| KI7AQJ |
Rating:     |
2016-08-31 | |
| Shu Guang made, not sure if there is anything special or not. |
Time Owned: more than 12 months. |
| All modern production tubes are kind of inferior to the original tubes made in "the western world". I have curve tracer matched a lot of these with a modified Tektronix 371B curve tracer (actually made by Sony). It has been modified with various power supplies for screens, & heater voltages. I can't really see any visible differences (physical or electrical) from the Taylor and the straight Shuguang branded 3-500ZG graphite plate RF transmitting/modulation/audio tubes. I do know RF Parts, so called matching, is adequate, but hardly superb, for tubes or final transistors. These seem to last okay, IF YOU TAKE CARE OF THEM, and you don't get a bum tube, or bum set of tubes. That does happen! Shuguang has worked with companies like Tube Amp Doctor, Valve Art, Ruby, Groove Tubes (Let's not go into an Aspen Pittman bashing rant. He is not all that bad.) The Tube Store, Penta Labs, and ???? (Lots of guitar amp companies like Mesa, Bugerra, Marshall, Fender, etc.) Amp builders just buy tubes and put their name on them. No testing. No special designs. No extra vacuum or burn in. No nothing, just a screen printed logo. Shuguang was caught back dooring proprietary Groove Tubes designs off to Tube Amp Doctor in Germany. I know GT sued, but am not sure of anything more than GT did get a cease & desist judgement. So Shuguang does make special audio tubes for various resellers, and rebranders. I have no evidence that Shuguang does anything at all special for Taylor, and I have no idea if Taylor pretests, or if Shuguang pretests, or if they both pretest these tubes. I do know for a fact that some batches of any modern production tube made, whether it be audio or radio, are better than others. I know no one modern tube manufacturer knows how to make a GZ34 that is worth two farts in a hurricane. Those are all just not right, for some reason, and it's just a full wave warm up timed rectifier. I do seem to see some evidence SOMEONE does SOME prescreening of the Taylor tubes. They seem to weed out the noisier, and bad tubes more so than what I see buying a straight Shuguang 3-500ZG, for a lower price. Ruby seems to just rebrand most of their stuff. Penta was famous for selling Soviet & Chinese tubes. Honestly, it is kind of a crap shoot, whether or not the Taylor 3-500Z is worth the extra money. If you buy from a good lot of Shuguangs, NO. If you get a bad batch, the warranty will definitely make up the difference. IF you buy a lot of tubes over time, you probably are not getting any better deal buying Taylor Tubes. I don't know very many people who will be buying 20,30, 40, 50 or 100, or 300 3-500ZGs. So you are kind of buying a pig in a poke with the Shuguangs, but those have a warranty too. It's just not as good, or as long. If the tubes are bad, bad, you will know within a few hours, days or weeks. Considering the price, I give them 4 stars. NOS properly stored and well made Eimacs will always be superior. Good used Eimacs will also usually be superior to a Shuguang tube. If Svetlana St Petersburg started making 3-500ZGs, I'd probably chose those over Shuguang. I'd surely give them a try just to see. If JJ could make one, I'd be skeptical, and if New Sensor made one I'd be really leery of it. If New Sensor was the only company making it, I know it would be absolute trash. Mr. Mathews is definitely NOT on my Christmas card list. The Chinese seem to put forth some effort in quasi good faith to make a semi-decent tube, whereas New Sensor does not care at all, if they are the only game in town. Shuguang, Guiguang, and the other Sino Chinese factories do okay. I believe they deliberately make tubes to a lesser standard so they can sell more tubes, rather than make a really great tube and charge a higher price. The Tektronix 371B will dissipate 3000 watts intermittently for 15 minutes. They claim 20 minutes on 10 off with the fans running, but the 371B is a $30,000 piece of test gear. I can only run 2000 volts plate, but it works more or less. I will probably make a curve tracer with some new transformers I have and a differential probe set I have that was used in commercial broadcasting. That set can attenuate & isolate 10KV or better. I have had new Taylors arc in testing at 2000 volts plate. they are Chinese and quality is not as consistent as it could be or should be. The Chinese tubes seem to be getting better and better, up to a point. I work with the "usual suspects" for guitar amps & hi fi (audio) all the time. The Chinese 12AX7s have gone through lots of changes, and a few really good designs were discontinued. The 3-500ZG and the 8877 seem to stay about the same. The quality seems to have maybe improved, or I am getting used to the darned things. No, they are actually a tad better, and good batches seem to be more frequent now. We used to do 3rd party testing for SGS Thomspon (ST Micro) and On Semi, until their exodus to China. We also did testing for Motorola until On Semi bought them. On was inaffectionately known as "The Death Star" by employees who's jobs & employers went away after On bought them out. Shuguan could make a better 3-500ZG, but don't hold your breath. It is a pretty well established fact that with audio tubes, the modern manufacturers deliberately make tubes that do not last as long, so they can make more money. I am still playing the same 6L6GCSTRs in my 1973 Fender guitar amp. I am still playing the original tubes in a 1957 Supro Supreme. The amps I have bought with Russian, Slovakian, or Chinese tubes wind up needing tubes every 2-3 years....if I am lucky. The same is true with the RF stuff I service. Chinese 6146Bs don't last like an RCA. Same with Eimac 3-500Zs and or Shuguang 3 500ZGs or 3CX1500A7 tubes. Same with Shuguang VT4Cs too! I am looking for an RCA for an old WWII transmitter. That one is destined for a museum, eventually. I have it modified for 160, 80 & 40 meters. It will barely do 40 meters. The Shuguang 211s really hate that radio. It takes 14 volts and likes as many amps as you can pump into it. As far as I can tell, only the guitar amp & hi fi tubes are made in different variants within the same tube type (number). The RF stuff, including the 6146B 8297A which was used in Ampeg's Super Valve Technology Public Address amplifiers, which became a staple amp for bass players, and was soon converted to 6550s. If audiophools or guitar players are not involved, you usually get ONE version from each manufacturer. I give Shuguang a nod of approval for not making total trash, like New Sensor, just because there is no other choice available. They seem to try a bit harder, but not quite hard enough. They COULD make really great tubes if they really wanted to. Shuguang has made more 300Bs than AT&T WECO ever did. If they made tubes that lasted like a real 300B I doubt that would be the case. |
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