately and they sound different. But how about the other half of the test? Plug in 10 different JJs of the same model, then try 10 different Sovteks of the same model. Now how much difference do you hear JJ to JJ, or Sovtek to Sovtek? it is entirely possible if not likely that there can be greater differences between JJs than between a particular JJ and a particular Sovtek. Most tube sellers these days offer selected tubes. Selected for higher gain is one criterion.

We all know tube testers are for detecting bad tubes, not promising good ones.

Anyway go by your ears, these are guitar amps, not Lab instrumentation

[Leo_Gnardo]

Tell them to do what you and I and most of the rest here did - buy a damned tube tester if they want to know that badly.

It's not just the "passed by tube tester" they're looking for. It's the "approved by a tube guru" imprimatur that will convince the potential buyer that they're purchasing something very special and very good. And I'm supposed to do it for free? Even if they did offer $$$ - hoss manure to that.

Two of my customers have bought tube testers. They still feel the need to consult me - and I tell them "use your ears." Enzo's absolutely right.

[Alan0354]

Allow me to interrupt.

I spent yesterday to build a ground lift A/B input box and a A/B two amps to two speakers switch box so I can switch each amp into speaker A and speaker B.

All these are to be able to switch guitar into one amp or the other with a click...AND switch the amp to drive one speaker or the other. All can be switched in split seconds so I can really compare the sound of the two amps into different speakers. I even go through 4 different speakers to compare the sound of the two amps.

I only tested the OD sound as the Bassman does not have a clean channel. I can't tell the difference between the Bassman build with Shuguang and KMD with JJ. I gone back and fore and back and fore already. Maybe my old ears are not that sensitive. But I can definitely say it is very very......emphasis.....very close.

[Audiotexan]

I forgot to mention yesterday..the "China Grand Tour 2009" was a great link btw g-one!
TY!

[Audiotexan]

First, I meant no implied disrepect to Enzo (nor anyone else for that matter). I mentioned Juan and Stan directly, as it seemed they were replying the most directly on this topic, however reading Juan's reply, I obviously didn't understand what Enzo was trying to say in the way he said it. Juan touched on another part: Miller capacitance! TY!

Second, I was hesitant to go on the subject anymore for fear of becoming an annoyance. As that's not my intent either. So I was going to post this in PM, but due to a 5000 character limit, I'll just take the risk and put it here.


For the purposes of trying to figure out what makes them sound different, I am not *nearly* as interested in trying to compare two-three current companies who don't desire to maintain a quality control of better than 20-30%. As Stan said, back 'when'... it would be approx. 5% variance to be "in spec". That should imply by default that 95% of what went to the wholesale/retail channels was in spec by set standards.

As I posted in a previous thread, which referenced GT (pre Fender) where Myles S Rose said flat-out that if it wasn't a 5-6
on the 1-10 scale...then 'basically' it didn't meet spec.

A 5-6 rating generally met design spec.

*see approx. 45-50% down the page*

Now I assume that means 'their spec', but IF they were using 'old spec standards' as a reference point, then that means that 80% of the crap that's currently being sold, would be in the 'destruction heap' that they used back in the day. That speaks to the lowered standards and push towards retail as was brilliantly stated/observed by Alex R.
Why build to engineering standards when you can (and have done so for 10-20 years now) sell tons more to folks that refuse to educate themselves and think of the current product as acceptible??? -Sorry. Just the base premise of that idea just pisses me off. Yes it's good business sense by today's standards. But a damned sad commentary on quality where we are now vs. where we were then.
/rant off



What follows is more to the meat of what I was trying to figure out...
Especially in regards to vintage vs vintage: aka Germany (Telefunken) vs Holland (Amperex/Philips) vs US (RCA/GE/TungSol/etc) vs Hungary (Tungsram) vs Tesla (Cz)...etc, etc.

Measure the basic parameters, such as interelectrode capacitance and there will be variation...

Might that difference be due to inherently differing gm, plate resistance etc of the differing tubes, and how that interacts with the surrounding circuitry, even when set up such that one static parameter remains the same?
Pete

Things like the above is what I'm still trying to ask/learn more about! =)
The actual 'why's' of it all.

The biggest differences are in gain...

Which is why I mentioned having the same mu, and having tested all ax7's on the same tester. Eliminate as many potential variables as possible up front. Using the same amp, at the same settings. Just a simple v1 tube swap.

What is seen from testing wide ranges of new tubes is variations that would suggest quality control and probably durability differences. The shape of the curves are very similar, but the placement of the lines for any given tracer anode sweep and grid step. But the differences are as great between two random tubes from the same brand as between brands so the claims here on these forums about how one brand is bright and airy and another is thick and fluid sounding is pure hogwash.

Which is again why I don't consider current tubes in my thought/comparison process when trying to get to the meat of what makes vintage tubes sound different. Current tubes are more of a foot-note of "oh yeah, there's these too" since they want to sell everything they produce that's even 'vaguely close' to working properly in my opinion.

It's an aspect of modern capitalism that has grown to baroque proportions in people's minds over the last maybe 50 years, so that now the label is often the most important thing about the goods, printed hugely on the front of tee shirts etc.

And those fools can have it. Which is also why label/brand means nothing to me.

This wildly irrational product of brand management manipulation in a highly competitive market can't be an objective way to judge the quality of an item.

Which is why I'm so desperately curious and trying to objectively find out what makes them unique. That's at it's simplest is the tech in me screaming 'what makes this /Telefunken ax7/ sound so different from that /RCA ax7/'?
(insert any other vintage tube manufacturer in the //'s)

But electronic components are not aimed at the retail market, and there lies the problem, as vacuum tubes have moved from the electronic wholesale to the retail market, so that inappropriate expectations created by branding are now applied to goods that weren't manufactured with the retail market in mind...

Brilliant observation Alex. I'd buy you your beverage of choice if I could man!!

..but for a much more demanding industrial market, that laid down required specs and maybe put you out of business if you didn't meet them. Electronic engineers and designers specified objective measures not labels. Brands are far less important in that world.

Don't get me wrong in all of this, as I've stated point blank before, I think there are some good things happening, and it's taken us a loooooooooong time to get back here from having lost all the tube treasures that we took for granted. And I appreciate that we have them! However, my nitpicking/criticisms of modern sales/methods aside, I'm earnestly trying to figure out the technical aspects that make a vintage tube sound different from another vintage tube with the same mu, at the same amp settings. Simple pluck-n-chuck of a tube. (specifically with regard to the 12AX7 family -again, trying to minimize variables)

Undertaking a spectrum analysis may be beyond the resource, capabilities and competence of many interested parties, myself included; so thanks for keeping that highlighted.

Definitely beyond my ability. Which is why I come to those who have that level of experience/expertise and hope to learn!

Apologies to those that I may be annoying. :x

[gui_tarzan]

EXCELLENT post AT! I can't speak for the others but you're not annoying me, I've always been a proponent for discussions laced with question after question after question. It brings out the obvious and not-so-obvious, especially when you're dealing with a group of people ranging from no experience to tons of it. Yes, sometimes those in the know get irritated with some questions because to them it's simple but they have all the information, we're trying to learn it. And who better to learn from than some of our own very knowledgeable members who are willing to share? That's why I like this place.

My dad had a body shop for many years and he had a sign in his office that I think was attributed to Henry Ford. It said "I'd rather explain the price than apologize for the quality" and that's how he ran his business. The same sign should be in the offices of every CEO, every quality manager, every stockholder and on the minds of every designer, builder and line worker. In addition, consumers should expect nothing but quality AND expect to pay for it.

I won't accept a sub-standard product as "good", even though we often have to tolerate many products like this because as a society we demand a low price on everything and to hell with the quality. "Good enough" is never good enough for me, I want my stuff to be better than the last time, every time. If that means refusing to buy sub-standard parts that's what I do. If that means I spend more time on it than another guy would that's what I do. People have forgotten what it's like to not have to buy a new washer & dryer every ten years, or a car every five years or even a TV that today only seems to last a few years at most. My grandmother still has a working chest freezer that works like a champ and it's forty years old. Today's products can't come near that. But I digress...

What does it take to reverse the trend? We have to change the mindset of an entire society. That takes time. But as Stan noted, the Shuguang people have been improving their products steadily and that takes time and money. And demand.

[exclamationmark]

Even though tube characteristics can vary greatly, they can sound pretty much identical in A/B tests. I suppose this depends on the amplifier though. If anyone is a part of any music/production recording forums, you'll see this issue come up quite a bit with some interesting results through re-amped recording rigs.

[Audiotexan]

Ok, giving my previous post some perspective, it was in the midst of being written largely before Juan and others replied IIRC (...it just took me that long to get all my thoughts together). lol

So! Taking the cumulative things I've gleened from this all so far...

..interelectrode capacitance..

another possible thought/question regarding

...plate resistance...

-non linear ear will hear different
-the next stage Miller capacitance do change frequency response
-The point is that the amps themselves are not linear.

Forgive me if I've missed/overlooked any!


Fundamental theoretical properties (such as Miller capacitance), and changes in construction materials (proprietary techniques/amounts used notwithstanding), and construction methodology were my key points of focus/interest due to so many having drastically different types of physical attributes.

Much like room acoustics (frequency response) changes due to the construction of a room. I figured that a partially responsible attribute had to be the way the electrons were handled internally were being changed by the tube construction. Silly as it sounds, "different bounce patterns" / proximity in relation from grid to plate...things like that. So even though I may be misapplying that notion (-I'm expecting correction/education ) however, that was my thought process behind why I was curious if it was a similar principle (when I was referring to the possibility about the way the electrons were handled inside the tube).

Even though tube characteristics can vary greatly, they can sound pretty much identical in A/B tests.

Oh yeah. No doubt about that either. That's another aspect of what's amazed me. Even with all the massively different construction methods/materials used, you can get some that are really really close tonally!
Just more of the amazing and infatuating things that are tubes!

[gui_tarzan]

Well I got my 12AX7Bs from that auction today. All but one look like they're well constructed, I'll check them out for sound later. If they check out I'm going to try to get some more.

[Alan0354]

I have been using 6 of the 12AX7 and one 12AT7 for a few days already. I tapped the tubes, no microphonics, everything works perfect. I would definitely buy more when I need it.

[Chuck H]

There was a good stretch of time when the Russian ax7's were failing in cathode follower type circuits (due to an under rate on the typical heater to cathode spec. I assume). Since there has been some ambiguity about who makes what brand, identification of what tubes might fail became hard to predict. For this reason, last year when I built an amp with a trem oscillator and a cathode follower I decided to go with the Shuguang preamp tubes. I bought ten. The gain seems to vary a good deal from tube to tube (not really a problem), there was one slightly noisy tube, one grossly noisy, and one somewhat microphonic tube. The slightly noisy tube went into service as the oscillator, so no problem. The slightly microphonic tube was used in a later stage, so no problem. I pitched the grossly noisy one. That's nine of ten tubes in service and working well. Way better than I've done with the Rusky tubes in the last ten years. Another benefit is that they all sound good. It's been discussed in this thread that this is relative, so take that however you want.

[PeanutNore]

For instance, I'd never use Telefunkens in a guitar amp. But they're first choice in a hi-fi. With Amperex B/B being a close second.

Interesting. Pre-war Yugoslavian 12AX7s are supposed to be made with the Telefunken design on Telefunken equipment. I've got one in my Special 6 head and it sounds great in there with the Mesa-relabled winged C 6L6GC.

[Audiotexan]

Interesting. Pre-war Yugoslavian 12AX7s are supposed to be made with the Telefunken design on Telefunken equipment. I've got one in my Special 6 head and it sounds great in there with the Mesa-relabled winged C 6L6GC.

If you're referring to the flat-plate Ei stuff by Nis Yugo...yes. That's been my long-standing impression as well (made on Telefunken equip).


Yes, I agree the one's pictured above are some great sounding tubes! No doubt! But again, it's a personal preference thing. If you dig using "diamond's" in a guitar amp, excellent! It works for ya!

IMO, It's harder to get a tube to fit in the hi-fi environment though, so that's why I save the cream of the crop for that. Having "two mouths to feed" (one: hi-fi, two: guitar amps) doesn't come cheap/nor easy, so I tend to be a bit more selective as to what I use where, so there's another difference that most guitar players don't have.

Though, again, they didn't use the same material's and processes in the 70s-80s as they did on the machines in Germany. So taking a vintage Telefunken and an Ei side by side, don't sound the same (at least to my ear). And that's regardless of whether they're used in a guitar amp or a hi-fi (all other aspects of the test bed remaining the same/unchanged).

As for the one's like this...

I consider it a Louie's Vittonia (a cheap imitation). It's so bad they couldn't even form/stamp the plates properly. LMAO